Proceedings

Research

Jump to: Other

1 pages, 145 KiB

Open AccessAbstract

Impact of Soil Water Stress at Seed Development Stage on Phenology, Fecundity and Seed Dormancy of Avena sterilis ssp. ludoviciana

by Mohammad Ali, Michael Widderick, Alwyn Williams and Steve Adkins

Proceedings 2019, 36(1), 1; https://doi.org/10.3390/proceedings2019036001 - 24 Dec 2019

Viewed by 1243

Abstract

Wild oat (Avena sterilis ssp. ludoviciana (Durieu) Nyman) is considered the most difficult-to-control winter weed in the northern grain region (NGR) of Australia particularly following the adoption of no-till conservation agriculture and the enhanced reliance on herbicides for weed control. A diversity [...] Read more.

Wild oat (Avena sterilis ssp. ludoviciana (Durieu) Nyman) is considered the most difficult-to-control winter weed in the northern grain region (NGR) of Australia particularly following the adoption of no-till conservation agriculture and the enhanced reliance on herbicides for weed control. A diversity of survival mechanisms is responsible for its persistence in no-till conservation cropping. Among them long-term, variable seed dormancy is the most important. A number of environmental stresses (for example drought) are known to affect the seed dormancy status. We hypothesized that the increasing frequency of hot and dry period in late winter/early spring season in the NGR might help to mature and shed less dormant wild oat seeds before the wheat crop is harvested. This early shedding of highly germinable seed better aids persistence in no-till conservation cropping systems. Our research showed that soil water stress applied at seed development stage resulted in lower number (16–22% less) of early maturing (5–20 days earlier) less dormant (28% less) seeds compared with control plants. This observation was made for a number of biotypes either coming from within one location or between locations within the NGR. Thus, the frequent hot and dry period at the time of seed development in the NGR is responsible for production of less dormant Avena sterilis ssp. ludoviciana seeds where no-till conservation cropping is helping to retain these seeds on the top soil. Under favourable germination conditions in the following season these less dormant seeds will immediately be available to re-infest the autumn/winter-sown wheat crop. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 132 KiB

Open AccessAbstract

The Role of Leadership and Local Ownership in Research 4 Development (R4D) Projects

by Kim Alexander

Proceedings 2019, 36(1), 2; https://doi.org/10.3390/proceedings2019036002 - 24 Dec 2019

Viewed by 1126

Abstract

All researchers for development struggle to achieve lasting results on the ground. Regardless of the introduced technology, the fundamental basis for achieving lasting results involves: 1) strategic project leadership, 2) local ownership of research objectives, research design, outputs and overall results, and 3) [...] Read more.

All researchers for development struggle to achieve lasting results on the ground. Regardless of the introduced technology, the fundamental basis for achieving lasting results involves: 1) strategic project leadership, 2) local ownership of research objectives, research design, outputs and overall results, and 3) local leadership and management of activities and finances. To support lasting results, research tools can assist in communicating the complexities of an introduced technology and can guide stakeholder interactions to bridge knowledge systems and create common understandings and new hybrid knowledge systems. We highlight a transdisciplinary process used to co-create a Research Discussion Tool and identification of 9 thematic areas which, in combination, enabled obstacles to technology uptake to be overcome and farmers to benefit from research-based innovations. The process involved assisting local researchers and extension agents to co-develop solutions, strategies and methods to improve technology uptake by farmers in Lao PDR, using a series of change management interventions. A complex ecology of factors involving farmers’ decision drivers and farmers’ decision enablers within farmers’ production systems influence technology uptake. The relative importance of each factor is dependent on the specific technology that is being introduced. Hence, projects that introduce new technologies grapple to address all relevant factors and often do not have the ability to deal with the complex array of factors that are at play. Co-constructed knowledge embeds local knowledge that becomes accessible to projects. The approach also has the potential to harness collaborative exchanges with other projects in similar geographical regions. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 113 KiB

Open AccessAbstract

Harnessing Asexual Seed Formation to Preserve Hybrid Vigour and Complex Yield Traits

by Anna M. G. Koltunow

Proceedings 2019, 36(1), 3; https://doi.org/10.3390/proceedings2019036003 - 24 Dec 2019

Viewed by 1197

Abstract

Efficiencies in plant breeding can fast-track the development of high yielding, resilient seeds to support food requirements of a growing world population. Seeds typically form via a sexual pathway resulting in diverse progeny through recombination during gamete formation and gamete fusion during fertilization. [...] Read more.

Efficiencies in plant breeding can fast-track the development of high yielding, resilient seeds to support food requirements of a growing world population. Seeds typically form via a sexual pathway resulting in diverse progeny through recombination during gamete formation and gamete fusion during fertilization. Breeders rely on sexual reproduction to generate diverse trait combinations, however, sexual reproduction makes it difficult to keep traits together during backcrossing required to stabilize a variety for evaluation. Hybrid crops can give significantly higher seed yields as a result of what is known as hybrid vigour (or heterosis). However, seeds from high yielding hybrids cannot simply be re-sown as heterosis is lost or inefficiently transmitted to the next generation because sexual reproduction breaks up heterosis and induces trait segregation in subsequent generations. Harnessing asexual reproduction (or apomixis) in plant breeding would enable rapid fixation of traits in F1 hybrids and the progeny of breeding crosses in a single generation as the progeny are derived from a cell that is not a product of meiosis or fertilization. The genotype is thus fixed and the seeds are clonal. In this talk, progress towards harnessing apomixis in a Bill and Melinda Gates Foundation funded project called Capturing Heterosis (CapHet) will be described. This multi-party project aims to develop the capability to synthesize apomixis in sorghum and cowpea and develop self-reproducing hybrid sorghum and cowpeas from which hybrid seeds can be economically saved and grown by smallholder farmers in sub-Saharan Africa without loss of yield or quality over multiple generations. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Integrating Crop Modelling, Physiology, Genetics and Breeding to Aid Crop Improvement for Changing Environments in the Australian Wheatbelt

by Karine Chenu, Andrew Fletcher, Behnam Ababaei, Jack Christopher, Alison Kelly, Lee Hickey, Erik Van Oosterom and Graeme Hammer

Proceedings 2019, 36(1), 4; https://doi.org/10.3390/proceedings2019036004 - 24 Dec 2019

Viewed by 1416

Abstract

Despite recent progress in genetics, genomics, and phenotyping, trait selection is limited by our ability to predict genotype x environment interactions, and to identify impactful traits for target environments. Here, we combined crop modelling, physiology, genetics, and breeding to identify relevant traits to [...] Read more.

Despite recent progress in genetics, genomics, and phenotyping, trait selection is limited by our ability to predict genotype x environment interactions, and to identify impactful traits for target environments. Here, we combined crop modelling, physiology, genetics, and breeding to identify relevant traits to increase wheat yields in the target environments of the Australian wheatbelt, develop high-throughput phenotyping methods for relevant traits, and identify their underlying genetic controls. Better transpiration efficiency (i.e., ‘more crop per drop’) and its components were identified as traits of interest and used as an example to illustrate how integrating modelling, phenotyping, and genetics can be used to improve crop adaptation. We anticipate that such an approach can enhance the efficiency of breeding programmes to increase productivity in target environments in current and future climates. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 136 KiB

Open AccessAbstract

Recent Trends in Drought, Heat and Frost-Induced Yield Losses Across the Australian Wheatbelt

by Behnam Ababaei and Karine Chenu

Proceedings 2019, 36(1), 5; https://doi.org/10.3390/proceedings2019036005 - 24 Dec 2019

Cited by 4 | Viewed by 1247

Abstract

While global food demand is projected to grow by 50–80% by 2050, Australia is expected to continue its significant contribution to global food security. We quantified how recent climatic changes have affected wheat crops in Australia over the last 38 years. Changes in [...] Read more.

While global food demand is projected to grow by 50–80% by 2050, Australia is expected to continue its significant contribution to global food security. We quantified how recent climatic changes have affected wheat crops in Australia over the last 38 years. Changes in drought, heat and frost stresses affecting a mid-maturing cultivar sown on May 15 were quantified over 1981–2018 using an improved version of the Agricultural Production Systems sIMulator (APSIM). Modifications to APSIM-wheat module included the addition of two calculation subroutines for estimating direct impact of frost events and heat shocks on grain setting and grain filling. National drought-induced yield loss exceeded 40%, significantly increasing by 3.6% per decade (P < 0.1), part of which being compensated for by rising atmospheric CO₂ concentration. The national average impact of hot days (T_max > 26 °C) on grain yield have significantly increased mostly due to a significant trend in the impact on individual grain weight. At the national level, frost damage has reached 14% of wheat yield and has been significantly increasing since 1981. Overall, wheat yield has decreased at a significant rate of 180 kg ha⁻¹ per decade (P < 0.01) with the largest decreasing rate in the South-East and East. As heat and drought are expected to remain predominant yield-limiting factors in the future, adaptation of wheat germplasm to warmer and drier environments appears to be a priority to enhance grain yield in Australia. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 118 KiB

Open AccessAbstract

Fall Armyworm Invasion and Impact in Africa

by Jerome Abiemo

Proceedings 2019, 36(1), 6; https://doi.org/10.3390/proceedings2019036006 - 25 Dec 2019

Viewed by 1128

Abstract

Maize is a major staple food crop grown in diverse ecological zones and consumed by many [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 140 KiB

Open AccessAbstract

Prepartum Supplementation to Improve Transfer of Passive Immunity and Growth

by Luis F. P. Silva, Jarud Muller, John Cavalieri and Geoffry Fordyce

Proceedings 2019, 36(1), 7; https://doi.org/10.3390/proceedings2019036007 - 26 Dec 2019

Viewed by 1326

Abstract

Late pregnant cows often experience nutritional stress in northern Australia, which reduces colostrum secretion, health, and likelihood of survival of neonatal calves. The effect of prepartum supplementation on the transfer of passive immunity and growth of calves was investigated. The decline in prepartum [...] Read more.

Late pregnant cows often experience nutritional stress in northern Australia, which reduces colostrum secretion, health, and likelihood of survival of neonatal calves. The effect of prepartum supplementation on the transfer of passive immunity and growth of calves was investigated. The decline in prepartum progesterone was the hypothesised mechanism regulating the transfer of passive immunity. Ninety pregnant Droughtmaster heifers and 45 Brahman cows were used. Animals were stratified by body weight and expected calving date, and separated into two blocks of heifers and one block of cows. Animals were randomly allocated into nutritional treatments, where all were fed low quality Rhodes-grass hay: (1) Control hay only; (2) Protein (PRO), supplemented with 1 kg/d of protein supplement; and (3) Yeast fermentation products (YFP), protein supplement plus 14 g Saccharomyces cerevisiae fermentation product (NaturSafe^TM). Data for final analyses was available from 92 calves on transfer of passive immunity and from 59 cow/calf pairs on prepartum progesterone decline. Treatment means were compared via orthogonal contrasts for the effect of supplementation PRO and YFP. Protein supplementation for an average of 14 d hastened the decline in the concentration of serum progesterone before parturition (p < 0.01) and tended (p = 0.09) to increase growth rate of calves during the first 10 d (1.0 vs. 0.9 kg/d). However, there was no effect of PRO on neonatal calves plasma immunoglobulin-G1 (IgG1) concentration (p = 0.43). Adding YFP further hastened the progesterone decline before parturition (p < 0.05) and tended to increase plasma IgG1 (p = 0.08). Short term nutritional supplementation prepartum may improve transfer of passive immunity and neonatal calf growth. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 124 KiB

Open AccessAbstract

Foliar Nutrient Management on Potato Grown under Zero Tillage and Mulching in Coastal Saline Soil of West Bengal, India

by Koushik Brahmachari, Sukamal Sarkar, Deepak Sahoo, Indranil Samui, Manoj Kumar Nanda, Argha Ghosh and Mohammed Mainuddin

Proceedings 2019, 36(1), 8; https://doi.org/10.3390/proceedings2019036008 - 26 Dec 2019

Viewed by 1312

Abstract

The Costal Saline Zone (CSZ) of West Bengal, India is dominated by rice-fallow-fallow system cropping system. Only 4% of the cultivated area of the coastal zone can be irrigated with available sweet water. To cope up with the present situation is introduction of [...] Read more.

The Costal Saline Zone (CSZ) of West Bengal, India is dominated by rice-fallow-fallow system cropping system. Only 4% of the cultivated area of the coastal zone can be irrigated with available sweet water. To cope up with the present situation is introduction of new high value crops to catch the fallow winter period emphasizing on water saving technologies. In this way mono-cropped saline soils of coastal region can be converted into multiple cropping through the adoption of zero tillage potato technology. Soils of the CSZ show multi-nutritional deficiencies and these deficiencies adversely affect the crop. To address this issue, field experiment was conducted in winter season of 2016–2018 in CSZ of West Bengal, India with the focal objectives of studying the feasibility of potato under zero-tilled-mulched condition in CSZ of West Bengal; assessing the effect of foliar nutrient management practices on growth, yield, quality and economics of potato. The foliar nutritional supplementation with 2% Urea at 30 & 50 days after planting (DAP) of potato along with 0.1% Boron at 30 DAP not only increased tuber number and yield but also quality parameters of potato tuber such as TSS, tuber hardness, vitamin C etc. were significantly increased. It may thus be concluded that 2% Urea at 30 & 50 at DAP of potato along with 0.1% Boron at 30 DAP as foliar application is the best foliar nutrient management option for potato grown under zero tillage and mulching in coastal saline soils of West Bengal, India. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 121 KiB

Open AccessAbstract

Clay Nanoparticles Facilitate Delivery of Antiviral RNA for Crop Protection

by Zhi Ping (Gordon) Xu

Proceedings 2019, 36(1), 9; https://doi.org/10.3390/proceedings2019036009 - 26 Dec 2019

Viewed by 1054

Abstract

Recently, nanotechnology, biotechnology and agriculture are gradually integrated into [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

RNAi-Mediated Management of Whitefly Bemisia tabaci by Oral Delivery of Double-stranded RNAs

by Ritesh G Jain, Karl Robinson and Neena Mitter

Proceedings 2019, 36(1), 11; https://doi.org/10.3390/proceedings2019036011 - 27 Dec 2019

Viewed by 1656

Abstract

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a significant global pest of economically important vegetable, fibre, and ornamental crops. Whiteflies directly damage the plants by piercing and sucking essential nutrients, indirectly through honeydew secretion and by transmitting more than 200 plant viruses that [...] Read more.

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a significant global pest of economically important vegetable, fibre, and ornamental crops. Whiteflies directly damage the plants by piercing and sucking essential nutrients, indirectly through honeydew secretion and by transmitting more than 200 plant viruses that cause millions of dollars in produce losses per year. Whitefly management is mostly reliant on the heavy use of chemical insecticides. However, this ultimately leads to increasing resistance development, detrimental effects on beneficial insects and biomagnification of ecologically harmful chemicals in the environment. Responding to consumer demands for more selective, less toxic, non-GM insect control strategies, RNA interference (RNAi) has emerged as a potential game-changing solution. The RNA interference (RNAi) is a homology-dependent mechanism of gene silencing that represents a feasible and sustainable technology for the management of insect pests. In the present study, twenty-two whitefly genes were selected based on their essential function in the insect and tested in artificial diet bioassays for mortality and gene silencing efficacy. The nine most effective dsRNA constructs showed moderate-to-high whitefly mortality as compared to negative controls six days post-feeding. qPCR analysis further demonstrated significant knockdown of target gene mRNA expression. Additionally, uptake and spread of fluorescently labelled dsRNA was evident beyond the midgut of the whitefly supporting the systemic spreading of RNAi effectors. Taken together, the oral delivery of dsRNA shows effective RNAi mediated gene silencing of target genes and offers a viable approach for the development of dsRNA biopesticides against hemipteran pest. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 132 KiB

Open AccessAbstract

The Effect of Water Stress Combined with a Heatwave on Reproduction and Yield of Roma-VF Tomatoes

by Felix Amuji

Proceedings 2019, 36(1), 12; https://doi.org/10.3390/proceedings2019036012 - 27 Dec 2019

Viewed by 1142

Abstract

Tomato (Solanum lycopersicum) is one of the most consumed fruits, supplying humanity with both economic and nutritional benefits. However, its production is affected significantly by climatic conditions especially extreme weather events, such as heat waves, flooding and drought. The objective of [...] Read more.

Tomato (Solanum lycopersicum) is one of the most consumed fruits, supplying humanity with both economic and nutritional benefits. However, its production is affected significantly by climatic conditions especially extreme weather events, such as heat waves, flooding and drought. The objective of this study was to evaluate the additively combined effects of heat and water stresses on the reproductive traits and yield of Roma-VF tomato variety. Pollen morphology, number of developed flowers, fruits and aerial biomass were monitored. At five weeks after sowing, the tomato plants were subjected to day/night temperatures of 28/20 °C as a control treatment and 35/23 °C as the heat stress treatment. The water stress was imposed by reducing the water received by plants in each 10-L plastic pot to 70% soil field capacity (moderate stress) and 40% (severe stress). The stress lasted for eight weeks, which was followed by five weeks of recovery period. Our results showed that plants under additively combined heat stress with either moderate or severe water stress produced flowers with no single pollens during the treatment period. We also found that Roma-VF tomato has a high plasticity in response to this particular heat stress for vegetative growth when well irrigated, but when heat and water stresses were additively combined the plants became highly susceptible. This is also the first report of yield response of Roma-VF tomatoes to the additively combined effect of heat and water stressors. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 129 KiB

Open AccessAbstract

Drivers of Phosphorus Efficiency in Tropical and Subtropical Cropping Systems

by Bianca Das, Neil Huth, Merv Probert, Birthe Paul, Job Kihara, Peter Bolo, Daniel Rodriguez, Mario Herrero and Susanne Schmidt

Proceedings 2019, 36(1), 13; https://doi.org/10.3390/proceedings2019036013 - 30 Dec 2019

Viewed by 1142

Abstract

Phosphorus (P) is an essential nutrient but is commonly limiting for food production in tropical and subtropical maize cropping. The efficiency of P fertiliser uptake is often low (5–30%) for various site-specific reasons and so identifying the drivers of P efficiency for different [...] Read more.

Phosphorus (P) is an essential nutrient but is commonly limiting for food production in tropical and subtropical maize cropping. The efficiency of P fertiliser uptake is often low (5–30%) for various site-specific reasons and so identifying the drivers of P efficiency for different systems is important. We conducted a sensitivity analysis on the parameters of a well-established cropping systems model (APSIM) for a wide range of soil, crop and management factors to understand their influence on yield. The analysis was conducted for two contrasting maize cropping systems: (a) a high-input, large-scale commercial system in subtropical Queensland, Australia and (b) a low-input, small-holder system in tropical, western Kenya. In Queensland, yield was most sensitive to available P and mineral N supply, and the sensitivity of both increased with in-crop rainfall. Available P was also the most important parameter in Western Kenya, but N supply had much weaker influence due to higher levels of organic matter. Parameters controlling P sorption were more important than other soil parameters at both sites irrespective of seasonal conditions. In conclusion, these results suggest that efforts to improve efficiency of P use by plants need to account for interactions between water and N supply in environments where these are limiting. They also highlight a potential constraint to modelling of these systems as some of the most influential parameters are difficult to measure directly. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 190 KiB

Open AccessAbstract

Diversity of Domestication Loci in Wild Rice Populations

by Sharmin Hasan, Agnelo Furtado and Robert Henry

Proceedings 2019, 36(1), 14; https://doi.org/10.3390/proceedings2019036014 - 30 Dec 2019

Viewed by 1143

Abstract

Domestication syndrome, i.e. seed shattering, seed dormancy and plant architecture have been selected during the domestication of wild rice around 10,000 years ago. These traits evolved through a series of genomic modifications, including selection of nucleotide polymorphisms resulting from spontaneous mutations, recombination, and [...] Read more.

Domestication syndrome, i.e. seed shattering, seed dormancy and plant architecture have been selected during the domestication of wild rice around 10,000 years ago. These traits evolved through a series of genomic modifications, including selection of nucleotide polymorphisms resulting from spontaneous mutations, recombination, and fixation of alleles and were incorporated into cultivated rice by hybridization or introgression. The Australian wild rice populations are geographically and genetically distinct and free from genetic exchange with cultivated rice unlike the wild populations in Asia. Furthermore, recent studies reveal they have numerous traits of value and unique alleles. Therefore, these populations seem to be suitable to use to investigate the genetic basis of domestication traits as well as other important traits. In this study, we aim to determine the origin and role of domestication loci using two Australian wild populations: Taxa A (like Oryza rufipogon) and Taxa B (like Oryza meridionalis) endemic near Cairns, Northern Queensland. To do so, firstly, we will analyse the variation of domestication loci in these two wild populations by the comparison with cultivated rice (Oryza sativa spp. japonica cv. Nipponbare) using the whole genome sequencing. Secondly, we will look at the gene expression of the domestication loci at different seed development stages using transcriptomics. Thirdly, we will determine the variation of starch synthesis related genes using whole genome sequencing. Next generation sequencing along with a set of bioinformatics tools will be applied. This research may enlighten our understanding about the domestication process as well as provide insights into how to domesticate these species through genetic manipulation for commercial purpose. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 190 KiB

Open AccessAbstract

Farmers’ Perceptions of Salinity for Ensuring Food Security: Evidence from Coastal Rice-Growing Areas of Bangladesh

by Md Aminul Islam, Lisa Lobry de Bruyn, Nigel W. M. Warwick and Richard Koech

Proceedings 2019, 36(1), 15; https://doi.org/10.3390/proceedings2019036015 - 30 Dec 2019

Viewed by 1216

Abstract

Achieving SDGs by 2030 such as “No poverty, zero hunger, good health” is the main priority for policy planning in Bangladesh. Key challenges faced in achieving these goals is encountered in the agricultural sector. This research focused on farmers’ perception of salinity and [...] Read more.

Achieving SDGs by 2030 such as “No poverty, zero hunger, good health” is the main priority for policy planning in Bangladesh. Key challenges faced in achieving these goals is encountered in the agricultural sector. This research focused on farmers’ perception of salinity and their management strategies, and the implications for policy makers to sustain rice production in the coastal areas of Bangladesh. Household survey data was collected from randomly selected 108 rice farming families from two south-west south-east coastal sub-districts. Semi-structured and pre-tested questionnaire were used to collect data from the respondents. Majority of the respondents (89%) reported that salinity has increased over the last 20 years and they also believe that the current salinity level in their fields are high. In a 2nd field trip 36 farmers from the original sample had soil from their fields measured over two time periods. Farmers’ perceived salinity level was then compared with measured field salinity in their rice field. Farmers’ perception of soil salinity level in their rice field aligns closely with the measured salinity level in the majority of the cases. It was also observed that farmers’ understanding of salinity level is strongly associated with in-field crop condition and soil appearance. 45% of respondents said their main signals of salinity were from the appearance of the plant and 22% of farmers also observed the inflorescence becoming white and grain unfilled in rice crops. Results also suggests that early transplanting of rice seedlings during Boro season rice and use of salt tolerant rice varieties having high tolerance during booting stage along with improved irrigation facilities can substantially reduce rice yield loss from salinity effects. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 170 KiB

Open AccessAbstract

Differential Gene Expression Among Genotypes of the Genus Saccharum Contrasting in Biomass Production

by Fernando Henrique Correr, Guilherme Kenichi Hosaka, Isabella Barros Valadão, Thiago Willian Almeida Balsalobre, Monalisa Sampaio Carneiro and Gabriel Rodrigues Alves Margarido

Proceedings 2019, 36(1), 16; https://doi.org/10.3390/proceedings2019036016 - 30 Dec 2019

Viewed by 1186

Abstract

The development of biomass crops aims to meet industrial yield demands to become a profitable and sustainable activity. Achieving these goals in an energy crop such as sugarcane relies on breeding for sucrose accumulation, fiber content and tillering capacity. Sucrose storage depends on [...] Read more.

The development of biomass crops aims to meet industrial yield demands to become a profitable and sustainable activity. Achieving these goals in an energy crop such as sugarcane relies on breeding for sucrose accumulation, fiber content and tillering capacity. Sucrose storage depends on transport from leaves to culms driven by enzymes involved in sucrose synthesis and hydrolysis. High biomass genotypes often use photosynthesis products to produce lignocellulosic compounds to form the cell wall. To expand the understanding of the pathways related to these traits, we evaluated gene expression of two groups of genotypes contrasting in biomass yield, as well as testing for differences among members within the same group. First visible dewlap leaves were collected from six genotypes of each group to perform RNA-Seq. We found evidence that both groups differ with regard to genomic stress caused by polyploidy, as indicated by the enrichment of genes involved in transposition activity and defense response processes. Although carbon assimilation terms were not enriched, genes annotated with such terms were co-expressed with those coding for members of hormonal pathways. Sucrose phosphate synthase and hydrolytic enzymes coding genes were upregulated in leaves of sucrose-accumulating genotypes, as genes coding for enzymes involved in the biosynthesis of lignin. Compared to other high biomass accessions, the hybrid US85-1008 presented upregulation of photosynthesis-related genes probably due to its sink demand to store sugar in culms. This study expands the knowledge of gene expression in sugarcane leaves, revealing differences between and within phenotypically distinct groups. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 122 KiB

Open AccessAbstract

Determination of Phylogenetic Relationships of the Genus Sorghum Using Nuclear and Chloroplast Genome Assembly

by Galaihalage Ananda, Roslyn Gleadow, Sally Norton, Agnelo Furtado and Robert Henry

Proceedings 2019, 36(1), 17; https://doi.org/10.3390/proceedings2019036017 - 30 Dec 2019

Cited by 1 | Viewed by 1408

Abstract

Sorghum (Sorghum bicolor [L.] Moench) is a multipurpose food crop which is ranked among the top five cereal crops in the world. It serves as a source of food, fodder, feed and bioenergy. The genus Sorghum consists of 25 species and is considered [...] Read more.

Sorghum (Sorghum bicolor [L.] Moench) is a multipurpose food crop which is ranked among the top five cereal crops in the world. It serves as a source of food, fodder, feed and bioenergy. The genus Sorghum consists of 25 species and is considered as a group of plants with enormous diversity. Crop wild relatives have played significant roles in assessing and utilizing genetic resources which is the fundamental step of crop improvement. Successful examples of introgression of novel alleles from the wild relatives of rice, wheat, maize and sugarcane have been reported, whereas studies on wild sorghum are limited. The wild genepool of sorghum harbours many useful genes for drought tolerance and disease resistance. However, the phylogenetic relationships in the genus remain unresolved due to the limited availability of sequencing data. The comparison of nuclear genomes along with the chloroplast genomes of sorghum species would expand this knowledge and aid in using these potential genetic resources as well as resolving the vague phylogeny of the genus. Todate the chloroplast genome of only four sorghum species have been sequenced. This first of its kind study aims to determine the phylogenetic relationships in the genus Sorghum by means of nuclear and chloroplast genome sequencing and assembly of all the 25 known Sorghum species. This effort would undoubtedly be a significant step towards exploiting the hidden genetic resources of sorghum in crop improvement. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 137 KiB

Open AccessAbstract

Evaluation of Mungbean Varieties for Northwest Cambodian Lowland Rice Systems

by Harry Campbell-Ross

Proceedings 2019, 36(1), 18; https://doi.org/10.3390/proceedings2019036018 - 30 Dec 2019

Viewed by 950

Abstract

Small-scale agriculture is the economic, social and cultural foundation of Cambodian rural communities. Crop diversification is not widespread in these traditionally rice-producing smallholder farms. Rice monoculture has led to a decline in farm productivity and farming household income. Mungbean is emerging as a [...] Read more.

Small-scale agriculture is the economic, social and cultural foundation of Cambodian rural communities. Crop diversification is not widespread in these traditionally rice-producing smallholder farms. Rice monoculture has led to a decline in farm productivity and farming household income. Mungbean is emerging as a high-value opportunity for crop diversification in smallholder farms in north-west Cambodia. However, its expansion is being constrained by the low quality of varieties available to farmers. This study aims to evaluate the locally available varieties with others from Cambodia and the region by comparing the varieties’ agronomic and economic characteristics. The varieties from Cambodia, CMB-3 and CARDI-Chey, had superior agronomic and quality characteristics compared with the varieties available to farmers. This was reflected in the price estimate and income of both varieties which had the highest gross margins. Hence, the varieties currently available to farmers are unsuitable for continued cultivation in the modern mungbean production environment. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 139 KiB

Open AccessAbstract

Promoting Social Learning in Soil Water and Nutrients Management Using Farmer—Friendly Monitoring Technology

by Isaac Rhinnexious Fandika, Richard Stirzaker and Grivin Chipula

Proceedings 2019, 36(1), 19; https://doi.org/10.3390/proceedings2019036019 - 30 Dec 2019

Cited by 1 | Viewed by 1312

Abstract

Soil water management is typically by trial and error among smallholder farmers. Social learning in the use of farmer—friendly soil-water and nutrients monitoring tools were promoted in Malawi to improve productivity. A simple tool (chameleon) which was designed to fit the mental model [...] Read more.

Soil water management is typically by trial and error among smallholder farmers. Social learning in the use of farmer—friendly soil-water and nutrients monitoring tools were promoted in Malawi to improve productivity. A simple tool (chameleon) which was designed to fit the mental model of African farmers and to give an output that is linked to action was deployed to 198 farmers in nine irrigation schemes. Chameleon illustrates information on soil moisture status by colours—blue, green and red colours representing adequate moisture, moderate and dry soil status, respectively. The use of colours and not numbers promoted inclusiveness across illiterate and all gender categories. Farmers participated in sensors’ installation, soil moisture measurement, data visualization and learning by doing to get insights from their participation. The chameleon was combined with an on-line communication and learning system to improve water management at scheme level. The results indicated that: (1) the tool gave farmers new frames of reference; (2) it improved farmers on time, labour and water saving by reducing irrigation intervals; (3) it gave farmers new reference of experience to change their irrigation traditions; (4) it also reduced conflict for water in irrigation schemes between users apart from improving water productivity. Use of these tools made a rigor that make scientists easily communicate science to lay farmer and initiated the movement of farmers who know how to manage water. Social learning in sensor technology helped to increase farmers’ resilience to climate change and shaping the science of the future. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 158 KiB

Open AccessAbstract

Aflatoxin Contamination of Village Grains in Central Tanzania: Dietary and Agricultural Practices in Relation to Contamination and Exposure Risk

by Godfrey Magoke, Mark Krockenberger, Wayne Bryden, Robyn Alders, Furaha Mramba and Wende Maulaga

Proceedings 2019, 36(1), 20; https://doi.org/10.3390/proceedings2019036020 - 30 Dec 2019

Cited by 1 | Viewed by 1231

Abstract

A study was conducted in the semi-arid Manyoni District of Central Tanzania, involving eight village communities to: (1) assess aflatoxin contamination of village grains; and (2) gain knowledge on grain food practices and habits associated with aflatoxin risk. To address the respective objectives, [...] Read more.

A study was conducted in the semi-arid Manyoni District of Central Tanzania, involving eight village communities to: (1) assess aflatoxin contamination of village grains; and (2) gain knowledge on grain food practices and habits associated with aflatoxin risk. To address the respective objectives, random immediate post-harvest (n = 134) and following 6 month or more after storage grain samples (n = 157) were screened (AFLACHECK^TM -VICAM), followed by quantitative HPLC determination of samples containing ≥10 µg/kg total aflatoxins. Responses were sought from 76 randomly selected adults by a questionnaire covering pre-harvest, harvest and post-harvest practices, food preparation and knowledge on food toxins. Aflatoxin contamination was particularly more significant in maize and groundnut samples ranging up to 198 µg/kg (mean = 25.46 µg/kg) in post-harvest grains and up to 351 µg/kg (mean = 50.83 µg/kg) in stored grains, well above the maximum limit of 10 µg/kg tolerated in foods for human consumption in Tanzania. Respondent questionnaires revealed farmers: had no knowledge of food toxins; received limited extension services; did not generally use irrigation, fertilisers or pesticides; relied on inadequate harvesting, drying and storage technologies; and frequently consumed unpolished grains. Village grains in Central Tanzania may contain high concentration of aflatoxins of potential significance to community health. Existing practices and lack of aflatoxin knowledge may facilitate contamination and exposure. Therefore, village farmers in Central Tanzania may benefit from better extension services, using livestock manure as fertilizer, access to drought tolerant seeds and better grain drying and storage technologies to reduce aflatoxin risk. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 160 KiB

Open AccessAbstract

Genotypic Variation in Biomass Produced Is Linked to Differences in Radiation Acquisition in Mungbean

by Geetika Geetika, Rachaputi C. Nageswara Rachaputi, Marisa Collins, Vijaya Singh, Kylie Wenham and Graeme Hammer

Proceedings 2019, 36(1), 21; https://doi.org/10.3390/proceedings2019036021 - 30 Dec 2019

Viewed by 1522

Abstract

Mungbean has become an important cash and legume rotation crop in the Australian Northern Grains region. Thus, it is necessary to narrow the gap between potential productivity and actual production by understanding the crop physiological attributes contributing to the acquisition of radiation, and [...] Read more.

Mungbean has become an important cash and legume rotation crop in the Australian Northern Grains region. Thus, it is necessary to narrow the gap between potential productivity and actual production by understanding the crop physiological attributes contributing to the acquisition of radiation, and it’s conversion into total biomass. A field experiment was conducted at Gatton, during 2018-19 summer season, growing two commercial varieties of mungbean; Jade-AU and Satin II under irrigated conditions. The varieties were planted at 0.5m and 1.0m row spacing and different plant densities. Weekly biomass cuts were taken from a square meter and separated into its components. The area of a green leaf sub-sample was used to compute the leaf area of the canopy. Weekly Ceptometer measurements were taken above and below the canopy at noon on clear, sunny days to obtain a measure of Fraction of radiation interception (F_i). Total shoot dry matter (TDM), pod dry mater (PDM) and leaf area index (LAI) was investigated. There was a significant effect of canopy density on F_i. There was no significant difference in total dry matter between the two varieties, however, there was a highly significant effect of canopy density on TDM. A highly significant variation in LAI amongst the two varieties and across canopy densities, with Satin II having a higher mean LAI compared to Jade-AU. There was significant effect of canopy density on PDM. Our data indicate variation in dry matter production across canopy densities and there is a need to examine varietal differences in radiation use efficiency which may provide better understanding of hot the captured radiation is utilized in biomass production in mungbean. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 138 KiB

Open AccessAbstract

Utilisation of Sludge from Ditches to Maintain Soil Nutrients and Increase Rice Yield in Rice-Shrimp Systems in Vietnam

by Dang Duy Minh, Minh Khoi Chau, Van Sinh Nguyen, Anh Duc Tran, Jason Condon and Jesmond Sammut

Proceedings 2019, 36(1), 22; https://doi.org/10.3390/proceedings2019036022 - 30 Dec 2019

Cited by 1 | Viewed by 1291

Abstract

An integration of a shrimp production cycle into the traditional system of rice farming is an adopted practice by farmers due to saline intrusion and changes of environmental condition in Vietnam. Aquacultural pond sludge or biological waste has the potential to cause environmental [...] Read more.

An integration of a shrimp production cycle into the traditional system of rice farming is an adopted practice by farmers due to saline intrusion and changes of environmental condition in Vietnam. Aquacultural pond sludge or biological waste has the potential to cause environmental pollution if it is not managed well. However, the sludge from shrimp ponds in rice-shrimp farming systems can provide nutrition and maintain soil fertility for the integrated rice crop production. A randomized block field experiment was conducted on a rice-shrimp farm to test the fertilizer value of sludge for rice over two consecutive seasons in Vietnam. Five treatments of sludge and fertilizer rates were applied in field experiments including control, sludge application alone, recommended fertilizer rate, reduced fertilizer rate, and combination of sludge and reduced fertilizer rate. The results consistently proved that the pond sludge can provide large quantities of plant available nutrients such as ammonium nitrogen, total nitrogen and organic matter. The use of sludge either alone or in combination with the reduced fertilizer rate produced optimal rice yields while fertilizer cost of rice production was reduced. This finding indicates that the use of sludge is able to save cost of production to rice-shrimp farmers and reduce adverse impacts of pond sludge released on the surrounding environment. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 115 KiB

Open AccessAbstract

Quantifying Gas Emissions and Denitrifying Genes in a Salt-Affected Soil

by Dang Duy Minh, Sören Warneke, Andrew Bissett, Van Phung Cao, Ben Macdonald and Craig Strong

Proceedings 2019, 36(1), 23; https://doi.org/10.3390/proceedings2019036023 - 30 Dec 2019

Viewed by 1144

Abstract

Salinity effects on microbial community relative to greenhouse gas emissions are not well understood in salt-affected soils. A better understanding of this interaction would be useful for agricultural practices to reduce nitrogen gas losses and manage environmental pollution. We hypothesized that elevated salinity [...] Read more.

Salinity effects on microbial community relative to greenhouse gas emissions are not well understood in salt-affected soils. A better understanding of this interaction would be useful for agricultural practices to reduce nitrogen gas losses and manage environmental pollution. We hypothesized that elevated salinity would increase the abundance of denitrifier genes resulting in a low rate of gas emissions. Objectives of this study were to measure induced-soil greenhouse gas emissions and to quantify denitrifying genes in a salt-affected soil over a 3-week incubation period. This incubation study was conducted by submerging field-moist samples of an acid sulphate soil in different saline solutions. A quantitative polymerase chain reaction (qPCR) was used to quantify the abundance of resident bacterial denitrification genes in the salt-affected soil. It was found that increased salinity caused a decrease in both flux and cumulative emission of N₂O from the incubated soil, relative to fresh water. Soil respiration was significantly reduced in salinity treatments compared to the treatment of distilled water. The study results showed that elevated salinity increased the denitrifying genes in the incubated acid sulfate soil. The abundance of the nir genes was usually high between the first and second week of incubation, while number copies of the nosZ gene were significantly low at those times. The study concludes that salinity controls the biological aspects of denitrification leading to a reduction of greenhouse gas emissions. Findings from this investigation extend our knowledge about the underlying molecular ecological mechanisms of denitrification that manage nitrogen cycling in salt-affected soils. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 169 KiB

Open AccessAbstract

Relationships between Iraqi Rice Varieties at the Nuclear and Plastid Genome Levels

by Hayba Badro, Agnelo Furtado and Robert Henry

Proceedings 2019, 36(1), 24; https://doi.org/10.3390/proceedings2019036024 - 31 Dec 2019

Viewed by 1140

Abstract

Due to the importance of the rice crop in Iraq, this study was conducted to determine the origin of the major varieties and understand the evolutionary relationships between Iraqi rice varieties and other Asian-rice accessions that could be significant in the improvement of [...] Read more.

Due to the importance of the rice crop in Iraq, this study was conducted to determine the origin of the major varieties and understand the evolutionary relationships between Iraqi rice varieties and other Asian-rice accessions that could be significant in the improvement of this crop. Five varieties of Oryza sativa were obtained from Baghdad, Iraq; among these varieties, one, Amber33, is local and is one of the most highly valued varieties in Iraq because of its fragrance, and two varieties, Furat and Yasmin were introduced from Vietnam while the other two, Buhoot1 and Amber al-Baraka, were improved varieties; the whole genomic DNA was sequenced. Raw sequence reads of 33 domesticated Asian-rice accessions were obtained from the National Centre for Biotechnology Information (NCBI). The sequence of the whole chloroplast genome of 5 Iraqi varieties and 34 domesticated rice accessions was assembled while for nuclear genome analysis, only the sequences of 916 concatenated nuclear genes were assembled. The phylogenetic trees of both chloroplast and nuclear genomes were similar with insignificant differences at the end of the clades. Two main clusters, Indica and Japonica, and further five subclusters based upon their ecotype, indica, aus, tropical-japonica, temperate-japonica and basmati were created, where Amber33, Furat, Yasmin and Buhooth1 belonged to the basmati, indica and japonica ecotypes, respectively. The phylogenetic analysis of both chloroplast and nuclear genomes placed Amber33 in the basmati ecotype group as a sister of cultivars from Pakistan and India. This confirms the old traditional story that the Amber variety was transferred by a group of people who had migrated from India (the Southeast) and settled in southern Iraq a long time ago Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 135 KiB

Open AccessAbstract

SNPs Linked to Key Traits in Hybrids between African and Asian Rice

by Hayba Badro, Marie-Noelle Ndjiondjop, Agnelo Furtado and Robert Henry

Proceedings 2019, 36(1), 25; https://doi.org/10.3390/proceedings2019036025 - 31 Dec 2019

Viewed by 1078

Abstract

Association analysis was performed to determine trait-associated variants (TAVs) influencing three quantitative agronomic traits, heading date (Hd), tiller number at maturity (T) and 1000-grain weight (TGW) in a population developed by crossbreeding between WAB56-104 (O. sativa) and CG14 (O. glaberrima [...] Read more.

Association analysis was performed to determine trait-associated variants (TAVs) influencing three quantitative agronomic traits, heading date (Hd), tiller number at maturity (T) and 1000-grain weight (TGW) in a population developed by crossbreeding between WAB56-104 (O. sativa) and CG14 (O. glaberrima). DNA derived from progenies with extreme phenotypes (high and low-value) for each trait was bulked, sequenced and then mapped against the reference genome of O. sativa cv Nipponbare for two types of analysis, general association analysis and candidate genes analysis. In the general association analysis, a total of 5152 non-synonymous SNPs in 3564 genes distinguished the low and high bulks of Hd, T and TGW traits; however, only 611 non-synonymous SNPs in 447 genes were involved in KEGG pathways. Among these non-synonymous SNPs, only six SNPs in the sequences of LOC107275952, LOC4334529, LOC4326177, LOC107275432, LOC4335790 and LOC107275425 genes were associated with H, T and TGW traits. These genes participated in the following KEGG pathways: abscisic-acid biosynthesis, carotenoid biosynthesis, starch and sucrose metabolism, and cytokinin biosynthesis. Analysis of candidate genes using 9, 10, and 5 genes associated with Hd, T, and TGW traits showed 2, 2, and 3 non-synonymous variations in the sequence of Hd3a and Ehd2 from the group of Hd genes (no KEGG pathway); D10 and D53 from the group of T genes (strigolactones biosynthetic pathway), and Gn1a and GIF1 from the group of TGW genes (cytokinin biosynthetic pathway, and starch and sucrose metabolism pathway), respectively. The results of this study provides significant TAVs for subsequent applications in rice breeding programmes. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 155 KiB

Open AccessAbstract

Remobilisation and Fate of Sulphur in Indian Mustard (Brassica juncea. L)

by Priyakshee Borpatragohain, Graham J. King, Terry Rose, Lei Liu, Tobias Kretzschmar, Bronwyn Barkla and Carolyn Raymond

Proceedings 2019, 36(1), 26; https://doi.org/10.3390/proceedings2019036026 - 31 Dec 2019

Viewed by 1031

Abstract

Understanding the basis of sulphur (S) use efficiency in higher S requiring crops such as brassicas can help develop more cost-effective cultivars. Oleriferous brassicas sequester reduced S in the mature seeds mainly as secondary metabolite-glucosinolate (GSL) and seed storage proteins (SSP). Glucosinolates have [...] Read more.

Understanding the basis of sulphur (S) use efficiency in higher S requiring crops such as brassicas can help develop more cost-effective cultivars. Oleriferous brassicas sequester reduced S in the mature seeds mainly as secondary metabolite-glucosinolate (GSL) and seed storage proteins (SSP). Glucosinolates have a wide range of positive aspects in food production, human nutrition and plant defence, and SSPs are a potential source of high quality vegetable proteins for human and livestock consumption. We carried out a developmental S audit to establish the net fluxes of S in two lines of B. juncea mustard where the level of seed GSL differed. We quantified S pools (sulphate, GSL and total S) in different organs at multiple growth stages until maturity. We have established that leaf S components accumulated as primary S sinks at early developmental stages in condiment type B. juncea become remobilised as a secondary S source to meet the demand of GSL as the dominant seed S sink at maturity. Our evidence for S remobilisation from leaves as primary S sink suggests that up or down regulation of signalling molecules which mediate between secondary S sinks and sources may help modulate economically valuable S compounds in brassica seed. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 149 KiB

Open AccessAbstract

Investigation of Insect Resistance Components in Wild Pigeonpea Cajanus Scarabaeoides

by Thi My Linh Hoang, Abigail Dawit, Brett Williams, TJ Higgins and Sagadevan Mundree

Proceedings 2019, 36(1), 27; https://doi.org/10.3390/proceedings2019036027 - 31 Dec 2019

Viewed by 1059

Abstract

Cajanus scarabaeoides (L.) Thouars is the closest wild relative of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh. However, unlike cultivated pigeonpea which is very susceptible to insects, especially Helicoverpa armigera (Hubner), this wild pigeonpea is strongly insect resistant. Since H. armigera causes damage [...] Read more.

Cajanus scarabaeoides (L.) Thouars is the closest wild relative of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh. However, unlike cultivated pigeonpea which is very susceptible to insects, especially Helicoverpa armigera (Hubner), this wild pigeonpea is strongly insect resistant. Since H. armigera causes damage to many important crops resulting in economic losses up to 2 billion USD/year, improvement in resistance to this insect in crops is highly desirable. Here we investigate insect resistance components in C. scarabaeoides and explore the possibility of transferring one or more of those factors to cultivated pigeonpea. A detached leaf assay was used to assess antibiosis and antixenosis resistance mechanisms in C. scarabaeoides. Artificial diet supplemented with lyophilised leaf powder was employed to investigate the antibiosis resistance mechanism. Data on larval mortality and larval and pupal weights were collected. Time taken for neonate larvae to pupate and for pupae to develop to the moth stage were determined through daily observations. Preliminary results showed that H. armigera larval weight was significantly reduced and larval development stages were prolonged when reared on different accessions of C. scarabaeoides as compared to the susceptible check, C. cajan (ICPL 87). Interspecific hybridization was carried out between C. scarabaeoides and a commercial pigeonpea variety. Results from insect challenge assays and trichome identification indicate that the hybrids have similar levels of insect resistance to their wild parent. Proteomic analysis is being used to identify possible antibiosis factors. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 156 KiB

Open AccessAbstract

The Relationship Between Bulb Yield and Allicin Concentration in Garlic Varieties

by Binh Nguyen, Bernhard Wehr, Timothy O’Hare, Hung Hong, Neal Menzies and Stephen Harper

Proceedings 2019, 36(1), 28; https://doi.org/10.3390/proceedings2019036028 - 31 Dec 2019

Cited by 1 | Viewed by 2171

Abstract

Garlic (Allium sativum L.) is used as a vegetable and medicinal plant. It is a rich source of organosulfur compounds, in particular allicin, which contributes to the flavour and health benefits. Although worldwide garlic production is increasing, demand continues to outstrip supply. [...] Read more.

Garlic (Allium sativum L.) is used as a vegetable and medicinal plant. It is a rich source of organosulfur compounds, in particular allicin, which contributes to the flavour and health benefits. Although worldwide garlic production is increasing, demand continues to outstrip supply. Improving the yield of garlic will address the increasing demand, while increasing allicin concentration will improve its potential health benefits and flavour. It is unknown if increasing garlic bulb size (yield) has a negative effect on allicin concentration of garlic. Therefore, a fundamental understanding of the relationship between yield and allicin concentration is required. A field experiment was conducted at Gatton (QLD, Australia) with 32 varieties, of which 29 varieties were sourced from World Vegetable Centre and 3 varieties from existing Queensland sub-tropical varieties. The garlic cloves were planted in March 2018 with 4 replicates in a randomised complete block design and harvested when garlic had 70% senescence. Varieties showed large variation in bulb size, ranging from about 35 to 120 g, with fresh yield ranging from about 5.5 to 16 t/ha. The allicin concentration ranged from 3.5 to 6.6 mg g⁻¹ fresh weight (FW) between varieties and more than 50% of varieties were under the minimum pharmaceutical standard for allicin concentration (>4.5 mg g⁻¹ in FW). Across varieties there was an inverse relationship between yield and allicin concentration. However, there were some varieties which had both high allicin concentration and yield. Current field trials investigate the effect of agronomic practices on yield and allicin concentration in garlic varieties. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 145 KiB

Open AccessAbstract

Performance of Zero Tillage Potato Cultivation with Different Mulch Materials in the South-Western Saline Area of Bangladesh

by M. Akkas Ali, Mustafa Kamal Shahadat and Md. Harunor Rashid

Proceedings 2019, 36(1), 29; https://doi.org/10.3390/proceedings2019036029 - 31 Dec 2019

Cited by 2 | Viewed by 1377

Abstract

Crop cultivation in the coastal saline area of Bangladesh during rabi season is limited due to late harvest of Aman rice, shorter winter period, difficulty in tillage, soil salinity, lack of fresh irrigation water etc. Zero tillage potato cultivation with mulching could minimize [...] Read more.

Crop cultivation in the coastal saline area of Bangladesh during rabi season is limited due to late harvest of Aman rice, shorter winter period, difficulty in tillage, soil salinity, lack of fresh irrigation water etc. Zero tillage potato cultivation with mulching could minimize these obstacles and thereby increase system productivity. However, selection of mulching material is crucial for higher yield and economic return. An experiment was conducted at coastal saline area of Bangladesh during rabi 2018–19 to observe zero tillage potato performance under different mulch materials. Three locally available mulch materials were employed in the trial viz. rice straw (T₁), rice husk (T₂) and compost (T₃) as control. Additionally, treatment T₁ and T₂ also received same amount of compost as T₃. Results from single factor randomized complete block design with three replications showed that leaf dry matter, leaf area index and number of tuber per plant did not varied significantly. Significantly highest stem and root dry matter were found from T₁ (69.56 kg ha⁻¹) and T₃ (138.92 kg ha⁻¹), respectively. Rice husk (T₂) produced numerically highest leaf dry matter (372.74 kg ha⁻¹) and significantly lowest root dry matter (87.92 kg ha⁻¹), which ultimately produced highest tuber yield (13.99 t ha⁻¹) followed by rice straw (T₁) (11.08 t ha⁻¹). However, weed growth was highest in rice husk (1.16 t ha⁻¹). Mulch treatments conserved 3.5 to 7.45% more moisture and 4.3% less salinity than control. Between two mulches rice straw is suggested for its profitability since it remains unused and readily available. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

Effect of Mulch Materials and Nitrogen Source on the Performance of Tomato in the South-Western Coastal Area of Bangladesh

by Md. Harunor Rashid, M. Akkas Ali and Mustafa Kamal Shahadat

Proceedings 2019, 36(1), 30; https://doi.org/10.3390/proceedings2019036030 - 31 Dec 2019

Viewed by 1016

Abstract

The major cropping pattern in the South-western coastal area of Bangladesh is transplanted aman rice followed by fallow during the rabi season (November to March) and kharif-I (April-July) season. Crop production during rabi season is limited due to various ecological factors including soil [...] Read more.

The major cropping pattern in the South-western coastal area of Bangladesh is transplanted aman rice followed by fallow during the rabi season (November to March) and kharif-I (April-July) season. Crop production during rabi season is limited due to various ecological factors including soil salinity, lack of fresh irrigation water, short winter period, late harvest of previous aman rice, heavy clay soil etc. Tomato is a popular winter crop in that area which is mainly cultivated around homestead and ridges of fish pond, where soil salinity and tillage is not a major problem. An attempt was taken to grow tomato in Khulna district of Bangladesh after T. Aman rice harvest during 2018–19 in order to investigate tomato performance at different mulch materials and Nitrogen sources. The two factors experiment was carried out in randomized complete block design with three replications. Mulch materials viz. rice straw (M₁), black polythene (M₂) and no mulch (M₃) were employed as factor one and nitrogen source viz. prilled urea (N₁) and urea super granule (N₂) were assigned as factor two. Results showed that there was no interaction effect of mulch and nitrogen treatments. Single effect of mulch and nitrogen treatments showed that highest fruit yield was found from rice straw (M₁) (17.32 t ha⁻¹) and prilled urea (N₂) (15.64 t ha⁻¹), respectively. So, tomato can be grown with rice straw mulch along with prilled urea for higher economic return (MBCR 2.24). Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 140 KiB

Open AccessAbstract

System Identification of Linearized Rice Growth Dynamic for Precision Irrigation

by John Audie Cabrera, Ando Mariot Radanielson and Jhoanna Rhodette Pedrasa

Proceedings 2019, 36(1), 31; https://doi.org/10.3390/proceedings2019036031 - 31 Dec 2019

Cited by 1 | Viewed by 1148

Abstract

Modeling crop growth dynamics has been used to predict and analyze the effects of water stress on crop yields for different irrigation managements. In particular, rice, a water intensive crop, has been extensively modeled using simulation software such as ORYZA3, Aquacrop, and WARM. [...] Read more.

Modeling crop growth dynamics has been used to predict and analyze the effects of water stress on crop yields for different irrigation managements. In particular, rice, a water intensive crop, has been extensively modeled using simulation software such as ORYZA3, Aquacrop, and WARM. Despite these established simulation models, only soil water balance models are utilized for real time irrigation control. The reasons are twofold: the complexity in incorporating non-linear and highly interactive nature of crop physiological mechanisms in a control framework; and the difficulty in estimating these physiological mechanisms compared to using soil water sensors for soil water balance models. This work developed a system identification technique that improves accuracy in irrigation timing, amount and efficiency by integrating crop growth dynamics to estimate evapotranspiration as feedback in the soil water balance model. Sample simulation runs from ORYZA3 were used to build and validate a water limited growth dynamics. A two level regression technique was used resulting in reduced expressions for leaf area index, biomass, and soil water depletion. With advancements in wireless sensor technologies, the modeling framework maximizes use of field sensor information to adequately estimate the crop state. Thus, it can be adopted in advance control techniques for irrigation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Rescheduling of Wet Season (T. Aman) Rice Planting for Cropping Intensification in Coastal Bangladesh

by Md. Maniruzzaman, Mohammed Mainuddin, Richard Bell, Jatish Chandra Biswas, Md. Jahangir Kabir, Md. Belal Hossain, Mst. Shetara Yesmin, A. B. M. Mostafizur and Palash Kumar Kundu

Proceedings 2019, 36(1), 32; https://doi.org/10.3390/proceedings2019036032 - 2 Jan 2020

Cited by 1 | Viewed by 1473

Abstract

About 1.0 million ha coastal lands in Bangladesh are mono-cropped suffer from varying degree of soil salinity, waterlogging and climate vulnerability. Low yielding, traditional T. Aman rice is grown only in wet season. Growing non-rice crop after late harvested T. Aman rice is [...] Read more.

About 1.0 million ha coastal lands in Bangladesh are mono-cropped suffer from varying degree of soil salinity, waterlogging and climate vulnerability. Low yielding, traditional T. Aman rice is grown only in wet season. Growing non-rice crop after late harvested T. Aman rice is not profitable. This study was aimed to introduce high yielding, short duration T. Aman rice varieties for advancing its harvesting time and to make the avenue for timely establishment of dry season crops. Varietal trials were made at Dacope and Amtali under ACIAR funded project during 2016-2018 and compared with local cultivars. Among tested varieties BRRI dhan76 followed by BRRI dhan77 and BRRI dhan54 in Dacope and BRRI dhan77 followed by BRRI dhan76 and BRRI dhan54 in Amtali were preferred for 0.5–1.0 tha⁻¹ yield advantage and 15–25 days earliness compared to traditional varieties. Early harvesting of T. Aman created the avenue of timely establishment of rice and non-rice crops depending on availability of fresh water and thus crop intensification and land productivity was improved. The new cropping system increased annual rice yield and farmers’ profits by 1.5- to 2-folds compared with traditional system without environmental degradation. This technique can be replicated in similar coastal zones of Bangladesh. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 138 KiB

Open AccessAbstract

Air Temperature an Influential Climatic Factor for Growth and Reproduction of Dry Flower Pathogens of Macadamia

by Kandeeparoopan Prasannath, Victor Galea and Olufemi Akinsanmi

Proceedings 2019, 36(1), 33; https://doi.org/10.3390/proceedings2019036033 - 3 Jan 2020

Cited by 1 | Viewed by 1442

Abstract

In order to assess the influence of climatic factors on abundance of conidia of dry flower pathogens, Pestalotiopsis macadamiae and Neopestalotiopsis macadamiae, a Burkard spore trap was used to determine daily aerial conidia concentration at Alstonville (28.852° S, 153.456° E), New South Wales, [...] Read more.

In order to assess the influence of climatic factors on abundance of conidia of dry flower pathogens, Pestalotiopsis macadamiae and Neopestalotiopsis macadamiae, a Burkard spore trap was used to determine daily aerial conidia concentration at Alstonville (28.852° S, 153.456° E), New South Wales, Australia. Weather data including minimum and maximum air temperatures, rainfall, wind speed and relative humidity were obtained from an automated weather station at the same location. The effect of each, and the combined climatic parameters on conidia abundance was analysed using the GLM procedure for the all-subset regression link functions. A model containing weekly maximum temperature and weekly rainfall produced the best significant effect on conidia abundance (R² = 72.7%, P = 0.003) compared with the model containing daily data of both climatic parameters (R² = 35.4%, P = 0.000). In vitro assays were established to examine the effect of different temperatures (12, 19, 22, 25, 29, 33, 37 and 41 °C) on growth and reproduction of the pathogens. The results showed that maximal mycelial growth, conidia production and germination occurred at 25 °C and declined significantly (P < 0.05) at cooler and warmer temperatures. Temperatures above 40 °C were lethal for growth and functioning of the pathogens. The results confirmed that air temperature significantly influenced growth and reproduction of both dry flower pathogens. These findings will underpin development of a disease prediction model for dry flower in macadamia. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 115 KiB

Open AccessAbstract

The Effect of Medium Type and Subculture Frequency on the Formation of Friable Embryogenic Callus for Coconut Cell Suspension Culture

by Eveline Y. Y. Kong, Julianne Biddle and Steve W. Adkins

Proceedings 2019, 36(1), 34; https://doi.org/10.3390/proceedings2019036034 - 3 Jan 2020

Cited by 1 | Viewed by 1819

Abstract

Coconut, a multipurpose palm, is facing increasing demand for its fruit as well as the pressure from industries to produce coconut-derived products. However, coconut production has been declined, and about half of the planted palms are facing senility in the producing countries. This [...] Read more.

Coconut, a multipurpose palm, is facing increasing demand for its fruit as well as the pressure from industries to produce coconut-derived products. However, coconut production has been declined, and about half of the planted palms are facing senility in the producing countries. This condition will not be alleviated with the continual practice of traditional breeding methods which produces only one seedling per fruit. Hence, coconut cloning by somatic embryogenesis is the focus of the present work. Although this has been attempted for over 60 years, improvements are still needed to increase the production rate. Therefore, a cell multiplication step to increase the production of embryogenic cells through cell suspension culture is proposed because the establishment of cell suspension culture and its regeneration in oil palm and date palm have been achieved with great success. Consequently, the establishment of coconut cell suspension culture is anticipated to bring a leap in production. The initial plant material for the initiation of cell suspension culture is friable embryogenic callus. As the nature of the embryogenic callus is often compact, the effect of medium type and subculture frequency on the induction of friable embryogenic coconut callus was studied. Based on the results, their effects on the friable embryogenic callus formation were minimal, so the formation is likely to depend on other factors. There were however effects on the callus and embryogenic callus formed and it was found that those cultures in solid media require less subculture than those in liquid media. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 186 KiB

Open AccessAbstract

Deploying New Technologies to Secure the Banana Industry

by Rosamond Godwin

Proceedings 2019, 36(1), 35; https://doi.org/10.3390/proceedings2019036035 - 4 Jan 2020

Viewed by 1051

Abstract

Bananas are Australia’s number-one selling supermarket product (in volume), with over five million of them eaten daily, all of which are grown in Australia. The 13,000 ha industry has a farm gate value of around $600 m and contributes $1.3 billion to the [...] Read more.

Bananas are Australia’s number-one selling supermarket product (in volume), with over five million of them eaten daily, all of which are grown in Australia. The 13,000 ha industry has a farm gate value of around $600 m and contributes $1.3 billion to the national economy annually. Over the last 3–4 years the industry has been under considerable financial pressure from poor prices but this has been exacerbated by dealing with major responses to banana Freckle and Fusarium Wilt Tropical Race 4 (TR4). Banana Freckle has successfully been eradicated from Australia but the threat from TR4 is ongoing. The Banana industry considers that R&D is critically important for successfully dealing with major disease threats and reducing their impact. The spread of TR4 has been slowed through a major control and containment program which has been underpinned by high quality research but this research needs to continue, to allow time to find long-term solutions that will safeguard the industry’s ongoing viability. The role science plays is multifaceted. The challenge for horticultural industries is to include both basic and applied research that is relevant to the needs of industry, fits within the constraints of legislation and the supply chain, meets the needs of consumers and will lead to outcomes that are implemented on farms by growers. Examples of how the banana industry is meeting these challenges will be discussed in this presentation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 120 KiB

Open AccessAbstract

Climate Change Impacts, Adaptation and Mitigation for Tropical Agriculture

by Mark Howden

Proceedings 2019, 36(1), 36; https://doi.org/10.3390/proceedings2019036036 - 4 Jan 2020

Cited by 1 | Viewed by 1169

Abstract

As climate change gains pace globally, many of the first and most severe impacts are falling on tropical regions [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Increasing the Diversity of Crops That Can Be Grown in Urban and Vertical Farms

by Cathryn A. O’Sullivan, Graham D. Bonnett, C. Lynne McIntyre, Ian B. Dry and Lekha Sreekantan

Proceedings 2019, 36(1), 37; https://doi.org/10.3390/proceedings2019036037 - 5 Jan 2020

Viewed by 1463

Abstract

The FAO estimates that more than 800 million people engage in urban agriculture producing more than 15% of the world’s food. Recently, there has been a resurgence of interest in urban agriculture in many wealthy, developed cities, with new technology and agro-architecture being [...] Read more.

The FAO estimates that more than 800 million people engage in urban agriculture producing more than 15% of the world’s food. Recently, there has been a resurgence of interest in urban agriculture in many wealthy, developed cities, with new technology and agro-architecture being employed to grow food in cities at commercial scale. This has been accompanied by an increase in media coverage. Big claims are being made, including that urban agriculture can help solve food security for growing urban populations, decrease greenhouse emissions, ‘climate proof’ farms, and provide chemical free food with no risk of pests and diseases. Many of these claims need to be rigorously tested to ensure that sound investments can be made in enterprises that are financially viable and capable of delivering on claims of social and environmental benefits. Traditionally, agricultural researchers have provided biological, chemical, physical, economic and social research help broad-acre and horticulture farming increases productivity and decrease risk. Urban agriculture needs similar support as the industry grows and develops around the world. There are opportunities to improve crop yields and quality by pairing advancements in environmental controls, phenomics and automation with breeding efforts to adapt traits for architecture, development and quality (taste and nutrition) allowing a more diverse set of crops to be grown in controlled-environment farms. CSIRO is looking to apply our establish capability and skills to support the urban and vertical farming industry to contribute to the nutrition of city dwellers as urban populations continue to rise. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 146 KiB

Open AccessAbstract

Effects of Pesticides on Nitrous Oxide Production in Sugarcane Cropping Soil

by Shilpi Das, Weijin Wang, Steven Reeves, Ram Dalal and Peter Kopittke

Proceedings 2019, 36(1), 38; https://doi.org/10.3390/proceedings2019036038 - 6 Jan 2020

Viewed by 1688

Abstract

This study aimed to assess the non-target impacts of pesticides on soil biological processes, particularly N₂O emissions and improve understanding of the contributions of nitrification and denitrification to N₂O production in sugarcane soils. We conducted a laboratory incubation experiment, [...] Read more.

This study aimed to assess the non-target impacts of pesticides on soil biological processes, particularly N₂O emissions and improve understanding of the contributions of nitrification and denitrification to N₂O production in sugarcane soils. We conducted a laboratory incubation experiment, in which a herbicide Roundup®, an insecticide Confidor®, a fungicide Shirtan®, and a fumigant metam sodium were added to a Ferrosol and then incubated at 25°C for 38 days at 2 moisture regimes (55 % and 90% water holding capacity (WHC)). At day 28, soil water contents in the 55% WHC treatments were also increased to 90% WHC to create a condition to favour denitrification. The 55% and 90% WHC treatments received NH₄SO₄ at 40µg N g⁻¹ dry soil and KNO₃ at 40µg N g⁻¹ dry soil, respectively, with K¹⁵NO₃ added at 2 µg N g⁻¹ of dry soil in all treatments. Compared with the control treatment, Confidor application significantly increased net nitrification rates and N₂O emissions at 55% WHC. After increasing water content from 55% to 90% WHC at day 28, net denitrification occurred in the metam sodium treatment; N₂O emissions increased in the order: metam sodium > Shirtan > Glyphosate treatment, with little changes in the Confidor and control treatments. During the 38-day incubation at 90% WHC, the metam sodium treatment emitted more N₂O emissions than other treatments in the first 15 days of the incubation but no significant differences were observed among the other treatments at the end of the incubation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Nanobubbles in Hydroponics

by Yimeng Li and Robyn Cave

Proceedings 2019, 36(1), 39; https://doi.org/10.3390/proceedings2019036039 - 6 Jan 2020

Cited by 1 | Viewed by 1722

Abstract

Maintaining oxygen levels in the nutrient solution of hydroponic systems, particularly those using the deep flow technique (DFT), is essential for root uptake of nutrients and for cellular respiration. However, more frequent, extreme and longer heatwaves, as a result of climate change, are [...] Read more.

Maintaining oxygen levels in the nutrient solution of hydroponic systems, particularly those using the deep flow technique (DFT), is essential for root uptake of nutrients and for cellular respiration. However, more frequent, extreme and longer heatwaves, as a result of climate change, are posing a threat to outdoor hydroponic growers because oxygen levels in the nutrient solution decrease as temperature increases. Low dissolved oxygen (DO) levels can adversely affect growth rates and yield, making it difficult for growers to meet customers’ demand. Current strategies for increasing DO include cooling the solution, introducing oxygen into the nutrient tank using air pumps with air stones and surface contact with atmospheric oxygen. However, nanobubbles could be a more effective solution for raising the DO level when the nutrient solution temperature is over 30 DegC. Nanobubbles (<200 nm in diameter) are generated using a nanobubble aerator and can exist in liquid for several weeks to several months due to a negative surface charge and high gas solubility in water. This study investigated the stability of air nanobubbles in distilled water at 14–48 °C and in nutrient solutions with pH levels of 5.0, 6.0 and 7.0 at 20, 30 and 40 °C. Air nanobubble water could be effective for managing DO levels in conventional and organic hydroponic systems in regions where temperatures are predicted to rise. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 151 KiB

Open AccessAbstract

Sorghum (Sorghum bicolour L.) Germination Dynamics at Extreme Temperatures

by Mengwei Li, Joseph X. Eyre, Ian Broad and Daniel Rodriguez

Proceedings 2019, 36(1), 40; https://doi.org/10.3390/proceedings2019036040 - 10 Jan 2020

Viewed by 1433

Abstract

Water and heat stressors during flowering are predominant limitations of dryland sorghum yields across Australia’s north-eastern cropping zone. Crops sown early could flower before seasonal heatwaves, but the seed must uniformly germination and emerge at soil temperatures between approximately 10 to 15 °C. [...] Read more.

Water and heat stressors during flowering are predominant limitations of dryland sorghum yields across Australia’s north-eastern cropping zone. Crops sown early could flower before seasonal heatwaves, but the seed must uniformly germination and emerge at soil temperatures between approximately 10 to 15 °C. Furthermore, chemical coatings applied to commercial hybrid seed lots effectively protected the developing crop from pest, disease and herbicide damage but the combined influence of low temperatures and seed coatings on germination of hybrid sorghum seed batches is unknown. In this experiment, germination dynamics were modelled for 10 commercial sorghum hybrid-seed lots (with or without seed coating of a.i. thiamethoxam, oxabetrinil and thiram) incubated at continuous temperatures ranging from 9.4 to 46.1 °C. Results also show commercial seed treatments negatively affect final germination proportion especially at sub- and supra-optimal temperatures. Some hybrid-seed lots in current experiment were more sensitive to seed coatings at either sub- or supra-optimal temperatures regardless of seed germination capability (i.e., germination proportion at 25 °C). Seeds took 5 days to reach 50% germination (t50) at 9.4 °C but germinated within 24 h at constant temperatures between 20 and 40 °C. The spread of germination (time between 10 and 90% germination) increased from 0.5 days at 30 °C to 3.8 days at 9.4 °C. Therefore, some hybrid-seedlots are suited to early sowing because they can maintain high germination proportion (>90%) even at soil temperatures (9.4 °C) as long as the seedbed remains moist for a least 12 days. Research continues identify the basis of cold tolerance in some-hybrid seedlots. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 132 KiB

Open AccessAbstract

Dynamics of Mango Seedlings and Mango Varieties: A Case Study of Nurseries in Mango Production Center in Majalengka, West Java, Indonesia

by Puspitasari, Sara Ratna Qanti and Hardiyanto

Proceedings 2019, 36(1), 41; https://doi.org/10.3390/proceedings2019036041 - 11 Jan 2020

Cited by 1 | Viewed by 1447

Abstract

Mango is a favorite tropical fruit in both domestic and international markets. Due to its features that are relatively easy to grow and more resistant to pests and diseases, the success rate of producing the seedlings is higher compared to the other perennial [...] Read more.

Mango is a favorite tropical fruit in both domestic and international markets. Due to its features that are relatively easy to grow and more resistant to pests and diseases, the success rate of producing the seedlings is higher compared to the other perennial fruit plants. Despite of these advantages, the sector is still facing several constrains. One of them is the low rate of certified seedling used that may affects the productivity of mango trees. Limited availability of superior certified mango seedlings that is faced by mango nurseries is suspected as one of the cause. This paper aims to describe the dynamic that occurs in mango nursery sector in one of mango production centres in West Java. The data was collected through survey of 260 nurseries in 2016 and was part of Indohort project research; a collaboration between Australian Centre for International Agricultural Research (ACIAR), Iindonesian Center for Horticulture Research and Development (ICHORD), and the University of Adelaide. The results showed that: (1) Only 7% of the total number of nurseries has a formal certification for seedlings that are produced, (2) in average, mango nurseries produce less mango seedlings in 2016 compared to 2011; (3) mango nursery’s specialization rate decreased from 32% in 2011 to 19% in 2016, (4) the share of Harumanis (mango variety that is most preferred in Indonesia) seedlings production per nursery, decreased from 89% in 2011 to 65% in 2016; (4) Further improvement related to mango seedlings marketting chain needs to be done to create a better mango seedling market structure along the chain. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 115 KiB

Open AccessAbstract

Assessing Food Safety and Quality Compliance: An Evidence from Vegetable Industry

by Rehan Riaz, Arfa Jawaid, Babar Ehsan Bajwa and Muhammad Asif

Proceedings 2019, 36(1), 42; https://doi.org/10.3390/proceedings2019036042 - 12 Jan 2020

Viewed by 1164

Abstract

The aim of present research was to assess and document the practices for prevailed food safety and quality standards as employed by small scale growers and market managers in the vegetable supply chains of Pakistan. For this purpose, cross-sectional data were collected from [...] Read more.

The aim of present research was to assess and document the practices for prevailed food safety and quality standards as employed by small scale growers and market managers in the vegetable supply chains of Pakistan. For this purpose, cross-sectional data were collected from two provinces (Sindh and Punjab) of Pakistan targeting commercial vegetables, i.e., potato, tomato, onion, and chilies. Information regarding the food safety and quality were recorded during field survey from all the supply chain participants, i.e., growers, harvesters, processors, traders, and exporters through well-designed questionnaires. The collected data adherence with the standard requirements and identifying constraints of chain actors were analyzed using descriptive analysis. Results showed that many practices such as soil and ground water contamination, pesticide and fungicide residuals, microbial contaminants, infected labour, diggers, packaging migrants, clothes, surfaces and non-food grade containers may enhance the chances of food borne diseases among consumers. Therefore, training needs have been identified for all stakeholders that need to be addressed which will develop their understanding about the quality requirements and safety regulations. It will create opportunity in the advanced markets at national and international levels and new opportunities may arise to enhance stakeholders’ income. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 135 KiB

Open AccessAbstract

Low Cost Glad Wrap Film Packaging Delays Postharvest Senescence and Maintains Fruit Quality of Green Chilies

by Samia Sarfraz, Mahmood Ul Hasan, Aman Ullah Malik, Raheel Anwar and Rehan Riaz

Proceedings 2019, 36(1), 43; https://doi.org/10.3390/proceedings2019036043 - 12 Jan 2020

Viewed by 1399

Abstract

Green chilies are highly perishable with limited postharvest life which substantially affects its quality and market potential. The present study was part of an ACIAR-funded project aiming at evaluating the effect low cost Glad wrap film packaging (GWFP) on eight commercial green chili [...] Read more.

Green chilies are highly perishable with limited postharvest life which substantially affects its quality and market potential. The present study was part of an ACIAR-funded project aiming at evaluating the effect low cost Glad wrap film packaging (GWFP) on eight commercial green chili cultivars (Kunri-1, Longi, Talhari, Skyline 1 and 3, Super-hot, Advanta and BSS-410) to help improve shelf life and quality during ambient storage at 18±2 °C. Chilies were weighed and filled in polyvinyl trays and wrapped with Glad wrap film. Chilies kept in Glad wrap film packaging improved marketability index and shelf life for 9 to 15 days compared to open top trays (control) with shelf life of 3 to 6 days depending on cultivar. GWFP storage of chili fruits markedly reduced weight loss, decay, disease incidence, wrinkling. red chili percentage and relative electrolyte leakage as compared with control. It was noted that chilies stored under GWFP displayed significantly higher firmness, soluble solid contents, acidity, ascorbic acid with maintained radical scavenging activity. In addition, total phenolic contents, enzymatic essays i.e. superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO) catalase (CAT) and ascorbate peroxidase (APX) activities were significantly higher in GWFP kept chilies. Conclusively, the low cost Glad wrap film packaging can be employed as promising technique to reduce postharvest losses, extend shelf life and maintain postharvest quality of chilies leading to more profit for the growers and linked stakeholders. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 140 KiB

Open AccessAbstract

Economic, Environmental, and Social Sustainability Assessment of Queensland Industries

by Alisher Ergashev

Proceedings 2019, 36(1), 45; https://doi.org/10.3390/proceedings2019036045 - 13 Jan 2020

Viewed by 1188

Abstract

In ‘Our Future State: Advancing Queensland’s Priorities’ the Queensland Government outlined how industries and government should contribute to community well-being. Agriculture’s contribution lies in generating economic activity, job creation and the Great Barrier Reef protection. While lack of data prevents the measurement of [...] Read more.

In ‘Our Future State: Advancing Queensland’s Priorities’ the Queensland Government outlined how industries and government should contribute to community well-being. Agriculture’s contribution lies in generating economic activity, job creation and the Great Barrier Reef protection. While lack of data prevents the measurement of some attributes in the government plan, composite sustainability indices have been used worldwide to represent the wider objectives of “triple bottom line” economics (growth and throughput), social justice (fair and equitable distribution of the wealth) and environment-friendliness (compatibility with the preservation of natural ecosystems). One such approach is an innovative self-designed iSENSE index—indicators of Sustainability: ENvironmental, Social, and Economic—that is based on 15 indicators with a maximum overall score of 30. The featured indicators are based on a literature review and represent commonly accepted parameters. In this study, iSENSE indicators have been enumerated for the analysis of three Queensland sectors: Agriculture, Mining, and Manufacturing. The results show that while Mining leads the group in terms of economic indicators, it is Agriculture that is the most socially oriented and environment-friendly. Overall, iSENSE score is equal 16 for both Agriculture and Mining, whilst Manufacturing stands at 13. While these results should be taken with caution, they can be used as a guidance for prospective policy proposals in conjunction with the sound ex post impact assessments around Queensland industries. Applying composite assessment tools can help to identify challenges related to environmental, economic and social impact, in the course of developing sustainable agriculture. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

The Economic Benefits of Improvements in Online Licensing of The Chemical Use in Queensland Crop Industries

by Alisher Ergashev

Proceedings 2019, 36(1), 46; https://doi.org/10.3390/proceedings2019036046 - 13 Jan 2020

Viewed by 1197

Abstract

The selective use of chemical products plays an important role in increasing production, improving the quality of Queensland’s agricultural produce and enabling producers to earn reasonable returns on their investments. Effective pest management, therefore, helps deliver high quality, healthy and affordable food for [...] Read more.

The selective use of chemical products plays an important role in increasing production, improving the quality of Queensland’s agricultural produce and enabling producers to earn reasonable returns on their investments. Effective pest management, therefore, helps deliver high quality, healthy and affordable food for all consumers. The efficiency of policy tools such as chemical use licensing hinges critically on supply-side knowledge levels. Although licence applications are available online, information can be difficult to find and often businesses need to contact the state authority to seek further assistance in completing their licence applications. The aim of this study is therefore to identify the benefits for the users of agricultural chemicals from improvements in licensing application process. Based on a rigorous literature review and statistical analysis of available data, this study modelled the per day/per application value of the use of crop protection products in Queensland. Results indicate a potential saving by farmers due to a faster process for chemical licence applications. Extreme values of these savings range from $87 thousand to $52 million per annum, with actual ones falling in between depending on the coincidence and level of individual risk factors. Since the chemicals subject to licensing are used beyond agriculture and are utilised not only for crop protection, the results of this analysis are thus underestimated, which implies even greater benefits for the economy. It therefore seems important to update the current licence application platform so that applicants can lodge their application in a more user-friendly and synchronised manner. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 174 KiB

Open AccessAbstract

Analysis of the Temporal and Spatial Distribution Patterns of Abnormal Vertical Growth in Commercial Macadamia Orchards in Australia

by Mohamed Cassim Mohamed Zakeel, Andrew D W Geering and Olufemi A Akinsanmi

Proceedings 2019, 36(1), 47; https://doi.org/10.3390/proceedings2019036047 - 14 Jan 2020

Viewed by 1212

Abstract

Abnormal vertical growth (AVG) syndrome, which has an unknown aetiology, is a serious threat to the Australian macadamia industry. AVG is characterized by vigorous upright growth and reduced flowering and nut set that results in over 70% yield loss. However, there is a [...] Read more.

Abnormal vertical growth (AVG) syndrome, which has an unknown aetiology, is a serious threat to the Australian macadamia industry. AVG is characterized by vigorous upright growth and reduced flowering and nut set that results in over 70% yield loss. However, there is a deficiency in knowledge about the distribution of AVG. In this study, we used spatial analysis to provide insights into the distribution and spread of AVG in commercial macadamia orchards in Australia. Using binary data of AVG occurrence from large-scale surveys of six affected commercial orchards in Queensland (five orchards) and New South Wales (one orchard) in 2012 and 2018, spatio-temporal dynamics of AVG was evaluated. Data were subjected to point-pattern and geostatistical analyses using the R package EPIPHY. The Fisher’s index of dispersion of all orchards showed aggregated patterns of affected trees in both years, with statistical significance (p < 0.01) of chi-square test. Goodness-of-fit comparisons of incidence data of all orchards with β-binomial distributions showed that AVG incidence increased by 64% over the six-year period. AVG distribution and the β-binomial parameters exhibited strong heterogeneity, which indicates high degree of aggregation and increasing spread of AVG over time. In addition, binary power law and spatial hierarchy tests confirmed the patterns of aggregation in all orchards. These results implicate a biotic agent as the cause of AVG. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 114 KiB

Open AccessAbstract

Analysis of Gross Margins in Queensland Tomatoes

by Alisher Ergashev

Proceedings 2019, 36(1), 48; https://doi.org/10.3390/proceedings2019036048 - 16 Jan 2020

Viewed by 1793

Abstract

Tomato is an important vegetable crop that contributes significantly to income security and healthy diets of people worldwide. Queensland produces the majority of tomatoes for fresh consumption accounting for 40 per cent of national supply in Australia. The purpose of this study is [...] Read more.

Tomato is an important vegetable crop that contributes significantly to income security and healthy diets of people worldwide. Queensland produces the majority of tomatoes for fresh consumption accounting for 40 per cent of national supply in Australia. The purpose of this study is to provide an analytical summary of the Queensland tomato supply chain, by focusing on margins along the supply chain. For that, a representative tomato gross margin model in Southern Queensland was used to analyse the estimated income, grouped variable costs and the gross margin for four tomato varieties: gourmet, round, grape, and cherry. The mean yields of the sampled varieties varied considerably, depending on climatic conditions, pests and diseases, the season and whether tomatoes are grown on the ground or trellises. Driven by high revenues and relatively low freight costs, grape tomatoes have the highest gross margin ($73 thousand per hectare) as well as the highest market price at $4.64 per kilo compared to other varieties. The cost of growing the crop up to harvest can exceed $10,000 per hectare with high labour requirement for harvesting and packing. While costs for machinery, fertiliser, herbicide, weed control, insecticide, and fungicide largely remain constant across four tomato varieties, it is planting and irrigation that makes a difference. With average value of $9303 per hectare, planting costs range from $5134 for round tomatoes to $12,241 for cherry tomatoes. The results of this gross margin analysis can be helpful to explore profitability at the farm level, allowing regional and international comparisons. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 126 KiB

Open AccessAbstract

Alternative Diagnostic Tools for White Spot Disease

by Beth Fowler and Rebecca Ambrose

Proceedings 2019, 36(1), 49; https://doi.org/10.3390/proceedings2019036049 - 16 Jan 2020

Viewed by 1253

Abstract

The Queensland prawn production industry is worth >$87 million annually and the 2016 White Spot Disease (WSD) outbreak caused >$25 million in losses and complete destruction of all livestock on eight farms in the Logan River region. Whilst the outbreak was restricted to [...] Read more.

The Queensland prawn production industry is worth >$87 million annually and the 2016 White Spot Disease (WSD) outbreak caused >$25 million in losses and complete destruction of all livestock on eight farms in the Logan River region. Whilst the outbreak was restricted to South East Queensland, its source, and hence the risk for re-infection, remains unknown, resulting in a need for ongoing surveillance. Early detection of WSD infection on farms is a high priority which can be facilitated via development of improved diagnostic tools. Current diagnosis requires specialised laboratory testing so there is a need for a simple, rapid, robust in-field diagnostic test to complement this. We have developed an alternative diagnostic tool for WSD that is suitable for use both in the laboratory and at pond-side. Assay performance was evaluated with pure DNA and crude tissue samples with minimal preparation, giving results similar to traditional DNA testing performed in the laboratory. Our assay is sensitive, specific & accurate; gives results comparable to quantitative PCR (current gold standard); has lower reagent costs; fast workflow of <90 min and is field-deployable. Point of care detection for WSD is an important tool for the future, and our assay is an ideal candidate to fill this space as it will complement the current diagnostic tools already available, to help manage high sample loads and facilitate faster disease diagnosis. This will assist in limiting the spread of the virus through early detection and reducing the risk of disease outbreak, thus protecting Queensland’s valuable prawn aquaculture industry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 119 KiB

Open AccessAbstract

Cropping Systems Modelling: Past, Present and Future

by Peter Thorburn and Brian Keating

Proceedings 2019, 36(1), 50; https://doi.org/10.3390/proceedings2019036050 - 16 Jan 2020

Viewed by 1074

Abstract

Cropping systems are characterised by complexity and variability, and modelling has evolved as a means of describing and interpreting multifaceted performance of these systems. It is also increasingly a means of predicting likely performance for better managing cropping systems. In this paper we [...] Read more.

Cropping systems are characterised by complexity and variability, and modelling has evolved as a means of describing and interpreting multifaceted performance of these systems. It is also increasingly a means of predicting likely performance for better managing cropping systems. In this paper we will briefly describe the development path over the past five decades that has resulted in our current well developed cropping systems modelling capability. We will also discuss new initiatives in sensing, data acquisition and processing (ML/AI) and how these might influence the future of models. These development will result in our models to having even greater impact on the performance of cropping systems in the future. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 117 KiB

Open AccessAbstract

Suitability Evaluation of Underutilized Crops Under Future Climate Change Using Ecocrop Model: A Case of Bambara Groundnut in Nigeria

by Ezinwanne Ezekannagha and Olivier Crespo

Proceedings 2019, 36(1), 53; https://doi.org/10.3390/proceedings2019036053 - 16 Jan 2020

Cited by 1 | Viewed by 1548

Abstract

The agricultural crop system depends on a few major staple crops such as rice, maize, wheat, sorghum, soybeans, amongst others for food production, leaving certain crops underutilized. Even though these underutilized crops have the potentials of diversifying and sustaining the food and nutrition [...] Read more.

The agricultural crop system depends on a few major staple crops such as rice, maize, wheat, sorghum, soybeans, amongst others for food production, leaving certain crops underutilized. Even though these underutilized crops have the potentials of diversifying and sustaining the food and nutrition systems while presenting different resilience to climatic conditions. As the world’s population continues to increase and climate change keeps occurring, these major staple crops are being negatively affected. This study focuses on evaluating the spatial suitability of Bambara groundnut (Vigna subterranea (L.) Verdc.), an indigenous underutilized African legume under past and future climate scenarios in Nigeria, West Africa, where farmers depend mostly on rainfed agriculture. Ten bias-corrected CMIP5 Global climate models simulation downscaled by the Coordinated Regional Climate Downscaling Experiment (CORDEX) regional climate model, RCA4 under the Representative Concentration Pathway (RCP) 8.5 scenario was used to drive the crop suitability model-Ecocrop. The spatial changes in Bambara groundnut suitability were evaluated under 1 past climate period -historical (1980-2010), and 3 future climate period - near future (2010-2040), mid-century (2040-2070), and end century (2070-2099). Our result projects southern Nigeria to remain suitable and an increase in the suitable areas across other parts of the country in future climates. Projected changes were observed in the planting month for Bambara groundnut. The study is relevant and will contribute to the discussions of increasing the number of crops cultivated under climate change as an adaptation strategy towards ensuring a sustainable food system in Nigeria. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Developing Plantain for Resistance to Banana Aphids by RNA Interference

by Temitope Jekayinoluwa, Jaindra Nath Tripathi, George Obiero, Edward Muge, James Dale and Leena Tripathi

Proceedings 2019, 36(1), 54; https://doi.org/10.3390/proceedings2019036054 - 16 Jan 2020

Cited by 2 | Viewed by 2160

Abstract

Banana bunchy top virus (BBTV) is one of the world’s invasive species. Banana aphid (Pentalonia nigronervosa) is found in all banana producing areas and it is the insect pest known to transmit BBTV causing banana bunchy top disease (BBTD) in bananas [...] Read more.

Banana bunchy top virus (BBTV) is one of the world’s invasive species. Banana aphid (Pentalonia nigronervosa) is found in all banana producing areas and it is the insect pest known to transmit BBTV causing banana bunchy top disease (BBTD) in bananas and plantains (Musa spp.) and can cause a significant yield loss of up to 100% in severe cases. Controlling the spread of BBTD has been very challenging since there is no known endogenous gene in the Musa germplasm that could confer resistance to BBTV. Excessive dependence on insecticides for disease control is detrimental to the environment and off-target-organisms. The objective of this study was to use RNA interference (RNAi) targeting the acetylcholinesterase (AChE) gene in banana aphid to develop resistance against aphids in farmer preferred plantain cultivars. This could help sustain smallholder farmers in areas where BBTD is an epidemic. To achieve this, plantain cultivars were initiated using plant tissue culture techniques and rapidly multiplied using Temporary Immersion Bioreactor. This was followed by generation of embryogenic cell suspension (ECS), Agrobacterium-mediated transformation of banana and plantain ECS using a RNAi plasmid construct and molecular characterization of putative transgenic lines. Agro-infected ECS of banana and plantain cultivars were regenerated on selective medium and produced several transgenic lines. Molecular characterization confirmed the presence of transgene in about 80% transgenic lines. Preliminary glasshouse screening of transgenic lines showed reduction in population of banana aphids in comparison to control non-transgenic plants. This is the first report on using RNAi targeting AChE gene for developing transgenic plantain that are resistant to banana aphids. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 115 KiB

Open AccessAbstract

Optimization of Coconut Micropropagation via Somatic Embryogenesis

by Zhihua Mu

Proceedings 2019, 36(1), 55; https://doi.org/10.3390/proceedings2019036055 - 16 Jan 2020

Cited by 2 | Viewed by 1999

Abstract

Coconut (Cocos nucifera L.) is one of the most important tropical palm crops worldwide, but the gap between decreasing productivity and expanding demand is growing and is now becoming a major problem. The global coconut industry is threatened not only by palm [...] Read more.

Coconut (Cocos nucifera L.) is one of the most important tropical palm crops worldwide, but the gap between decreasing productivity and expanding demand is growing and is now becoming a major problem. The global coconut industry is threatened not only by palm senility but by pests/pathogen attack which is becoming exacerbated by climate change. However, conventional breeding methods cannot provide sufficient new planting materials to meet the replacement of senile and damaged palms. Hence, coconut clonal propagation via somatic embryogenesis (SE) is being developed to help meet the demand of the growing market. However, with refined medium composition, improved technical skills, optimized environmental conditions, proper acclimatization steps employed and the application of a cell suspension culture step, a much higher multiplication rate can be predicted. Several factors that affect the rate of clonal propagation are being studied: 1) determination of the effect of a non-activated charcoal (AC) medium and 2) the development of culture induction medium composition with a reduced auxin concentration. Results of the study so far show that a non-activated charcoal medium with more frequent subculture (monthly) and a lower auxin concentration is an efficient alternative approach to the traditional mainstream AC-containing medium for the initiation of embryogenic callus. With a better understanding of the callus induction medium composition, and with a liquid cell suspension culture step medium to be applied in the future, should elevate the multiplication rate of clonal plantlet production. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 112 KiB

Open AccessAbstract

Innovation in Plant Protection in the Citrus Industry

by Andrew Miles

Proceedings 2019, 36(1), 57; https://doi.org/10.3390/proceedings2019036057 - 16 Jan 2020

Viewed by 1042

Abstract

Citrus production is a significant component of the Australian horticulture portfolio. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 157 KiB

Open AccessAbstract

Strategic Supplementation Enhances Rumen Microbiome Efficiency in Pregnant Tropical Beef Cows

by Christopher McSweeney, Gonzalo Martinez-Fernandez and Stuart Denman

Proceedings 2019, 36(1), 58; https://doi.org/10.3390/proceedings2019036058 - 16 Jan 2020

Viewed by 1088

Abstract

Lick-blocks that are used in northern Australian beef enterprises contain varying levels of macro-nutrients (crude protein, sulfur and phosphorus) to correct deficiencies in the forage. It is thought that organic forms of nitrogen and sulfur are used more efficiently for growth and function [...] Read more.

Lick-blocks that are used in northern Australian beef enterprises contain varying levels of macro-nutrients (crude protein, sulfur and phosphorus) to correct deficiencies in the forage. It is thought that organic forms of nitrogen and sulfur are used more efficiently for growth and function of the rumen than the inorganic nutrients. A trial was undertaken in pregnant heifers grazing a poor-quality dry season diet in the Northern Territory. The animals received three lick supplements containing varying forms of organic and inorganic N. No significant differences on animal performance and rumen fermentation parameters were observed between supplements. Animals were initially deficient for rumen ammonia-N (15.8 mg/L) and BUN (4.7 mg/100 mL) concentration. All nitrogen supplements led to a significant improvement in ammonia N (24.7–31.8 mg/L) but levels remained deficient until the wet season and availability of higher quality pasture. Even though the rumen ammonia levels were sub-optimal, the supplemented animals gained approximately 650 g liveweight daily compared with a weight loss of 330 g daily in unsupplemented animals. The increased availability of N in either an organic or inorganic form had a similar influence on the rumen microbiome and rumen fermentation products with increases in ammonia, branched fatty acids, butyrate and the acetic: propionic ratio. All three N supplements showed the same significant increase in species of Ruminocococcus, Bacteroidetes and Cyanobacteria (Melainabacteria) involved in cellulose and hemicellulose digestion. It appears inorganic N is as effective as organic N in improving rumen efficiency when there is a gross deficiency of N for microbial growth. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 114 KiB

Open AccessAbstract

Intelligent Systems for Commercial Application in Perennial Horticulture

by Everard J. Edwards and Peyman Moghadam

Proceedings 2019, 36(1), 59; https://doi.org/10.3390/proceedings2019036059 - 17 Jan 2020

Cited by 1 | Viewed by 1993

Abstract

Production in perennial horticulture relies on a high degree of crop management, but, due to that perenniality, management decisions need to balance short- and long-term impacts. Optimising these decisions requires information about the plants and it requires that information at multiple time-points. The [...] Read more.

Production in perennial horticulture relies on a high degree of crop management, but, due to that perenniality, management decisions need to balance short- and long-term impacts. Optimising these decisions requires information about the plants and it requires that information at multiple time-points. The development of intelligent systems, based on new technologies and new data analytics that take advantage of always available high-performance edge computing, provide a unique opportunity to create a step-change in the management of perennial horticulture crops. For example, combining LiDAR (3D laser imaging) with simultaneous localization and mapping (SLAM) enables the capture of 3D canopy structure on a per tree basis at the orchard scale. Vegetation indices like light penetration, light distribution or foliage density can be estimated directly, in real-time, without a labour-intensive process. Overlaying such an analysis with the output of other sensing modalities extends their application to provide real time, on-farm, decision support by monitoring the condition of every plant in 3D. Even consumer RGB video cameras provide a resolution and frame-rate adequate for a wide range of applications when combined with computer-based image segmentation and machine learning techniques. Such technologies offer the prospect of imaging and analysing a future orchard at any phenological time-point and having a block-level result for the parameter of interest, together with the spatial variability data that will assist in long-term management decisions. In this presentation we will provide examples of these technologies, their current application and how they will be utilised in a future orchard system. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Collaborative Planning and Shared Decision Making in Biosecurity Emergency Management

by Suzy Perry and Rebecca Laws

Proceedings 2019, 36(1), 60; https://doi.org/10.3390/proceedings2019036060 - 17 Jan 2020

Viewed by 1354

Abstract

Robust planning and decision making processes are essential to manage biosecurity risks, particularly in emergency response situations that are highly complex, often contentious and can change rapidly. Effective risk management involves analysing large amounts of diverse scientific, technical and practical information; and dealing [...] Read more.

Robust planning and decision making processes are essential to manage biosecurity risks, particularly in emergency response situations that are highly complex, often contentious and can change rapidly. Effective risk management involves analysing large amounts of diverse scientific, technical and practical information; and dealing with competing priorities and conflicting interests amongst stakeholders. Furthermore, Australia’s biosecurity system relies on shared responsibility, where governments, industry and the community work together to manage biosecurity risks. For shared responsibility to be successful, improved planning and decision making processes are required to ensure that decision making processes enable input from stakeholders. Stakeholder input into risk assessment and the development of risk management options results in more rigorous ‘risk-informed’ decision making. We have developed a collaborative planning and shared decision making framework for risk-informed decision making in biosecurity. It is an integrated system that incorporates principles for involving stakeholders in risk analysis (including risk assessment, management and communication), good decision making and risk governance. We will present the application of the framework during the incursion of the tropical race 4 (TR4) strain of Panama disease in north Queensland, Australia where growers and other industry stakeholders were involved in the development and implementation of the risk mitigation during the emergency response. The collaborative planning and shared decision making framework enables end-users to better manage biosecurity risks, with a logical and analytical planning and decision making process that integrates scientific, technical and practical knowledge and accounts for the political, social and economic values of stakeholders. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 149 KiB

Open AccessAbstract

Discerning Wine Astringency Sub-Qualities by Tribological Approaches in a Model System—What Is the Role of Saliva?

by Shaoyang Wang, Heather E. Smyth, Sandra M. Olarte Mantilla, Jason R. Stokes and Paul A. Smith

Proceedings 2019, 36(1), 61; https://doi.org/10.3390/proceedings2019036061 - 17 Jan 2020

Cited by 1 | Viewed by 1320

Abstract

Astringency is an important indicator of wine sensory quality. As a complex sensation that the loss of in-mouth lubrication is recognised as an important mechanism, astringency can be perceived as a set of different sub-qualities. In addition to sensory evaluations, chemical approaches measuring [...] Read more.

Astringency is an important indicator of wine sensory quality. As a complex sensation that the loss of in-mouth lubrication is recognised as an important mechanism, astringency can be perceived as a set of different sub-qualities. In addition to sensory evaluations, chemical approaches measuring interactivity of astringents-proteins have provide ways of astringency quantification, but they do not capture how specific wine components elicit those sub-qualities. In this study, we developed several tribological approaches, which considered saliva interactions, in an effort to explore if any salivary lubrication change is linked to different sensorily perceived wine astringency sub-qualities. In model wine systems with defined matrix compositions, we found that model wines with equivalent responses in chemical assay for astringency possessed various astringency sub-qualities. In particular, the sub-quality drying corresponded to samples exhibiting higher boundary friction. High-acidity matrix induced pucker, which is found to be independent of drying. It was also linked to a faster salivary film collapse. The rough seemed to be a secondary astringency sub-quality combining drying and pucker, because these 2 sensations were found either elicit rough independently. Polysaccharide reduced the drying in a low-tannin-high-acidity matrix. This is the first study demonstrating that astringency sub-qualities are likely to have different perceptive mechanisms by using tribological measures. The outcomes would provide insights into employing those tools to help manage wine matrix to attain preferable mouthfeels and astringency characteristics. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 159 KiB

Open AccessAbstract

Impacts of Heat Stress on the Physiological and Production Responses of Lactating Dairy Cows Grazing Pastures over Hot Summer Months

by Richard Osei-Amponsah, Frank R. Dunshea, Brian J. Leury, Long Cheng, Brendan Cullen, Aleena Joy, Archana Payyanakkal, Michael H. Zhang and Surinder S Chauhan

Proceedings 2019, 36(1), 62; https://doi.org/10.3390/proceedings2019036062 - 19 Jan 2020

Viewed by 1271

Abstract

Heat stress (HS), a major challenge for sustainable livestock production justifies the need for productive thermotolerant cattle. We measured body temperature (non-invasively using a FLIR T1200 thermal imaging camera), respiratory rate and panting scores of 120 Holstein Friesian cows at the University of [...] Read more.

Heat stress (HS), a major challenge for sustainable livestock production justifies the need for productive thermotolerant cattle. We measured body temperature (non-invasively using a FLIR T1200 thermal imaging camera), respiratory rate and panting scores of 120 Holstein Friesian cows at the University of Melbourne Dookie Dairy Farm weekly during the summer period (December 2018-February 2019). The effect of Temperature-Humidity Index (THI) on milk production, protein content, fat content was also measured. We categorized THI as low (≤72), moderate (73–82) and high (≥83) and observed a highly significant (P ≤ 0.01) effect of THI on respiratory rate (66.7, 84.7 and 109.1/min), panting scores (1.4, 1.9 and 2.3) and average body temperature of cows (38.4, 39.4 and 41.5). Average milk production parameters were also significantly (P ≤ 0.01) affected by THI: daily milk production dropped by 14% from high to low THI, milk temperature and fat% increased by 3% whilst protein% increased by 2%. Highly significant (P ≤ 0.01) positive correlations were obtained between THI and milk temperature, fat% and protein% whilst the reverse was observed between THI and milk yield, feed intake and rumination minutes. Under moderate and high THI, most cows sought shade, spent more time around watering points and showed signs of distress (excessive drooling and open mouth panting). These findings clearly indicate that lactating dairy cows grazing summer pastures experience severe HS compromising their welfare. The quantum of production losses, though significant may however be lower than previously reported in studies using climatic chambers. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 148 KiB

Open AccessAbstract

Association of Thermotolerance with Milk Production, Feed Saver, Fertility and Fat Percentage Breeding Values in Holstein Friesian Dairy Cattle

by Richard Osei-Amponsah, Frank R. Dunshea, Brian J. Leury, Long Cheng, Brendan Cullen, Aleena Joy, Archana Payyanakkal, Michael H Zhang and Surinder S Chauhan

Proceedings 2019, 36(1), 63; https://doi.org/10.3390/proceedings2019036063 - 19 Jan 2020

Viewed by 1460

Abstract

In Australia, heat waves are becoming hotter and longer, and more frequent, compromising dairy cattle welfare and productivity. Selection for heat tolerance (HT) may help to ensure sustainability of production under hot summer conditions. In a study at the University of Melbourne’s Dookie [...] Read more.

In Australia, heat waves are becoming hotter and longer, and more frequent, compromising dairy cattle welfare and productivity. Selection for heat tolerance (HT) may help to ensure sustainability of production under hot summer conditions. In a study at the University of Melbourne’s Dookie Robotic Dairy Farm, we identified the 20 most heat-sensitive and 20 most heat-tolerant cows in a herd of 150 Holstein Friesian lactating cows based on phenotypic responses (increase in body temperature, panting score, and decline in milk production) of dairy cows grazing pasture and given concentrate at milking during hot summer conditions for 3 months. Hair samples were collected from the tip of the tail according to a standard protocol for genotyping (Zoetis). Results based on 36 successfully genotyped cows indicated a significant variation in feed saved (FS) genomic estimated breeding values (GEBVs) across age indicating a potential for its selection. The thermotolerant group had relatively higher GEBV for FS and fat% but lower milk production potential. Highly significant (P ≤ 0.05) negative correlations (−0.39 to −0.69) were observed between heat tolerance and current dairy industry economic indices (Balanced Performance Index (BPI), Type Weighted Index (TWI), Australian Selection Index (ASI) and milk production), while positive correlations exist between HT and feed saved (0.44) and fertility (0.27). These findings indicate a positive association between HT and feed saved, fertility, and fat percent breeding values. However, a more extensive study including large number of lactating cows is required to confirm these genomic associations and incorporating in future breeding objectives. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessAbstract

Understanding the Metabolic Fate and Bioactivity of Dietary Anthocyanins

by Gabriele Netzel, Olivia Wright, Yasmina Sultanbawa and Michael Netzel

Proceedings 2019, 36(1), 64; https://doi.org/10.3390/proceedings2019036064 - 19 Jan 2020

Cited by 1 | Viewed by 1186

Abstract

Anthocyanins are plant pigments and dietary phytochemicals, and may have potential health benefits. There is emerging evidence from epidemiological and experimental studies that suggests a higher consumption of anthocyanin-rich foods is associated with a reduced risk of heart disease and diabetes. To better [...] Read more.

Anthocyanins are plant pigments and dietary phytochemicals, and may have potential health benefits. There is emerging evidence from epidemiological and experimental studies that suggests a higher consumption of anthocyanin-rich foods is associated with a reduced risk of heart disease and diabetes. To better understand the observed beneficial effects of anthocyanins and their underlying mode of action, bioavailability and metabolic fate needs to be studied in more detail. Healthy human subjects (10–12 in two different studies) received red grape pomace (700 mg anthocyanins/mainly as malvidin-3-glucoside) or Queen Garnet plum (QGP) juice (426 mg anthocyanins/mainly as cyanidin-3-glucoside) and an anthocyanin-free control in a randomised crossover design. Malvidin- and cyanidin-glycosides are common in many fruits and beverages such as red grapes, red grape juice, red wine, blueberry, cherry, elderberry, (Japanese) plum and are therefore of dietary significance. 24-hr urine samples were collected and analysed for anthocyanins and metabolites by UHPLC-PDA-MS. Methylated, glucuronidated and sulphated anthocyanins could be identified as characteristic metabolites in both studies. Furthermore, the increase in urinary hippuric acid (microbial/hepatic metabolite) was considerable in both studies after the consumption of red grape pomace or QGP juice (1.8–4.5-fold vs. control; p < 0.05). These findings suggest that structurally different anthocyanins are exposed to a similar extensive metabolism by enzymes and the gut microbiome and that the generated metabolites are most likely the bioactive compounds in vivo. Therefore, more human studies are warranted to investigate the metabolic fate of dietary anthocyanins and the bioactivity of generated metabolites. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 124 KiB

Open AccessAbstract

Pregnancy Nutrition Affects Calf Survival in the Tropics

by Geoffry Fordyce

Proceedings 2019, 36(1), 66; https://doi.org/10.3390/proceedings2019036066 - 19 Jan 2020

Cited by 1 | Viewed by 1144

Abstract

The net cost of calf loss between confirmed pregnancy and weaning in a north Australian beef business is >$400. In an epidemiological study of >46,000 pregnancies in commercial beef herds, median wastage was 9.5%, ranging from 0% to >30%, consistent with the situation [...] Read more.

The net cost of calf loss between confirmed pregnancy and weaning in a north Australian beef business is >$400. In an epidemiological study of >46,000 pregnancies in commercial beef herds, median wastage was 9.5%, ranging from 0% to >30%, consistent with the situation in many tropical countries. Detailed study of >9500 pregnancies in multiple research herds with similar loss showed 30% and 50% of losses occur within a day and week of calving, respectively. Stress and under-nutrition of the pregnant cow, e.g., low dietary energy, protein or phosphorus, low body condition, poor handling and exposure to environmental extremes, have substantially-more impact on calf wastage than any of the risk factors traditionally blamed, i.e., infectious disease, inherited, congenital or acquired defects of the calf and or cow, and natural causes such as predation or accidents. Nutrition- and stress-related risk factors with large impact on calf wastage may influence milk delivery, especially to neonates that require colostrum and as much as 5 L/day from birth. Neonatal calf diarrhoea is not usually a feature. Low milk delivery can be due to either insufficient milk production or to reduced calf capacity to suckle. Calf loss is also associated with mortality of poorly-nourished cows. Causal webs explaining calf loss in non-intensive tropical beef systems demonstrate the high degree of complexity, intervention points with greatest potential impact and that any potential interventions to reduce calf wastage have both negative and positive impacts. Systematic solutions should target critical control points and are situation-specific. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 200 KiB

Open AccessAbstract

Phylogenetic Relationship among Macadamia integrifolia and Macadamia tetraphylla Wild Accessions

by Thuy Thi Phuong Mai, Mobashwer Alam, Robert Henry, Craig Hardner and Bruce Topp

Proceedings 2019, 36(1), 67; https://doi.org/10.3390/proceedings2019036067 - 19 Jan 2020

Viewed by 1375

Abstract

Two of Australia’s endemic rainforest species, Macadamia integrifolia and M. tetraphylla, produce edible nuts with high-value kernel. The majority of commercial varieties are based on the limited gene pool of M. integrifolia and hybrids between M. integrifolia and M. tetraphylla. An [...] Read more.

Two of Australia’s endemic rainforest species, Macadamia integrifolia and M. tetraphylla, produce edible nuts with high-value kernel. The majority of commercial varieties are based on the limited gene pool of M. integrifolia and hybrids between M. integrifolia and M. tetraphylla. An understanding of the existing genetic diversity within the species can be utilized for future genetic improvement. Aiming to identify the genetic diversity, we conducted phylogenetic analyses of 98 wild accessions of M. integrifolia collected from 23 population sites, and 94 accessions of M. tetraphylla from 21 sites using 2,872 high-quality DArTseq-based SNP markers. The phylogenetic tree clearly distinguished clades of the two species. Within species, most of the accessions from the same population clustered together. Genetic and geographic distances among M. integrifolia populations were positively correlated (r = 0.26, p = 0.01), whereas the correlation was poor and not significant among M. tetraphylla populations (r = 0.08, p = 0.13). The relationship between genetic and geographic distance allows evaluating the relative influences of gene flow and drift on population structure within and between regions. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 120 KiB

Open AccessAbstract

Start Clean, Stay Clean

by Mark Whattam

Proceedings 2019, 36(1), 68; https://doi.org/10.3390/proceedings2019036068 - 19 Jan 2020

Viewed by 980

Abstract

Starting clean and staying clean is one of the simplest ways to maximise and sustain a productive farming operation. Australia’s geographical isolation and strict quarantine regulations has meant we have relatively fewer pests that affect primary industries compared to overseas. Healthy plants are [...] Read more.

Starting clean and staying clean is one of the simplest ways to maximise and sustain a productive farming operation. Australia’s geographical isolation and strict quarantine regulations has meant we have relatively fewer pests that affect primary industries compared to overseas. Healthy plants are easier to grow, require fewer chemicals and produce higher crop yield and quality. To remain internationally competitive and economically viable, the Australian agriculture sector needs to consider the positive impact that starting with healthy planting material and seed provides. Accurate and rapid diagnosis for viruses and other graft transmissible diseases that can spread through infected propagation material, plays a critical role in providing healthy plants for growers and supporting profitable production. Quarantine services provided by the Australian government and use of certified pathogen tested planting material greatly reduces the chance of introducing pests onto your property, that once established, can be difficult and costly to control. This presentation will provide a brief overview of programs available to ‘start clean’ and then concludes by summarising actions you, the farmer, can do to help ‘stay clean.’ Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 134 KiB

Open AccessAbstract

Rice Biofortification—Progress and Challenges in Improving the Nutritional Value of Rice

by Russell Reinke, Mallikarjuna Swamy, Abdul Kader, Reynante Ordonio, Untung Susanto and Emily Arocena

Proceedings 2019, 36(1), 69; https://doi.org/10.3390/proceedings2019036069 - 19 Jan 2020

Cited by 1 | Viewed by 1385

Abstract

Rice is the principal source of calories for more than half of the world’s population, and while an excellent source of energy is a relatively poor source of micronutrients. Developing rice varieties with increased levels of bioavailable micronutrients is a sustainable and complementary [...] Read more.

Rice is the principal source of calories for more than half of the world’s population, and while an excellent source of energy is a relatively poor source of micronutrients. Developing rice varieties with increased levels of bioavailable micronutrients is a sustainable and complementary approach to tackle micronutrient malnutrition, and may be achieved through transgenic or conventional breeding approaches. Using the former approach Golden Rice has been genetically engineered to produce β-carotene in the grain to address the persistent and pervasive problem of vitamin A deficiency, while high levels of iron and zinc have also been achieved via a transgenic approach. The primary focus of conventional breeding is increasing zinc content. This paper reports on the progress and challenges in developing and delivering rice with improved micronutrient content. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

Autoencoding Genetic Markers to Predict the Value of Ecophysiological Model Parameters - Proof of Concept Using a Sorghum Diversity Panel

by Florian Larue, Grégory Beurier, Lauriane Rouan, David Pot, Jean-François Rami and Delphine Luquet

Proceedings 2019, 36(1), 70; https://doi.org/10.3390/proceedings2019036070 - 19 Jan 2020

Viewed by 1276

Abstract

Crop growth modelling formalizes the biological processes at which genotype X environment interactions (GxE) are expressed. It has the potential to evaluate, in silico, the effect of elementary traits and related genetic factors on phenotype and yield elaborations. Recent studies showed that, by [...] Read more.

Crop growth modelling formalizes the biological processes at which genotype X environment interactions (GxE) are expressed. It has the potential to evaluate, in silico, the effect of elementary traits and related genetic factors on phenotype and yield elaborations. Recent studies showed that, by driving the value of crop model parameters using a genomic selection model, yield was predicted more accurately than by a classical genetic model. However these studies dealt with few, integrative parameters and a narrow genetic diversity, i.e., a reduced number of molecular markers. This contrasts with the necessity to make crop models more responsive to climate change variables and thus increase the number of physiological parameters, while studying wider genetic diversity to seek for adaptive markers. With this respect, methods that reduce the dimensionality of the problem are needed. The autoencoder, a semi-supervised machine learning method, can reduce the number of predictors (markers) without prior information, by compressing input data into an encoded neural network layer. Applied to genetic diversity, it should ease modelling and predicting the genetic value of crop model parameters underlying GxE and yield variability, compared to classical regression methods. This study aimed at testing the autoencoding of the genetic data (ca. 1.5M markers) within a West-African sorghum diversity panel of 200 individuals. It evaluated then the relevance of autoencoded data to predict the genetic value of the dozen of crop/plant parameters controlling growth and plasticity in Ecomeristem model, estimated using data from an experiment in the Phenoarch platform. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 112 KiB

Open AccessAbstract

Nutritional Programming of Beef Heifers

by Tryon Wickersham, Colton Oney and Jason Sawyer

Proceedings 2019, 36(1), 71; https://doi.org/10.3390/proceedings2019036071 - 20 Jan 2020

Viewed by 969

Abstract

Sustainability of beef cattle production is, in part, dependent on a supply of females selected and adapted to meet the production environment of a given operation. Ideally, replacement females would have no maintenance requirements, wean infinity calves, and each calf would perfectly match [...] Read more.

Sustainability of beef cattle production is, in part, dependent on a supply of females selected and adapted to meet the production environment of a given operation. Ideally, replacement females would have no maintenance requirements, wean infinity calves, and each calf would perfectly match beef value chain expectations. However, bovine physiology has limitations (e.g., generally one calf per year and maintenance requirements are significant) and beef cattle operations have access to divergent quantities and qualities of nutrients with greater variability in those regions subject to drought. Therefore, developing heifers to meet performance expectations as efficiently as possible, under the constraints of an individual operation becomes an essential component of sustainable beef production. Heifer development generally is discussed as the period from weaning to breeding, with successful breeding defined as the endpoint, a critical outcome. However, nutrition at each stage of a heifer’s life from conception to her subsequent rebreeding for a second calf plays a role in her long-term productivity and operational success. For example, the role of maternal nutrition is receiving increasing attention for its effects across the entire lifespan of the offspring. Therefore, describing the effects of nutritional programming at each stage of life and the plasticity of nutritional requirements will improve our ability to produce females capable of meeting production goals. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 128 KiB

Open AccessAbstract

Drought Impacts on Grassland Productivity: The Role of Plant-Soil Feedbacks

by Kamrul Hassan, Yolima Carrillo and Uffe N. Nielsen

Proceedings 2019, 36(1), 72; https://doi.org/10.3390/proceedings2019036072 - 20 Jan 2020

Viewed by 1166

Abstract

Drought influences pasture productivity with potentially severe impacts on livestock. However, not all plant species are impacted equally indicating that plant community composition can be managed to improve resistance to drought. We conducted a plant-soil feedback (PSF) experiment to assess impacts of drought [...] Read more.

Drought influences pasture productivity with potentially severe impacts on livestock. However, not all plant species are impacted equally indicating that plant community composition can be managed to improve resistance to drought. We conducted a plant-soil feedback (PSF) experiment to assess impacts of drought at the species and community level. We grew twelve plant species representing C3 and C4 grasses, forbs and legumes in monocultures and in 4-species mixtures (one from each functional group) in soils with a legacy of ambient or drought (5 years) conditions for two generations. We measured plant biomass in the second generation to calculate PSF. Species with positive PSF under drought are likely to be more resistant to drought than those with negative PSF. Under ambient rainfall PSFs were generally negative for C3 grasses, positive for C4, forbs and legumes. Drought promoted negative PSFs in C3 grasses and forbs, but positive PSFs were observed in C4 grasses and legumes. These results indicate that C3 grasses and forbs are likely to be sensitive to drought while C4 grasses and legumes will be less negatively impacted by drought due to changes in PSFs. PSFs at the community level were positive at the community level under ambient but shifted towards neutral under drought indicating that drought may destabilize plant communities. Our results indicate that presence of C4 grasses and legumes may reduce drought impacts providing a tool for future pasture management for healthy livestock production in Australian rangeland. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 119 KiB

Open AccessAbstract

New Technologies for Weed Eradication—Invasive Plants Have No Place to Hide When DNA Is Involved

by Laura Simmons, Joe Vitelli and Steve Csurhes

Proceedings 2019, 36(1), 73; https://doi.org/10.3390/proceedings2019036073 - 20 Jan 2020

Viewed by 1214

Abstract

Building on the advances in molecular technology, two genetic based tools are being developed by Biosecurity Queensland to improve conventional invasive plant detection, monitoring and control. Sporobolus is a genus of almost 200 grass species from tropical and subtropical parts of the world. [...] Read more.

Building on the advances in molecular technology, two genetic based tools are being developed by Biosecurity Queensland to improve conventional invasive plant detection, monitoring and control. Sporobolus is a genus of almost 200 grass species from tropical and subtropical parts of the world. In Australia, 19 Sporobolus species are endemic and 8 species are introduced. Of these, 10 (5 natives and 5 introduced) are closely allied species and overlapping morphological traits makes accurate identification very difficult. Five of the introduced weedy Sporobolus grasses including Giant Rat’s Tail Grass (GRT), threaten to cost the grazing industry of eastern Australia $60 million per annum, having the potential to infest 60% of Queensland and 30% of Australia. The success of four GRT biological control programs in Australia, hinge on the accurate identification of the host plant. The GRT project relies on a molecular approach to delimit and accurately identify these Sporobolus species, allowing for a more accurate and targeted control strategy to be used in the paddock. The second molecular project focuses on the dioecious Mexican bean tree (Cecropia spp.), a restricted pioneer tree that has invaded rainforests in tropical and subtropical Queensland. Molecular markers are being used to genotype an eradicated population to identify if there are any undetected parent trees within surveyed areas that may be residing in inaccessible rainforest patches, thereby preventing extirpation to occur. Dust monitoring devices to capture pollen are being trialed as an eDNA surveillance method for detecting unknown Mexican bean tree populations in remote rainforest locations. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 119 KiB

Open AccessAbstract

Differences in the Anthocyanin Profile of Different Tissues of the Strawberry Fruit

by Hung T. Hong, Aiqi Chen, Michael E. Netzel and Tim J. O’Hare

Proceedings 2019, 36(1), 74; https://doi.org/10.3390/proceedings2019036074 - 20 Jan 2020

Viewed by 1208

Abstract

Strawberries are most commonly red in colour, which is largely due to the anthocyanin, pelargonidin-3-glucoside, a bioactive flavonoid with potential health benefits. Variation in the intensity of red colour across strawberry varieties, from a light pink to a deep cherry colour, is solely [...] Read more.

Strawberries are most commonly red in colour, which is largely due to the anthocyanin, pelargonidin-3-glucoside, a bioactive flavonoid with potential health benefits. Variation in the intensity of red colour across strawberry varieties, from a light pink to a deep cherry colour, is solely associated with a change in concentration of this single anthocyanin, rather than the synthesis of an anthocyanin with a different colour. In this study, the anthocyanin profiles of the two constituent edible tissues of strawberry fruit were determined. The main tissue of the strawberry consists of a swollen fleshy receptacle. The second tissue consists of the achenes, visible on the surface of the strawberry, with each achene consisting of a dry single-seeded fruit formed from a fertilised ovule. The current study showed that the anthocyanin profile of a strawberry achene is totally different from that of the receptacle. While red-coloured pelargonidin-3-glucoside is the main anthocyanin component (about 94%) in the receptacle, purple-coloured cyanidin-3-glucoside accounts for approximately 90% of the anthocyanin content in the achene. This would indicate that flavonoid 3’-hydroxylase (F3’H), the enzyme responsible for shifting anthocyanin biosynthesis towards cyanidin and away from pelargonidin, is functional in strawberry achene tissue, but not in the receptacle tissue. This may indicate that other factors, such as transcription factors, can modulate the anthocyanin profile of different strawberry tissues, rather than strawberries having a non-functional F3’H gene. However, the relevance of these findings for potential strawberry breeding programs and subsequently the nutritional quality of strawberry fruit needs to be investigated further. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 123 KiB

Open AccessAbstract

In-Plant Insect-Proofing by Trans-Kingdom RNAi

by Julia Bally, Elane Fishilevich, Samanta Bolzan De Campos, Marcelo German, Kenneth Narva and Peter Waterhouse

Proceedings 2019, 36(1), 75; https://doi.org/10.3390/proceedings2019036075 - 20 Jan 2020

Viewed by 1258

Abstract

Helicoverpa armigera, the cotton bollworm, is a major insect pest for a wide range of agricultural crops. It causes huge yield losses through feeding damage and increasing the crop’s vulnerability to bacterial and fungal infection. H. armigera has evolved substantial resistance to [...] Read more.

Helicoverpa armigera, the cotton bollworm, is a major insect pest for a wide range of agricultural crops. It causes huge yield losses through feeding damage and increasing the crop’s vulnerability to bacterial and fungal infection. H. armigera has evolved substantial resistance to many different chemical insecticides, prompting the development of transgenic crop plants with alternative insect-resistance-conferring mechanisms. For example, transgenic crops producing Bacillus thuringiensis (Bt) toxins have been very successful. However, there is still a concern about insect populations emerging with resistance to these biopesticides. Novel strategies that give effective protection, without affecting the environment, need to be continuously developed and implemented. Such a strategy is Trans-kingdom RNAi, which is based on making plants express double-stranded (ds) or hairpin (hp) RNA for ingestion by herbivorous pests. The RNA triggers silencing of specific genes within the pest leading to its death or impaired growth. However, the efficacy of the approach appears to depend on the means of delivering the RNA. We will describe new approaches and delivery strategies, including chloroplast-based expression, which greatly enhance the potency of insect protection. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 129 KiB

Open AccessAbstract

Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management

by Wiebke Kämper, Helen M. Wallace, Steven M. Ogbourne and Stephen J. Trueman

Proceedings 2019, 36(1), 76; https://doi.org/10.3390/proceedings2019036076 - 21 Jan 2020

Cited by 2 | Viewed by 1618

Abstract

Cross-pollination is essential for the reproduction of self-incompatible plants and it improves the yield and fruit quality of some self-compatible plants. Cross-pollination of clonal horticultural crops is achieved only when pollen from one cultivar reaches the stigma of another cultivar. We quantified self- [...] Read more.

Cross-pollination is essential for the reproduction of self-incompatible plants and it improves the yield and fruit quality of some self-compatible plants. Cross-pollination of clonal horticultural crops is achieved only when pollen from one cultivar reaches the stigma of another cultivar. We quantified self- and cross-fertilisation rates in macadamia nuts (Macadamia integrifolia, M. tetraphylla and hybrids) that were harvested at different distances from a cross-pollen source in two different plantation designs (mixed blocks of multiple cultivars vs. pure blocks of a single cultivar). We also estimated the distance of effective pollen movement, evaluated how different pollen parents affect nut quality, and assessed whether distance from a cross-pollen source affected the number of nuts harvested. We found that almost all nuts resulted from cross-pollination in both plantation designs, with almost all nuts being cross-pollinated even at 23 rows from another cultivar. However, most pollen did not travel far, and nearby cultivars were usually the pollen parent. Cross-pollination increased nut mass and changed the nutritional quality of the nut. The number of nuts harvested decreased with increasing distance from a cross-pollen source in large pure blocks, but not in mixed blocks. Dependence on cross-pollination coupled with low distances of pollen movement may cause suboptimal fruit set. Our results suggest that fruit set in macadamia plantations comprised of large single-cultivar blocks is limited and that plantations can benefit from closer interplanting of different cultivars Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 146 KiB

Open AccessAbstract

Brassica Biofumigants for Improved Soil Health

by Gayathri Rajagopal, John Duff and Zara Hall

Proceedings 2019, 36(1), 77; https://doi.org/10.3390/proceedings2019036077 - 21 Jan 2020

Cited by 2 | Viewed by 1551

Abstract

Biofumigation involves growing specialised cover crops that have the ability to suppress certain soil-borne diseases. Species such as those in the Brassicaceae family, (e.g., radish, mustard and rocket) are known to have this capability. Biofumigation activity is initiated by the degradation of glucosinolates [...] Read more.

Biofumigation involves growing specialised cover crops that have the ability to suppress certain soil-borne diseases. Species such as those in the Brassicaceae family, (e.g., radish, mustard and rocket) are known to have this capability. Biofumigation activity is initiated by the degradation of glucosinolates within the tissues of the plant when the crop is incorporated into the soil at approx. 25% flowering rate. In this experiment, nine bio-fumigant varieties were assessed over six planting dates for biomass yield, irrigation management, glucosinolate concentration and efficacy against three soilborne pathogens, namely; Sclerotium rolfsii, Sclerotinia sclerotiorum and Macrophomina phaseolina. Preliminary results showed incorporation dates varied across varieties and planting times. Winter planting had highest biomass yield across all varieties, compared with the summer plantings (e.g., 14.82 t/ha in winter, versus 5.02 t/ha in summer for Caliente). The efficacy of disease suppression was variable between variety and planting date. For example, Nemfix and BQ Mulch produced a higher percentage mortality rate (100% and 98%) against S. sclerotiorum, compared with autumn (22% and 12%) and winter (37% and 13%) planting. High glucosinolate production was observed during the summer plantings, where irrigation treatments including drought conditions (Low; 0.75 ML/ha), moderate watering (Medium; 2 ML/ha) and field capacity (High; 2.5 ML/ha) were applied. Increased glucosinolate concentrations were observed in the Low irrigation treatments (e.g., Mustclean; 32.31 μmol/g DW), versus High irrigation (e.g., Mustclean; 17.11 μmol/g DW). Summer data pending analysis. These findings can help growers to identify biofumigant varieties that compliment rotation program and optimise disease management practices. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 148 KiB

Open AccessAbstract

Do GAP Practices Improve Market Access for Vegetable Farmers? A Case Study from Vientiane Capital, Laos

by Maiyer Xiong, Gomathy Palaniappan and Laurie Bonney

Proceedings 2019, 36(1), 78; https://doi.org/10.3390/proceedings2019036078 - 21 Jan 2020

Viewed by 1686

Abstract

A case study on Good Agricultural Practices (GAP) of vegetable was conducted in 2018, with an objective to understand whether GAP practices improve market access for vegetable farmers in the Lao PDR. The case study was conducted in Nasala Village, Xaythany District, Vientiane [...] Read more.

A case study on Good Agricultural Practices (GAP) of vegetable was conducted in 2018, with an objective to understand whether GAP practices improve market access for vegetable farmers in the Lao PDR. The case study was conducted in Nasala Village, Xaythany District, Vientiane capital, Lao PDR. The data was collected using 10 semi-structured interviews and one group discussion with Nasala farmers. The results were summarized based on the themes such as community characteristics, market access and farmers’ perception about GAP. The Nasala community has 585 households, majority being farmers with 50% of them growing vegetables with an average farm size of 1.5 hectare. District Agriculture and Forestry Office (DAFO) introduced GAP practices as a pilot project to 28 farmers in Nasala in 2014 through farmer trainings. The DAFO pilot project enabled Nasala farmers to export Thorny Coriander to Japan during 2016–2017. Nasala farmers sold 50 kg/day of Thorny Coriander for about one year at the price of 15,000 kip/kg in comparison to 7000–10,000 kip/kg at the local market. Farmers agreed that they were motivated by the market incentives and collectively sold the produce by alternating production for continuous supply. This export opportunity was withdrawn after the pilot period resulting in no incentives to practice GAP. Farmers agreed that GAP enabled them to produce better quality, healthier and safer vegetables. However, the barriers to GAP are lack of government policies, institutional support, inadequate incentives and complex certification process. To enable farmers to continue GAP practices appropriate supporting system must be developed. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 172 KiB

Open AccessAbstract

Buffalo Flies Receptive to Wolbachia Infection: An Opportunity for Population Control?

by Mukund Madhav, Geoff Brown, Jess A. T. Morgan, Sassan Asgari, Elizabeth McGraw and Peter James

Proceedings 2019, 36(1), 79; https://doi.org/10.3390/proceedings2019036079 - 21 Jan 2020

Viewed by 1547

Abstract

Buffalo flies, Haematobia (irritans) exigua (BF), are obligate haematophagous ectoparasites of cattle that cause significant economic and welfare impacts in northern Australian cattle. With climate change and the development of resistance to commonly used chemicals, BF are rapidly spreading southwards. Wolbachia is [...] Read more.

Buffalo flies, Haematobia (irritans) exigua (BF), are obligate haematophagous ectoparasites of cattle that cause significant economic and welfare impacts in northern Australian cattle. With climate change and the development of resistance to commonly used chemicals, BF are rapidly spreading southwards. Wolbachia is a maternally transmitted bacterial endosymbiont of insects that induces a range of effects on its host, including cytoplasmic incompatibility (male sterility), reduced fitness, and inhibition of pathogen transmission. We are examining the potential for use of Wolbachia in area-wide control of BF. Following a survey of Australian BF populations that showed Wolbachia was not present, we have tested embryonic microinjection, pupal injection and injection of adults as a first step towards the development of a Wolbachia infected BF line. Here we report distribution and growth of Wolbachia in somatic and germline tissue of BF injected with the three Wolbachia strains; wAlbB, wMel and wMelPop. Our results to date suggest that pupal or adult injection may be a more suitable method for transinfecting BF than embryonic microinjection. We also demonstrate Wolbachia induced fitness effects in injected BF including shortened lifespan, decreased pupal emergence, and reduced egg production. Future work will focus on establishing a stably infected BF strain, towards the design of Wolbachia-based control programs for BF. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Impact of Photosensitization on Physicochemical Properties in Strawberries

by Shammy Sarwar, Ram Mereddy, Michael E. Netzel, Gabriele Netzel and Yasmina Sultanbawa

Proceedings 2019, 36(1), 80; https://doi.org/10.3390/proceedings2019036080 - 21 Jan 2020

Viewed by 1282

Abstract

Strawberries, depending on the cultivar and environmental conditions, can be a rich source of nutrients like folates and vitamin C as well as bioactive phytochemicals, mainly polyphenols. But at room temperature, this fruit is highly perishable and has a relative short shelf life [...] Read more.

Strawberries, depending on the cultivar and environmental conditions, can be a rich source of nutrients like folates and vitamin C as well as bioactive phytochemicals, mainly polyphenols. But at room temperature, this fruit is highly perishable and has a relative short shelf life of only a couple of days. An innovative, cost effective and environmentally friendly technique, photosensitization, has been applied with the aim to extend the shelf life of strawberries and to minimize the loss of nutrients and also phytochemicals. Photosensitization works based on the combined action of photosensitizer, light and oxygen, which produce reactive oxygen species that inactivate microorganisms. Curcumin, known for its antifungal activity was used as the photosensitizer in this study. To see the effect of photosensitization, physicochemical parameters of both fresh and photosensitized strawberries have been tested. There were no significant (p < 0.05) changes in pH, titratable acidity, total soluble solids and moisture content between treated and untreated (control) strawberries. However, total sugar content of photosensitized strawberry was significantly (p < 0.05) higher than that of the control (5.29 ± 0.26 g/100 g FW vs. 4.12 ± 0.13 g/100 g FW). No significant difference was observed in the total phenolic content of the treated (192.9 ± 3.16 mg gallic acid equivalents (GAE)/100 g FW) and the control (195.8 ± 3.05 mg GAE/100 g FW) samples. These preliminary findings show that photosensitization could be a promising technique that has the potential to be used in the horticulture industry to extend the shelf life of fresh produce such as strawberries. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 149 KiB

Open AccessAbstract

Antimicrobial Activity and Ellagitannins from Terminalia Ferdinandiana

by Saleha Akter, Hung T. Hong, Michael E. Netzel, Ujang Tinggi, Simone Osborne, Mary Fletcher and Yasmina Sultanbawa

Proceedings 2019, 36(1), 81; https://doi.org/10.3390/proceedings2019036081 - 21 Jan 2020

Cited by 1 | Viewed by 1894

Abstract

Extracts were prepared from Terminalia ferdinandiana (Kakadu plum) fruits, leaves, seedcoats, and barks using accelerated solvent extraction with methanol, ethanol, water, acetone, and hexane. Antioxidant activity was assessed using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and by determining the total phenolic [...] Read more.

Extracts were prepared from Terminalia ferdinandiana (Kakadu plum) fruits, leaves, seedcoats, and barks using accelerated solvent extraction with methanol, ethanol, water, acetone, and hexane. Antioxidant activity was assessed using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and by determining the total phenolic content (TPC). Methanol fruit extracts had the strongest free radical scavenging activity and the highest TPC (12 g/100 g DW). The antimicrobial activity of all extracts (except hexane) was analysed by agar disc diffusion. Fruits and leaves showed larger inhibition zones against foodborne bacteria Listeria monocytogenes, Bacillus cereus, methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa compared to seedcoats and barks. The minimum inhibitory and minimum bactericidal concentration of the extracts ranged from 1.0 to 3.0 mg/mL against the tested microorganisms. Scanning electron microscopy images of bacteria treated with the extracts showed morphological changes consistent with cell death. A new UHPLC-MS/MS method for the determination of punicalagin and castalagin, bioactive ellagitannins, was developed and validated. Punicalagin contents in the fruits and leaves were 74 and 49 mg/100 g DW whilst castalagin contents were 1.1 and 0.8 mg/100 g DW. To the best of our knowledge, this is the first report about punicalagin and castalagin concentrations in Kakadu plum fruits and leaves. These initial findings are very promising in regards to the potential use of Kakadu plum fruit and leaf extracts as natural preservatives in the food industry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 152 KiB

Open AccessAbstract

High-amylose Rice: Starch Molecular Structural Features Controlling Cooked Rice Texture and Preference

by Keyu Tao, Wenwen Yu, Prakash Sangeeta and Robert Goulston Gilbert

Proceedings 2019, 36(1), 82; https://doi.org/10.3390/proceedings2019036082 - 21 Jan 2020

Cited by 1 | Viewed by 1920

Abstract

Cooked high-amylose rices have slower digestibility, giving nutritional benefits, but inferior eating qualities. In this study, Rapid Viscosity Analysis, quantitive descriptive sensory analysis with all panellists from China and Textural Profile Analyser (TPA) have been used to measure rice texture and eating quality [...] Read more.

Cooked high-amylose rices have slower digestibility, giving nutritional benefits, but inferior eating qualities. In this study, Rapid Viscosity Analysis, quantitive descriptive sensory analysis with all panellists from China and Textural Profile Analyser (TPA) have been used to measure rice texture and eating quality of cooked rice. Molecular structural mechanisms for this inferior eating quality are found here using structural analysis by size-exclusion chromatography of both the parent starch and starch leached during cooking. All commonly-accepted sensory attributes of cooked rice were characterized by a trained human panel. Hardness, with the strongest negative correlation with panelist preference, is the dominant but not sole factor determining palatability. Rice with larger amylopectin size can bond more water, thereby have lower hardness value. Meanwhile, hardness is controlled by the amounts of medium and long amylopectin chains and amylose in the starch, and by amylose content and amount of longer amylopectin chains in the leachate. With this, it is concluded for the first time that rice containing 19~25% amylose content are most preferred by the panel. Meantime, it is showed that breakdown viscosity and swelling power of native rice flour can be and should be used as indicators for predicting rice eating quality. This gives knowledge and understanding of the molecular structural characteristics of starch controlling cooked-rice preference: not just high amylose but also other aspects of molecular structure. This can help rice breeders to target starch-synthesis genes to select slowly digested (healthier) rices with acceptable palatability. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 177 KiB

Open AccessAbstract

Exploring the Nutritional Profile and Bioactive Potential of Australian Grown Saltbush (Atriplex sp.)

by Sukirtha Srivarathan, Michael E. Netzel, Anh Dao Thi Phan and Yasmina Sultanbawa

Proceedings 2019, 36(1), 83; https://doi.org/10.3390/proceedings2019036083 - 21 Jan 2020

Cited by 1 | Viewed by 1838

Abstract

Plant foods play a vital role in human nutrition due to their diverse range of macro- and micro-nutrients, fibre and phytochemicals. However, more than 90% of the plant-food demand is satisfied by less than 0.1% of the edible plant species available. Moreover, none [...] Read more.

Plant foods play a vital role in human nutrition due to their diverse range of macro- and micro-nutrients, fibre and phytochemicals. However, more than 90% of the plant-food demand is satisfied by less than 0.1% of the edible plant species available. Moreover, none of the highly consumed ‘food-plants’ can survive without freshwater irrigation. As the world’s population rises and food sources become limited, alternative avenues for satisfying the world’s food demand are necessary. This persistent situation urges the domestication of wild terrestrial salt tolerant (halophytes) edible plants, of which saltbush (SB) was found to have a long history of use as animal feed and soil erosion control, while very little scientific information is available on its nutritional profile and dietary relevance. Therefore, the present study assessed the nutrient and phytochemical composition of Australian grown oldman SB (Atriplex nummularia) leaves to better understand its nutritional ‘value’ and potential bioactivity. The proximate results showed that SB leaves were rich in protein (20.1 ± 0.18 g/100 g DW), fibre (41.5 ± 0.20 g/100 g DW) and minerals (particularly Ca (1.44 ± 0.03 g/100 g DW), Na (4.13 ± 0.02 g/100 g DW), Mg (0.90 ± 0.01 g/100 g DW), and Fe (11.68 ± 0.35 mg/100 g DW). These initial findings provide important nutritional information to a very promising plant source that could be used alone or synergetic with other foods (e.g., alternative protein and/or fiber source, potential salt substitute). However, further studies need to be carried out to determine the complete nutritional profile of oldman SB leaves, the bioaccessibility/bioavailability of its main nutrients and phytochemicals as well as consumer acceptance in order to develop SB based food products. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 174 KiB

Open AccessAbstract

Optimizing Planting Method and Fertilizer Application Rate for Producing High Quality Nursery of Onion cv. Phulkara

by Khurram Ziaf, Muhammad Wasim Haider, Aman Ullah Malik, Raheel Anwar and Rehan Riaz

Proceedings 2019, 36(1), 84; https://doi.org/10.3390/proceedings2019036084 - 21 Jan 2020

Viewed by 1601

Abstract

Onion (Allium cepa L.), locally famous as “Piaz”, occupies a prominent place among commercial crops of Pakistan, by supplementing the income of small/marginal land-hold farmers. One of the major constraints of onion farming in Pakistan is poor nursery due to adoption of [...] Read more.

Onion (Allium cepa L.), locally famous as “Piaz”, occupies a prominent place among commercial crops of Pakistan, by supplementing the income of small/marginal land-hold farmers. One of the major constraints of onion farming in Pakistan is poor nursery due to adoption of traditional planting methods and overfertilization, which ultimately increases cost of production and loss of resources. The current study, comprised of two experiments, was carried out at Vegetable Area, University of Agriculture Faisalabad, to determine the most suitable nursery raising system and fertilizer application rate for onion nursery in order to get maximum plant population of good quality seedlings. The first experiment comprised of four different nursery growing methods: (1) flat bed + broadcast sowing, (2) flat bed + line sowing, (3) raised bed (6 inches height from ground surface) + broadcast sowing, and (4) raised bed + line sowing. The largest plant population, and highest plant fresh and dry weights were obtained on flat beds under line sowing. The smallest plant population was obtained on raised beds under broadcast sowing, however, the lowest fresh and dry weights of seedlings were found with flat beds under broadcast sowing. The second experiment comprised of three diammonium phosphate (DAP) application rates (50 g, 100 g and 150 g per 272.25 ft⁻² applied at one-week interval) and a control. The maximum shoot and root lengths as well as fresh and dry weights were obtained with 100 g DAP 272 ft⁻². In conclusion, line sowing on flat beds and application of 100g DAP 272 ft⁻²at one-week interval produced high quality nursery of onion cv. Phulkara. But, flat bed system must be coupled with proper drainage to avoid excessive water due to frequent rainfall in tropical areas. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 150 KiB

Open AccessAbstract

Jatropha Curcas Development as Intervention Potential to Tackling Land, Energy and Food Challenges of Rural Communities in Dryland Sub-Saharan Africa

by Joshua Ogunwole, Gunnar Kirchhof, Birhanu Z. Birhanu, Sjoerd Duiker and Luiz F. Pires

Proceedings 2019, 36(1), 85; https://doi.org/10.3390/proceedings2019036085 - 21 Jan 2020

Viewed by 1297

Abstract

Global population growth is placing increasing pressures on land for food and feed production as well as energy security. In particular in sub-Saharan Africa (SSA), these issues require urgent attention. This is clearly stated in The United Nations Global Goals for Sustainable Development [...] Read more.

Global population growth is placing increasing pressures on land for food and feed production as well as energy security. In particular in sub-Saharan Africa (SSA), these issues require urgent attention. This is clearly stated in The United Nations Global Goals for Sustainable Development emphasizing the importance of sustainable use of land resources to increase food productivity and energy requirement. SSA lags behind most regions of the world in household food security and access to energy. The rural agriculture-dependent communities of SSA are the hardest hit by food and energy scarcity and the impact is felt most by communities in the dryland farming areas. In terms of energy supply appropriate measures and interventions are required to address this challenge. Jatropha curcas L. oil fast tracked itself from obscurity to prominence. Its main advantage is the high content of methyl ester (or bio-diesel). It conforms to EN 14214 specifications, exhibiting emission reduction potential and qualifying as a lucrative bio-diesel alternative to fossil diesel. This paper proposes a focus on Jatropha technology as a holistic approach to tackling the land, energy and food degradation challenges in unison for dry-land SSA. The new Jatropha strategy would be innovative and environmentally friendly soil resource recapitalization and supply feed stock for rural energy generation while fulfilling the criteria of delivering other benefits, such as addressing land use conflict for food and energy production Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessAbstract

The Inside and out of Folate in Strawberries and Avocados

by Michael E. Netzel, Caroline Dumler, Nadine Weber, Lisa Striegel, Michael Rychlik, Hung T. Hong and Tim O’Hare

Proceedings 2019, 36(1), 86; https://doi.org/10.3390/proceedings2019036086 - 2 Feb 2020

Viewed by 1522

Abstract

Folate, an important B-group vitamin, is considered a critical vitamin in many countries, with folate deficiency being associated with neural tube defects in newborns. Strawberries and avocados are considered a healthy, tasty snack by many consumers, and may potentially be an important dietary [...] Read more.

Folate, an important B-group vitamin, is considered a critical vitamin in many countries, with folate deficiency being associated with neural tube defects in newborns. Strawberries and avocados are considered a healthy, tasty snack by many consumers, and may potentially be an important dietary source of natural folates, depending on variety and growing environment. A selection of Australian-grown strawberry varieties and breeding lines, as well as commercial avocado cultivars, were screened for their folate content and vitamer profile by stable isotope dilution assay. Total folate content ranged from 69–170 μg/100 g fresh weight (fw) for strawberries and 76–196 μg/100 g fw for avocados, which was well above the values in the Australian Food Composition Database (39 μg/100 g fw for strawberries and 90 μg/100 g fw for avocados, respectively). Furthermore, folate concentration in the outer strawberry tissue was found to be 1.7-fold higher than the inner tissue of the fruit, whereas the inner avocado tissue had 1.4-fold higher folate than the outer green edible tissue. 5-Methyltetrahydrofolate, the biologically active form in humans, was the principal vitamer present. With these high folate concentrations, a punnet (250 g) of Australian-grown strawberries or 200 g of Australian-grown avocados would deliver the FSANZ recommended dietary intake (RDI) for folate (400 μg dietary folate equivalents/day/adult). Furthermore, the differences between outer and inner tissue could indicate that flatter, longer strawberries may have greater potential to accumulate folate than fruit with a more spherical shape, whereas more folate could be accumulated in a rounder-shaped avocado. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 126 KiB

Open AccessAbstract

Comparative Analysis and Evaluation of Handheld X-ray Fluorescence Spectrometry to Measure Silicon in Crop Plants

by Daniel Howell, Daniel Tan, Stanislav Ulitzka and Rosanne Quinnell

Proceedings 2019, 36(1), 87; https://doi.org/10.3390/proceedings2019036087 - 2 Feb 2020

Viewed by 1207

Abstract

Rice, wheat and corn are the three most consumed crop foods worldwide and, as such, are important when considering future global food security. All three species are members of the Poaceae family and are silica accumulators. For those plants that accumulate silica, silica [...] Read more.

Rice, wheat and corn are the three most consumed crop foods worldwide and, as such, are important when considering future global food security. All three species are members of the Poaceae family and are silica accumulators. For those plants that accumulate silica, silica fertilisation is considered to improve plant health and alleviate abiotic and biotic stresses thereby lessening reliance on pesticides. Measuring the silicon (Si) content in soils and plants is useful for identifying Si-poor systems; however, traditional chemical digestion methods to measure Si are hazardous and time consuming. Advances in the sensitivity of handheld X-ray fluorescence spectrometers (hh-xrf) create new opportunities for rapid plant elemental analyses. We present a Si analysis of using two handheld X-ray fluorescence devices (SciAps X-300 and the Niton XL3t GOLDD+) compared with a traditional NaOH-digestion method. The SciAps was found to be more accurate than the Niton and the average time taken to analyse Si using the SciAps was four seconds per sample. These data support the use of hh-xrf for rapid analysis of Si and indicate there are additional opportunities for future research to accurately quantify potassium and phosphorus using this technology. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 145 KiB

Open AccessAbstract

Utilization of Forgoing Coastal Rice Fallow Lands of Bangladesh with Zero Tillage Potato Cultivation using Different Rates of Residues

by Mustafa Kamal Shahadat, Mohammad Harunor Rashid, Mohammad Akkas Ali and Mohammed Mainuddin

Proceedings 2019, 36(1), 88; https://doi.org/10.3390/proceedings2019036088 - 2 Feb 2020

Viewed by 1039

Abstract

An experiment was conducted in south-western coastal saline area of Khulna district of
Bangladesh (22°35′53.463″ N latitude and 89°27′42.617″ E longitude) during the period from
December 2018 to March 2019. The experiment was laid out in two factor Randomized Complete
Block (RCB) design [...] Read more.

An experiment was conducted in south-western coastal saline area of Khulna district of
Bangladesh (22°35′53.463″ N latitude and 89°27′42.617″ E longitude) during the period from
December 2018 to March 2019. The experiment was laid out in two factor Randomized Complete
Block (RCB) design with three replications. Factor A included two potato varieties (V1= BARI Alu-
72 and V2= BARI Alu-73) and factor B consisted with three rates of rice straw mulch viz. M1= 4 ton
ha−1, M2= 7 ton ha−1 and M3= 10 ton ha−1. Average thickness of mulch treatments were 11 cm, 13 cm
and 15 cm, respectively. Mulch rate had significant effect on different soil and crop parameters,
however there was no significant effect observed in variety and variety vs mulch rate. At harvest,
highest plant height (50.7 cm), stem dry weight (1.33 g plant-1) and leaf dry weight (7.29 g plant−1)
were recorded from M3 treatment. In case of yield components and yield, M3 treatment gave
highest value for number of tuber per plant (7.11), individual tuber weight (59.38 g), tuber yield
(15.62 t ha−1), haulm yield (2.26 t ha−1). Significantly highest moisture was conserved by M3 treatment
(27.13%) at harvest as well effectively controlled salinity (ECe) increase (only 1.25% increase than
initial). So, it is observed that rice straw @ 10 t ha-1 is most suitable for zero tillage potato cultivation
in the coastal area of Bangladesh. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 157 KiB

Open AccessAbstract

Modelling the Controlled Release of Toxins in a Rumen Environment

by Yue Yuan, Emilie Gauthier, Natasha L. Hungerford, Diane Ouwerkerk, Mary T. Fletcher and Bronwyn Laycock

Proceedings 2019, 36(1), 89; https://doi.org/10.3390/proceedings2019036089 - 12 Feb 2020

Viewed by 1585

Abstract

Pimelea poisoning in grazing cattle, also known as St George or Marree Disease, has been a long-time pestilence for the pastoral industry throughout arid regions of inland Australia. The causative species Pimelea (Thymelaeaceae), native to Queensland, New South Wales and South Australia, have [...] Read more.

Pimelea poisoning in grazing cattle, also known as St George or Marree Disease, has been a long-time pestilence for the pastoral industry throughout arid regions of inland Australia. The causative species Pimelea (Thymelaeaceae), native to Queensland, New South Wales and South Australia, have been confirmed, with the secondary metabolite simplexin, a daphnane orthoester, being extracted and identified as the principal toxin. Despite the lack of effective prevention or treatment for Pimelea poisoning, naïve calves have previously been demonstrated to develop detoxification capability following prolonged low-dose simplexin intake. A variety of composites are being fabricated by encapsulating Pimelea plant material or a crude extract in biodegradable and biocompatible polyesters, aiming to develop a sustained toxin release mechanism. Studies on screening potential rumen microflora able to decompose simplexin during rumen-fluid fermentation are being conducted simultaneously. In this project, a quantification method for simplexin within these biocomposites was developed and validated utilising solid-phase extraction combined with UHPLC-Q-Orbitrap MS/MS. Reliable simplexin measurement in matrices will allow investigations into the material composition, geometry and rumen microorganism’s effects on the controlled release kinetics of simplexin in vitro. The degradation patterns of toxin delivery systems when exposed to simulated rumen environments will also be thoroughly assessed on both microscopic and chemical scales. Mathematical models of the underlying mass transport mechanisms will ultimately be established through approaches ranging from simple empirical correlations to stochastic simulations, which hold the potential to facilitate future design, optimisation, and prediction of other intra-ruminal devices based on biodegradable polymers. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 193 KiB

Open AccessAbstract

Adsorbents for the Sequestration of the Pimelea Toxin, Simplexin

by Russell J. Gordon, Natasha L. Hungerford, Bronwyn Laycock, Diane Ouwerkerk and Mary T. Fletcher

Proceedings 2019, 36(1), 90; https://doi.org/10.3390/proceedings2019036090 - 12 Feb 2020

Viewed by 1373

Abstract

Pimelea poisoning affects cattle grazing arid rangelands of Australia, has no known remedy and significant outbreaks can cost the industry $50 million per annum. Poisoning is attributable to consumption of native Pimelea plants containing the toxin simplexin. Charcoal, bentonite and other adsorbents are [...] Read more.

Pimelea poisoning affects cattle grazing arid rangelands of Australia, has no known remedy and significant outbreaks can cost the industry $50 million per annum. Poisoning is attributable to consumption of native Pimelea plants containing the toxin simplexin. Charcoal, bentonite and other adsorbents are currently used by the livestock industry to mitigate the effects of mycotoxins. The efficacy of such adsorbents to mitigate Pimelea poisoning warrants investigation. Through a series of in vitro experiments, different adsorbents were evaluated for their effectiveness to bind simplexin using a simple single concentration, dispersive adsorbent rapid screening method. Initial experiments were conducted in a rumen fluid based medium, with increasing quantities of each adsorbent: sodium bentonite (Trufeed®, Sibelco Australia), biochar (Nutralick®Australia) and Elitox® (Impextraco, Belgium). Data showed the unbound concentration of simplexin decreased with increasing quantities of each adsorbent tested. Sodium bentonite performed best, removing ~95% simplexin at 12 mg/mL. A second experiment using a single amount of adsorbent included two additional adsorbents: calcium bentonite (Bentonite Resources, Australia) and a synthetic adsorbent (Waters, USA). The concentration of simplexin remaining in the solution after 1 h, the amount able to be desorbed off the adsorbent-toxin matrix with replacement fresh fluid, and the amount remaining bound to the adsorbent were measured. All samples containing an adsorbent were statistically different compared to the blank (p < 0.05), indicating some binding activity. Future work will explore the binding mechanisms and behaviour of the toxin-adsorbent complex in the lower gastrointestinal tract. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 164 KiB

Open AccessAbstract

High Level of Energy and Protein Supplementation Effect on Feed Intake and Liveweight Gain of Bali Bulls Fed Elephant Grass

by I Wayan Sulendre, Marsetyo Marsetyo, Muh Takdir, Karen Harper and Dennis Paulus Poppi

Proceedings 2019, 36(1), 91; https://doi.org/10.3390/proceedings2019036091 - 12 Feb 2020

Viewed by 1024

Abstract

This research was carried out on-farm at Malonas village, Central Sulawesi, Indonesia to examine the effect of high level supplementation of by-products formulated for high ME and CP. Feed intake, faecal pH and liveweight gain of Bali bulls was observed. The basal diet [...] Read more.

This research was carried out on-farm at Malonas village, Central Sulawesi, Indonesia to examine the effect of high level supplementation of by-products formulated for high ME and CP. Feed intake, faecal pH and liveweight gain of Bali bulls was observed. The basal diet was elephant grass, and supplements were rice bran (RB), cassava (C), palm kernel meal (PKM), gliricidia (G) and urea. Fifty Bali bulls (weight 168 ± 4.48 kg) were housed in individual pens for 18 weeks (2 introductory and 16 experimental) and allocated into five treatments: A = elephant grass (EG) ad libitum, B = EG offered at 1%W/d, plus 2.5%W/d mixed RB:G, (1:1), C = EG offered at 1%W/d plus 2.5%W/d mixed RB:PKM(1:1), D = EG offered at 1%W/d plus 2.5%W/d mixed C:G (1:1), E = EG offered at 1%W/d plus 2.5%W/d mixed C+ urea: PKM (1:1). Faecal pH was measured at weeks 3, 9 and 15. Bali bulls fed B, C, D and E, consumed supplement at the rate of 2.15, 2.19, 2.09 and 2.29 %W/d, respectively. Total feed intake was 2.47, 2.98, 2.99, 2.93, 3.13%W/d, liveweight gain was 0.30, 0.57, 0.60, 0.66, 0.69 g/d and faecal pH was 6.93, 6.76, 6.65, 6.45, 6.33 for treatment A, B, C, D, and E, respectively. Supplementation increased significantly (P < 0.05) total feed intake, liveweight gain, but reduced faecal pH. The highest total feed intake and liveweight gain was achieved by treatment E. It is concluded that cassava can be provided at 1.15%W/d in combination with protein supplement for high liveweight gain of Bali bulls. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 132 KiB

Open AccessAbstract

Digital Twin for the Future of Orchard Production Systems

by Peyman Moghadam, Thomas Lowe and Everard J. Edwards

Proceedings 2019, 36(1), 92; https://doi.org/10.3390/proceedings2019036092 - 12 Feb 2020

Cited by 17 | Viewed by 3796

Abstract

The evolution of orchard production systems towards higher density layouts, makes monitoring of canopy and disease increasingly important. Technological advances over the last few years have greatly increased our ability to collect, collate and analyse our data on a per-tree basis at large [...] Read more.

The evolution of orchard production systems towards higher density layouts, makes monitoring of canopy and disease increasingly important. Technological advances over the last few years have greatly increased our ability to collect, collate and analyse our data on a per-tree basis at large orchard scales. We call this the Digital-Twin Orchard. A digital-twin is a virtual model of every tree and surroundings. The pairing of the virtual and physical worlds allows analysis of data and continuous monitoring of orchards production systems to predict stress, disease and crop losses, and to develop new opportunities for end-to-end learning. Monitoring of orchards is not a new concept but the digital-twin is a continuously learning system that could be queried automatically to analyse specific outcomes under varying simulated environmental and orchard management parameters. Digital-twin enables improvement of production and dynamic prediction of disease, stress and yield gaps using an end-to-end AI platform. In this paper, we present AgScan3D+: our automated dynamic canopy monitoring system to generate a digital-twin of every tree on a large orchard scale. AgScan3D+ consists of a spinning 3D LiDAR plus cameras that can be retrofitted to a farm vehicle and provides real time on-farm decision support by monitoring the condition of every plant in 3D such as their health, structure, stress, fruit quality, and more. The proposed system has been trialled in mango, macadamia, avocado and grapevines orchards and generated a digital-twin of 15,000 trees. The results were used to model canopy structural characteristics such as foliage density and light penetration distribution. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 182 KiB

Open AccessAbstract

Exploring the Nutritional and Functional Properties of Two Understudied Australian Endemic Plants: Diploglottis bracteata and Syzigium aqueum

by Mridusmita Chaliha, Anh Dao Thi Phan Phan, Hung Trieu Hong, Geraldine McGuire, Michael E. Netzel and Yasmina Sultanbawa

Proceedings 2019, 36(1), 93; https://doi.org/10.3390/proceedings2019036093 - 1 Feb 2020

Viewed by 1216

Abstract

Despite the growing national and international interest for Australian traditional plant foods, information on nutritional and functional properties of many endemic species is limited. This restricts their incorporation in food, beverage and nutraceutical applications. This pilot study explored the phytochemical profiles and antimicrobial [...] Read more.

Despite the growing national and international interest for Australian traditional plant foods, information on nutritional and functional properties of many endemic species is limited. This restricts their incorporation in food, beverage and nutraceutical applications. This pilot study explored the phytochemical profiles and antimicrobial activity of two Australian endemic fruits: Diploglottis bracteata and Syzigium aqueum, to explore their marketability. Profiling of major bioactive phytochemicals showed the presence of 3 anthocyanins in S. aqueum (delphinidin-3-glucoside, cyanidin-3-glucoside and peonidin-3-glucoside) and four carotenoids in D. bracteata (lutein, zeaxanthin, β-cryptoxanthin and β-carotene). The total carotenoid content was comparable to that of orange coloured carrots, an important dietary source of carotenoids. Elemental analysis revealed that, compared to blueberry (a popular dietary source), D. bracteata had 4.5 times higher potassium, and 3.7 times higher magnesium content. Calcium levels of S. aqueum was 4.9 times higher than blueberry. Methanol, acetone and water extracts of both fruits were analysed for total phenolic content (TPC) and antimicrobial activity. TPC of D. bracteata and S. aqueum methanolic extracts were 2.9 and 1.4 mg gallic acid equivalents/g FW which is in the same range as blueberry, a popular dietary source of bioactive phenolic compounds. Antimicrobial analysis showed methanol, acetone and water extracts of both fruits have strong inhibitory effects against both Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria, but no effects against fungi (Candida albicans). These promising initial results, diverse phytochemical profiles and strong antibacterial activity, warrant further investigation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 170 KiB

Open AccessAbstract

Optimizing the Antimicrobial Activity of Tasmanian Pepper Leaf Oil Emulsion as a Natural Preservative for Capsicum

by Maral Seidi Damyeh, Ram Mereddy, Michael E. Netzel and Yasmina Sultanbawa

Proceedings 2019, 36(1), 94; https://doi.org/10.3390/proceedings2019036094 - 1 Feb 2020

Viewed by 1268

Abstract

Abstract: The aim of this study was to produce and optimize Tasmanian pepper leaf (Tasmannia lanceolate; TPL) oil contained emulsion using sonication and Response Surface Methodology (RSM). Encapsulating hydrophobic bioactive components is influential in enhancing their applicability as well [...] Read more.

Abstract: The aim of this study was to produce and optimize Tasmanian pepper leaf (Tasmannia lanceolate; TPL) oil contained emulsion using sonication and Response Surface Methodology (RSM). Encapsulating hydrophobic bioactive components is influential in enhancing their applicability as well as their respected antimicrobial activity. The antimicrobial activity of investigated emulsions was evaluated through well diffusion assay against four different spoilage microorganisms isolated from fresh-cut capsicums. In order to optimize the preservative emulsion for further in vivo application, Box-Behnken design with three factors of TPL oil, Tween 80, and citric acid was used. According to the results, bacterial and fungal growth inhibition activity of the investigated emulsions was enhanced through increasing the concentration of citric acid and TPL oil, respectively. Optimization of the investigated variables was conducted after model fitting according to desirability function of Design Expert software. Our main goal was to obtain the maximum inhibitory effect against microbial growth. Therefore, the calculated optimum values were TPL at 1.08%, Tween 80 at 0.15%, and citric acid at 1.50%, with the desirability of 0.978. By and large, the susceptibility of yeast (i.e., Rhodotorula diobovata) against TPL contained emulsions showed to be the highest, which was followed by mold (i.e., Alternaria sp.), Gram-positive bacteria (i.e., Bacillus subtilis), and Gram-negative bacteria (i.e., Pseudomonas viridiflava), with predicted inhibition zones of 46.41, 33.03, 13.10, and 11.33 mm. Optimized emulsion using Box-Behnken design is capable of inhibiting the growth of spoilage microorganisms in capsicum, and this understanding can help develop a natural-based preservative for fresh-cut capsicum. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 141 KiB

Open AccessAbstract

Shoot Borer Earias Vittella—A Threat to the Indigenous Vegetable Pele Abelmoschus Manihot in the Pacific

by Samuel Hone and Rashmi Kant

Proceedings 2019, 36(1), 95; https://doi.org/10.3390/proceedings2019036095 - 13 Feb 2020

Viewed by 1411

Abstract

The indigenous vegetable Abelmoschus manihot (Malvaceae) is one of the staple crops in the Pacific island countries. It is known by various local names, including Pele (Samoa, Tonga), Bele (Fiji), Aibika (Papua New Guinea), and slippery cabbage (Solomon Islands). The Food and Agriculture [...] Read more.

The indigenous vegetable Abelmoschus manihot (Malvaceae) is one of the staple crops in the Pacific island countries. It is known by various local names, including Pele (Samoa, Tonga), Bele (Fiji), Aibika (Papua New Guinea), and slippery cabbage (Solomon Islands). The Food and Agriculture Organisation (FAO) has recommended this as one of the top crops for nutritional security. The leaves of A. manihot are consumed raw, in soups and in various local cuisine. Herbivory is a major problem in growing A. manihot; however, farmers are reluctant to use pesticides. We examined the damage caused by the shoot borer Earias vittella (Lepidoptera: Noctuidae) to three common A. manihot varieties, Green (GN), Red Broad (RB) and Red lobed (RL) in Samoa. In both field and laboratory assessments, E. vittella attacked all the selected varieties. Female lay eggs on shoot tips, and the hatched larvae bore into young shoots. The succulent green variety was found to be more susceptible to the borer attack than red varieties. In field assessment, RL was the least attacked by the borers. In the laboratory bioassay, the larvae that developed on RL were much smaller and weaker than those on the other varieties. In sensory testing, the shoot tips of RN were found to have a tougher/fibrous texture that probably made RN undesirable to the borer. Furthermore, the taller plants were found more vulnerable to borer attack. The study suggests that pruning A. manihot could minimise borer attack; and that RN is a potential variety for future breeding programmes. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 170 KiB

Open AccessAbstract

Effect of Feeding Different Cultivars of Leucaena leucocephala on Rumen-Based in vitro Anaerobic Fermentations

by Diane Ouwerkerk , Anita Maguire , Jenny Gravel , Cathy Minchin , Michael Gravel , Athol Klieve and Ros Gilbert

Proceedings 2019, 36(1), 96; https://doi.org/10.3390/proceedings2019036096 - 13 Feb 2020

Viewed by 1290

Abstract

The leguminous forage shrub, Leucaena leucocephala, is one of the few nutritional options available to significantly improve beef productivity in Northern Australia. A mixed bacterial rumen inoculum for the detoxification of mimosine (present in Leucaena) and its toxic derivatives 3,4 DHP [...] Read more.

The leguminous forage shrub, Leucaena leucocephala, is one of the few nutritional options available to significantly improve beef productivity in Northern Australia. A mixed bacterial rumen inoculum for the detoxification of mimosine (present in Leucaena) and its toxic derivatives 3,4 DHP and 2,3 DHP has been produced in an anaerobic fermenter for the last 23 years by the Queensland Department of Agriculture and Fisheries, using the commercial cultivar Cunninghamii. The development and release of a new psyllid-resistant cultivar ‘Redlands’, offers potential for increasing uptake by the beef industry but brings unanswered questions about its impact on the survival of the toxin degrading bacteria Synergistes jonesii and the overall efficacy of the current inoculum. A series of 30-day anaerobic fermentations were undertaken using the same starter cultures used in the production of commercial inoculum but fed daily with one of three Leucaena cultivars: Cunninghamii, Redlands or Wondergraze. Populations of S. jonesii were monitored daily using a quantitative PCR assay and the ability of the fermentation to detoxify mimosine and its derivatives were assayed on days 10, 15, 20, 25 and 30. Feeding the new Redlands cultivar had a negative impact on S. jonesii numbers and the ability to detoxify 3,4 DHP. However, as fermentation time increased, the S. jonesii populations adapted to the Redlands cultivar. A follow-on fermentation using a starter culture obtained from Day 30 of a Redlands fermentation, showed an immediate increase in S. jonesii populations and was able to detoxify mimosine and its toxic derivatives. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 150 KiB

Open AccessAbstract

Biopolymer Composites for Slow Release to Manage Pimelea Poisoning in Cattle

by Emilie Gauthier, Diane Ouwerkerk, Bronwyn Laycock and Mary Fletcher

Proceedings 2019, 36(1), 97; https://doi.org/10.3390/proceedings2019036097 - 13 Feb 2020

Viewed by 1237

Abstract

Cattle grazing the pastures of inland Australia can be poisoned by ingestion of certain native Pimelea plant species, particularly Pimelea trichostachya and Pimelea simplex. The Pimelea toxin, simplexin, causes often fatal restriction of the pulmonary venules, with resultant heart impacts and characteristic [...] Read more.

Cattle grazing the pastures of inland Australia can be poisoned by ingestion of certain native Pimelea plant species, particularly Pimelea trichostachya and Pimelea simplex. The Pimelea toxin, simplexin, causes often fatal restriction of the pulmonary venules, with resultant heart impacts and characteristic fluid accumulation (oedema) of the jaw and brisket regions. In certain years heavy livestock losses can occur. Currently, there is no effective vaccine or antidote for Pimelea poisoning and the only management strategy is to reduce contact between toxic plants and susceptible stock, for beef producers to avoid potentially devastating poisoning events. Nevertheless, previous research has demonstrated that prolonged low dose feeding diminished the effect in animals. It was postulated that the animal exposed to prolonged low doses developed a mechanism for detoxifying simplexin, possibly through adaptation of the rumen microbial environment. The present study seeks to investigate the use of a biopolymer/toxin composite to foster toxin-degrading microbe populations. The objectives are to manufacture biopolymer composites based on biodegradable polylactic acid (PLA), polyhydroxyalkanoates (PHAs) and/or polycaprolactone (PCL), as toxin slow-release systems for the rumen that would have broad utility across a range of plant toxins and other beneficial rumen compounds. The poster covers the manufacturing, characterisation and performance of the biopolymers in a simulated rumen environment. Preliminary results of different biopolymers/composites containing Pimelea material and toxin extracts in an in vitro simulated rumen environment for up to 30 days are presented. It was found that the release rate could be tailored by choosing the right type of biopolymer. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 148 KiB

Open AccessAbstract

DNA Testing and Genetic Evaluation for Poll Breeding in Tropically Adapted Beef Cattle

by Imtiaz A.S. Randhawa, Michael R. McGowan, Laercio R. Porto-Neto, Ben J. Hayes and Russell E. Lyons

Proceedings 2019, 36(1), 98; https://doi.org/10.3390/proceedings2019036098 - 13 Feb 2020

Viewed by 1279

Abstract

In beef cattle, horn management is practiced to physically or surgically remove horns for the safety of animals and workers. However, invasive practices of dehorning and disbudding are a great threat to animal welfare, health, production and human safety, as well as labour [...] Read more.

In beef cattle, horn management is practiced to physically or surgically remove horns for the safety of animals and workers. However, invasive practices of dehorning and disbudding are a great threat to animal welfare, health, production and human safety, as well as labour intensive and costly. The most effective way to limit the impacts and costs of horns is to prevent their occurrences by breeding naturally polled (hornless) herds. Horn development is complex, although two mutually exclusive genetic variants (Celtic and Friesian) have been found prevalent on each copy of chromosome 1 in most polled cattle. Predicting genotypes in an animal is challenging. Available genetic testing assays were often limited in tropically adapted beef cattle. In this study we present a new optimized poll testing (OPT) assay, which has been bundled with SNP genotyping arrays being used for genomic evaluation in cattle. Breeding schemes can profile future parents for pure-polled stock based on the OPT results. We also evaluated the factors causing complexity in horn conditions. Thus, we coupled OPT predictions with head-status and sex distributions, by modelling genetic and non-genetic impacts, revealing that genetics, sex and sex hormones control horn ontology. Finally, concerns of polledness adversely affecting production and reproduction were investigated by using estimated breeding values of several beef traits. We found no detrimental effects of polledness on production or reproduction. Overall, this research concludes that genetically polled cattle will minimize issues about animal welfare and management costs without reducing production potentials in the tropically adapted beef cattle. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 119 KiB

Open AccessAbstract

The Effect of Post-Harvest Storage on the Physicochemical Properties and Phytochemical Content of Queen Garnet Plum

by Gethmini Kodagoda, Michael E. Netzel, Yasmina Sultanbawa, Tim O’Hare and Hung T. Hong

Proceedings 2019, 36(1), 99; https://doi.org/10.3390/proceedings2019036099 - 13 Feb 2020

Viewed by 1316

Abstract

The Queen Garnet Plum (QGP), a cultivar of Japanese plum (Prunus salicina Lindl.), was developed as a high anthocyanin plum in a Queensland Government breeding programme. Anthocyanins have been associated with various health attributes, including diabetes control, cardiovascular disease prevention and anti-inflammatory [...] Read more.

The Queen Garnet Plum (QGP), a cultivar of Japanese plum (Prunus salicina Lindl.), was developed as a high anthocyanin plum in a Queensland Government breeding programme. Anthocyanins have been associated with various health attributes, including diabetes control, cardiovascular disease prevention and anti-inflammatory activity. This study was aimed at identifying the changes in physiochemical properties and important phytochemicals of QGP when stored under two storage temperatures. QGP from two growers were stored at 4 and 23 °C for 0, 4, 7, 10 and 14 days. At the end of each storage period the peel, outer flesh (up to 7 mm from the peel) and inner flesh were separated and analysed for chroma, total soluble solids (TSS) and titratable acidity (TA). The grower source had a significant effect on the measured parameters when considered as a covariate. Chroma values of the peel, inner and outer flesh were significantly (P < 0.05) different at 4 and 23 °C, after 14 days. There was no significant difference in the inner flesh TSS (IF-TSS) and outer flesh TSS (OF-TSS) between the different storage temperatures, but compared to day 0, after 14 days IF-TSS and OF-TSS were significantly (P < 0.05) lower. TA of the inner and outer flesh were significantly (P < 0.05) different at the two storage temperatures, but only the inner flesh TA was significantly (P < 0.05) different after 14 days. Further analysis is in progress for anthocyanins, total phenolics, carotenoids, folates and vitamin C. The current study indicates that QGP is climacteric and grower source, storage temperature and time as well as tissue can significantly affect the studied physicochemical parameters. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 177 KiB

Open AccessAbstract

Nutritional Characteristics of Australian Grown Feijoa (Acca sellowiana) and Its Antimicrobial Activity

by Anh Dao Thi Phan, Mridusmita Chaliha, Rohan Bicknel, Yasmina Sultanbawa and Michael E. Netzel

Proceedings 2019, 36(1), 100; https://doi.org/10.3390/proceedings2019036100 - 13 Feb 2020

Cited by 1 | Viewed by 1084

Abstract

The present study determined the chemical composition, bioactive compounds and biological properties of Australian grown feijoa (Acca sellowiana) (including whole fruit with peel, fruit peel and pulp) in order to assess the nutritional quality and antimicrobial activity of this tropical fruit. [...] Read more.

The present study determined the chemical composition, bioactive compounds and biological properties of Australian grown feijoa (Acca sellowiana) (including whole fruit with peel, fruit peel and pulp) in order to assess the nutritional quality and antimicrobial activity of this tropical fruit. Polyphenolic compounds and vitamins were determined by UHPLC-PDA-MS/MS, showing that the feijoa fruit not only contains a high amount of antioxidant flavonoids, but is also a rich source of vitamin C (63 mg/100 g FW in the whole fruit and 95 mg/100 g FW in the peel; Recommended Dietary Intake (RDI) for adults: 45 mg/day). The proximate, essential minerals and selected trace elements indicate that feijoa fruit is a valuable source of dietary fibre and potassium. The edible fruit peel possesses significantly more antioxidant flavonoids and vitamin C than the fruit pulp. This is most probably the reason for the observed strong antimicrobial activity of feijoa peel-extracts against a wide-range of microorganism responsible for food spoilage and food poisoning. The consumption of feijoa, whole fruit with peel, can deliver a considerable amount of bioactive compounds such as vitamin C, flavonoids and fibre, and therefore, may contribute to a healthy diet. Furthermore, the potential use of feijoa-peel as a natural food perseverative needs to be investigated in follow-up studies. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 171 KiB

Open AccessAbstract

Analysis of Environmental Contaminants in Australian Honey and Comparison to Stingless Bee Honey from Queensland and Malaysia

by Natasha L. Hungerford, Benjamin L. L. Tan, Ujang Tinggi, Norhasnida Zawawi, Madeleine Farrell, Heng Hang Tsai, Darina Hnatko, Lorinda J. Swann, Cassandra L. Kelly, Shalona R. Anuj, Dennis C. Webber, Stephen T. Were and Mary T. Fletcher

Proceedings 2019, 36(1), 101; https://doi.org/10.3390/proceedings2019036101 - 13 Feb 2020

Viewed by 1493

Abstract

Honey is a widely available natural sweetener containing sugars, and small quantities of vitamins and minerals, proteins, amino acids and fatty acids. Owing to its nutritious components, commercial honeys are sold in bulk blends or as trendy and premium products. Meanwhile, honey bees [...] Read more.

Honey is a widely available natural sweetener containing sugars, and small quantities of vitamins and minerals, proteins, amino acids and fatty acids. Owing to its nutritious components, commercial honeys are sold in bulk blends or as trendy and premium products. Meanwhile, honey bees are considered as environmental monitors and have the potential to transfer environmental contaminants, if present, to honey. In high density urban and industrial environments polycyclic aromatic hydrocarbons (PAHs) and heavy metals can be prevalent, whilst pesticides and mineral and trace elements are ubiquitous. Honey hives are traditionally located in rural and forested areas, but there is a growing trend to locate hives in urban areas. This project has investigated the presence of environmental contaminants in honey samples from high density urban, peri-urban as well as rural areas. Australian honey samples (n = 211) were purchased between 2016 and 2018, including 52 honeys claiming to be of urban origin purchased online. Stingless bee honeys (n = 36) from Queensland and Malaysia were compared. Processed samples were analysed by UHPLC-MS/MS (herbicides), GC-MS/MS (pesticides and PAHs) and ICP-MS and ICP-OES (elemental analyses). The results showed low or negligible pesticide, herbicide, and PAH contamination, and that these low results were similar regardless of urban or rural origins. Wide variations of essential trace element (Fe, Zn, Cu, Mo, Co, Mn, Cr) and mineral levels (K, Na, P, Mg, Ca) were found in honey products, which are a good dietary source of K and Zn. Relatively low levels of toxic heavy metals were found in honeys. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Purple Sweetcorn—An innovative Horticultural Product—Consumer Views

by Sandra Milena Olarte Mantilla, Philippa Lyons, Tim J. O'Hare and Heather Eunice Smyth

Proceedings 2019, 36(1), 102; https://doi.org/10.3390/proceedings2019036102 - 13 Feb 2020

Viewed by 1087

Abstract

Purple sweetcorn has been conceptualized as an innovative premium horticultural product that may provide consumers with the potential health benefit of anthocyanins. Gathering consumer insights is crucial to inform the breeding program to obtain a purple sweetcorn product closer to consumer’s requirements. Thirty-six [...] Read more.

Purple sweetcorn has been conceptualized as an innovative premium horticultural product that may provide consumers with the potential health benefit of anthocyanins. Gathering consumer insights is crucial to inform the breeding program to obtain a purple sweetcorn product closer to consumer’s requirements. Thirty-six non-food neophobic sweetcorn consumers participated in a focus group session on the concept of purple sweetcorn, as well as visually evaluating early breeding lines. Consumers were very positive about the concept of purple sweetcorn and had clear ideas of potential uses. Consumers preferred that purple sweetcorn taste different to commercial yellow sweetcorn, and that health claims would support a premium price position. A small scale follow up consumer study (n = 10) was carried out where consumers were asked to rate acceptability for visual (raw and cooked), flavour, textural and overall of two purple sweetcorn breeding lines (reddish-purple and purple) and compared against commercial yellow sweetcorn. Visual acceptability scores were higher for purple than the reddish-purple lines for both cooked and raw forms, but the yellow cobs were the most preferred. In contrast, flavour and overall acceptability scores were higher for the reddish-purple and yellow cobs than the purple lines. It was also noted that the reddish-purple and purple lines had a slight raspberry flavour. Consumer’s discussions outcomes from both studies were that consumers preferred better color coverage across the kernel, which will be the direction in continuing the development of purple sweetcorn lines. This study demonstrated there is a market for a premium purple sweetcorn product among consumers. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 161 KiB

Open AccessAbstract

Breeding for Resistance to Husk Spot Disease in Macadamia

by Jasmine Nunn, Mobashwer Alam, Olufemi Akinsanmi, Craig Hardner and Bruce Topp

Proceedings 2019, 36(1), 103; https://doi.org/10.3390/proceedings2019036103 - 13 Feb 2020

Viewed by 1250

Abstract

In Australian macadamia orchards, significant decreases in saleable nuts have been reported due to husk spot caused by the fungal pathogen, Pseudocercospora macadamiae. In some cultivars, husk spot induces early fruit abscission. This may result in under developed nuts and consequently, increased proportions [...] Read more.

In Australian macadamia orchards, significant decreases in saleable nuts have been reported due to husk spot caused by the fungal pathogen, Pseudocercospora macadamiae. In some cultivars, husk spot induces early fruit abscission. This may result in under developed nuts and consequently, increased proportions of commercial rejects. While fungicides are able to reduce impacts of husk spot, breeding for resistance offers a cost-effective and sustainable control option. Quantification of genetic variation for resistance in Australian macadamia breeding germplasm will assist selection. Previous husk spot studies have utilised different inoculation methods including the insertion of diseased husk into tree canopies and the direct application of P. macadamiae suspensions to fruit. Insertion of diseased husk best reflects natural infection processes; however, it requires rainfall or overhead irrigation to disperse spores and may result in the delivery of unequal quantities of inoculum. Different disease parameters have also been measured to compare susceptibility, including proportions of diseased fruit, mean number of lesions per fruit or mean diameter of chlorosis or necrotic lesions. It is unknown which of these parameters are most valuable to assess when screening for resistance. Determining the proportions of variation in such phenotypic traits that is due to genetic variance could identify which of these will better respond to selection. Finally, the use of marker assisted selection may reduce time and costs of disease screening, but no studies have investigated associations between markers and susceptibility to husk spot. In this study, breeding progeny and parents and wild accessions will be screened for husk spot resistance. Repeatability of different inoculation methods will be compared. The heritability of parameters used to measure husk spot incidence and severity will be estimated. Analysis will be undertaken to identify genetic markers associated with resistance. Screening of a wide genetic base for husk spot resistance will enable selection of parents for current breeding. Optimisation of inoculation and phenotypic screening methods and the identification of markers associated with resistance will increase the efficiency of future trials. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 126 KiB

Open AccessAbstract

Determinants of Food Inflation in Pakistan: Empirical Evidences

by Mukaddas Afzal and Sarfraz Ahmad Mian

Proceedings 2019, 36(1), 104; https://doi.org/10.3390/proceedings2019036104 - 13 Feb 2020

Viewed by 3399

Abstract

Today food inflation is a rising issue. The world food problem is getting more complicated as the world population is increasing more rapidly than food production. Pakistan being a developing country is a victim of higher food prices. The present study is an [...] Read more.

Today food inflation is a rising issue. The world food problem is getting more complicated as the world population is increasing more rapidly than food production. Pakistan being a developing country is a victim of higher food prices. The present study is an attempt to identify main determinants affecting food inflation in Pakistan. The study is based upon the time-series data from 1997 through 2017, collected from secondary sources including published issues of Economic Survey of Pakistan, Agricultural Statistics of Pakistan and annual reports of State Bank of Pakistan. Method of OLS (Ordinary Least Square) was applied by developing an equation for food price inflation and five major determinants; food imports, food exports, wheat support price, value-added in agriculture and money supply respectively. These variables were regressed with CPI (Consumer Price Index) food, the measure of food inflation. The results indicated that agricultural value addition is highly significant and negatively affecting the food inflation while Food imports have most significant positive effect on food inflation. Supply of money in the country and wheat support price are effecting food inflation significantly. The study suggested that increase in agricultural output and tight monetary policy are the key factors to decrease food inflation. The government should adopt measures to improve the productivity of agricultural sector, encourage agro-based industry, moderation in government administered price and should control the supply of money in the country. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 154 KiB

Open AccessAbstract

Aligning Pacific Cocoa Genetics to Productivity and Quality for the Craft Speciality Chocolate Market

by Natalie Dillon, Yan Diczbalis, John Oakeshott and Paitia Nagalevu

Proceedings 2019, 36(1), 105; https://doi.org/10.3390/proceedings2019036105 - 14 Feb 2020

Cited by 1 | Viewed by 1591

Abstract

Cocoa (Theobroma cacao L.) is an important agricultural export of South Pacific countries, providing livelihoods for an estimated 310,000 people. The wet tropical coast of Far North Queensland has also started producing cocoa for a local boutique chocolate making industry. Although the [...] Read more.

Cocoa (Theobroma cacao L.) is an important agricultural export of South Pacific countries, providing livelihoods for an estimated 310,000 people. The wet tropical coast of Far North Queensland has also started producing cocoa for a local boutique chocolate making industry. Although the volumes of cocoa produced are small by global standards, Pacific island and north Australian cocoa is well placed to compete in the high-value, low-volume markets—based on fine flavour, unusual genetic resources and novel ‘single origin’ branding. A member of the Malvaceae family, cocoa has its origins in Central and South America. First domesticated over 2000 years ago, cocoas’ global dispersal was mediated by humans and cultivation is now widespread across the humid tropics. The use of molecular markers to characterize the diversity of genetic resources available and identify superior genetic material is vital to the continued improvement and selection of clones. This work used single nucleotide polymorphism (SNP) markers to identify the parentage of Pacific island cocoa selections in relation to the 10 distinct cocoa families formerly identified from the original Central and South American populations. On farm collections from Pacific island countries has revealed distinct geographic cocoa populations. Specific populations show strong Criollo parentage, a source of fine flavour qualities, while others exhibit a high component of Amelonado parentage. Small populations showed a higher percentage of IMC, Parinari, National or Scavina parentage. Production and quality data linked to these populations assists to identify superior parentage to enable local programs to rapidly bring these into commercial production thereby improving cocoa productivity and quality in the Pacific. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 150 KiB

Open AccessAbstract

Nutritional Composition of Solid-State Fermented Camelina Meal (An Enriched Protein Source for Broiler Chickens)

by Oladapo Oluwaseye Olukomaiya, Chrishanthi Fernando, Ram Mereddy, Xiuhua Li and Yasmina Sultanbawa

Proceedings 2019, 36(1), 106; https://doi.org/10.3390/proceedings2019036106 - 14 Feb 2020

Cited by 2 | Viewed by 1512

Abstract

Camelina (Camelina sativa) also known as false flax or gold of pleasure is an oilseed crop of the Brassica (Cruciferae) family. Camelina is not a food crop, however, the by-product (meal or cake) obtained from the oil extraction of [...] Read more.

Camelina (Camelina sativa) also known as false flax or gold of pleasure is an oilseed crop of the Brassica (Cruciferae) family. Camelina is not a food crop, however, the by-product (meal or cake) obtained from the oil extraction of camelina seeds is useful as animal feed because of its moderate crude protein content. The dietary use of camelina meal in broiler diets is limited to low inclusion due to the presence of anti-nutritional factors such as fibre, phytic acid, glucosinolates and tannins which have negative effects on broiler performance. Solid-state fermentation (SSF) is a suitable processing method for enriching agroindustrial by-products since it offers several cost-effective and practical advantages. In the present study, the effect of SSF on the nutrient composition, phytic acid and total phenolic contents of expeller-extracted camelina meal was evaluated. Aspergillus ficuum (ATCC 66876) was used for SSF under aerobic conditions at 30^oC for 7 days. Unfermented and fermented camelina meals were analyzed for dry matter, crude protein, crude fat, crude fibre, total sugar (sucrose) and starch as well as for pH, phytic acid and total phenolic contents. Crude protein was improved by 6.79% while total sugar and starch were reduced by 90.99% and 75.78%, respectively in the solid-state fermented camelina meal. Phytic acid and total phenolic contents were also decreased by 39.17% and 56.11%, respectively. This study revealed that SSF could be used to improve the nutritional quality of camelina meal for improved use in poultry feed formulation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 182 KiB

Open AccessAbstract

Benefits and Challenges for Expanding Protected Cropping in the Australian Tropics

by Elio Jovicich and Heidi Wittl

Proceedings 2019, 36(1), 107; https://doi.org/10.3390/proceedings2019036107 - 19 Feb 2020

Viewed by 1138

Abstract

Protected cropping of vegetables in Australia is largely located in temperate climate regions, however there are opportunities for growers in the Northern tropics to benefit from technologies that mitigate risks associated with climate variability and assist accessing domestic and export markets. Evidence from [...] Read more.

Protected cropping of vegetables in Australia is largely located in temperate climate regions, however there are opportunities for growers in the Northern tropics to benefit from technologies that mitigate risks associated with climate variability and assist accessing domestic and export markets. Evidence from overseas and research by the Queensland Department of Agriculture and Fisheries (DAF) suggests that, for some high value commodities, protective cropping technologies are a cost-effective way for growers to mitigate the effects of extreme temperature, rainfall, changes in humidity, wind, solar radiation and pest and disease pressures which can negatively impact yield, quality and consistency of supply. Research for development of suitable protected cropping systems for growers in northern Australia has been focusing in awareness, proof of concepts, advice and information sharing. Discussions with industry stakeholders, on-farm demonstrations and trials, and industry study tours have been critical for the identification of cost-effective structure designs and agronomy practices. There are many aspects of these farming systems that still need to be advanced for warm climatic regions. To enable adoption, research will need to consider economic and environmental aspects within the context of resource diversity and availability and markets to be targeted. A new project aims to map potential pathways that will support adoption of protected cropping in the Australian tropics. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 142 KiB

Open AccessAbstract

Detection of Stephanofilaria (Nematoda: Filariidae) in Buffalo Fly Lesions

by Muhammad Noman Naseem, Ala Tabor, Ali Raza, Constantin Constantinoiu, Jess Morgan and Peter James

Proceedings 2019, 36(1), 108; https://doi.org/10.3390/proceedings2019036108 - 20 Feb 2020

Viewed by 1313

Abstract

Haematobia irritans exigua, commonly known as buffalo fly (BF), causes economic losses of about AUD $100 million per annum to the Australian cattle industry in terms of decreased production and costs of control. Lesions associated with BF infestation range from raised, dry, alopecic, [...] Read more.

Haematobia irritans exigua, commonly known as buffalo fly (BF), causes economic losses of about AUD $100 million per annum to the Australian cattle industry in terms of decreased production and costs of control. Lesions associated with BF infestation range from raised, dry, alopecic, hyperkeratotic or scab encrusted to severe hemorrhagic areas of ulceration which represent a major animal welfare concern. BF transmits a filarial nematode, Stephanofilaria sp., which has been speculatively associated with BF lesion development. The existing literature indicates that the sensitivity of currently used diagnostic techniques to detect Stephanofilaria in skin lesions is low and that there is currently no sequence for Stephanofilaria available on GenBank. Our objective is to develop a PCR method to detect Stephanofilaria in BF lesions. Skin biopsies were collected from 10 freshly slaughtered cattle hides having obvious BF eye lesions. Samples were collected from the center and the edge of the BF lesion as well as from adjacent normal tissue. Each skin punch was cut into 5-6 slices and immersed in normal saline before incubation overnight at 22°C. Eight nematodes were recovered from the saline by microscopic examination and preserved in ethanol. Nematode DNA will be extracted using conventional extraction methods. Specific primers will be used to amplify the ITS regions of rDNA and coxI region of the mtDNA and the amplified DNA will be sequenced. Primers will be designed from these regions to detect the presence of Stephanofilaria and used in PCR studies to clarify the etiology and epidemiology of BF lesions. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

Variations in macadamia varietal susceptibility to Phytophthora multivora and P. cinnamomi

by Olumide Jeff-Ego, Juliane Henderson, Bruce Topp, Andre Drenth and Olufemi Akinsanmi

Proceedings 2019, 36(1), 109; https://doi.org/10.3390/proceedings2019036109 - 21 Feb 2020

Viewed by 1134

Abstract

Incidence of diseases caused by various Phytophthora spp. in macadamia is increasing worldwide, often resulting in severe yield loss and death of both juvenile and old macadamia trees. In Australia, P. cinnamomi and P. multivora has been identified to cause severe stem canker [...] Read more.

Incidence of diseases caused by various Phytophthora spp. in macadamia is increasing worldwide, often resulting in severe yield loss and death of both juvenile and old macadamia trees. In Australia, P. cinnamomi and P. multivora has been identified to cause severe stem canker in macadamia orchards. Currently, various varietal improvement research programs on macadamia are underway, not only to obtain high-yielding and precocious macadamia germplasm but to develop macadamia genotypes with acceptable levels of tolerance/resistance to pests and diseases. In this study, we selected macadamia genotypes for their acceptable levels of tolerance/resistance to Phytophthora infection, after screening about 360 macadamia genotypes against to P. cinnamomi and P. multivora, using a rapid detached leaf and plant inoculation assays. These macadamia plant materials were collected from a major macadamia arboretum in Queensland. Our results revealed segregation of macadamia genotypes into two spectrum of susceptible and tolerant macadamia genotypes. Hence, strong representatives within the tolerant and susceptible spectrum were further investigated in order to understand if the basis of the differential response is driven by a variation in structural, physiological or genetic markers, following a challenge with Phytophthora spp. Our result revealed a marked variation in structural response during the infection process, between the selected susceptible, ‘HAES816’ and tolerant germplasm and ‘HAES344’. This information will provide evidence to support potential preferential selection of tolerant macadamia genotypes potentially useful for breeding against Phytophthora diseases. Further studies will characterize tolerant macadamia progenies to develop marker-assisted selection protocols for resistance, and explore defense mechanisms response. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 117 KiB

Open AccessAbstract

How Can Protected Cropping Ensure an Export Supply of High Quality Melons in the Tropics?

by Heidi Wittl and Elio Jovicich

Proceedings 2019, 36(1), 110; https://doi.org/10.3390/proceedings2019036110 - 21 Feb 2020

Viewed by 1381

Abstract

Queensland production of melons (Cucumis melo L.), typically rockmelon and honeydew fruits, is seasonal and practiced entirely outdoors. The horticulture industry has limited knowledge about using protected cropping as a technology to mitigate the effects of climate variability in melon crops. Some [...] Read more.

Queensland production of melons (Cucumis melo L.), typically rockmelon and honeydew fruits, is seasonal and practiced entirely outdoors. The horticulture industry has limited knowledge about using protected cropping as a technology to mitigate the effects of climate variability in melon crops. Some new specialty melon types now available in Australia require favourable environmental conditions and specific growing practices in order to obtain fruits with good visual and eating quality. Adoption of protected cropping could be a forthcoming technology to add diversity in fruit appearance, flavour and aroma, and guarantee consistent high quality of melons grown for export markets and niche domestic markets. The Queensland Department of Agriculture and Fisheries has been conducting agronomic research to develop guidelines that will assist growers produce specialty melons with protective cropping systems in the tropics. In a series of evaluations, crop performance and visual and eating quality were assessed. A range of desired fruit attributes were identified for rind colour and net patterns, flesh colour, texture and shelf life. There were examples of cultivars with remarkable sweet flesh (total soluble solids up to 16 °Bx) in large fruits. A group of promising cultivars had total marketable yields that ranged from 5.5 to 10 kg/m² with fruit weights that ranged from 0.9 to 2.0 kg/fruit, and where total soluble solids ranged from 12 to 16 °Bx. A market-driven approach is providing information about the range of melon commodities that are desired in targeted markets. This approach is guiding the development of agronomic recommendations to assist with the delivery of consistent superior fruit quality in melon export programs. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Australian Native Plant Foods and Their Contribution to Diet Diversity

by Yasmina Sultanbawa

Proceedings 2019, 36(1), 111; https://doi.org/10.3390/proceedings2019036111 - 3 Mar 2020

Viewed by 1857

Abstract

The triple burden of malnutrition is identified with overnutrition, undernutrition and hidden hunger. Although global food production in terms of calories has kept pace with population growth, low-quality diets that lead to micronutrient deficiencies and chronic diseases have become a global problem. Over [...] Read more.

The triple burden of malnutrition is identified with overnutrition, undernutrition and hidden hunger. Although global food production in terms of calories has kept pace with population growth, low-quality diets that lead to micronutrient deficiencies and chronic diseases have become a global problem. Over 2 billion people globally suffer from micronutrient deficiencies as a result of insufficient intake of vitamins and trace elements in the diet. Currently, about 60% of dietary calories come from staple foods such as rice, maize, wheat, potato and soybean. There is a clear relationship between the reliance on a few staple crops or low dietary diversity and malnutrition. Dietary diversity is increased when consumption of cereals is accompanied by a high intake of fruits, vegetables and pulses. The occurrence of antioxidants and important dietary phytochemicals in these underutilised fruits and vegetables further enhances their value as dietary interventions to promote health and wellbeing. Australian native plant foods are rich sources of micro nutrients. Some better known examples are, the Kakadu plum (Terminalia ferdinandiana) which is a good source of vitamin C, green plum (Buchanania obovata) which is rich in folates and the wattle seeds (Acacia spp.) which are high in protein, dietary fibre and trace elements. Therefore, there is a need to develop strategies to include these food crops in nutrition intervention programmes and promote them as healthy food choices to be incorporated into the diets of Australians. The introduction of Australian native plant foods among nutritionally vulnerable communities where undernutrition, hidden hunger and chronic diseases have been reported will help alleviate these health problems. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

A New Method for the Authentication of Australian Honey

by Sadia A. Chowdhury, Shalona R. Anuj, James F. Carter, Natasha L. Hungerford, Dennis Webber, Yasmina Sultanbawa and Mary T. Fletcher

Proceedings 2019, 36(1), 112; https://doi.org/10.3390/proceedings2019036112 - 3 Mar 2020

Viewed by 1650

Abstract

The honey bee industry in Australia is small but has a big impact on both producers and consumers. Alarmingly, it has been recently reported that an international laboratory, specializing in honey authentication, found that almost half of the 28 blended and imported honey [...] Read more.

The honey bee industry in Australia is small but has a big impact on both producers and consumers. Alarmingly, it has been recently reported that an international laboratory, specializing in honey authentication, found that almost half of the 28 blended and imported honey samples selected from Australian supermarket shelves were “adulterated”. The Official method of honey analysis (AOAC 998.12) is based on the stable-isotope ratio mass spectrometry analysis of δ¹³C value of honey versus δ¹³C of honey protein to detect the addition of C₄ plant derived sugars, such as cane sugar or high fructose corn syrup. This method is used as the primary C₄ sugar adulteration test around the world, but honey derived from some Australian plants, particularly Manuka (Leptospermum species), fails this process. Our research aims to examine the characteristics of Australian honey and develop a test that is fit for purpose, particularly where honeys derived from Leptospermum species are concerned. We have focused on the isotopic values of “proteins” precipitated using the standard AOAC method and “proteins” precipitated after incorporation of a further modification step which removes insoluble material (including pollen) from the honey before precipitation. Our modified method includes the analysis of different isotopes of the precipitated protein, sugar profiles and Manuka markers. A key advantage of the proposed modification is that it does not preclude the detection of residual sugar feeding of bees or extension of honey with C₄ sugar. The proposed modification to the AOAC test will reduce false identification of C₄ sugars and improve the overall reliability of Australian honey authentication. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 157 KiB

Open AccessAbstract

Ensiling Unsalable Vegetables with Crop Sorghum to Produce High Quality Feed

by Daniel L. Forwood, Kristian Hooker, Eleonora Caro, Yuxin Huo, Devin Holman, Alex V. Chaves and Sarah J. Meale

Proceedings 2019, 36(1), 113; https://doi.org/10.3390/proceedings2019036113 - 3 Mar 2020

Viewed by 1483

Abstract

Vegetables regarded as unsalable at processing often undergo disposal into landfill, threatening food security and increasing emissions through decomposition. Ensiling vegetables with forage crops is a suggested method of waste reduction that could also double as a livestock feed. Carrot or pumpkin, ensiled [...] Read more.

Vegetables regarded as unsalable at processing often undergo disposal into landfill, threatening food security and increasing emissions through decomposition. Ensiling vegetables with forage crops is a suggested method of waste reduction that could also double as a livestock feed. Carrot or pumpkin, ensiled at 0%, 20% or 40% DM with crop sorghum, and with or without a second-generation silage inoculant were assessed for nutritive composition, organic acid profiles, aerobic stability and in vitro rumen fermentation characteristics. Silage was sampled after 70-days ensiling for nutrient composition, 14-day aerobic stability, organic acid profiles and microbial diversity. Sorghum ensiled with carrot or pumpkin at 20% or 40% DM increased crude fat (P ≤ 0.01) and decreased (P ≤ 0.01) silage surface temperature upon aerobic exposure compared to the control. Bacterial communities analyzed through 16S rRNA gene sequencing linearly increased (P ≤ 0.01) in diversity as vegetable proportion increased in the silage; dominated by Lactobacillus species. Upon assessment in vitro, there was an increase (P ≤ 0.04) in in vitro digestibility and some CH₄ parameters (% CH₄, and mg CH₄/g DM), with no effect (P ≥ 0.17) on remaining CH₄ parameters (mL CH₄/g DM, mg CH₄/g DMD), gas production or pH. However, increasing vegetable proportion decreased acetic and increased propionic acid concentrations respectively, decreasing A:P ratio and total VFA as a result (P ≤ 0.01). Results from this study indicate including carrot or pumpkin at 20% or 40% DM in a sorghum silage can produce a highly digestible, microbially diverse and energy-rich livestock feed whilst acting as a method of waste diversion of considerable environmental benefit. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 148 KiB

Open AccessAbstract

Kakadu Plum (Terminalia Ferdinandiana)—A Native Australian Fruit with Functional Properties

by Eshetu M. Bobasa, Michael E. Netzel, Stan Kubow, Mridusmita Chaliha, Anh Phan and Yasmina Sultanbawa

Proceedings 2019, 36(1), 114; https://doi.org/10.3390/proceedings2019036114 - 3 Mar 2020

Viewed by 4971

Abstract

Abstract: Kakadu plum (KP), a native Australian fruit, is a rich source of vitamin C, minerals and phenolic compounds. A better understanding of the (phyto)chemical composition and biological properties of KP will facilitate the development of functional KP products for the [...] Read more.

Abstract: Kakadu plum (KP), a native Australian fruit, is a rich source of vitamin C, minerals and phenolic compounds. A better understanding of the (phyto)chemical composition and biological properties of KP will facilitate the development of functional KP products for the food, pharmaceutical, nutraceutical and cosmetic industry. KP is usually harvested wild and hence, its composition and functional properties may vary considerably depending on the cultivar, maturity, environmental conditions as well as post-harvest treatment. The present study aimed to assess the levels of ascorbic acid (AA) and ellagic acid (EA), the main bioactive compounds in KP, in a commercially available freeze-dried KP powder. The functional properties of a polyphenol-enriched extract obtained from this product were also evaluated. AA and EA were quantified by UHPLC_PDA. The polyphenol-enriched extract was tested for in vitro antioxidant and antimicrobial properties, using the DPPH radical scavenging assay and agar well diffusion, respectively. Total AA content in the freeze-dried powder was 200 mg/g dry weight (DW) and total EA was 46.6 mg/g DW. The polyphenol-enriched extract had a high DPPH radical scavenging capacity and strong antimicrobial activity against methicillin resistant Staphylococcus aureus. Our findings demonstrate that AA and EA, the main bioactive compounds in KP, are retained at high levels in the freeze-dried KP fruit powder. Furthermore, the polyphenol-enriched KP extract has the potential to be used as a natural preservative in the food industry due to its strong antioxidant and antimicrobial activity. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessAbstract

Linking Smallholder Farmers to Potential Beef Markets: A Case Study of Livestock Farmers in Pakistan

by Humera Iqbal, Khizar Hayat, Anam Afzal, Emma Hand and David McGill

Proceedings 2019, 36(1), 115; https://doi.org/10.3390/proceedings2019036115 - 3 Mar 2020

Viewed by 1617

Abstract

In Pakistan there are no dedicated beef breeds consequently beef meat is a by-product of the dairy industry in the form of cull cows and male calves. Smallholder farmers supply up to 80% of animals slaughtered and decisions to sell their animals is [...] Read more.

In Pakistan there are no dedicated beef breeds consequently beef meat is a by-product of the dairy industry in the form of cull cows and male calves. Smallholder farmers supply up to 80% of animals slaughtered and decisions to sell their animals is driven by a need to generate cash in a time of necessity rather than in response to market signals. The aim of this study was to identify and evaluate beef market opportunities for smallholder farmers with the objective of increasing their income from their beef animals. Using a rapid value chain assessment seven potential beef markets in Punjab and Sindh were assessed and one was studied in detail to evaluate the opportunities and risks for smallholder farmers in beef value chains. Semi-structured interviews were conducted with beef value chain actors including; consumers (10), retailer (1), traders (12), feedlot farmer (1) and smallholder farmers (9). The interview data was analyzed using content analysis within value chain framework comprising of different flows (product, information and financial) and relationships among the chain actors. The results indicated that supplying directly to the retailer was indeed a potential opportunity for smallholder farmers provided they can meet product specifications. This study describes what capacity building support would be required to enable smallholder farmers to implement more focused and cost-effective rearing strategies leading to a reliable and consistent supply for this retailer. If successful, this could be used as a model for market interventions for other farmers leading to increased beef production and profitability. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 148 KiB

Open AccessAbstract

Effect of Photosensitization on Inactivation of Aspergillus flavus in Maize

by Rafael Nguenha, Maral Seidi Damyeh, Hung T. Hong and Yasmina Sultanbawa

Proceedings 2019, 36(1), 116; https://doi.org/10.3390/proceedings2019036116 - 5 Mar 2020

Viewed by 1394

Abstract

Mycotoxins are naturally occurring toxins produced by certain types of fungi that contaminate food and feed, posing serious health risks to human and livestock. Photosensitization is a light-based technique, which has emerged as a novel and promising green technology to control microbial growth [...] Read more.

Mycotoxins are naturally occurring toxins produced by certain types of fungi that contaminate food and feed, posing serious health risks to human and livestock. Photosensitization is a light-based technique, which has emerged as a novel and promising green technology to control microbial growth in food and feed. This study aimed to evaluate the effect of solvent medium including ethanol (EtOH), 50% (v/v) propylene glycol (PG), 20 % (v/v) tween 20 (TW-20), and 20 % (v/v) tween 80 (TW-80), on curcumin-mediated photosensitization to inactivate Aspergillus flavus spores in vitro and on the surface of yellow and white maize kernel and flour. Results showed a reduction in the phototoxic activity of curcumin in TW-20 and TW-80. However, curcumin-based photosensitization using EtOH and PG as solvents led to a significant decrease in the colony forming ability of A. flavus spores in vitro, up to 2.04 and 3.33 log colony-forming unit (CFU), respectively. Interestingly, fungal growth was delayed in photosensitized maize kernel and flour for 14 and 7 days, respectively, which were stored at 25 °C. Consequently, no Aflatoxin B1 (AFB1) was detected in maize kernels after 20 days of storage at 25 °C, whereas accumulation of the toxin was reduced by 91% in photosensitized flour. Thus, photosensitization showed to be a potential alternative to reduce A. flavus contamination on maize kernel and flour, giving rise to low concentrations of AFB1. This technique has the potential for use in feed applications resulting in the reduction of postharvest losses in maize. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 135 KiB

Open AccessAbstract

Farmer Perception and Resources for Calf Fattening Under Smallholder Production System

by Humera Iqbal, Anam Afzal, Khizar Hayat, Emma Hand and David McGill

Proceedings 2019, 36(1), 117; https://doi.org/10.3390/proceedings2019036117 - 5 Mar 2020

Viewed by 1527

Abstract

In Pakistan, smallholder farmers are primarily engaged in dairy farming while keeping beef animals as secondary products. Farmers experience poor production due to lack of focus on beef farming, traditional calf rearing practices and limited resources. The objective of this study was to [...] Read more.

In Pakistan, smallholder farmers are primarily engaged in dairy farming while keeping beef animals as secondary products. Farmers experience poor production due to lack of focus on beef farming, traditional calf rearing practices and limited resources. The objective of this study was to understand the perceptions of smallholder farming households of beef production and the available resources for farmers to engage in beef fattening to increase overall farm profitability. Data was collected using a focus group discussion approach, from farming households in villages across Punjab (n = 7) and Sindh (n = 8). An integrated framework incorporating gender and value-chain considerations was used as a tool to assess farmer interest, goals and resources for rearing livestock. The data was analyzed using content analysis. The majority of farmers interested in calf fattening were more resource rich, with livestock as their primary source of income. A smaller proportion of farmers, with limited resources, also took interest in calf fattening. Women from a few villages mentioned that they were reluctant to be involved in beef businesses due to an emerging focus on childhood education as well as a lack of agency for livestock sales and control over income. Another factor contributing to farmer perceptions of beef included their enterprise focus (dairy or cropping). Overall, smallholder farmers perceived that calf fattening could be a profitable business if claves were reared properly, had adequate feed resources and good market return. Training and farm support targeting these areas is critical for calf fattening to become a profitable market strategy. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 128 KiB

Open AccessAbstract

The Small Trees High Productivity Initiative: Principles and Practice in High Density Orchard Design

by Helen Hofman, John Wilkie and Paula Ibell

Proceedings 2019, 36(1), 118; https://doi.org/10.3390/proceedings2019036118 - 6 Mar 2020

Viewed by 1360

Abstract

The Small Trees High productivity Initiative aims to address low productivity in avocado, [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 121 KiB

Open AccessAbstract

Improving Crop Adaptation through Improved Phenology Prediction: A Case Study with Chickpea

by Yash Chauhan and Merrill Ryan

Proceedings 2019, 36(1), 119; https://doi.org/10.3390/proceedings2019036119 - 6 Mar 2020

Viewed by 1064

Abstract

Flowering time is a key phenological stage which in chickpea has been considered to be mainly driven by photoperiod and temperature. However, in spite of being able to be measured very accurately, these two factors are not able to fully account for seasonable [...] Read more.

Flowering time is a key phenological stage which in chickpea has been considered to be mainly driven by photoperiod and temperature. However, in spite of being able to be measured very accurately, these two factors are not able to fully account for seasonable and locational variation in flowering time. Analysis of published information and flowering data collected in various projects on chickpea has led to the discovery of soil water being an additional critical driver of flowering and pod set in chickpea. High soil water status delays flowering in chickpea. An equation that captures the effect of soil water on flowering time has been developed. This equation enables prediction of flowering time in a very diverse range of environments and seasons with a high accuracy, further suggesting a putative role of soil water in modulating flowering. Similar improvements in prediction of flowering time have been noted in lentil and wheat also suggesting that soil water, similar to temperature and photoperiod, may have a universal role in modulating flowering of winter crops. The delaying effect of high soil water, while on one hand could assist in avoiding frosts, on the other hand it could lead to greater soil water and heat stress later in the season if the delay is considerable. This new research will enable more effective optimisation of flowering time of winter crops in different environments and provide breeders and physiologists the opportunity to unravel the genetic and physiological basis of phenological responses to soil water and exploit this response to improve crop adaptation to climatically variable environments. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 119 KiB

Open AccessAbstract

The Effect of Heat Treatments and Drip Line Placements on The Yield and Quality of Garlic

by Alina Djanie, Stephen Harper and Robyn Cave

Proceedings 2019, 36(1), 120; https://doi.org/10.3390/proceedings2019036120 - 7 Mar 2020

Viewed by 1179

Abstract

Despite garlic being a crop with significant economic value, the plant has severe productivity constraints and challenges that contribute to low yield and quality. One of the main difficulties in garlic production is Fusarium basal rot (FBR) caused by Fusarium oxysporum formae speciales [...] Read more.

Despite garlic being a crop with significant economic value, the plant has severe productivity constraints and challenges that contribute to low yield and quality. One of the main difficulties in garlic production is Fusarium basal rot (FBR) caused by Fusarium oxysporum formae speciales cepae (FOC). The soil-borne fungus infects the roots and basal plates of alliums causing delayed emergence and bulb rot at pre- and postharvest stages. The incidence of the pathogen is increasing and is expected to increase further due to growth being promoted under warmer temperatures associated with climate change. Management of the pathogen is difficult because it produces chlamydospores that can survive for years in the soil. Potential practices for reducing FBR in garlic are hot water or dry heat treatments applied to cloves at 50 °C or 45 °C, respectively, for 30 min prior to planting, and controlling irrigation using single or double drip line placement for 1.5 m wide beds with two rows of garlic. The current study investigated the impact of controlled irrigation on FBR prevalence. These chemical-free practices are relatively easy to apply and could be effective for managing FBR in conventional and organic grown garlic. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 118 KiB

Open AccessAbstract

Introgression of Large Grain Size from Australian Wild Rice and Its Agronomical Importance

by Ryuji Ishikawa, Takahiro Mishimaki, Daiki Toyomoto, Koki Katano, Katsuyuki Ichitani and Robert Henry

Proceedings 2019, 36(1), 121; https://doi.org/10.3390/proceedings2019036121 - 7 Mar 2020

Viewed by 1093

Abstract

There are a few wild species belonging to genus Oryza in Australia. Taxon A and Taxon B have been characterized genetically and ecologically. We have backcrossed the Taxon B carrying larger seed size with Japonica type cultivated rice, Taichung 65 (T65). BC4F1 seeds [...] Read more.

There are a few wild species belonging to genus Oryza in Australia. Taxon A and Taxon B have been characterized genetically and ecologically. We have backcrossed the Taxon B carrying larger seed size with Japonica type cultivated rice, Taichung 65 (T65). BC4F1 seeds selected the seed size of BC4F2 showed that Taxon B type subgroup carries 21.5% larger seeds size than T65. The heterozygous group showed incomplete dominance in seed size. Introgressed segments suggested that the causal gene could be a single and located on chromosome 3. By using BC4F2, we characterized agronomical traits to show how the large seed size gene affects to yield. The larger seed size did not show any correlation to number of panicles and panicle length. However, it affected negative effect on number of spikelets. It is explained as Trade-off relation. The negative effect will be resolved to introduce genetic factor related to number of tillers or spikelets per panicle, or they may be tried improved ways of cultivation. The seed size is attractive to improve new varieties as “Australian native rice” to be adopted with a variety of cooking style which prefer large grain size or a variety of application of the size. Japanese Sake is another way because it generally requires larger grain size to expect white core. We are generating pure lines carrying only the gene involving to the seed size with other negative traits for cultivation. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Light Relation in Intensive Mango Orchards

by Kare Mahmud, Paula Ibell, Carole Wright, Zac Scobell, John Wilkie and Ian Bally

Proceedings 2019, 36(1), 122; https://doi.org/10.3390/proceedings2019036122 - 8 Mar 2020

Cited by 1 | Viewed by 1369

Abstract

The amount of light intercepted by a tree and its distribution within the canopy is critical in optimizing tree photosynthesis efficiency, carbon partitioning and productivity. Here we compare light relations in experimental high-density mango orchard systems with current commercial orchards. A baseline study [...] Read more.

The amount of light intercepted by a tree and its distribution within the canopy is critical in optimizing tree photosynthesis efficiency, carbon partitioning and productivity. Here we compare light relations in experimental high-density mango orchard systems with current commercial orchards. A baseline study of current commercial mango orchards showed a maximum light interception of approximately 67% was reached in trees aged between 26-31 years old, with canopy volume of approximately 15,187 m³/ha. Light interception did not significantly increase beyond 67% regardless of increase in canopy volume per hectare or the increase in orchard age. In these conventional orchards, maximum yields were reached approximately 16 t/ha when light interception was around 49% and as light interception increased above 49%, yields declined. In the high density orchard systems, light interception increased with canopy volume, with high density systems intercepting more available light than medium and low density orchard systems. In 5 year old high-density, espalier trained trees with approximately 5000 m³/ha canopy volume, yields reached close to 50 t/ha at 40% light interception. Trees trained as single leader or espalier had more evenly distributed light in the inner canopy compared to conventionally closed vase trained trees. in current commercial orchards, increasing the canopy volume and light interception above the maximums noted above had no benefit to increase economic returns whereas in high density mango orchards with alternate tree training, yields increases more than four times early in the orchards development. Further productivity gains are likely as the experimental high density have yet to fill their allocated space in the orchard. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 118 KiB

Open AccessAbstract

Advancing Brewing Science

by Birgitte Skadhauge

Proceedings 2019, 36(1), 123; https://doi.org/10.3390/proceedings2019036123 - 8 Mar 2020

Viewed by 1056

Abstract

Cereals were some of the first crops to be domesticated by humans. Today, cereals represent the biggest starch source in the world and are the primary raw material for food and feed. Modern breeding techniques produced high yielding varieties, but were based on [...] Read more.

Cereals were some of the first crops to be domesticated by humans. Today, cereals represent the biggest starch source in the world and are the primary raw material for food and feed. Modern breeding techniques produced high yielding varieties, but were based on a limited genetic background, which resulted in significant loss of genetic diversity. This could potentially result in major challenges due to recent climate changes and altered growing conditions. It is estimated that an increased global temperature will lead to dramatic loss in plant productivity in many parts of the world. The barley breeding effort of the Carlsberg Research Laboratory combines decades of expertise to provide new varieties with unique quality and sustainability traits such as drought tolerance. Combining traditional breeding, genome data and a new method for screening genetics variants, we have radically shortened the development time of varieties with new traits. This has already resulted in the identification of several hundred genetic variants related to climate adaptation, sustainability, productivity and brewing quality. This accelerated approach can easily be applied for the development of other crops in both developing and matured markets around the globe, and help securing a sustainable supply of food and other agricultural products. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 154 KiB

Open AccessAbstract

Comparison of Antioxidant Properties of Coconut Testa Flour of Selected Local Coconut Cultivars of Sri Lanka

by Sanjila Marasinghe, Nazrin Marikkar, Swarna Wimalasiri, Lalith Jayasinghe and Ruvini Liyanage

Proceedings 2019, 36(1), 124; https://doi.org/10.3390/proceedings2019036124 - 14 Mar 2020

Viewed by 1562

Abstract

Coconut testa is the thin brown colored outer skin of coconut endosperm. It is often peeled off from the kernel during coconut processing due to unfavorable brown colour it might impart on finished products. An attempt was made to utilize coconut testa to [...] Read more.

Coconut testa is the thin brown colored outer skin of coconut endosperm. It is often peeled off from the kernel during coconut processing due to unfavorable brown colour it might impart on finished products. An attempt was made to utilize coconut testa to produce defatted flour as a substitute for wheat flour in bakery products. Aim of this study was to compare the total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) of coconut testa flour of four local cultivars namely san raman (SR), gon thembili (GT), ran thembili (RT), TallxTall (TxT) against the commercial hybrid (COM) grown in Sri Lanka. Hundred grams of coconut testa flour produced from partially defatted coconut pairings was extracted with 70% ethanol-water mixture. The TPC and FRAP assays were conducted using a 96 well micro plate reader. Percentage yield (%) of crude extracts of SR, RT, GT, TXT and COM were 8.26, 6.87, 7.66, 8.06 and 11.17, respectively. The maximum TPC content was observed in TXT (62.58 ± 5.99 mg GAE/g of extract) while the minimum TPC content was recorded for GT (27.53 ± 4.54 mg GAE/g of extract). The lowest FRAP value was observed for SR (0.26 ± 0.02 mmol FeSO₄/g of extract) while the highest FRAP value was observed for COM (0.67 ± 0.00 mmol FeSO₄/g of extract) variety. In conclusion, coconut testa flour is a rich source of phenolics and antioxidants. The presence of these bioactives would make it a potential functional ingredient in food processing industry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 139 KiB

Open AccessAbstract

Women Empowerment and Poverty Reduction in Rural Okara, Punjab Pakistan

by Iqbal Uzma, Sandra Heaney-Mustafa and Mukaddas Afzal

Proceedings 2019, 36(1), 125; https://doi.org/10.3390/proceedings2019036125 - 15 Mar 2020

Viewed by 772

Abstract

In Pakistan, women have limited access to credit, property, education, skill, paid job and land. There are many hindrances in women empowerment in rural such as socio-economic and cultural values, norms, patriarchal structure of society. Research was planned to analyze different determinants of [...] Read more.

In Pakistan, women have limited access to credit, property, education, skill, paid job and land. There are many hindrances in women empowerment in rural such as socio-economic and cultural values, norms, patriarchal structure of society. Research was planned to analyze different determinants of empowerment of rural women for poverty reduction in agrarian communities by taking the case study of rural Okara, Pakistan. Multistage random sampling technique was used for data collection at different stages. Okara was selected through simple random sampling technique and four union councils and then eight villages were selected randomly. Twenty-five from each village were selected through convenient sampling thereby making total sample size of 200 women. Most important finding of the study that the households where women have higher decision making authority are better-off and in other words women empowerment is likely to reduce poverty and increase wellbeing. The results also revealed significantly positive relationship between women age, education, decision making authority and paid work involvement with empowerment and poverty reduction. It is also concluded that education is the most important factor in empowerment but majority (64.5%) of respondents had only up to 5 years’ education. Respondents had very limited decision making authority and control over economic resources mostly significant and important decisions and resources are controlled by the male members. Though rural women have great contribution in poverty reduction but majority of them were facing the problems of low education, wages, less control over resources, freedom of mobility and lack of decision making authority Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Milk Delivery in Tropically-Adapted Neonatal Beef Calves

by Jarud Muller, Luis Prada e Silva and Geoffry Fordyce

Proceedings 2019, 36(1), 126; https://doi.org/10.3390/proceedings2019036126 - 16 Mar 2020

Cited by 2 | Viewed by 1286

Abstract

Across beef breeding herds of northern Australia, poor pre-partum nutrition of cows is consistently associated with increased calf wastage between confirmed pregnancy and weaning. With key nutrients at play (especially energy, protein, phosphorus and water) also being associated with milk yields, a specific [...] Read more.

Across beef breeding herds of northern Australia, poor pre-partum nutrition of cows is consistently associated with increased calf wastage between confirmed pregnancy and weaning. With key nutrients at play (especially energy, protein, phosphorus and water) also being associated with milk yields, a specific problem mediating calf mortality is likely to be low milk production and delivery during the highest-mortality-risk period that is the first week after birth. Recent research demonstrated that milk-deprived newborn calves die of dehydration within 1–3 days. Newborn Brahman and tropical composite calves across three grazing herds (n = 75) and two penned herds (n = 106) were investigated. Calf milk uptake during the first 1–2 days of life was measured by plasma immunoglobulin (IgG) levels and overall milk uptake and health during the first two weeks of life was measured by growth rate from birth. Grazing calves with average IgG levels of 2247, 2508, and 2656 mg/100 mL had respective average growth rates of 0.5, 1.0, and 1.4 kg/d. Penned calves with average IgG levels of 2064, 2498 and 2504 mg/100 mL had respective average growth rates of 0.6, 1.0, and 1.4 kg/d. The association between calf immunoglobulin uptake and initial growth demonstrates individual variation between tropical beef calves for early milk uptake and that risk factors limiting milk delivery in the first days of life would place calves at greater risk of poor health and mortality. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 185 KiB

Open AccessAbstract

Photosensitization, a Green Treatment for the Inactivation of Aspergillus Flavus in Peanuts Mediated by Curcumin

by Nalukui Mukubesa, Hung T. Hong, Maral Seidi Damyeh and Yasmina Sultanbawa

Proceedings 2019, 36(1), 127; https://doi.org/10.3390/proceedings2019036127 - 16 Mar 2020

Viewed by 1424

Abstract

The aim of this study was to investigate the efficiency of curcumin-based photosensitization (CUR-PS) in inactivating Aspergillus flavus spores and in turn reducing the aflatoxin B1 production and extending the shelf-life of raw peanuts. The inoculated peanuts with A. flavus spores were illuminated [...] Read more.

The aim of this study was to investigate the efficiency of curcumin-based photosensitization (CUR-PS) in inactivating Aspergillus flavus spores and in turn reducing the aflatoxin B1 production and extending the shelf-life of raw peanuts. The inoculated peanuts with A. flavus spores were illuminated for 15 min at 420 nm (Xenon Arc light source) using three different curcumin concentrations of 50, 75, and 100 μM. The highest reduction in A. flavus spores on peanuts (1.7 log CFU) was obtained by 50 μM curcumin (p > 0.05). Interestingly, shelf life of treated peanuts with 75 μM curcumin was extended by 7 days. In order to evaluate the influence of CUR-PS treatment on aflatoxin B1 generation, treated and untreated peanuts were analysed after 20 days of storage 25 °C. Results showed that the average level of aflatoxin B1 in untreated (control) peanuts was 800 mg/kg, while light treatment of peanuts reduced the aflatoxin production to the level of 296 mg/kg. A significant reduction in aflatoxin production was observed in curcumin (75 μM) treated peanuts, where 38.3 and 41.1 mg/kg aflatoxin were detected in illuminated and not-illuminated peanuts, respectively. Moreover, 59.2 and 58.1 mg/kg aflatoxin were detected in CUR-PS treated peanuts with 50 and 100 μM curcumin, respectively. However, not illuminating curcumin treated peanuts with 50 and 100 μM showed higher levels of aflatoxin, 108.8 and 105.3 mg/kg, respectively (p > 0.05). This study demonstrated the efficiency of CUR-PS treatment as a safe and green technology to control fungal growth and mycotoxin production in agro-food sector. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 123 KiB

Open AccessAbstract

Maximising Reproduction under Extensive Grazing Conditions, Regardless of Rainfall

by Kylie Schooley

Proceedings 2019, 36(1), 129; https://doi.org/10.3390/proceedings2019036129 - 18 Mar 2020

Viewed by 982

Abstract

Maximising reproduction in beef cows under normal grazing conditions takes planning, discipline and a firm belief in science. The things that hinder producers in this arena are the extreme variations in weather conditions, subjective beliefs, tradition and paradigms. What producers need to use [...] Read more.

Maximising reproduction in beef cows under normal grazing conditions takes planning, discipline and a firm belief in science. The things that hinder producers in this arena are the extreme variations in weather conditions, subjective beliefs, tradition and paradigms. What producers need to use to maximise Kg produced per hectare year in year out is objective measurement, benchmarking and solid adherence to science. The confounding factors that make this difficult are the vast array of variables which impact on cattle production. At Rocky Springs we endeavor to simplify these variables into a few objective measures, clearly defined trigger points and a very solid year around calendar of main events on farm. This translates into ground cover assessments at key seasonal points, condition score assessments of cows during lactation, pregnancy testing with foetal aging, weight recording and condition assessments at weaning. Nutritional manipulation where needed. We always protect the feed base first, then breeder cow condition with a specific target of a condition score of 3.5 at calving to ensure strong mothering behavior and good quality colostrum. This is done with manipulation of stocking rate, early reductions in stock numbers if rainfall is poor and strict adherence to management calendar, regardless of rainfall. We always have trigger dates and live by them, if things get tough, responding early is most important for the bottom line. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 134 KiB

Open AccessAbstract

Proteomics as a Potential Tool for Identifying Biomarkers for Host Resistance to Cattle Tick

by Ali Raza, Peter James and Ala Tabor

Proceedings 2019, 36(1), 131; https://doi.org/10.3390/proceedings2019036131 - 21 Mar 2020

Viewed by 1434

Abstract

The cattle tick, Rhiphicephalus microplus, and the diseases it transmits lead to massive economic losses to cattle industries in tropical and subtropical countries. The emergence of widespread resistance to acaricide drugs and the absence of an effective vaccine for tick control had [...] Read more.

The cattle tick, Rhiphicephalus microplus, and the diseases it transmits lead to massive economic losses to cattle industries in tropical and subtropical countries. The emergence of widespread resistance to acaricide drugs and the absence of an effective vaccine for tick control had led to genetic selection of host resistance as a method of choice for non-chemical control of cattle tick. Research to identify host genetic markers associated with tick susceptibility or resistance has been limited to the comparison of local breeds in specific geographic regions. Previous studies have also focused on gene expression profiles, localizing cellular and humoral immune responses, and genome-wide association studies (GWAS) to identify functional genetic variants associated with tick resistance/susceptibility. Given the fact that gene expression results and actual dynamics occurring at the protein level often do not correlate due to post-transcriptional, post-translational and degradation regulation, host proteomics may provide reliable biomarkers to assist in selection to support traditional breeding programs. The present study aims to investigate the variation in protein profiles among tick resistant and susceptible cattle following tick infestation. Preliminary findings suggest that different serum proteins exist between tick resistant and susceptible Santa Gertrudis cattle. This research is supported by Meat & Livestock Australia. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 142 KiB

Open AccessAbstract

Increasing Heat Tolerance in Wheat to Counteract Recent and Projected Increases in Heat Stress

by Najeeb Ullah, Behnam Ababaei and Karine Chenu

Proceedings 2019, 36(1), 132; https://doi.org/10.3390/proceedings2019036132 - 28 Mar 2020

Cited by 4 | Viewed by 1202

Abstract

The frequency of heat shocks during grain filling of wheat crops across the Australian wheatbelt has significantly increased over the last 30 years. These post-flowering heat events significantly reduce wheat yields with a relatively greater impact on grain size than grain number. A [...] Read more.

The frequency of heat shocks during grain filling of wheat crops across the Australian wheatbelt has significantly increased over the last 30 years. These post-flowering heat events significantly reduce wheat yields with a relatively greater impact on grain size than grain number. A controlled environment study was conducted to assess the impact of post-flowering heat shocks on wheat recombinant inbred lines SB062 and SB003. Plants were submitted to 7-day heat shocks (33/21 °C day/night temperature) at different periods during grain filling. Heat shocks significantly accelerated leaf senescence, with a greater impact on older leaves and for mid post-flowering stresses. Overall, the tolerant line (SB062) could maintain leaf greenness longer than the sensitive line (SB003), especially when submitted to heat stress. Further, heat shocks during early-to-mid grain filling reduced the grain size and weight. While the impact on developing grains was significant in SB003, no significant effect of post-flowering heat was observed on leaf senescence nor on grain size in the tolerant line SB062. Delayed leaf senescence appeared to play a role in maintaining grain size under heat stress. The research findings will assist improving crop models for post-flowering heat effects and developing techniques for screening heat tolerant wheat lines. Increased post-flowering assimilate production through sustained leaf greenness could improve the performance of wheat crops in increasingly warmer environments. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 115 KiB

Open AccessAbstract

Northern Beef Industry Emerging Market, Supply Chain Gap Analysis & Sector Capacity Baseline Study

by Chris Chilcott

Proceedings 2019, 36(1), 133; https://doi.org/10.3390/proceedings2019036133 - 29 Mar 2020

Viewed by 1162

Abstract

With an ongoing interest in developing northern Australia, we undertook a beef situation analysis to assist the Cooperative Research Centre for Developing Northern Australian in tailoring their investment decisions. The northern beef industry is dominated by rangeland enterprises that include family farms, indigenous [...] Read more.

With an ongoing interest in developing northern Australia, we undertook a beef situation analysis to assist the Cooperative Research Centre for Developing Northern Australian in tailoring their investment decisions. The northern beef industry is dominated by rangeland enterprises that include family farms, indigenous pastoral enterprises and large corporate interests. The analysis was a whole of supply chain examination of current practices, strategies and plans. It included consultation with producers, industry groups, research organisations and government departments. The competitive advantages of the northern beef industry are its adapted production systems, low cost base and geographic positioning that allows it to take advantage of south-east Asian markets. However, the inherent low productivity, high capital costs and over reliance on a small number of markets make it vulnerable to market shocks. We found that the industry faces challenges in maintaining profitability and the ability to translate research to practice to enhance productivity its social license to operate. The review makes recommendation under four themes: There is an ongoing need for research and develop for profitability and productivity gains for the top businesses; There is a need to improve the translation of proven R and D to farm practice for the majority of the northern Australian beef industry; There is a need to support and develop business cases for economic enabling infrastructure to allow the northern Australian beef industry to remain competitive and intensify production, and; There remains some regulatory reform and derisking required to support investment in the industry and allow diversification. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 164 KiB

Open AccessAbstract

Transcriptomics Analysis for the Detection of Novel Drought Tolerance Genes in Jojoba (Simmondsia Chinensis)

by Othman Al-Dossary, Ardashir Kharabian, Ibrahim Al-Mssallem, Agnelo Furtado and Robert Henry

Proceedings 2019, 36(1), 135; https://doi.org/10.3390/proceedings2019036135 - 30 Mar 2020

Viewed by 1387

Abstract

Jojoba (Simmondsia Chinensis) is a perennial stress tolerant desert shrub that has oil containing seeds and inhabits the Sonoran desert in the southwest of the United States and northwest Mexico. It has attracted a growing worldwide interest for multi-purpose uses. However, the most [...] Read more.

Jojoba (Simmondsia Chinensis) is a perennial stress tolerant desert shrub that has oil containing seeds and inhabits the Sonoran desert in the southwest of the United States and northwest Mexico. It has attracted a growing worldwide interest for multi-purpose uses. However, the most attractive characteristics of Jojoba are the richness of the oil content of the seed and the superior stress tolerance of the plant. Little has been done towards Jojoba genetic improvement. The exploration of jojoba genetic resources will define a molecular and biochemical fingerprint for jojoba and will aid sustainable crop commercialisation define. In this research, we aim to establish a reference genome database for Jojoba, which will help to facilitate crop improvement. Besides, the contribution to reveal the molecular background of its outstanding drought tolerance using transcriptional profiling during a water stress. RNA sequencing will be performed for samples collected under moderate and severe stress. The genetic database of jojoba will help to reveal the genetic mechanism of response and identify the genes responsible for the drought tolerant phenotype of this crop. Application of this knowledge will support the researchers, farmers, and the Jojoba industry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Blood Phosphorus Concentration as an Indicator of Phosphorus Deficiency in Growing Cattle

by Rob Dixon, Stephen Anderson, Lisa Kidd and Mary Fletcher

Proceedings 2019, 36(1), 136; https://doi.org/10.3390/proceedings2019036136 - 1 Apr 2020

Viewed by 1039

Abstract

Inadequate intakes of phosphorus (P) by cattle can cause P deficiency and severely reduce productivity. Blood inorganic P concentration (Pi) is often used as an indicator of P deficiency. Results from two experiments (E1 and E2) with young cattle grazing tropical P-deficient rainy [...] Read more.

Inadequate intakes of phosphorus (P) by cattle can cause P deficiency and severely reduce productivity. Blood inorganic P concentration (Pi) is often used as an indicator of P deficiency. Results from two experiments (E1 and E2) with young cattle grazing tropical P-deficient rainy season pastures without or with additional P, or fed in pens on higher energy pelleted diets ranging in P concentration (E3), were used to examine the relationships between Pi and liveweight (LW) gain. When Pi was >2.0 mmol/L average LW gains were 0.71, 0.85 and 1.04 kg/day in E1, E2 and E3, respectively. These differences between experiments were most likely associated with diet limitations other than P. LW gain was related curvilinearly in E1 and E2, and linearly in E3, with Pi. The Pi ranged from ca. 1.0 mmol/L through to 2.5–3.0 mmol/L in each experiment. The reductions in LW gains from the maximum at Pi > 2.0 mmol/L for several lower Pi concentrations were calculated from these relationships. At Pi = 1.0 mmol/L the LW gains were 36–60% of the maximum, at Pi = 1.5 mmol/L LW gains were 59–84% of the maximum, and at Pi = 2.0 mmol/L the LW gains were 82–98% of the maximum. The reductions in LW gain at each Pi were substantially greater for E3 than for E1 and E2. It is concluded that the Pi threshold indicative of P deficiency varies with the diet quality and that the threshold values are substantially higher with higher diet quality. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 149 KiB

Open AccessAbstract

Adaptive and Productive Sheep Breed for Changing Climate

by Surinder S. Chauhan, Minghao Zhang, Aleena Joy, Richard Osei-Amponsah, Brian J. Leury, Robyn D. Warner, Iain J. Clarke and Frank R. Dunshea

Proceedings 2019, 36(1), 137; https://doi.org/10.3390/proceedings2019036137 - 1 Apr 2020

Viewed by 1192

Abstract

Sheep in semi-arid environments are likely to be affected by warming environment due to climate change. To identify genotypes best suited to warmer climates we assessed thermotolerance and meat quality of 5 female sheep of each of 4 breeds (Merino, Wiltshire, Dorper, and [...] Read more.

Sheep in semi-arid environments are likely to be affected by warming environment due to climate change. To identify genotypes best suited to warmer climates we assessed thermotolerance and meat quality of 5 female sheep of each of 4 breeds (Merino, Wiltshire, Dorper, and Southdown) under simulated summer conditions. The sheep were housed in metabolic crates within climate-controlled rooms and were exposed to thermo-neutral (TN; 18–21 °C and 40–50% relative humidity) or cyclic heat stress (HS; 28–40 °C and 30–40% RH) conditions for two weeks. Physiological responses were recorded 3 times daily, and brown fat tissue temperature was measured by data loggers inserted into the brisket. Sheep were slaughtered at an abattoir as per standard commercial procedure and samples obtained for carcass and meat quality attributes. When exposed to HS, Dorpers and Merinos exhibited lower respiration rate (151, 142 breaths/min, respectively) and rectal temperature (39.39, 39.32 °C, respectively) (P < 0.05) than Southdowns (192 breaths/min, 40.05 °C) and Wiltshires (200 breaths/min, 39.91 °C). Dorper and Wiltshire (n = 3) showed lowest sternal fat temperatures during HS indicating inherent differences in thermogenesis. HS had significant effect (P < 0.05) on post mortem muscle pH decline which was slower than TN sheep, except in Dorper again indicating better thermotolerance. There were significant (P = 0.03) breed effects on meat cooking loss % such that Southdown showed minimum cooking loss (17%) while Merino showed the greatest loss (24%). These results suggest that there are genetic (breed) differences in thermotolerance and meat quality of sheep, providing an opportunity to select best sheep suited to a warming climate. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 138 KiB

Open AccessAbstract

Shining a Light on Haemonchus contortus in Sheep

by Elise Kho, Jill Fernandes, Andrew Kotze, Maggy Lord, Glen Fox, Anne Beasley, Stephen Moore and Peter James

Proceedings 2019, 36(1), 138; https://doi.org/10.3390/proceedings2019036138 - 2 Apr 2020

Viewed by 1258

Abstract

Heavy infestations of the Barber’s pole worm, Haemonchus contortus, can cause severe wasting, morbidity and mortality in animals if not promptly treated. The current detection methods for this blood-sucking parasite involve faecal worm egg counts and diagnosis of anaemia, both of which [...] Read more.

Heavy infestations of the Barber’s pole worm, Haemonchus contortus, can cause severe wasting, morbidity and mortality in animals if not promptly treated. The current detection methods for this blood-sucking parasite involve faecal worm egg counts and diagnosis of anaemia, both of which are time consuming and require expertise. As blood is detected in sheep faeces sooner during infection than worm eggs, quantitative evaluation of blood may serve as a sensitive indicator of H. contortus infection. Here we investigated the feasibility of rapid estimation of haemoglobin (Hb) in sheep faeces using visible near-infrared spectroscopy. Haemoglobin (Hb) was assessed at various concentrations in moist sheep faeces using portable visible near-infrared (vis-NIR) spectrometers. Calibration models were developed for the region of 400–600 nm, where Hb absorption bands can be found. Within this wavelength region, Hb in sheep faeces can be estimated with minimal interference from background moisture (970 nm) or chlorophyll (670 nm), suggesting that difference in diets in sheep will have minimal effect on prediction accuracy. Predictions for sheep faeces based on a drenching threshold of 3 µg Hb/mg faeces showed high levels of accuracy with minimal sample preparation (Sensitivity = 89%, specificity = 80%). The success in detecting Hb in sheep faeces indicates the potential of vis-NIR spectroscopy as a rapid, on-farm diagnostic method for predicting blood in sheep faeces, and timing treatment of H. contortus infections. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 139 KiB

Open AccessAbstract

Demand Driven Common Bean Variety Development and Promotion for Enhanced Productivity and Production

by Berhanu Amsalu Fenta, Kassay Negash, Kidane Tumssa, Tigist Shiferaw, Dagmawit Tsegaye, Rubyogo Jean Claude and Clare Mugisha Mukankusi

Proceedings 2019, 36(1), 139; https://doi.org/10.3390/proceedings2019036139 - 2 Apr 2020

Cited by 1 | Viewed by 1191

Abstract

Common bean research program of Ethiopia aimed at development of demanded variety for enhanced adoption, improve food and nutrition security as well as to boost income of smallholder farmers thereby enhancing foreign earnings of the country. To achieve these aim, the breeding program [...] Read more.

Common bean research program of Ethiopia aimed at development of demanded variety for enhanced adoption, improve food and nutrition security as well as to boost income of smallholder farmers thereby enhancing foreign earnings of the country. To achieve these aim, the breeding program use different strategies. These incudes, importing demanded variety and fast-track testing release, introducing bean germplasm and release stable variety and participatory variety selection for incorporating growers traits on variety selection. Accordingly, bean improvement program selected six major bean products that includes, small/large white beans, speckled bean, small/large reds and mottled beans. During variety selection stakeholders’ choice and trait of preference has been incorporated during interactive consultative forums of the value chain actor at bean innovation multi-stakeholder platform. Apart from bean variety development, integrated crop management technologies has been developed to implement good agricultural practice. To facilitate common variety adoption, bean seed system have been enhanced through integration of early generation seed production with formal and informal seed production of public and private seed producers. These efforts has enhanced transformed productivity from 0.7 to 1.5 t/ha and area expanded from 150,000 ha to 520,121 ha and total production up to 568,243 t. Due to this fact bean export has been increased up to 100–150 million USD per annum. Generally, the demand led breeding and value chain approach, synergetic and innovative technology generation and promotion has transformed bean productivity, area produced and market; consecutively livelihood of growers and income of the country has been enhanced. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 116 KiB

Open AccessAbstract

Wxlv, the Ancestral Allele of Rice Waxy Gene

by Changquan Zhang, Jihui Zhu, Shengjie Chen and Qiaoquan Liu

Proceedings 2019, 36(1), 140; https://doi.org/10.3390/proceedings2019036140 - 2 Apr 2020

Cited by 4 | Viewed by 1477

Abstract

In rice endosperms, the Waxy (Wx) gene is important for amylose synthesis, and various Wx alleles control the amylose content and affect the taste of cooked rice. Herein, we report the cloning of the ancestral allele Wx^lv of the Wx [...] Read more.

In rice endosperms, the Waxy (Wx) gene is important for amylose synthesis, and various Wx alleles control the amylose content and affect the taste of cooked rice. Herein, we report the cloning of the ancestral allele Wx^lv of the Wx locus, which affects the mouthfeel of rice grains by modulating the size of amylose molecules. Using evolutionary analysis, we demonstrated that Wx^lv originated directly from wild rice, and the three major Wx alleles in cultivated rice (Wx^b, Wx^a, and Wxⁱⁿ) differentiated after the substitution of one base pair at the functional sites. These data indicate that the Wx^lv allele played an important role in artificial selection and domestication. The findings also shed light on the evolution of various Wx alleles, which have greatly contributed to improving the eating and cooking quality of rice. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 166 KiB

Open AccessAbstract

Estimating Soil Organic Carbon Under Different Land-Use Types in Australia’s Northern Grains Region Using Mid-Infrared Spectroscopy

by Alwyn Williams, Ryan Farquharson, David Lawrence, Jeff Baldock and Mike Bell

Proceedings 2019, 36(1), 141; https://doi.org/10.3390/proceedings2019036141 - 3 Apr 2020

Viewed by 1398

Abstract

Land-use type is known to affect levels of soil organic carbon (SOC). However, the degree to which SOC is affected by land-use type over the short—(<10-years) and long—(≥10-years) term remains relatively uncertain. Moreover, there is limited data on the distribution of SOC across [...] Read more.

Land-use type is known to affect levels of soil organic carbon (SOC). However, the degree to which SOC is affected by land-use type over the short—(<10-years) and long—(≥10-years) term remains relatively uncertain. Moreover, there is limited data on the distribution of SOC across particulate (POC), humus (HOC) and resistant (ROC) fractions, and the responses of these fractions to land-use. Using mid-infrared spectroscopy (MIR) coupled with partial least squares regression (PLSR) algorithms generated from the Australian Soil Carbon Research Program (SCaRP), soil organic carbon (TOC, POC, HOC and ROC) was estimated across 280 paired samples across Australia’s Northern Grains Regions. Our analysis covered five land-use types: remnant native vegetation, long-term pasture (≥10-years), short-term pasture (<10-years), short-term cropping (<10-years) and long-term cropping (≥10-years). All land-use types except long-term pasture generated significant declines across all SOC fractions compared with native vegetation. Long-term cropping resulted in the greatest declines, with an average decrease of 6.25 g TOC/kg soil relative to native vegetation. Long-term cropping also reduced POC (−0.71 g/kg) and HOC (−3.19 g/kg) below that of short-term cropping. In addition, the ROC fraction responded to land-use type, with native vegetation and long-term pasture maintaining greater ROC compared with other land-use types. The results demonstrate substantial reductions across all SOC fractions with long-term cropping. The ability of long-term pastures to maintain levels of SOC similar to that of native vegetation indicates the importance of limiting soil disturbance and maintaining more continuous living plant cover within cropping systems. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 134 KiB

Open AccessAbstract

Agroforestry Suitability Mapping for the Northwest Provinces of Vietnam

by Quyet Manh Vu and Tri Dan Nguyen

Proceedings 2019, 36(1), 142; https://doi.org/10.3390/proceedings2019036142 - 3 Apr 2020

Viewed by 1280

Abstract

This study aims to assess the potential development of selected agroforestry options for three provinces in the Northwest of Vietnam. Available spatial data including Land use/land cover maps and forest inventory maps were used as the base maps in combination with supplementary data [...] Read more.

This study aims to assess the potential development of selected agroforestry options for three provinces in the Northwest of Vietnam. Available spatial data including Land use/land cover maps and forest inventory maps were used as the base maps in combination with supplementary data and field survey to determine the potential agroforestry areas. Soil types, soil depth, soil texture, elevation, slope, temperature and rainfall were used to evaluate the biophysical suitability of ten typical agroforestry options in the study region. For assessing the impact of climate change to agroforestry suitability in the future, temperature and precipitation data extracted from two climate changes scenarios (Representative Concentration Pathway 4.5 and 8.5 in 2046–2065) were used. The results showed that the suitable areas for agroforestry development in Dien Bien, Sơn La and Yen Bai provinces were 267.74.01 ha, 405,597.96 ha; and 297,995.55 ha, respectively. Changes in temperature and precipitation by 2 climate change scenarios affected significantly to the suitability of Docynia indica + livestock grass, Teak + plum + coffee + grass and Plum + maize + livestock grass options. The map of agroforestry suitability can be served as a useful source in developing and expanding the area of agroforestry in the target provinces, and can be applied for other provinces in the same region in Vietnam. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Grain Oats—An Alternative Winter Cereal for the Australian Sub-Tropics?

by Bruce Winter and Richard Uebergang

Proceedings 2019, 36(1), 143; https://doi.org/10.3390/proceedings2019036143 - 3 Apr 2020

Viewed by 978

Abstract

Current production of oats for grain in Queensland is minor due to unsuitable varieties bred for different climates, and high disease pressure from leaf and stem rust late in the growing season. A range of grain oat breeding lines developed by the Federal [...] Read more.

Current production of oats for grain in Queensland is minor due to unsuitable varieties bred for different climates, and high disease pressure from leaf and stem rust late in the growing season. A range of grain oat breeding lines developed by the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, was screened for leaf rust resistance and subsequently identified as potential grain oat cultivars for sub-tropical Queensland. The evaluation of these grain oat lines from Brazil may provide an opportunity to re-establish oats as a winter grain crop in central and southern Qld and northern NSW. Two replicated trials were established near Toowoomba in Qld and Grafton in NSW to assess grain yield and agronomic characteristics. These trials showed significant differences in grain yield within the set of Brazilian grain oat lines, compared with the Australian cultivars, showing the potential for selection of higher yielding lines. The Brazilian line coded UFRGS037031-3 was the highest yielding line in both high yielding conditions at Grafton and moisture stressed conditions at Wellcamp, and should be the focus of any further evaluation. The Brazilian grain oat lines have very strong resistance to leaf rust compared with Australian cultivars. Further research is needed to determine the potential demand for grain oats as a feed grain in Queensland and to determine the profitability of grain oats to farmers as an alternative winter cereal. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 162 KiB

Open AccessAbstract

Effects of Fresh and Saline Water Irrigation for Maize in Coastal Areas of Bangladesh

by Khokan Kumer Sarker, SK Shamshul Alam Kamar, Md. Anower Hossain, Mohammed Mainuddin, Richard Bell, Ed Graham Barrett-Lennard, Donald Gaydon, Mark Glover, Md. Harunor Rashid, Md Shahidul Islam Khan, Md Moniruzzaman, Md Belal Hossain and Bidhan Chandro Sarker

Proceedings 2019, 36(1), 144; https://doi.org/10.3390/proceedings2019036144 - 4 Apr 2020

Viewed by 1451

Abstract

Farmers are being encouraged to represent the conjunctive use of fresh water (FW) and saline water (SW) irrigation for the future agriculture in the coastal saline prone areas of Bangladesh where the scarcity of FW. Therefore, the effects of fresh and saline water [...] Read more.

Farmers are being encouraged to represent the conjunctive use of fresh water (FW) and saline water (SW) irrigation for the future agriculture in the coastal saline prone areas of Bangladesh where the scarcity of FW. Therefore, the effects of fresh and saline water irrigation for maize was performed on the crop performances, water use, water productivity (WP), soil salinity and scope for maize cultivation in coastal areas. The experiment was carried out at farmers’ field at two locations with six irrigation treatments and replicated thrice during 2016–2017 and 2017–2018. Results showed that the effect of FW (0.5 ≤ salinity ≤ 1.5 dS/m) at early growth stages and SW (1.5 ≤ salinity ≤ 5 dS/m) at later growth stages had insignificant difference compared to the treatment of FW irrigation. Yield slightly increased with increased number of irrigations but there was no significant differences among the treatment. WP significantly affected by irrigation frequency in both locations, decreasing greatly with increasing amount. The more changes in soil water occurred at upper layer than lower depth of soil profiles. The highest changes soil salinity (EC_e) occurred at mid-February of the crop growing season compared to the beginning and later growth stages of maize in 60 cm soil profiles. The technique of fresh and saline water irrigation at different growth stages of maize in coastal regions could be an alternative irrigation scheduled and method for increasing yield and WP through establishment of maize compared to no crops at fallow lands during rabi (dry) season in the salt affected areas of Bangladesh. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 150 KiB

Open AccessAbstract

Effect of Straw Mulch and Irrigation on Sunflower and Maize Cultivation in No Tillage Systems of Coastal Heavy Soils

by Khokan Kumer Sarker, SK Shamshul Alam Kamar, Md. Anower Hossain, Mohammad Mainuddin, Richard W. Bell, Ed. Graham Barrett-Lennard, Donald Gaydon, Mark Glover, Rina Rani Saha, Md Harunor Rashid, Md Shahidul Islam Khan, Priya Lal Chandra Paul and Md Enamul Kabir

Proceedings 2019, 36(1), 145; https://doi.org/10.3390/proceedings2019036145 - 4 Apr 2020

Cited by 1 | Viewed by 1591

Abstract

Three constraints affect the growth of crops in the Rabi (dry) season in southern Bangladesh: these are the clay nature of the soils which decreases the infiltration of water, the conserving of soil moisture with the increasingly dry conditions and the accumulation of [...] Read more.

Three constraints affect the growth of crops in the Rabi (dry) season in southern Bangladesh: these are the clay nature of the soils which decreases the infiltration of water, the conserving of soil moisture with the increasingly dry conditions and the accumulation of salts on the soil surface through capillary from saline groundwater. Field experiments were conducted in the salt-affected areas of southern Bangladesh. The objectives of the study were to: (i) evaluate the effect of straw and irrigation frequency on crop growth and yield in maize and sunflower, and (ii) determine the combined effect of straw and irrigation frequency on the salinity, osmotic potential and moisture of soils. The experiment was carried out in farmers’ fields with eight treatments and was replicated three times during the dry (rabi) season of 2018–2019. There were two rice straw treatments (with or without straw), and 4 irrigation frequencies (at intervals of 5–7,10–12,15–17 or 20–25 days). Maize and sunflower seeds were sown by dibbling in no-tilled systems. The results showed that rice straw significantly affected the crop growth and yield, increasing the yield of maize and sunflower by 22% and 4.3% compared to treatments of without residue. The irrigation treatments also significantly affected crop yields. There was no interaction between straw levels and irrigation. The causes of these effects appeared to be improved water relations: rice straw and more frequent irrigations both reduced the salinity and osmotic potential of soils compared with treatments without straw while the soil moisture was greater in rice straw treatments and increased with the increased soil layers. We conclude that straw mulching and irrigation management practice could be used in coastal saline of heavy soils to reduce soil salinity, osmotic potentials thereby increasing crop yields in no-tilled systems. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 156 KiB

Open AccessAbstract

Modelling Yield and Seasonal Soil Salinity Dynamics in Rice-Grasspea Cropping System for the Coastal Saline Zone of West Bengal, India

by Sukamal Sarkar, Donald S Gaydon, Koushik Brahmachari, Manoj Kumar Nanda, Argha Ghosh and Mohammed Mainuddin

Proceedings 2019, 36(1), 146; https://doi.org/10.3390/proceedings2019036146 - 4 Apr 2020

Cited by 1 | Viewed by 1436

Abstract

Due to seasonal dry-season salt accumulation in the coastal saline zone (CSZ) of West Bengal, India, the cultivation of winter crops (following summer rice) is rare. To address this issue, field experiments were conducted over two years (2016–18) in the CSZ to study [...] Read more.

Due to seasonal dry-season salt accumulation in the coastal saline zone (CSZ) of West Bengal, India, the cultivation of winter crops (following summer rice) is rare. To address this issue, field experiments were conducted over two years (2016–18) in the CSZ to study the feasibility of cropping system intensification through incorporating grass pea into the dominant rice-fallow rotation. The experiment was conducted in strip plot design with two factors namely, Factor A: Six dates of rice sowing (at one-week intervals—2nd week of June to 3rd week of July) and Factor B: Two land situations (Medium-upland and Medium-lowland). The experiment was simulated using APSIM (Agricultural Production Systems sIMulator) utilizing the APSIM-SWIM water balance module to understand the mechanisms of seasonal soil salinity dynamics and the associated crop responses. The results suggest that irrespective of land situation, early sown rice (2nd week of June) produces higher dry matter and yield compared to late sown crops. This early rice sowing also facilitated better subsequent grass pea performance, by avoiding the worst of the salinity build-up and drought stress later in the winter. The model performed well in simulating the observed rice and grass pea yields (R²= 0.97 with low bias (slope, α = 0.93, intercept, β = 149 kg ha⁻¹), RMSE = 558 kg ha⁻¹). It may be concluded that ASPIM-SWIM is an effective tool to understand, assess and predict the complex bio-physical mechanisms of ground water and soil salinity dynamics in rice-pulse-based cropping systems of CSZ of West Bengal. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 157 KiB

Open AccessAbstract

Zero Tilled-Paddy Straw Mulched Potato (Solanum tuberosum) Cultivation in the Coastal Saline Soils Reduce Soil Salinity, Increase Yield and Profitability

by Sukanta Kumar Sarangi, Buddheswar Maji, Parbodh Chander Sharma, Saheb Digar, Kshirendra Kumar Mahanta, Dhiman Burman, Uttam Kumar Mandal, Subhasis Mandal and Mohammed Mainuddin

Proceedings 2019, 36(1), 147; https://doi.org/10.3390/proceedings2019036147 - 5 Apr 2020

Cited by 2 | Viewed by 1685

Abstract

Rice is the predominant crop during wet season (July–December) and majority of land remain fallow during dry season (January–June) in the coastal saline region of West Bengal, India. Sustainable cropping system intensification in this salt affected region needs improved package of practices which [...] Read more.

Rice is the predominant crop during wet season (July–December) and majority of land remain fallow during dry season (January–June) in the coastal saline region of West Bengal, India. Sustainable cropping system intensification in this salt affected region needs improved package of practices which conserve soil moisture, facilitate early crop establishment, ensures profitability and has positive effect on soil health. To achieve these objectives in a rice-based cropping system, we evaluated seven treatments for potato crop during the dry season viz. T1: ridge sowing (control), T2: Zero tillage (ZT) sowing with 9 t ha⁻¹ paddy straw mulching (PSM), T3: T2 + foliar spray of nutrients, T4: ZT sowing with 12 t ha⁻¹ PSM, T5: T4 + foliar spray of nutrients, T6: ZT sowing with 15 t ha⁻¹ PSM, T7: T6 + foliar spray of nutrients in randomized block design with five replications. This study was conducted during 2016-2019 in the Gosaba island of the Indian Sundarbans. Cost of cultivation of potato reduced by about 27% due to ZT sowing (₹ 81,287 ha⁻¹) compared to ridge sowing (₹ 1,11,260 ha⁻¹). Tuber yield, net return and irrigation water productivity was significantly increased in T5, T6 and T7 over other treatments. There was reduction in soil salinity (ECe reduced from 5 to 3 dS m⁻¹), bulk density (from 1.49 to 1.44 Mg m⁻³), irrigation water use (less 20 cm), conservation of soil moisture (4–8%), and increase in organic carbon (0.39 to 0.44%) due to ZT sowing with PSM. Rice-ZT potato-green gram cropping system was the most profitable one with highest net return (₹ 1,71,752 ha⁻¹), however, the benefit-cost ratio was highest (2.33) with Rice-ZT potato cropping system. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 140 KiB

Open AccessAbstract

Pedigree Data Analysis of a Wheat Population

by Sepideh Rouholamin, Vivi Arief, Ian Delacy and Kaye Basford

Proceedings 2019, 36(1), 148; https://doi.org/10.3390/proceedings2019036148 - 5 Apr 2020

Viewed by 1150

Abstract

Genetic diversity is an essential part of successful crop development and can be evaluated by different methods, e.g. the Coefficient of Parentage (COP). This coefficient is established on pedigree data. This method can determine the variation among genotypes without the influence of environment [...] Read more.

Genetic diversity is an essential part of successful crop development and can be evaluated by different methods, e.g. the Coefficient of Parentage (COP). This coefficient is established on pedigree data. This method can determine the variation among genotypes without the influence of environment effects as would be the case for field data. This study measured genetic diversity among 317 wheat cultivars from a population generated by the speed breeding technique. Using pedigree data, we determined the associations between parents and individuals, and then used the pattern analysis techniques of principal component analysis and clustering. The results enabled an appropriate graphical representation of wheat cultivars. This information is useful for selecting future parents in breeding programs. This demonstrates that using COP is a viable way to evaluate diversity among genotypes, especially in inbred populations. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 160 KiB

Open AccessAbstract

Host Plant Resistance to Helicoverpa armigera Has Been Observed in Australian Wild Cajanus (Pigeonpea) Species

by Vanambathina Prameela Rani

Proceedings 2019, 36(1), 149; https://doi.org/10.3390/proceedings2019036149 - 5 Apr 2020

Viewed by 1052

Abstract

Pigeonpea (Cajanus cajan (L) Millspaugh) is extensively grown in tropical subtropical and warmer equatorial regions of the world and ranks 6th in the global legume production (6.8MT; 2017). It is consumed by billions of people as a major source of protein in [...] Read more.

Pigeonpea (Cajanus cajan (L) Millspaugh) is extensively grown in tropical subtropical and warmer equatorial regions of the world and ranks 6th in the global legume production (6.8MT; 2017). It is consumed by billions of people as a major source of protein in developing countries. Despite the increasing demand the crop is facing severe yield losses (2.4 billion US$/Annum) due to the insect pest Helicoverpa.armigera (68% globally). As this pest is polyphagous was exposed to several pesticides and gained strong resistance, it necessities a strong need for identifying host plant resistance towards this pest. Australia is the second hub with 15 out of 32 Cajanus species next to Asia. This is the pilot study exploring the potential of Australian Cajanus species as wild were proven sources for potential trait information in many other crops. My study firstly characterized the Australasian wild species and their derivatives for phenotypic variation and secondly tested for their resistance to Helicoverpa armigera. My research also demonstrated a very high levels of resistance to Helicoverpa armigera in some of the Australian wild species and their derivatives, compared to cultivated species. This research also revealed a high levels of total phenolic compounds in the wild species and a significant negative correlation of total phenols with the pest survival. We were successful in identifying the major phenolic compound in resistant species. Exploring the role of that specific compound related to host plant resistance and identifying the genetic markers associated with phytochemicals triggering the pest resistance is underway. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Understanding Sclerotinia Risks Associated with Growing Peanuts in the South Burnett Area

by Claire-Marie Pepper

Proceedings 2019, 36(1), 150; https://doi.org/10.3390/proceedings2019036150 - 6 Apr 2020

Viewed by 1126

Abstract

Sclerotinia Blight, caused by ascomycete fungal pathogen S. minor (Jagger), is a serious soil-borne disease of peanut crops within the South Burnett area in Queensland, Australia. The pathogen can infect root, stem and foliage tissues, forming characteristic fluffy white mycelial growth on stems [...] Read more.

Sclerotinia Blight, caused by ascomycete fungal pathogen S. minor (Jagger), is a serious soil-borne disease of peanut crops within the South Burnett area in Queensland, Australia. The pathogen can infect root, stem and foliage tissues, forming characteristic fluffy white mycelial growth on stems leading to tissue wilting and necrosis. The disease can cause significant yield reductions and, in some cases, complete crop losses in peanut production. Outbreaks occur in cooler weather (under 18 °C) with high humidity levels (above 95%) as the higher humidity levels promote germination of sclerotia (Smith 2003, Maas, Dashiell et al. 2006). Therefore, knowledge of inoculum levels prior to sowing could enhance cropping systems through enhanced capacity to predict outbreaks. The South Australia Research and Development Institute (SARDI) offers a new soil test for Sclerotinia sp., called PreDictaB, available for farmers to asses inoculum levels pre-planting as a crop risk assessment tool. This project validated the accuracy of the PreDictaB test for Sclerotinia inoculum levels in the South Burnett soils, while gathering paddock and weather data to identify key characteristics linked to high risk of Sclerotinia Blight incidence to be transposed in a pre-season risk matrix model. Results demonstrated a close positive relationship between the level of Sclerotinia in the soil pre-planting and the paddock disease severity observed at harvest. The significance of the results for future research into potential management strategies is discussed. This new test has the potential to reduce the impact and presence of Sclerotinia in the field within the South Burnett region. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 137 KiB

Open AccessAbstract

Genotypic Effects on the Response of Soybean (Glycine max (L.) Merrill) to Sulfonylurea Herbicides

by Catherine Lawn, Andrew T. James and Mark Dieters

Proceedings 2019, 36(1), 151; https://doi.org/10.3390/proceedings2019036151 - 6 Apr 2020

Viewed by 1159

Abstract

In soybean cropping, sulfonylurea (SU) herbicides are a potentially useful alternative to glyphosate-based herbicides. Normally, soybeans are susceptible to SU herbicides, but two unlinked non-GMO genes (ALS1 and ALS2), have been identified that confer SU tolerance. In this project, we explored the effectiveness [...] Read more.

In soybean cropping, sulfonylurea (SU) herbicides are a potentially useful alternative to glyphosate-based herbicides. Normally, soybeans are susceptible to SU herbicides, but two unlinked non-GMO genes (ALS1 and ALS2), have been identified that confer SU tolerance. In this project, we explored the effectiveness of these genes in Australian soybean genetic backgrounds. Four lines, carrying both ALS1 and ALS2, were derived by backcrossing different Australian genotypes to a SU-tolerance donor line ‘W4-4’ and then using molecular markers, plants homozygous for both ALS genes were selected. The W4-4 donor and the four derived lines were evaluated in a hydroponic system at increments up to 4× the recommended field rate of metsulfuron-methyl. The ALS genes provided high levels of tolerance, with evidence of some minor interaction with the genetic background. To further test whether there was an effect of background, the five lines were crossed together in a half-diallel mating design and the resulting ten F₂ populations were screened hydroponically for tolerance to metsulfuron-methyl herbicide at 4× the recommended field rate. Analyses of seedling dry weight of the five parental lines and their F₂ progeny in response to the herbicide, identified differences among the crosses. These results indicated that the development of commercial varieties with maximum herbicide tolerance requires incorporation of both ALS genes, and if combined with selection in segregating populations in the presence of SU herbicide may capture additional tolerance from background genes of minor effect. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Land Situation and Sowing Date Effects Growth and Yield of Crops in the Rice-Pulse Based Cropping Systems of Coastal India

by Koushik Brahmachari, Sukamal Sarkar, Donald S. Gaydon, Manoj Kumar Nanda, Argha Ghosh and Mohammed Mainuddin

Proceedings 2019, 36(1), 152; https://doi.org/10.3390/proceedings2019036152 - 6 Apr 2020

Cited by 1 | Viewed by 1151

Abstract

The costal saline zone of West Bengal in India is the home for millions of the world’s poorest and most vulnerable people. Due to gradual increase in salt accumulation on soils of the costal saline zone of West Bengal in India from winter [...] Read more.

The costal saline zone of West Bengal in India is the home for millions of the world’s poorest and most vulnerable people. Due to gradual increase in salt accumulation on soils of the costal saline zone of West Bengal in India from winter to summer days, cultivation of the second crop in winter season becomes possible in a limited area. To address this issue, field experiment was conducted both in rainy and winter seasons of 2016–2017 and 2017–2018 in this zone to study the feasibility of incorporating different winter pulses (lentil and grass pea) in the rice based cropping system. The experiment was conducted in strip plot design having two factors namely, Factor I: Six dates of sowing of rice at an interval of one week (2nd week of June to 3rd week of July) and Factor II: Two land situations (Medium-upland and Medium-lowland). Date of sowing significantly influenced dry matter and macro-nutrients (NPK) partitioning in rice. Irrespective of land situation, crop sown on 1st and 2nd dates recorded significantly higher grain yield and macro-nutrient uptake by rice. Date of sowing of rice and land situation also significantly influenced the seed and stover yield of different pulse crops. Pulse crops sown on 1st and 2nd dates recorded significantly higher seed yield in coastal saline ecology of West Bengal, India. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Assessments of Lowland Rice-Based Farming Systems and Prospects for Future Research and Development Priorities

by Van Touch, Rebecca Cross, Clemens Grünbühel, Peter Ampt, Try Yorn, Robert John Martin, Floris Van Ogtrop and Daniel K. Y. Tan

Proceedings 2019, 36(1), 153; https://doi.org/10.3390/proceedings2019036153 - 7 Apr 2020

Viewed by 2015

Abstract

Projections of global demand for rice is expected to increase at the rate of 1.5% per year (or 48.5% by 2050). The crop production increase must be done sustainably from existing farming land due to the reduction in availability and quantity of resources. [...] Read more.

Projections of global demand for rice is expected to increase at the rate of 1.5% per year (or 48.5% by 2050). The crop production increase must be done sustainably from existing farming land due to the reduction in availability and quantity of resources. Having more local studies enhances our understanding of different farmer characteristics and behaviour, socio-economic conditions and other essential constraints faced by individual farmers. This is needed for fine-tuning farming systems research which will lead to a profitable and sustainable increase in farming production. This study aims to understand and assess the lowland rice-based farming systems in Northwest Cambodia, and examine options to enhance rice production, profitability and sustainability. Farmer surveys were conducted using the CommCare Mobile Acquired Data (MAD) system and 524 farmers were interviewed. The survey identified farmers’ key constraints on crop production, their knowledge gaps and limitations and the rice yield gaps which exist in Northwest Cambodia. Agricultural research and development priorities should be focused on crop establishment method, sowing window, weed and nutrient management strategies, overall soil health improvement, crop rotations and cover crops that can improve cropping systems, profitability and sustainability. An increase in understanding of farmer behaviour, adoption constraints and barriers, together with other essential interaction at the local level is also crucial when aiming to promote improved farming innovations. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 140 KiB

Open AccessAbstract

Exploring the Potential of High Resolution Satellite Imagery for Yield Prediction of Avocado and Mango Crops

by Moshiur Rahman, Andrew Robson, Surantha Salgadoe, Kerry Walsh and Mila Bristow

Proceedings 2019, 36(1), 154; https://doi.org/10.3390/proceedings2019036154 - 7 Apr 2020

Cited by 1 | Viewed by 1401

Abstract

Accurate pre-harvest yield estimation of high value fruit tree crops provides a range of beneﬁts to industry and growers. Currently, yield estimation in Avocado (Persea americana) and Mango (Mangifera indica) orchards is undertaken by a visual count of a [...] Read more.

Accurate pre-harvest yield estimation of high value fruit tree crops provides a range of beneﬁts to industry and growers. Currently, yield estimation in Avocado (Persea americana) and Mango (Mangifera indica) orchards is undertaken by a visual count of a limited number of trees. However, this method is labour intensive and can be highly inaccurate if the sampled trees are not representative of the spatial variability occurring across the orchard. This study evaluated the accuracies of high resolution WorldView (WV) 2 and 3 satellite imagery and targeted ﬁeld sampling for the pre-harvest prediction of yield. A stratified sampling technique was applied in each block to measure relevant yield parameters from eighteen sample trees representing high, medium and low vigour zones (6 from each) based on classified normalised difference vegetation index (NDVI) maps. For avocado crops, principal component analysis (PCA) and non-linear regression analysis were applied to 18 derived vegetation indices (VIs) to determine the index with the strongest relationship to the measured yield parameters. For mango, an integrated approach of geometric (tree crown area) and optical (spectral vegetation indices) data using artiﬁcial neural network (ANN) model produced more accurate predictions. The results demonstrate that accurate maps of yield variability and total orchard yield can be achieved from WV imagery and targeted sampling; whilst accurate maps of fruit size and the incidence of phytophthora can also be achieved in avocado. These outcomes offer improved forecasting than currently adopted practices and therefore offer great benefit to both the avocado and mango industries. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 162 KiB

Open AccessAbstract

Differences in Thermoregulatory Responses between Dorper and Second Cross Lambs to Heat Stress Challenges

by Aleena Joy, Frank R. Dunshea, Brain J. Leury, Kristy DiGiacomo, Iain J. Clarke, Minghao Zhang, Archana Abhijith, Richard Osei-Amponsah and Surinder Singh Chauhan

Proceedings 2019, 36(1), 155; https://doi.org/10.3390/proceedings2019036155 - 7 Apr 2020

Cited by 2 | Viewed by 1259

Abstract

We compared the thermotolerance of Dorper (D) and second cross (SC) (Poll Dorset x Merino/Border Leicester) lambs by assessing physiological and biochemical responses. After acclimatization, 4–5 month old lambs of each breed were exposed to either thermo-neutral (18 °C–21 °C, 40%–50% RH, n [...] Read more.

We compared the thermotolerance of Dorper (D) and second cross (SC) (Poll Dorset x Merino/Border Leicester) lambs by assessing physiological and biochemical responses. After acclimatization, 4–5 month old lambs of each breed were exposed to either thermo-neutral (18 °C–21 °C, 40%–50% RH, n = 12/group) or cyclic heat stress (HS) (28 °C–40 °C; 40%–60% RH, n = 12/group) for 2 weeks in climatic chambers. The HS involved exposure to temperatures of 38 °C–40 °C between 0800 and 17.00 h daily; otherwise the temperature was maintained at 28 °C. Elevated temperature increased rectal temperature (p < 0.01), respiration rate (p < 0.01) and skin temperature (p < 0.01) in both breeds, (data for 12.00 and 16.00 h pooled), but to a lesser extent in D than in SC lambs (p < 0.01). The HS increased (p < 0.01) water intake to a greater extent in SC than in D lambs and HS reduced (p < 0.05) food intake in SC lambs but not in D lambs. There were no treatment effects on blood glucose and lactate levels in either breed. Significant effects of breed (p < 0.01) and treatment (p < 0.01) were observed in blood creatinine levels, being higher in SC lambs. Higher pH (p < 0.01) and lower pCO₂ (p < 0.01) were recorded under HS in both breeds. Among blood electrolytes, Cl⁻, Na⁺ and base excess were significantly (all p < 0.01) reduced under HS, with no breed differences. In conclusion, the attenuated physiological responses to HS in Dorper lambs indicates better adaptation of this breed to high environmental temperature. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 141 KiB

Open AccessAbstract

A Novel Biomarker Test for Sugarcane Yellow Canopy Syndrome

by Kate Wathen-Dunn, Gerard Scalia, Annelie Marquardt and Frikkie Botha

Proceedings 2019, 36(1), 156; https://doi.org/10.3390/proceedings2019036156 - 7 Apr 2020

Viewed by 1135

Abstract

Yellow canopy syndrome (YCS) is a condition that affects sugarcane crops throughout Queensland, and is most apparent in the warmer summer months when plants are actively growing. Key symptoms of YCS include a yellowing of the mid-canopy leaves, and the accumulation of sucrose [...] Read more.

Yellow canopy syndrome (YCS) is a condition that affects sugarcane crops throughout Queensland, and is most apparent in the warmer summer months when plants are actively growing. Key symptoms of YCS include a yellowing of the mid-canopy leaves, and the accumulation of sucrose and α-glucans in the lamina, midrib and sheath tissue. As no cause for the syndrome has yet been found, a biomarker test for identifying YCS, as distinct from other conditions that cause leaf yellowing, is important to enable early detection before any signs of visual yellowing. This will inform YCS management practices, and drive the research forward. We used an RNAseq and bioinformatic approach to identify six YCS-specific biomarker candidate plant transcripts that were uniquely and consistently up-regulated in YCS. We designed primers against these transcripts, and developed a novel reverse-transcriptase polymerase chain reaction (RT-PCR) test to identify sugarcane plants affected by YCS. The YCS biomarker test is showing early signs of success and is undergoing further validation, with the aim of correctly identifying YCS-affected sugarcane plants before symptoms become apparent. This poster outlines the biomarker candidate discovery and test development process. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 147 KiB

Open AccessAbstract

Building Farming Resilience to Climate Change: Upland Crop Production in Northwest Cambodia

by Van Touch, De Li Liu, Robert John Martin, Jeannette Fiona Scott, Annette Cowie and Daniel K. Y. Tan

Proceedings 2019, 36(1), 157; https://doi.org/10.3390/proceedings2019036157 - 7 Apr 2020

Viewed by 1517

Abstract

Production of upland crops such as maize, cassava, soybean, mungbean, peanut and sesame contribute importantly to Cambodia’s economy and food security, especially for those who live in the upland areas found in almost every province of Cambodia. The upland farmers are highly vulnerable [...] Read more.

Production of upland crops such as maize, cassava, soybean, mungbean, peanut and sesame contribute importantly to Cambodia’s economy and food security, especially for those who live in the upland areas found in almost every province of Cambodia. The upland farmers are highly vulnerable to climate variability and climate change due to low adaptive capacity and high dependence on rainfed crop production for their livelihoods. This study involved in-depth review of literature, conducting on-farm experiments, downscaling climate projections from the coupled Model Intercomparison Project Phase 5 (CMIP5) General Circulation Models (GCMs), running Agricultural Production Systems sIMulator (APSIM) simulations and farmer consultation to define climate impacts and explore adaptation options that could build resilience to the existing and projected climate change scenarios for upland cropping farmers in Northwest Cambodia. Insufficient water and nutrient depletion were the main production risks and yield limiting factors. On-farm adaptation options such as modifying sowing windows, including legumes in crop rotations and additional fertiliser application are likely to substantially minimise risks from climatic impacts, and increase and sustain returns. Wider adoption of conservation agriculture practices—including reduced tillage and crop residue retention, that enhance soil structure and soil water holding capacity and reduce soil erosion, should enhance productivity and incomes, while making the farming systems more resilient to the existing and projected climate variability and climate change, and other production stressors. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

Exploring Common Bean Fresh Pod Market in East African Region: A Case of Uganda

by Stanley Tamusange Nkalubo, Richard Ariong, Gabriel Luyima, Clare Mukankusi Mugisha and Jean Claude Lubyogo

Proceedings 2019, 36(1), 158; https://doi.org/10.3390/proceedings2019036158 - 7 Apr 2020

Viewed by 1100

Abstract

Common bean fresh pod is a niche market product consumed worldwide including in Eastern Africa region. It is more preferred to dry bean due to the fresh taste and ease to cook. A lot of research has been done on production and disposition [...] Read more.

Common bean fresh pod is a niche market product consumed worldwide including in Eastern Africa region. It is more preferred to dry bean due to the fresh taste and ease to cook. A lot of research has been done on production and disposition of dry bean product; however, little information is available on production and marketing of fresh bean pod in Uganda. The general observation indicates wide consumption of fresh bean pods however, there is limited information on its entire value chain, yet, its value cannot be undermined. Based on this background, a reconnaissance study was undertaken in Mpigi district, a major fresh bean growing area and eight retailing markets within Uganda’s capital, Kampala, to understand the economic feasibility of fresh bean pod market. Using qualitative approaches, farmer and market analysis was conducted to explore and understand fresh bean market dynamics. The results show that there are over 10 varieties being sold for fresh pod, unstandardized weight measures are being used, and price variation of over 50%. Additionally, unsatisfied demand for fresh pod beans is 45%. The results indicate existence of a lucrative fresh pod market valued at more than USD 2.0 million within Kampala and suburbs. It was also revealed that production faces significant gaps in seed availability to ensure consistent quality supply to the market while at selling points, bronzing effect was a major challenge leading to product deterioration. Thus, interventions are needed to eliminate the existing production and marketing challenges for a sustainable fresh bean pod business. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

Performance of Garlic (Allium sativum) Varieties under Zero Tillage Mulch Condition in Southern Coastal Region of Bangladesh

by Rina Rani Saha, Md. Abul Khayer Mian, Subarna Kundu and Khokan Kumer Sarker

Proceedings 2019, 36(1), 159; https://doi.org/10.3390/proceedings2019036159 - 7 Apr 2020

Cited by 1 | Viewed by 1351

Abstract

The experiment was carried out under ACIAR-KGF project at farmers’ field of Tildanga village at Dacope Upazilla under Khulna District during rabi season of 2018–19 after harvest of previous transplanted aman rice to find out the suitable variety of garlic (Allium sativum) for [...] Read more.

The experiment was carried out under ACIAR-KGF project at farmers’ field of Tildanga village at Dacope Upazilla under Khulna District during rabi season of 2018–19 after harvest of previous transplanted aman rice to find out the suitable variety of garlic (Allium sativum) for cultivation in southern coastal region of Bangladesh and to observe the effect of straw mulching on the yield of garlic. The experimental area faces slight to moderately drought and saline prone at later part of winter season and beginning of summer. The salinity causes unfavorable environment and hydrological situation restricting the normal crop production. Farmers generally cultivate only single transplanted aman (T.aman) rice in a year at south and south-western coastal saline areas. Garlic is one of the important spices crop in Bangladesh. The treatments of the experiment were five garlic varieties viz., V₁ = BARI Roshun-1, V₂ = BARI Roshun-2, V₃ = BARI Roshun-3, V₄ = BARI Roshun-4 which were developed by Bangladesh Agricultural Research Institute (BARI) and V₅ = Local cultivar. The experiment was laid out in a randomized complete block design with three replications. All five varieties of garlic were sown on 17 December 2018 under zero tillage condition. BARI Roshun-1 gave the highest number of bulb/m²(57), pseudostem height (37 cm), weight of individual bulb (7.65 g) and bulb yield (5.81 t/ha). BARI Roshun-3 gave the lowest yield (3.87 t/ha). It was also observed that the soil moisture of the farmers’ field were higher during sowing of garlic which was not suitable for ploughing the land. So timely establishment of garlic is possible by following hand dibbling methods under zero tillage condition on the muddy soil surface and also cost effective. Mulching can protect the evaporation loss and reduces the salinity stress which ultimately influence the crop establishment and yield. Earlier farmers of Tildanga at Dacope under Khulna District had no idea about the cultivation of garlic under zero tillage along with straw much. When the experimental results were demonstrated and discussed about the technology to the farmers gathering during Field Day then they were impressed and interested to grow garlic. Fallow land of coastal areas of Bangladesh could be utilized through disseminating this technology and ultimately cropping intensification increased. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 168 KiB

Open AccessAbstract

Plant and Seed Mortality of Fireweed Senecio madagascariensis Following Herbicide Application

by Kusinara Wijayabandara, Shane Campbell, Joseph Vitelli and Steve Adkins

Proceedings 2019, 36(1), 160; https://doi.org/10.3390/proceedings2019036160 - 7 Apr 2020

Viewed by 1296

Abstract

Fireweed (Senecio madagascariensis Poir), is a weed of National significance and one of the worst weeds of coastal pastures in South Eastern Australia. Chemical control has been found to be effective in killing plants but there is no information on the effect [...] Read more.

Fireweed (Senecio madagascariensis Poir), is a weed of National significance and one of the worst weeds of coastal pastures in South Eastern Australia. Chemical control has been found to be effective in killing plants but there is no information on the effect of herbicides on the seeds that may be present on plants at the time of application. Consequently, a study was undertaken to determine the effect of five selective herbicides (1) on plant mortality at different life stages and (2) on the viability (as assessed by germination) of fireweeds seeds at different stages of maturity. Potted plants of the required growth stages were obtained through several collections of different sized seedlings from a field site near Brisbane. Before herbicide application, in the mature plant cohort the inflorescences were tagged according to their maturity as being either immature (IM) or intermediate (INT). Plants were sprayed with either fluroxypyr/aminopyralid (HotShot™) (A), bromoxynil (Bromicide^® 200) (B), metsulfuron-methyl (Brush-Off^®) (C), triclopyr/picloram/aminopyralid (Grazon™ extra) (D), triclopyr/picloram/aminopyralid (Tordon^TM regrowthMaster) (E) at the recommended rates with untreated control plants of the three growth stages also included for comparison. All herbicides killed fireweed seedlings and juvenile plants, but only treatments A, D and E gave high plant mortality (>80%) of mature plants. All herbicides also caused nil germination of seeds collected 30 days after spraying, except for a small percentage (8% germination) of mature seeds from Bromoxynil treated plants. These results have identified several herbicides capable of killing mature fireweed plants and minimizing replenishment of soil seed reserves. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 123 KiB

Open AccessAbstract

A Biocontrol Option to Control a Foodborne Pathogen; Using Campylobacter Bacteriophages to Control Campylobacter in Poultry

by Nalini Chinivasagam, Wiyada Estella, Samuel Cockerill, Lance Maddock, David Mayer, Craig Billington, Aruni Premaratne, Lu Liang, Phillipa Connerton and Ian Connerton

Proceedings 2019, 36(1), 162; https://doi.org/10.3390/proceedings2019036162 - 7 Apr 2020

Viewed by 1376

Abstract

Campylobacter is a leading cause of foodborne illnesses both in Australia and internationally, and is frequently found in poultry. There is a need for sustainable options to support current farm management strategies that address food-safety. The use of bacteriophages provides a safe biocontrol [...] Read more.

Campylobacter is a leading cause of foodborne illnesses both in Australia and internationally, and is frequently found in poultry. There is a need for sustainable options to support current farm management strategies that address food-safety. The use of bacteriophages provides a safe biocontrol option. A collaborative study by the Department of Agriculture and Fisheries (QLD), the University of Nottingham (UK) and the Institute of Environmental Science and Research (NZ) is focused on the control of Campylobacter in broiler chickens. Campylobacter bacteriophages were sourced from Queensland poultry farms and following extensive screening, suitable candidates to be used in cocktails were identified. This followed an on-farm proof of concept study on a small sample of chickens, using selected cocktail candidates, to provide an understanding of the hurdles for practical application. The trial demonstrated a 2-log CFU/g reduction of Campylobacter in the caeca of treated birds compared to non-treated (p < 0.05). Another important finding of this study was the absence of bacteriophage resistance, a concern with phage therapy. Work at ESR has addressed approaches to select and adapt bacteriophage cocktails to particular hosts, which included screening against NZ and Australian hosts. This approach enabled the formulation of high performing bacteriophage cocktails for Australian and international markets. Work in the UK is exploring the understanding of the host-bacteriophage relationships to ensure safety to meet regulatory requirements and support potential scale-up options. In summary, the work in progress via international collaborations is aimed at delivering a safe biocontrol option that can meet both commercial and regulatory needs aiming at controlling on-farm Campylobacter. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Outcomes of Agroforestry and Monocropping—Comparison and Assessment

by Nguyen La

Proceedings 2019, 36(1), 163; https://doi.org/10.3390/proceedings2019036163 - 7 Apr 2020

Viewed by 1306

Abstract

Agroforestry is considered as a solution for improving livelihoods of smallholder farmers and reducing land degradation. However, the upscale is required objective assessments and appropriate solutions. Five agroforestry options established in 2014 in Northwest Vietnam include Macadamia+coffee+soybeans, Acacia+mango+maize+forage grass, Acacia+longan+coffee+soybeans+forage grass, Teak+plum+coffee+soybeans and [...] Read more.

Agroforestry is considered as a solution for improving livelihoods of smallholder farmers and reducing land degradation. However, the upscale is required objective assessments and appropriate solutions. Five agroforestry options established in 2014 in Northwest Vietnam include Macadamia+coffee+soybeans, Acacia+mango+maize+forage grass, Acacia+longan+coffee+soybeans+forage grass, Teak+plum+coffee+soybeans and Docynia indica+forgare grass, were used to evaluate the annual income, cumulative profit, multi-year return on investment (ROI) and efficiency on soil erosion control compared with mono-maize and mono-Docynia indica. Mono-maize provides annual income. However, tends to decrease. Break-even point of mono-Docynia indica happened in the year 4th after planting. Depend on agroforestry options, the break- even presented in the year 2nd to year 4th. The cumulative profit of mono-maize and mono-Docynia indica for five-year study were 1196 and 875 USD ha⁻¹, respectively. Meanwhile, five agroforestry options were provided the cumulative profit from 29 to 10,000 USD ha⁻¹. ROI of five-year investment of monoculture maize and Docynia indica were 38% and 33%, respectively. Agroforestry options gave the value of 1%, 25%, 39%, 59% and 141% for Macadamia+coffee+soybeans, Acacia+mango+maize+forage grass, Acacia+longan+coffee+soybeans+forage grass, Teak+plum+coffee+soybeans+forage grass and Sontra+forage grass, respectively. The effectiveness on soil erosion control in agroforestry options are clear, decreasing from 53% in the second year to 98% in the fifth year after establishment compared to mono-maize. The analysis results show that agroforestry options provided attractive income for farmers only 2nd or 3rd year after establishment. However, higher investment cost is required, and appropriate supports are needed for wider application. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 142 KiB

Open AccessAbstract

Analysis of Differences in Gene Expression Associated with Variation in Biomass Composition in Sugarcane

by Virginie Perlo, Agnelo Furtado, Frikkie Botha and Robert Henry

Proceedings 2019, 36(1), 164; https://doi.org/10.3390/proceedings2019036164 - 7 Apr 2020

Viewed by 1135

Abstract

Sugarcane has a high potential to support second-generation ethanol production and environmentally friendly by-products for use in chemical, pharmaceutical, medical, cosmetic and food industries. A crucial challenge for a long-term economic viability is to optimise the crop for production of a biomass composition [...] Read more.

Sugarcane has a high potential to support second-generation ethanol production and environmentally friendly by-products for use in chemical, pharmaceutical, medical, cosmetic and food industries. A crucial challenge for a long-term economic viability is to optimise the crop for production of a biomass composition that will ensure maximum economic benefit. Transcriptome data analysis provides a relevant explanation of phenotypic variances and gives a more accurate prediction of phenotypes than genomic information. This multi-omic approach, with an integrated transcriptomics and metabolomics analysis may reveal details of biological mechanisms and pathways. A global view of transcriptional regulation and the identification differentially expressed genes (DEGs) and metabolites may help the feasibility of tailoring engineering targeted biosynthetic pathways to improve the production of these bio-products from sugarcane. We propose a profiling analysis workflow (pipeline) to generate empirical correlations between gene expression, metabolites, proteins and phenotypic traits and pathway analysis, with a highlight focus on data visualisation. This study of genetic variation in gene expression and correlations with metabolic and protein phenotype relies on high-throughput methodology, measurement and analysis of 360 samples, 24 commercial sugarcane cultivars with different phenotypic characteristics at 5 different development stages with 3 replicates. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 129 KiB

Open AccessAbstract

The Genetics of Rumen Phage Populations

by Rosalind Gilbert and Diane Ouwerkerk

Proceedings 2019, 36(1), 165; https://doi.org/10.3390/proceedings2019036165 - 7 Apr 2020

Cited by 2 | Viewed by 1412

Abstract

The microbial populations of the rumen are widely recognised as being essential for ruminant nutrition and health, utilising and breaking down fibrous plant material which would otherwise be indigestible. The dense and highly diverse viral populations which co-exist with these microbial populations are [...] Read more.

The microbial populations of the rumen are widely recognised as being essential for ruminant nutrition and health, utilising and breaking down fibrous plant material which would otherwise be indigestible. The dense and highly diverse viral populations which co-exist with these microbial populations are less understood, despite their potential impacts on microbial lysis and gene transfer. In recent years, studies using metagenomics, metatranscriptomics and proteomics have provided new insights into the types of viruses present in the rumen and the proteins they produce. These studies however are limited in their capacity to fully identify and classify the viral sequence information obtained, due to the absence of rumen-specific virus genomes in current sequence databases. The majority of commensal viruses found in the rumen are those infecting bacteria (phages), therefore we genome sequenced phage isolates from our phage culture collection infecting the common rumen microbial genera Bacteroides, Ruminococcus and Streptococcus. We also created a pan-genome using 39 whole genome sequences of predominantly livestock-derived Streptococcus isolates (representing S. bovis, S. equinus, S. henryi, and S. gallolyticus), to identify and characterise integrated viral genomes (prophage sequences). Collectively this approach has provided novel rumen phage sequences to increase the accuracy of rumen metagenomics analyses. It has also provided new insights into how viruses or virus-encoded proteins can potentially be used to modulate specific microbial populations within the rumen microbiome. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessAbstract

Breaking and Flowering: The Budding Story of Macadamia

by Francois Barbier, Ye Gong, Carola Parfitt, Craig Hardner, John Wilkie and Christine Beveridge

Proceedings 2019, 36(1), 166; https://doi.org/10.3390/proceedings2019036166 - 7 Apr 2020

Viewed by 1360

Abstract

Macadamia is the only Australian native crop tree. Unlike some model crop trees like apple or peach trees, the understanding of the physiological mechanisms regulating bud break and flowering in macadamia has never been investigated. We have recently attempted to fill this gap [...] Read more.

Macadamia is the only Australian native crop tree. Unlike some model crop trees like apple or peach trees, the understanding of the physiological mechanisms regulating bud break and flowering in macadamia has never been investigated. We have recently attempted to fill this gap by improving the genetic resources available for macadamia. We identified several components involved in flowering and bud break, including the FLOWERING LOCUS T (FT). FT is a mobile protein, synthesized in the leaves which triggers flowering in terminal and axillary buds. In macadamia, we found two FT-related genes, FTa and FTb namely. FTa and FTb are differentially regulated; FTa being more abundant in axillary buds than leaves, which is unexpected based on the studies performed in model plants. Analysis of the promoter sequences of FTa and FTb, revealed that the FTa regulation may be closer to FT regulation in the model plant Arabidopsis thaliana. Gene expression in buds revealed that the expression of TERMINAL FLOWER1 (TFL1), a gene previously reported to inhibit flowering, was induced prior to bud break and flowering. The patterns of marker gene expression in buds highlighted that the bud dormancy decreased before May, after which flowering induction occurs. Altogether these results shed light on the regulation of bud break and flowering in macadamia and demonstrate that some regulatory mechanisms may be different from other models. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 124 KiB

Open AccessAbstract

Is Broadcasting Mung Bean into Rice Crops a Useful Practice in Timor-Leste?

by Luis Almeida, Robert Williams and William Erskine

Proceedings 2019, 36(1), 167; https://doi.org/10.3390/proceedings2019036167 - 7 Apr 2020

Viewed by 1612

Abstract

Mung beans (Vigna radiata) are a potential crop in rotation with rice on the south coast of east Timor. When Mung beans are planted after rice, the soil is cultivated after rice harvest, before mung beans are planted by hand with the use [...] Read more.

Mung beans (Vigna radiata) are a potential crop in rotation with rice on the south coast of east Timor. When Mung beans are planted after rice, the soil is cultivated after rice harvest, before mung beans are planted by hand with the use of a dibble stick. This paper looks at the cost and benefits of broadcasting mung beans into rice just prior to or just after rice harvest. Broadcast mung beans requires much less labour than planted by dibble stick. Broadcast mung beans require more seed, and can be more difficult to weed. Based on a gross margin analysis mung bean yield could be 35% lower and be as profitable as conventionally grown mung beans. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Technology Package for Sustainable Productivity and Resiliency to Climate Variability: The Proof from SIMLESA Studies in Tanzania

by John Sariah and Daniel Rodriguez

Proceedings 2019, 36(1), 168; https://doi.org/10.3390/proceedings2019036168 - 7 Apr 2020

Viewed by 1015

Abstract

The agricultural sector in Tanzania is mainly dryland and dominated by smallholder farmers. Unreliable rainfall, short than normal duration of cropping season and fluctuations of onset and end of cropping season are main challenges facing farmers. The increased frequency and intensity of droughts, [...] Read more.

The agricultural sector in Tanzania is mainly dryland and dominated by smallholder farmers. Unreliable rainfall, short than normal duration of cropping season and fluctuations of onset and end of cropping season are main challenges facing farmers. The increased frequency and intensity of droughts, unpredictability of weather, shorter than normal duration of cropping seasons have significant impact on farmers’ productivity, profitability and resilience. This paper report study on Conservation agriculture for Sustainable Intensification (CASI) technology package tested on farm for productive, resilient and sustainable smallholder maize-legume cropping systems across five districts in Tanzania. Three practices namely Conservation practice (CA), Current applied recommended practice (CONV. or sometimes referred to as IMPROV) and primitive farmers practice (FP) were compared in experimental plots on farmers’ fields. Improved (DT maize and Pigeonpeas) was intercropped in all practices. Only CA and CONV practices were statistically compared, whereas FP was for farmer’s visual observations and comparisons. Data recorded were, soil carbon, moisture, yields and economic analysis. Results showed that, the average maize yields for four seasons in CA and CONV doubled and for tripled. An average of 30.5% hours of labour were saved in CASI relative to non CASI practice. The benefit cost ratio of maize-pigeonpea intercrops under CASI was 2.1 as compared to 1.4 in conventional agriculture investments. The institutionalization of CASI at local and national policy decision levels will be required for the scaling of CASI technologies across Tanzania. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Delay in Progesterone Decline Before Parturition is Connected with Failure of Passive Immune Transfer in Tropical Composite Beef Calves

by Luis F.P Silva, Jarud Muller and Geoffry Fordyce

Proceedings 2019, 36(1), 169; https://doi.org/10.3390/proceedings2019036169 - 7 Apr 2020

Viewed by 1181

Abstract

A shortage of nutrients during the final period of gestation can decrease secretion of colostrum, which is critical to newborn calf survival. The physiological mechanism modulating the nutritional control of colostrum secretion is poorly understood. Because the decline in progesterone before parturition is [...] Read more.

A shortage of nutrients during the final period of gestation can decrease secretion of colostrum, which is critical to newborn calf survival. The physiological mechanism modulating the nutritional control of colostrum secretion is poorly understood. Because the decline in progesterone before parturition is required for lactogenesis to occur, the objective was to evaluate the correlation between prepartum progesterone in cows and plasma immunoglobulin-G1 (IgG1) concentration in neonatal calves. From 135 pregnant cows, successful data on both prepartum progesterone and calf IgG1 was collected from 59 cow/calf pairs (animal ethics approval SA2018/05/638). The cow/calf pairs were classified into three categories according to the transfer of passive immunity: low (n = 19), medium (n = 18), or high (n = 22). Plasma IgG1 was 1025, 2395, and 3347 mg/dL for the low, medium, and high groups, respectively. Plasma progesterone 1 day prepartum was 18.3, 14.2, and 12.4 nmol/L for the low, medium and high groups, respectively. This indicates that calves with failure of passive transfer were born from cows with higher prepartum progesterone, compared to calves with high IgG1 (P = 0.05). Non-linear modelling of the progesterone data indicated the moment that progesterone started to decline (change-point). Change-point was 0.8, 2.5, and 2.4 days before parturition for the low, medium, and high groups, respectively. There was a delay in progesterone decline in the Low group compared with the High group (P < 0.05). These results corroborate the hypothesis that the delay in progesterone decline before parturition is responsible for the failure of IgG1 transfer from cows to calves. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 122 KiB

Open AccessAbstract

Sustainable Intensification in the Eastern Gangetic Plains: Key to Food Security and Livelihood Improvement of Smallholders

by Thakur Tiwari, Mahesh Gathala, Apurba Chowdhury, Renuka Shrestha, Sanjay Kumar, Ujjwal Kumar, Saiful Islam, Mamunur Rashid, Mazharul Anwar and Illias Hossain

Proceedings 2019, 36(1), 171; https://doi.org/10.3390/proceedings2019036171 - 7 Apr 2020

Cited by 1 | Viewed by 1236

Abstract

The Eastern Gangetic Plains (EGPs) has the potential to become a major contributor to South Asian regional food security, despite the world’s highest concentration of rural poverty and a strong dependence on agriculture. A regional project entitled ‘Sustainable and Resilient Farming Systems Intensification [...] Read more.

The Eastern Gangetic Plains (EGPs) has the potential to become a major contributor to South Asian regional food security, despite the world’s highest concentration of rural poverty and a strong dependence on agriculture. A regional project entitled ‘Sustainable and Resilient Farming Systems Intensification (SRFSI), managed by CIMMYT with over 20 partners with ACIAR/DFAT funding was launched in May 2014 to sustainably reduce the poverty. A total of 436 farmer-participatory on-farm trials comparing the performance of three conservation agriculture based sustainable intensification (CASI) technologies like Zero/Strip till as base (ZT/ST) over the conventional tillage (CT; T1) practices were conducted across eight districts in northwest Bangladesh, Bihar and West Bengal in India, and eastern Terai of Nepal for two consecutive years i.e. 2015/16 and 2016/17. The three CASI treatments comprised a “partial CASI” option (T2: at least one crop in the cropping system established with ZT management) and two “full CASI” options (T3 and T4: all crops established with ZT/ST management; in T3 rice was direct seeded (DSR) while in T4, it was unpuddled transplanted (UPTR)). Multicriteria assessment showed an increase in rice equivalent system yield (RESY) by 4%, gross margin by 19–20%, input water productivity by 7–9% and energy productivity by 13–14% while decrease in requirements for irrigation water, energy, labor and the production cost by 15–17%, 10–11%, 32–38% and 15–18% respectively, and reduction in CO₂ equivalent emission by 8–13% in full CASI over CT. CASI has shown great promise for food security and livelihood improvement at small scale. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 135 KiB

Open AccessAbstract

Cropping System Intensification for Increasing Crop Productivity in Salt-Affected Coastal Zones of Bangladesh

by Rina Rani Saha, Md. Alimur Rahman, Md. Hafijur Rahman, Mohammed Mainuddin, Richard Bell and Don S. Gaydon

Proceedings 2019, 36(1), 172; https://doi.org/10.3390/proceedings2019036172 - 7 Apr 2020

Cited by 1 | Viewed by 1159

Abstract

In Global Climate Risk Index 2019, Bangladesh has been ranked seventh among the countries most affected by extreme weather events. The salinity intrusion has increased by 27% from 1973 to 2009 in coastal areas of Bangladesh due to impacts of climate change. The [...] Read more.

In Global Climate Risk Index 2019, Bangladesh has been ranked seventh among the countries most affected by extreme weather events. The salinity intrusion has increased by 27% from 1973 to 2009 in coastal areas of Bangladesh due to impacts of climate change. The cropping intensities of the coastal zones are below than the country’s average intensity (195%), which causes severe food insecurity. In southern coastal zone, soil and water (river/canal) salinity remain the minimum (<4 dS/m) during in July/August but attain the maximum (upto 11 and 25 dS/m, respectively) in March/April. Farmers grow single T.aman rice a year. Therefore, five cropping patterns were tested under ACIAR funded project in Amtali (Barguna district) and Dacope (Khulna) upazilas during 2016–2017 and 2017–2018 irrigating with low salinity surface water (canal/pond) to increase crop productivity. In Amtali, T.aman-Potato-Mungbean-T.aus cropping pattern gave the highest (20.18 t/ha) rice equivalent yield (REY), which increased 360% REY over the farmers’ practice (T.aman-fallow-fallow). However, in Dacope, T.aman-spinach-fallow showed the highest REY (13.99 t/ha) that increased 211% REY compared to farmers’ practice. The improved cropping patterns can be practiced within the polder (embankment for water control) for increasing crop productivity and profitability in salt-affected coastal zones of Bangladesh. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 148 KiB

Open AccessAbstract

Response of Mungbean Root System Architecture to Phosphorus Application Methods

by Vijaya Singh, Marisa Collins, Colin Andrew Douglas and Michael Bell

Proceedings 2019, 36(1), 173; https://doi.org/10.3390/proceedings2019036173 - 7 Apr 2020

Viewed by 1162

Abstract

In recent years phosphorus application methods have become an important management strategy for optimising the uptake of the immobile nutrient phosphorus (P). Root system architecture (RSA) could play a particularly important role in the uptake of P by grain legumes, due to their [...] Read more.

In recent years phosphorus application methods have become an important management strategy for optimising the uptake of the immobile nutrient phosphorus (P). Root system architecture (RSA) could play a particularly important role in the uptake of P by grain legumes, due to their relatively coarse root systems. The objective of this study was to understand the response of mungbean root systems to P application methods. Four mungbean varieties were grown in purpose-built soil filled root chambers that received five P application methods. Phosphorus treatments consisted of a control (no application of P) compared with 30 mg P/kg soil throughout the soil volume (high P treatment) or restricted to 10cm deep layers in the topsoil or in a layer from 20-30cm deep. A fifth treatment consisted of the same amount of P as applied in deeper dispersed layer applied in a concentrated band at 25cm depth. After 50 days of growth, plant were destructively harvested and shoot and root parameters were measured. Mungbean varieties responded differently to P application methods, with Jade and Berken varieties showing greater root proliferation at depth and greater shoot growth in response to banded and deeper dispersed P applications, relative to the late maturing variety Putland. Shallow dispersed P and the no-P control both resulted in poor root growth in all the genotypes except Celera II, which did not respond to P application from any placement strategy. Results suggest that P application strategies may need to vary with variety to maximize the uptake of P. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 145 KiB

Open AccessAbstract

Isolation and Characterization of Full-Length Phenylalanine Ammonium Lyase and Cinnamyl Alcohol Dehydrogenase Genes Involved in Lignin Biosynthesis of Erianthus Arundinaceus

by Lakshmi Kasirajan, Prathima Perumal Thirugnanasambandam, Agnelo Furtado, Frikkie C. Botha and Robert J. Henry

Proceedings 2019, 36(1), 174; https://doi.org/10.3390/proceedings2019036174 - 7 Apr 2020

Viewed by 1212

Abstract

Lignocellulosic biomasses available in abundance is the most promising raw material for alternate energy production considering the issues of dwindling oil prices, and global warming. Recently, Erianthus arundinaceous has been identified as a potential target for second generation biofuel crop due to its [...] Read more.

Lignocellulosic biomasses available in abundance is the most promising raw material for alternate energy production considering the issues of dwindling oil prices, and global warming. Recently, Erianthus arundinaceous has been identified as a potential target for second generation biofuel crop due to its high biomass production, and adaptability to extreme growth environments. Lignin is a major plant cell wall polymer indispensable for plant growth and development, however it hinders the saccharification of lignocellulosic biomass. Based on the previous transcriptome studies in a set of sugarcane genotypes differing for lignin content, genes encoding cinnamyl alcohol dehydrogenase (CAD), and Phenylalanine ammonia lyase (PAL) genes playing major roles in genetic regulation of lignin production have been cloned and characterized from an Erianthus clone IK 76-81. The genomic region of EriCAD was 3524 bp sequence containing four exons and three introns, among which the exon 1&2 of 88 and 80 bp were conserved with sorghum and Miscanthus CADs. The coding region of CAD was identified with 1086 bp open reading frame (ORF), a 68 bp 5′ untranslated region (UTR), and a 86 bp 3′ untranslated region (UTR). In the PROSITE analysis, a zinc-containing alcohol dehydrogenase signature (GHEVVGEVVEVGPEV) and an NADP-binding domain motif (GLGGLG) was identified. Similarly sequence analysis of PAL showed an ORF of 2106 bp encoding for 702 amino acid residues. It was flanked by 172 bp of 5′ UTR and 121 bp of 3′ UTR. This sequence information on PAL and CAD from Erianthus might be useful for subsequent research on lignin modification for improved biomass conversion. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessAbstract

Identifying Plants that Reduce Methane Production Using an In Vitro System—Helping the Challenge to Become C Neutral

by Philip E. Vercoe, Amriana Hifizah, Joy Vadhanabhuti, Graeme B. Martin and Zoey Durmic

Proceedings 2019, 36(1), 175; https://doi.org/10.3390/proceedings2019036175 - 7 Apr 2020

Viewed by 1148

Abstract

The Australian red meat industry has set a goal to be carbon neutral by 2030. Reaching this goal will be a challenge and will involve targeting ways to increase carbon in the landscape, improve efficiency of production and reduce methane emissions from ruminants. [...] Read more.

The Australian red meat industry has set a goal to be carbon neutral by 2030. Reaching this goal will be a challenge and will involve targeting ways to increase carbon in the landscape, improve efficiency of production and reduce methane emissions from ruminants. There are a number of different options the industry can pursue to try and achieve its goal, including changing grazing management practices and land-use to changing the animal, what it eats and the microbial ecology in their rumen. No single one of these options will enable the red meat industry to become carbon neutral by 2030, it will take a combination of all of them to help meet the challenge. We have been using an in vitro batch fermentation system and a Rusitec system as a quick, relatively inexpensive, way to screen; plants that already exist in our grazing systems, novel plants, plant extracts and organic waste products from the horticultural industry, for their potential to improve the efficiency of fermentation and reduce methane production in the rumen. We have also used these systems to provide an initial clue about the mechanism of action at the level of the ruminal microorganisms. We have identified variation in these traits amongst the plants, plant extracts and horticultural waste products we have tested that could help develop systems that reduce the environmental footprint of ruminants in tropical production systems in Australia and in other parts of the world. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 121 KiB

Open AccessAbstract

A Systematic Approach to Defining Nutritional Quality of Underutilised Crops

by Razlin Azman Halimi, Bronwyn J. Barkla, Liliana Andrés-Hernandéz, Sean Mayes and Graham J. King

Proceedings 2019, 36(1), 176; https://doi.org/10.3390/proceedings2019036176 - 7 Apr 2020

Viewed by 1219

Abstract

Underutilised crops have potential to play an increasing role in the diet of many who may lack adequate nutrition. At present, there appears to be no comprehensive or systematic effort to collate and analyse nutritional composition data, although this is likely to make [...] Read more.

Underutilised crops have potential to play an increasing role in the diet of many who may lack adequate nutrition. At present, there appears to be no comprehensive or systematic effort to collate and analyse nutritional composition data, although this is likely to make a significant contribution to global food and nutritional security. For example, determining intra- and inter- species variation for nutritional components would enable direct comparison with commodity crops. Using bambara groundnut (Vigna subterranea; BG) as a use-case, we present a systematic work-flow that facilitates comparison of nutritional composition and function for underutilised crops. This includes (i) critical literature review of available data sources for the target and comparator crops, to determine the extent of variation reported for a range of nutritional components; (ii) development of a Crop Dietary Nutritional Data Framework (CDN-DF) to assist in data curation; (iii) de novo analysis of seed nutritional components for a subset of BG accessions selected to represent the global genepool. The CDN-DF includes controlled vocabularies organised in a hierarchical structure that represent a simplified subset of relationships for nutritional composition and dietary function This facilitates comparison of datasets between species and can help identify data gaps. This framework is currently guiding establishment of a formal nutritional ontology that more fully represents the complex relationships between nutritional components. Based on our analysis, it appears that BG seed protein, lipid and fibre concentrations cover a similar range in chickpea and mungbean. Variation in BG protein concentration indicates scope for developing high protein cultivars. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 136 KiB

Open AccessAbstract

Breeding Low Emitting Ruminants: Predicting Methane from Microbes

by Suzanne J. Rowe, Melanie Hess, Larissa Zetouni, Sharon Hickey, Rudiger Brauning, Hannah Henry, Holly Flay, Juliana Budel, Brooke Bryson, Peter Janssen, Arjan Jonker and John McEwan

Proceedings 2019, 36(1), 177; https://doi.org/10.3390/proceedings2019036177 - 7 Apr 2020

Cited by 2 | Viewed by 1772

Abstract

The greatest source of global anthropogenic methane (CH₄) emissions is from ruminant livestock. Multiple mitigation strategies in livestock are currently being explored. Of these breeding for lower CH₄ emitting ruminants has the advantage of being permanent and cumulative and universally [...] Read more.

The greatest source of global anthropogenic methane (CH₄) emissions is from ruminant livestock. Multiple mitigation strategies in livestock are currently being explored. Of these breeding for lower CH₄ emitting ruminants has the advantage of being permanent and cumulative and universally applicable to all classes of livestock. Here, we show that methane emissions can be predicted by the complex community of microbiota sampled from rumens enabling evaluation of systems and individuals. Furthermore, there is evidence that the microbial community is controlled not only be the feed substrate but also by the host itself and that selecting hosts that favour a microbial fermentation with lowered methane emissions changes the energy source to the animal, and in turn both rumen physiology and body composition. Current methods for obtaining microbial DNA and subsequent sequencing of an animal’s microbiome, however, are too expensive to implement in commercial selection programs. A methodology that offers fast, low-cost, high throughput profiling of rumen microbiomes using Genotyping-by-sequencing (GBS) has been developed using an unbiased reference free approach to group microbiota. To date, this has been applied to over 4000 sheep samples and validated in cattle. Results show that microbial profiles are heritable and correlated with methane emissions and feed intake. This research is part of a flagship program funded by the global research alliance to disseminate global access to technologies that lower greenhouse gas emissions in ruminant livestock. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 124 KiB

Open AccessAbstract

Simulating Bee Pollination for Horticultural Applications

by Alan Dorin

Proceedings 2019, 36(1), 178; https://doi.org/10.3390/proceedings2019036178 - 7 Apr 2020

Viewed by 994

Abstract

We depend on wild and managed bees for the pollination of a third of fruits, vegetables and nuts for human consumption. Consequently, the details of the interactions between bees and flowers are of utmost concern to growers and seed producers. However, due to [...] Read more.

We depend on wild and managed bees for the pollination of a third of fruits, vegetables and nuts for human consumption. Consequently, the details of the interactions between bees and flowers are of utmost concern to growers and seed producers. However, due to the increasing variability of our climate, the loss of bees’ natural habitat, the use of pesticides and the industrialisation of agriculture, the interactions between bees and our flowering crops are changing in complex ways. Traditional field trials are one approach helping to establish how these changes are impacting on food production, but these techniques are time-consuming, season-limited, and susceptible themselves to the same rapid and dynamic disruptions the ecosystems are subject to. Instead, we propose an iterative experimental approach, in which detailed computer simulations that predict how best to run field trials, are repeatedly informed by field observations and field trial outcomes. The simulations account for bee species’ unique perceptual, behavioural, physiological and morphological characteristics, and realistically model the bees’ foraging environments, including open fields, protected crops, and natural ecosystems. We explain how our simulations work, and provide case studies detailing the results of experiments with planting layout to boost pollination. These models lead to improved plant/pollinator interaction management. They have the potential to boost yield, quality, and shelf-life for a variety of crops, to raise food security generally, and to improve the sustainability of our farm and natural ecosystem management practices. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 135 KiB

Open AccessAbstract

Lime and Fertiliser Applications Increase Yield of Leafy Vegetable Crops in Cambodia

by Sarith Hin, Veasna Touch, Vanndy Lim, Jochen Eberhard, Alice R. Melland, John McPhee, Suzie Jones, Stephen Ives and Vang Seng

Proceedings 2019, 36(1), 179; https://doi.org/10.3390/proceedings2019036179 - 7 Apr 2020

Cited by 1 | Viewed by 1125

Abstract

Growing vegetables after rice harvest allows Cambodian farmers to use land that would otherwise be unproductive between rice crops. Producing vegetables on these soils is limited by low soil pH, low cation exchange capacity and limited nutrient retention capacity. Soil pH in the [...] Read more.

Growing vegetables after rice harvest allows Cambodian farmers to use land that would otherwise be unproductive between rice crops. Producing vegetables on these soils is limited by low soil pH, low cation exchange capacity and limited nutrient retention capacity. Soil pH in the top 20 cm is generally low (pH 5.5 H₂O) and may limit the availability of nutrients. Farm-based trials in Siem Reap and Kampot provinces assessed the effect of lime and fertiliser on leafy vegetable crop growth and yield. At lime-only sites, lime was applied at rates of 0.5, 1.0 and 2.0 tonnes per hectare (t/ha) in conjunction with farmer practice fertiliser rates. For sites with lime and fertiliser treatments, combinations of farmer practice and optimal fertiliser rates, no lime and 2.0 t/ha of lime were applied. Two consecutive crops were planted at one site to examine the residual effect of lime on soil pH and crop yield. At lime-only sites, all crops responded to lime application with yield increases of up to 100%. For sites that assessed combinations of lime and fertiliser, the treatment of lime and optimum fertiliser rates showed the highest yield increase (92%). Application of 2.0 t/ha lime increased soil pH by approximately 1.0 unit. This effect was still evident after a second crop of Bok Choy. For the 0.5 t/ha lime treatment, an initial soil pH increase of 0.4 units had reduced to 0.2 units after the second crop. The first crop yield was higher than the second crop yield. Long-term field trials are needed to examine residual lime effects. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 163 KiB

Open AccessAbstract

Unique Secreted in Xylem Genes in Banana-Infecting Endophytic Fusarium Oxysporum

by Rebecca Lyons, Elizabeth Czislowski, Isabel Zeil-Rolfe, Shubhdeep Kaur, Zhendong Liu, Andy Chen and Elizabeth Aitken

Proceedings 2019, 36(1), 180; https://doi.org/10.3390/proceedings2019036180 - 7 Apr 2020

Cited by 1 | Viewed by 1619

Abstract

Members of the Fusarium oxysporum species complex include pathogenic and non-pathogenic isolates and infect a broad range of plant species. F. oxysporum f. sp. cubense (Foc) causes the destructive Fusarium wilt of banana, and the recently emerged Foc tropical race 4 [...] Read more.

Members of the Fusarium oxysporum species complex include pathogenic and non-pathogenic isolates and infect a broad range of plant species. F. oxysporum f. sp. cubense (Foc) causes the destructive Fusarium wilt of banana, and the recently emerged Foc tropical race 4 strain threatens the global banana industry. Secreted in xylem (SIX) genes encode for F. oxysporum effector proteins that are associated with virulence in pathogenic F. oxysporum, however they have rarely been reported from non-pathogenic F. oxysporum isolates. Our recent survey of asymptomatic banana plants grown in Foc-infested fields in Queensland and northern NSW revealed that diverse Fusarium spp, including F. oxysporum, reside in the plant roots and pseudostem without causing obvious damage to the plant. Intriguingly, we amplified SIX genes from several of the putative endophytic F. oxysporum isolates identified in the survey and found that they differ in their profile to known Foc SIX genes. To study the role of the endophytic F. oxysporum isolates in planta and the biological function of their SIX genes in more detail, we will re-inoculate cultivated and wild diploid banana lines with the endophytic F. oxysporum strains under glasshouse conditions to assess if they are non-pathogenic on banana. Secondly, we will determine whether the endophytic F. oxysporum SIX genes are expressed in planta and/or in vitro and look at the transcriptome changes occurring in the host following infection. Finally, endophytic F. oxysporum strains transformed with GFP will be used to investigate the extent of fungal colonisation in the plant. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

Back to Basics: Does Seed Size Affect Germination and Plant Uniformity in Broccoli (Brassica Oleracea var Italica)?

by Celia van Sprang and Gayathri Rajagopal

Proceedings 2019, 36(1), 181; https://doi.org/10.3390/proceedings2019036181 - 7 Apr 2020

Viewed by 1073

Abstract

Hand harvested crops, such as brassicas and lettuce, are prone to high levels of variability during growth and at harvest. This necessitates multiple harvest passes and substantially increased labour costs for the grower. Both biotic and abiotic factors contribute to this lack of [...] Read more.

Hand harvested crops, such as brassicas and lettuce, are prone to high levels of variability during growth and at harvest. This necessitates multiple harvest passes and substantially increased labour costs for the grower. Both biotic and abiotic factors contribute to this lack of field uniformity. The main objective was to evaluate the impact of broccoli (Brassica oleracea var. Italica) seed size variability on germination, subsequent crop growth and harvest uniformity. An initial experiment was conducted where germination counts across three seed-size categories including, 2.0mm (SS1), 2.3 mm (SS2) and 2.45 mm (SS3), were recorded at 3, 7, 10 and 14 days after sowing (DAS). At 14 DAS, germination was greater in the SS1 (95%) and SS2 (91%) than the SS3 (66%) (P < 0.005). A second experiment evaluated the same seed categories planted under direct seeded (DS) and transplanted (TR) conditions to identify differences in crop growth and development. At 49 DAS, DS plant counts per plot were lowest for the SS3 (54.5 plants plot⁻¹) compared with the SS1 (70.5 plants plot⁻¹) and SS2 (64 plants plot⁻¹). This could be attributed to the reduced seed coat thickness evident in the SS3 (66.3 μm) which can potentially lead to increased damage and mortality of the seed, compared with the SS1 (79.3 μm) and SS2 (73.1 μm). The TR treatment gave greater uniformity with no significant difference (P < 0.05) in plant populations across seed size categories (SS1 = 95, SS2 = 90 and SS3 = 96 plants plot⁻¹). Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 137 KiB

Open AccessAbstract

Assessment of Soil Structural Properties in Relation to Land Use Change in South-East Asia

by Rachel de Lastic, Thảo Hoàng, Phuong Nguyen, Sovanda Son, Vuthy Suos and Gunnar Kirchhof

Proceedings 2019, 36(1), 182; https://doi.org/10.3390/proceedings2019036182 - 7 Apr 2020

Viewed by 1067

Abstract

For many emerging economies, rapid land use change from forest to farmland is resulting in high levels of land degradation. Farming systems such as maize cultivation under conventional tillage after slash and burn degrade the soil resource through declining soil structural stability. Cultivation [...] Read more.

For many emerging economies, rapid land use change from forest to farmland is resulting in high levels of land degradation. Farming systems such as maize cultivation under conventional tillage after slash and burn degrade the soil resource through declining soil structural stability. Cultivation enhances mineralisation and hence loss of soil organic matter, which in turn reduces soil structures stability and promotes further carbon losses through soil erosion. Alternative land uses such as fruit tree plantations, or practise change to reduced tillage or conservation agriculture have the potential to counter this spiral of accelerated soil degradation through improving soil structural stability and build-up of soil organic matter. This project assessed how land use influences soil structural stability in Cambodia near Battambang and the North-Western Mountain regions of Vietnam where maize based system are most common. Soil properties measured were: (1) total carbon and nitrogen content analysis, (2) particle and aggregate size distribution using laser refraction, (3) hydraulic conductivity, (4) bulk density and (5) microbial CO₂ respiration. Information on land use history was also collected through farmer surveys. Land use significantly influenced aggregate stability and hydraulic conductivity. This was largely associated with differences in soil organic carbon content. Forest system had the highest, and conventional maize systems had the lowest amount of large aggregates. Fruit tree plantations are relatively new to these regions but they already showed improved soil aggregate sizes though the level of improvement varied and depended on remnant soil. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 153 KiB

Open AccessAbstract

Evaluation of the Effect of Organic Fertilisers on Lettuce Yield in Lao People’s Democratic Republic (PDR)

by Phimmasone Sisouvanh, John McPhee, Suzie Jones, Stephen Ives, Alice R. Melland, Jochen Eberhard, Tounglien Vilayphone, Phaythoune Mounsena and Bounneuang Douang Boupha

Proceedings 2019, 36(1), 183; https://doi.org/10.3390/proceedings2019036183 - 7 Apr 2020

Viewed by 1078

Abstract

Production of leafy vegetables, such as lettuce, in Lao People’s Democratic Republic (PDR) is limited by low nutrient soils. Organic fertilisers or composts made from agricultural residues may provide Lao PDR farmers with economical and environmentally sustainable alternatives to chemical fertilisers. Research is [...] Read more.

Production of leafy vegetables, such as lettuce, in Lao People’s Democratic Republic (PDR) is limited by low nutrient soils. Organic fertilisers or composts made from agricultural residues may provide Lao PDR farmers with economical and environmentally sustainable alternatives to chemical fertilisers. Research is needed to increase awareness and knowledge of organic fertilisers suited to vegetable production in Lao PDR. An experiment at the Horticultural Research Centre (HRC) in Vientiane assessed the effect of four organic fertilisers on growth and yield of lettuce. Two commercially available fertilisers (fermented manure compost and an organic fertiliser) were compared with a mixture of cow manure plus rice husks, and a fourth compost made from vegetable leaves, straw and cow manure at the HRC. The experimental design was a randomised block with four replicates for each fertiliser treatment. Lettuce was grown in raised beds with 10 tonnes per hectare (t/ha) fertiliser applied before seedlings were transplanted. The fermented manure compost treatment had the highest yield (1.95 kg/m²) and was significantly higher than the other three treatments (p < 0.001). Growth rates were also highest for the fermented manure compost at all measured growth intervals (14, 28 and 45 days after transplanting). Rapid nutrient release from fertiliser is important for short-term crops. The higher growth rates and yields found for the fermented manure compost indicate that nutrients were released sooner and were more readily available compared to the other treatments. Mature compost releases nutrients more rapidly than compost that contains partially decomposed rice husks, vegetable leaves and straw. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Linkages for Life: Assessing Tomato Value Chain Pathways and Opportunities for Better Livelihoods of Marginal and Vulnerable Groups in Pakistan

by Sajida Taj, Gomathy Palaniappan and Zubair Anwar

Proceedings 2019, 36(1), 184; https://doi.org/10.3390/proceedings2019036184 - 8 Apr 2020

Viewed by 1205

Abstract

This case study offers insights into assessing tomato value chain to improving rural livelihoods of marginal and vulnerable groups in rural Punjab, Pakistan. This research is based on qualitative data collected through Focused Group Discussions (FGDs) in two pilot villages of district Muzaffargarh [...] Read more.

This case study offers insights into assessing tomato value chain to improving rural livelihoods of marginal and vulnerable groups in rural Punjab, Pakistan. This research is based on qualitative data collected through Focused Group Discussions (FGDs) in two pilot villages of district Muzaffargarh with men and women farmers separately. The research aims to explore the pathways, linkages and new avenues and opportunities for marginal and vulnerable groups especially women to increase their household incomes under a collaborative Pakistan-Australia Strengthening Vegetable Value Chain Project (SVVCP). It is imperative to identify effective linkages between farmers and other chain actors to have a comprehensive understanding of how these works and what roles public and private actors play in making them work more effectively to plan and implement the project activities with farmers, for farmer and by farmers. It was found that most of farming households operate less than an acre of land and supplement their income with farm labour and small businesses. Both men and women farmers indicated lack of linkages and opportunities for them besides their limited access to agricultural knowledge, skills and resources. Men have diverse linkages with male dominant institutions such as agriculture and marketing. In contrast, women have no linkages with viable economic institutions such as production and marketing and tend to be associated with domestic and community affairs. The findings suggest that, it is imperative that farmers must have access to required information and skills and opportunities for networking to build sustainable linkages with value chain actors. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 134 KiB

Open AccessAbstract

Evaluation of the Effect of Lime and Irrigation on Lettuce Yield in Laos

by John McPhee, Suzie Jones, Stephen Ives, Alice Melland, Jochen Eberhard, Phimmasone Sisouvanh, Inthong Somphou, Bounneuang Douang Boupha and Phaythoune Mounsena

Proceedings 2019, 36(1), 185; https://doi.org/10.3390/proceedings2019036185 - 8 Apr 2020

Viewed by 1273

Abstract

Diversification of food sources and agricultural production systems has potential to enhance domestic supplies and provide export market opportunities for Laos. Major constraints to agricultural productivity are related to soil management and include inefficient irrigation, poor soil structural stability, low pH and nutrient [...] Read more.

Diversification of food sources and agricultural production systems has potential to enhance domestic supplies and provide export market opportunities for Laos. Major constraints to agricultural productivity are related to soil management and include inefficient irrigation, poor soil structural stability, low pH and nutrient availability. An experiment at the National University of Laos (NUOL) in Vientiane assessed the effect of lime and irrigation scheduling on growth and yield of lettuce. The soil was a sandy clay loam with pH 4.89 (H₂O) in the top 15 cm. Lime (CaCO₃) was applied at rates of 2 and 4 tonnes per hectare (t/ha). Irrigation scheduling was based on calculated evapotranspiration (ETc) with frequencies of either twice daily, once daily or alternate days. Urea, chicken manure and rice husks were added to soil in all trial plots. The experimental design was split-plot with two treatments (lime and irrigation scheduling) and four replications. The combination of 4 t/ha lime and irrigation every second day had the highest yield (mean > 2 kg/m²). The combined treatment of irrigation once a day and no added lime showed significantly higher leaf number (p = 0.01) and plant height (p < 0.001) compared to the other treatment combinations. However, increased biomass of individual plants did not translate into increased marketable yield per square metre. The application of lime raised the pH of soil but the effect on plant growth and yield was not conclusive. Separation of the two treatments into single factor trials is needed to elucidate the effects of individual treatments in future trials. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

Impact of Insect Larvae on Meat Quality

by Louwrens C. Hoffman

Proceedings 2019, 36(1), 186; https://doi.org/10.3390/proceedings2019036186 - 8 Apr 2020

Viewed by 1289

Abstract

The use of the black soldier fly (BSF: Hermetia illucens) as a means of upstreaming waste has enjoyed increasing research the past few years. One of the uses of the resultant larvae is as animal feed, with particular success achieved when fed [...] Read more.

The use of the black soldier fly (BSF: Hermetia illucens) as a means of upstreaming waste has enjoyed increasing research the past few years. One of the uses of the resultant larvae is as animal feed, with particular success achieved when fed to mono-gastric animals. Most of the research has been on the use of BSF as feed in poultry and fish species. In poultry, larvae were produced on abattoir waste, kitchen waste or faecal matter (human and animal manure). The insects were grown until harvest as larvae, pre-pupae or pupae. The post-harvest processing included freezing, drying and/or milling. Where the poultry were fed Iso-nitrogenous/Iso-energetic diets containing various proportions of BSF, no differences in production performance or carcass yields (breast-, thigh-yields) were found. As pertaining to meat quality, no differences for initial pH or ultimate pH of the meat were noted. Differences for breast colour measurements were found; larvae fed chicken breast meat was generally lighter and redder whilst results on the breasts’ water binding capacity was inconclusive. For sensory attributes, no differences were observed except for juiciness and sustained juiciness. Sometimes a metallic flavour was noted, particularly on larvae fed on abattoir wastes. Manipulating the larvae’s diet as a strategy to change the chemical composition of the poultry has focused on attempts to change the fatty acid profiles and yielded mixed results; irrespective of the fatty acid profile, the fat of BSF larvae contains large amounts of lauric acid; known to have profound antiviral and antibacterial activity. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 144 KiB

Open AccessAbstract

Enzymatic Fractionation of Protein, Fat and Chitin from Hermetia illucens (L.) (Diptera: Stratiomyidae)

by Michael Josias Woods, Louwrens Christiaan Hoffman, Elsje Pieterse and Neill Jurgens Goosen

Proceedings 2019, 36(1), 187; https://doi.org/10.3390/proceedings2019036187 - 8 Apr 2020

Cited by 1 | Viewed by 1705

Abstract

Insects have the ability to convert biowaste into valuable functional compounds, such as proteins, fat and chitin. Currently, unlike with conventional commodities, there are few fractionation methods to isolate these compounds for diversification of use. Enzymatic hydrolysis is a possible method to fractionate [...] Read more.

Insects have the ability to convert biowaste into valuable functional compounds, such as proteins, fat and chitin. Currently, unlike with conventional commodities, there are few fractionation methods to isolate these compounds for diversification of use. Enzymatic hydrolysis is a possible method to fractionate Hermetia illucens larvae, into protein, fat and chitin. This method is a particularly attractive due to the milder process conditions required compared to chemical methods, the relative ease to control the reaction and minimal formation of unpalatable and toxic by-products. A central composite design was used to help identify the optimum hydrolysis conditions for fractionation. At these conditions the fat recovery was ?~81%; substantially more than previous attempts and the fatty acid profile stayed unchanged from the original larvae material. The protein solubility was ~57%, with a degree of hydrolysis of ~22%, and was on par with previous studies. The amino acid profile of the soluble proteins differed from the original larvae material with a slight decrease in the ratio of essential to total amino acids. The insoluble proteins were accounted for with the chitin. A washing-and-sieving step, as means to recover the insoluble proteins from the chitin is envisaged. Also, the spray drying of the protein hydrolysate produced and its functional properties allows for future investigation. This technology allows for higher margins to be made, both environmentally as well as financially, compared to the use of the ‘intact’ biomass. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 124 KiB

Open AccessAbstract

Provenance in Sheep: The Karoo Lamb Story

by Louwrens Hoffman and Sara Erasmus

Proceedings 2019, 36(1), 188; https://doi.org/10.3390/proceedings2019036188 - 8 Apr 2020

Viewed by 1362

Abstract

Noted for its unique herbaceous flavour which is imbued from a diet of indigenous fragrant plants, Karoo lamb is marketed as one of South Africa’s finest meat products and enjoys Protected Geographical Indication (PGI) status in South Africa and the European Union. Its [...] Read more.

Noted for its unique herbaceous flavour which is imbued from a diet of indigenous fragrant plants, Karoo lamb is marketed as one of South Africa’s finest meat products and enjoys Protected Geographical Indication (PGI) status in South Africa and the European Union. Its distinct quality is imparted through natural grazing of the sheep on the Karoo veld that has a significant influence on the sensory and chemical profile of the meat. Descriptive sensory analysis, fatty acid analysis, solid-phase microextraction, isotope ratio mass spectrometry, portable near-infrared reflectance spectroscopy and proton transfer reaction-mass spectrometry proved to be very successful analytical tools for the authentication of regionally unique lamb meat, distinguishing Karoo from Non-Karoo lamb. Characteristic volatiles, specifically terpenes, present in both the Karoo bushes and the Karoo lamb meat and fat were detected. The dominant terpenes were tentatively identified as α-pinene, β-pinene, limonene and trans-caryophyllene, and they were particularly prominent in the fat tissue. Within the Karoo, regional differences were apparent as Hantam Karoo lamb had the highest ratings for herbaceous aroma and flavour and contained the greatest concentration of terpenes. Herbaceous aroma and flavour attributes associated with a diet rich in fragrant Karoo plants were verified with stable isotope ratio analysis. The results confirm that Karoo bushes are responsible for the distinct aroma and flavour of Karoo lamb, thereby providing vital evidence for its certification and to justify the protection of its indicator status. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 112 KiB

Open AccessAbstract

Prediction of Northern Australian Rainfall Onset Using the ACCESS-Seasonal Model

by Tim Cowan, Matthew Wheeler and Roger Stone

Proceedings 2019, 36(1), 189; https://doi.org/10.3390/proceedings2019036189 - 8 Apr 2020

Cited by 3 | Viewed by 1195

Abstract

The development of the Australian Community Climate Earth-System Simulator-Seasonal version 1 (ACCESS-S1) prediction system signifies a major step in addressing predictive limitations in multi-week to seasonal forecasting. It is anticipated that ACCESS-S1 will provide greater skill in its prediction of the wet season [...] Read more.

The development of the Australian Community Climate Earth-System Simulator-Seasonal version 1 (ACCESS-S1) prediction system signifies a major step in addressing predictive limitations in multi-week to seasonal forecasting. It is anticipated that ACCESS-S1 will provide greater skill in its prediction of the wet season onset and intensity, which are crucial to the viability of cattle grazing across northern Australia. We evaluate the hindcast skill of the ACCESS-S1 for the northern rainfall onset, defined as the date when 50 mm of precipitation has accumulated at a given location from the 1st of September, heralding the start of the seasonal dry-to-wet transition over northern Australia. We show that the raw ACCESS-S1 hindcasts, regridded to a 5 km observed grid, capture the broad-scale features of the median onset, including an early October onset over the western Top End and southeast Queensland. However, the hindcasts fail to capture the later December onsets over central Australia. The greatest improvement in onset skill comes from first calibrating the hindcasts using observations, which outperform the raw model and bias corrected hindcasts over central Australia and the far west in the Pilbara-Gascoyne basin. Based on its simulation of realistic northern rainfall onset dates and variability alone, ACCESS-S1’s prediction performance can be considered an improvement over the older predictive system. As the real-time onset forecasts have were issued using ACCESS-S1 in July 2019, it is expected that the calibrated predictions will help improve the resilience of cattle producers and graziers to drought across northern Australia. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 114 KiB

Open AccessAbstract

Modelling Heat and Drought Adaptation in Crops

by Erik van Oosterom, Greg McLean, Kurt Deifel, Vijaya Singh, David Jordan and Graeme Hammer

Proceedings 2019, 36(1), 190; https://doi.org/10.3390/proceedings2019036190 - 8 Apr 2020

Cited by 1 | Viewed by 1313

Abstract

Drought and heat stress are increasingly important abiotic limitations to productivity of sorghum. Here, we use long-term simulations to quantify the importance of transpiration rates to drought adaptation and the importance of threshold temperatures and tolerance above the threshold for adaptation of seed [...] Read more.

Drought and heat stress are increasingly important abiotic limitations to productivity of sorghum. Here, we use long-term simulations to quantify the importance of transpiration rates to drought adaptation and the importance of threshold temperatures and tolerance above the threshold for adaptation of seed set to heat stress. Simulations were parameterised using results of detailed physiological studies. The importance of transpiration rates to drought adaption was studied by comparing productivity of maize and 3dwarf sorghum. These crops have similar transpiration efficiency but contrasting transpiration rates per unit green leaf area (TGLA), which was captured through differences in RUE. Results showed that the greater TGLA of maize reduced productivity under drought stress, but increased productivity in well-watered conditions, indicating a trade-off between yield potential and drought adaptation. The increased water use of maize associated with higher yield potential could negatively affect carry-over of soil water in a cropping systems context. Simulations for sorghum productivity under heat stress, using long-term weather records for six locations across the Australian sorghum belt, showed that the most common incidence of heat stress around anthesis was the occurrence of individual days with maximum temperatures of 36–38 °C. Because these temperatures were near the threshold that limits seed set, increased temperature thresholds generally minimised yield reductions. However, predicted temperature increases in coming decades justify additional selection for increased tolerance above the threshold. As manipulating sowing dates did not reduce risks of heat stress around anthesis, genetic improvement provides the best prospect to mitigate adverse effects on grain yield. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Impact of Agroforestry Practice on Soil Conservation- Initial Assessment in Northwest Vietnam

by Hung Do, Thach Nguyen and Nguyen La

Proceedings 2019, 36(1), 191; https://doi.org/10.3390/proceedings2019036191 - 8 Apr 2020

Viewed by 1386

Abstract

In the Northwest Vietnam, traditional maize (Zea mays) cultivation practices of farmers mainly based on sole cropping, intensive tillage combined with burning crop residues on steep slopes. These cultivation practices resulted in severe erosion, soil degradation, reducing crop production and un-sustainable [...] Read more.

In the Northwest Vietnam, traditional maize (Zea mays) cultivation practices of farmers mainly based on sole cropping, intensive tillage combined with burning crop residues on steep slopes. These cultivation practices resulted in severe erosion, soil degradation, reducing crop production and un-sustainable production systems. It requires assessing of the impact of agroforestry practice on the soil conservation in the context of the upland areas in Northwest Vietnam. This study has been carried out since 2017 to present the actual impact of agroforestry practice including longan (Dimocarpus longan)+mango (Mangifera indica L.)+maize+forage grass strips (Guinea-Panicum maximum) on soil conservation. The assessment based on quantifying soil loss by soil traps and evaluating terrace’s formation by erosion pins placing above forage grass strips. The sole maize system had been using for the comparison. The initial results showed that the evaluated agroforestry practice reduced soil loss from 18.3 to 37.4% in compared with the sole maize system in 2017 and 2018, respectively. In the second year (2018), the deposition of sediment on the front and rear pins at the above grass trips was 0.81 and 0.41 cm, respectively. It indicated the increment in soil surface at the above grass strips. In contrast, the negative value of the deposition of sediment was recorded in the sole maize system. We are continuing to monitor the impact of agroforestry practices on reducing soil loss and terrace formation, and evaluate the function of the system on soil fertility improvement, nutrient use efficiency and economic profitability. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 126 KiB

Open AccessAbstract

Zeaxanthin-Biofortified Popcorn for Eye Health

by Tim J. O’Hare

Proceedings 2019, 36(1), 192; https://doi.org/10.3390/proceedings2019036192 - 8 Apr 2020

Viewed by 1317

Abstract

Zeaxanthin is one of only two dietary carotenoids accumulated in the human macula. A key role of zeaxanthin is to protect the eyes’ photoreceptors from damage induced by blue light. Photoreceptor damage can lead to macular degeneration, which is the leading cause of [...] Read more.

Zeaxanthin is one of only two dietary carotenoids accumulated in the human macula. A key role of zeaxanthin is to protect the eyes’ photoreceptors from damage induced by blue light. Photoreceptor damage can lead to macular degeneration, which is the leading cause of blindness in Australia. Unfortunately, zeaxanthin is fairly rare in our diet. Popcorn (Zea mays var. everta) is a good dietary source of zeaxanthin, but the creation of zeaxanthin-biofortified popcorn potentially allows less popcorn to be consumed for an increased dietary dose of zeaxanthin. As zeaxanthin is an orange pigment, breeding for zeaxanthin gives popped kernels a naturally buttery colour, unlike standard popcorn, which is virtually white. The creation of naturally buttery-coloured popcorn potentially negates the practise of adding artificial butter-colourants, while also providing an excellent source of dietary zeaxanthin. The action of popping involves a combination of high-temperature and high-pressure, sufficient enough for starch to liquefy, and for the tiny beads of moisture within starch bodies to reach an extremely high pressure. Eventually, the kernel pericarp can no longer withstand this pressure, and an explosion occurs, resulting in butterfly-shaped popcorn. These extreme conditions, however, lead to an approximate 50% decline in zeaxanthin concentration following popping, and a gradual further 25% reduction over the next 24 h. Consequently, in order to optimise zeaxanthin intake, popcorn should be eaten as soon as possible after popping. Zeaxanthin-biofortified popcorn provides an additional dietary source of zeaxanthin, potentially reaching a sector of the community more prone to low zeaxanthin intake. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 138 KiB

Open AccessAbstract

Heterobeltiosis in Banana and Genetic Gains through Crossbreeding

by Michael Batte, Brigitte Uwimana, Rony Swennen, Allan Brown, Helena Persson Hovmalm, Mulatu Geleta and Rodomiro Ortiz

Proceedings 2019, 36(1), 193; https://doi.org/10.3390/proceedings2019036193 - 8 Apr 2020

Viewed by 8077

Abstract

Heterosis, or hybrid vigour, is the superiority of the hybrid for a certain trait over the mean of its two parents. Heterobeltiosis is a form of heterosis where the hybrid is superior to its best parent. Banana breeding is a tedious, time-consuming process, [...] Read more.

Heterosis, or hybrid vigour, is the superiority of the hybrid for a certain trait over the mean of its two parents. Heterobeltiosis is a form of heterosis where the hybrid is superior to its best parent. Banana breeding is a tedious, time-consuming process, taking up to two decades to develop a hybrid. Understanding heterosis in banana breeding will contribute to selecting right breeding materials for further crossing, thus increasing banana breeding efficiency. Here we document heterobeltiosis by using the recently bred NARITA ‘Matooke’ hybrids and their ancestors. NARITA hybrids, their parents (4x and 2x), grandparents (3x and 2x), and local 3x ‘Matooke’ cultivar checks were planted in a rectangular lattice design with two replications. Yield and other agronomic data were collected at flowering and harvest. The NARITAs were compared with their 3x ‘Matooke’ grandmothers. Heterobeltiosis on bunch weight was calculated with the data of 3 cycles. All the NARITAs showed heterobeltiosis for bunch weight. NARITA 17 had the highest grandparent heterobeltiosis (ca. 250%). Genetic gains due to crossbreeding were determined for fruit yield considering three generations: matooke cultigen (C₀), primary tetraploid hybrids (C₁) and secondary tetraploid hybrids (C₂). The average genetic gain (from C₀ to C₂) rates for bunch weight (kg) and yield potential (t ha⁻¹ year⁻¹) were 1.4% and 1.3% per year, respectively. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 146 KiB

Open AccessAbstract

Diversity Breeding Program on Common Bean (Phaseolus vulgaris L.) Targeting Rapid Cooking and Iron and Zinc Biofortification

by Clare Mukankusi, Wallace A. Cowling, Kadambot H.M. Siddique, Li Li, Brian Kinghorn and Jean Claude Rubyogo

Proceedings 2019, 36(1), 194; https://doi.org/10.3390/proceedings2019036194 - 8 Apr 2020

Cited by 1 | Viewed by 1413

Abstract

Common bean (Phaseolus vulgaris L.) is a major component of agricultural systems and diets of the urban and rural populations of East and Central Africa, providing Fe and Zn essential to the health and well-being of African women and children, and protein [...] Read more.

Common bean (Phaseolus vulgaris L.) is a major component of agricultural systems and diets of the urban and rural populations of East and Central Africa, providing Fe and Zn essential to the health and well-being of African women and children, and protein essential for the entire household. However, bean consumption is limited by constraints such as long cooking time (CT). Cooking demands large amounts of water, fuel and time. It has negative effects on the environment, livelihoods, security and health. Genetic variability in cooking time is documented. Recent development of new breeding methods based on pedigree and genomic selection together with optimal contribution selection (OCS) offers an opportunity to accelerate breeding for rapid CT and higher Fe and Zn grain content. Genotypic and phenotypic data of an African diversity pool, representing key bean market classes, were used to generate genomic estimated breeding values (GEBVs) for grain yield, CT, Fe and Zn. GEBV’s were weighted to maximise the desired outcome in an economic index. From 161 candidate bean genotypes with GEBVs, 67 were chosen for 80 matings within six major grain market classes. An additional 22 breeder nominated matings were included. The predicted outcomes in the first cycle showed a major improvement in population mean for index (+286.77 US$/ha), 6.2% increase in GY and 7.3% reduction in CT, with an achieved increase in population co-ancestry of 0.0753. A 30% reduction in the mean population CT and improved Fe (15%) and Zn (10%), is expected after 5 cycles of annual recurrent selection. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 156 KiB

Open AccessAbstract

Novel Source of Biotic Stress Resistance Identified from Brassica Species and its Wild Relatives

by Rashmi Yadav, J. Nanjundan, Ashish K. Gupta, Mahesh Rao, Jameel Akhtar, J. C. Rana, Ashok Kumar and Kuldeep Singh

Proceedings 2019, 36(1), 195; https://doi.org/10.3390/proceedings2019036195 - 8 Apr 2020

Cited by 1 | Viewed by 2080

Abstract

In rapeseed and mustard, the major diseases (downy mildew, white rust, Alternaria blight and Sclerotinia stem rot) cause 37–47%loss in pod formation and 17–54% reduction in grain yield. The identification of new sources of resistance is a high priority in breeding programs. About [...] Read more.

In rapeseed and mustard, the major diseases (downy mildew, white rust, Alternaria blight and Sclerotinia stem rot) cause 37–47%loss in pod formation and 17–54% reduction in grain yield. The identification of new sources of resistance is a high priority in breeding programs. About 3000 germplasm accessions of Indian mustard were evaluated under multiple environments (3 seasons) at hot spots (4 locations) and under artificial epiphytophic conditions against insect pests and diseases (aphids, white rust, powdery mildew and Alternaria blight). Accessions IC265495, IC313380, EC766091, EC766133, EC766134, EC766192, EC766230, EC766272 were identified as highly resistant to white rust (A. candida) with disease severity reaction (Percent disease severity Index, PDI = 0) under artificial inoculation. Accession RDV 29 showed the inheritance of resistant source for powdery mildew in Indian mustard. Screening of brassica wild relatives (about 25 species) for white rust found that Brassica fruticulosa, Brassica tournefortii, Camelina sativa, Diplotaxis assurgens, D. catholica, D. cretacia, D. Erucoides, D. Muralis, Lepidium sativum had highly resistance (PDI = 0) to Delhi isolates of white rust. Several traits identified from cultivated and related species will be useful for genetic improvement of rapeseed and mustard. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 134 KiB

Open AccessAbstract

Combining Trait Physiology, Crop Modelling and Molecular Genetics to Improve Wheat Adaptation to Terminal Water-Stress Targeting Stay-Green and Root Traits

by Jack Christopher, Cecile Richard, Karine Chenu, Mandy Christopher, Valeria Paccapello, Andrew Borrell and Lee Hickey

Proceedings 2019, 36(1), 196; https://doi.org/10.3390/proceedings2019036196 - 8 Apr 2020

Viewed by 1299

Abstract

Terminal drought stress is currently a major constraint in many wheat production regions. This is predicted to worsen with future climate change. The stay-green phenotype allows crops to remain green and photosynthesize for longer after anthesis, potentially improving yields in terminal drought environments. [...] Read more.

Terminal drought stress is currently a major constraint in many wheat production regions. This is predicted to worsen with future climate change. The stay-green phenotype allows crops to remain green and photosynthesize for longer after anthesis, potentially improving yields in terminal drought environments. Root systems with greater root length density at depth can contribute by increasing access to deep soil moisture late in the season. To study the genetics of root and stay-green traits in wheat, a multi reference parent nested association mapping (NAM) population was developed. Using the “speed breeding” system of rapid generation advance, over 1500 recombinant inbred lines (RIL) were generated in approximately 18 months. Genome-wide association studies (GWAS) using a novel whole-genome NAM method (WG-NAM) identified genetic regions associated with the target traits. High-throughput techniques were developed and used for the NAM lines to (i) phenotype seedling roots in controlled conditions, and (ii) objectively characterize novel stay-green traits for hundreds of genotypes in standard yield plots in the field. NAM lines were phenotyped for yield and stay-green traits at multiple water-stressed and non-stressed environments during 4 seasons. Particular traits were associated with superior adaptation to certain environments. Many lines with adaptive root and stay-green traits exhibited superior yield to the reference parent in relevant target environments and 54 such lines have been provided to commercial Australian wheat breeders for cultivar development. This combination of technologies is increasing understanding of physiological adaptation to water-limited environments in wheat and helping accelerate genetic progress. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 138 KiB

Open AccessAbstract

Genetic Elucidation of Glucosinolates in a Diverse Collection of Indian Mustard (Brassica juncea L.)

by Erwin Tandayu, Priyakshee Gohain, Terry Rose, Graham King and Tobias Kretzschmar

Proceedings 2019, 36(1), 197; https://doi.org/10.3390/proceedings2019036197 - 8 Apr 2020

Viewed by 1223

Abstract

Glucosinolates (GSLs) are secondary metabolites produced by members of the genus Brassica. These compounds impart the pungency to brassica vegetables and oils. Due to their health benefits, which include anti-cancer and anti-fungal properties, they have been attracting interest in research. Indian mustard [...] Read more.

Glucosinolates (GSLs) are secondary metabolites produced by members of the genus Brassica. These compounds impart the pungency to brassica vegetables and oils. Due to their health benefits, which include anti-cancer and anti-fungal properties, they have been attracting interest in research. Indian mustard (B. juncea L.), used as condiment and oil crop has high natural levels of seed glucosinolates and displays exploitable natural variation in this trait. In this study a diverse collection of 161 mustard lines originating from 21 countries, will be genotyped and phenotyped. Traits of interest include seed GSLs (sinigrin, gluconapin, progroitin, epi-progoitin and glucoiberin), oil and protein content, as well as basic agro-morphological performance such as height, flowering time and yield. Current knowledge on GSL biosynthesis and its genetic regulation mostly relies on data from Arabidopsis thaliana. We aim to elucidate the genetic architecture of GSL content and composition in relation to other seed traits (oil and protein content) in our diversity panel through association mapping. Additionally, we are aiming to resolve genome complexity of GSL genes in mustard genome in contrast to A. thaliana by identifying gene copy number through in silico analysis. Outcome of this study will help streamline the breeding and product development for either high GSL mustard lines for condiment use or low GSL lines for canola-type oil use. Our preliminary data on seed GSLs seems to reflect the historical use of mustard in different geographical regions. Chinese and European lines featured higher GSL while lines from the Indian subcontinent displayed lower GSL contents. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 125 KiB

Open AccessAbstract

Evaluation of Copra Meal (CM) in Corn-Animal Protein Meal-Based Diets and Enzyme on Broiler Performance

by Ashika Devi and Siaka Diarra

Proceedings 2019, 36(1), 198; https://doi.org/10.3390/proceedings2019036198 - 8 Apr 2020

Viewed by 1147

Abstract

The effects of increasing CM level in corn-animal protein-based diets and enzyme supplementation in broilers was investigated in a 30-day experiment. A total of 168, one-week old Cobb broilers were assigned to 8 diets consisting of 2 controls (with and without enzyme) and [...] Read more.

The effects of increasing CM level in corn-animal protein-based diets and enzyme supplementation in broilers was investigated in a 30-day experiment. A total of 168, one-week old Cobb broilers were assigned to 8 diets consisting of 2 controls (with and without enzyme) and 6 other diets with 15, 30 and 45% CM levels with and without enzyme in a completely randomized design. Results showed significant interactions effects on growth parameters, fat digestibility, White Blood Cell (WBC) count, Saturated Fatty Acids (SFA) and Mono Unsaturated Fatty Acid (MUFA) (P < 0.05). Feed intake and WG were reduced on 30 and 45% diets (P < 0.05). Fat digestibility was improved on control and 30% CM diets with enzyme (P < 0.05). Higher WBC counts were recorded in control and 15% CM with enzyme (P < 0.05). Higher SFA and lower MUFA were on 15 and 45% diets (P < 0.05). In the main effects, feed intake and weight gain (WG) were reduced and feed conversion ratio (FCR) increased with increasing level of CM above 15% (P < 0.05). The diet with 45% CM showed lower SFA (P < 0.05) compared to 15% CM diet, MUFA and PUFA reduced with increasing CM levels (P < 0.05). Enzyme supplementation reduced SFA and MUFA content (P > 0.05) but improved crude fibre and fat digestibility of broilers (P < 0.05). In conclusion, 30% dietary CM inclusion is detrimental in terms of WG but has no effect on the fatty acid composition of broiler meat. More research into enzyme source and concentration above 30% CM is recommended. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 165 KiB

Open AccessAbstract

Characteristics of the Underutilised Pulse Bambara Groundnut (Vigna subterranea (L.) Verdc.) Relevant to Food & Nutritional Security

by Razlin Azman Halimi, Bronwyn J. Barkla, Sean Mayes and Graham J. King

Proceedings 2019, 36(1), 199; https://doi.org/10.3390/proceedings2019036199 - 8 Apr 2020

Cited by 3 | Viewed by 1526

Abstract

Underutilised crops contribute only marginally to global food and nutritional security, despite their regional nutritional, economic, and cultural significance. Their potential to make a greater contribution is often overlooked, in part due to the scarcity of data reflecting the range of nutritional variation. [...] Read more.

Underutilised crops contribute only marginally to global food and nutritional security, despite their regional nutritional, economic, and cultural significance. Their potential to make a greater contribution is often overlooked, in part due to the scarcity of data reflecting the range of nutritional variation. Bambara groundnut (BG; Vigna subterranea (L.) Verdc.), a pulse native to West Africa has been proposed as an exemplar underutilised crop. We analysed variation in the major nutritional components of 100 BG accessions of diverse geographical origins and compared these values with representatives of four related pulse crops. We found considerable intra-species variation for major components: 13.8–26.4% protein, 4.6–8.2% oil, 0.9–12.9% total dietary fibre, and 47.8–71.4% available carbohydrate. The range in seed protein and oil concentrations was similar to that measured in chickpea and mungbean. Linoleic (C18:2, n-6) accounted for up to 48% of total fatty acids in BG seed oil, and oleic (C18:1, n-9) up to 28%, with palmitic (C16:0) representing the other major component. Principal component analysis indicated that oleic, behenic (C22:0) and lignoceric (C24:0) acids are strongly associated with seed oil concentration. These data were obtained from material where there has been no systematic selection for enhancement of nutritional composition. The range of variation suggests that there is potential within the BG genepool to develop distinct sets of high-protein, high-oil cultivars. With the addition of more detailed genomic information, BG could benefit from similar breeding approaches that have been successfully adopted for crops such as cowpea and soybean. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Phosphorus Nutrition in Ruminants Grazing Tropical Rangelands

by Rob Dixon, Stephen Anderson, Lisa Kidd and Mary Fletcher

Proceedings 2019, 36(1), 200; https://doi.org/10.3390/proceedings2019036200 - 8 Apr 2020

Viewed by 1173

Abstract

Nutritional deficiency of phosphorus (P) is a major constraint to productivity of cattle grazing many tropical rangelands with low P soils, particularly in northern Australia, South America and Africa. Cattle growth and reproductive rates may be severely reduced. Such P deficiency is usually [...] Read more.

Nutritional deficiency of phosphorus (P) is a major constraint to productivity of cattle grazing many tropical rangelands with low P soils, particularly in northern Australia, South America and Africa. Cattle growth and reproductive rates may be severely reduced. Such P deficiency is usually addressed by providing supplements containing calcium phosphates. In the seasonally dry tropics such supplements are most effective when fed during the summer rainy season when the pasture quality as energy and protein are highest. Young cattle often continue to grow slowly when P deficient, but with reduced bone mineralization. Cows with normally high bone mineral reserves (from previously P-adequate diets) can mobilize bone P during late pregnancy and lactation when diet P is insufficient. This mobilization may contribute up to ca. one-third of the P requirements and allow P-deficient cows to maintain milk production and calf growth, but is associated with reduced pasture intake and severe loss of cow liveweight. Cows can replenish bone minerals when P intake exceeds immediate requirements for growth and milk. Since on large commercial farms in rangelands it is often difficult to effectively implement P supplementation of cattle during the rainy season the mobilization and replenishment of body mineral reserves are important for managing P nutrition through the annual cycle. Biochemical markers in blood are valuable for diagnosis of P deficiency in grazing cattle. In conclusion, understanding of the nutritional physiology of cattle provides opportunities to improve management of P nutrition of cattle grazing P deficient rangelands and alleviating production losses. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 127 KiB

Open AccessAbstract

Response of Grain Legume Species to Terminal Drought in Timor-Leste

by Marcal Gusmao, Delfim Da Costa, Angelo Da Costa Freitas, Kadambot H. M. Siddique and Robert Williams

Proceedings 2019, 36(1), 201; https://doi.org/10.3390/proceedings2019036201 - 8 Apr 2020

Cited by 1 | Viewed by 1171

Abstract

Growth, development and yield of three-grain legumes (mung bean [F1], soybean [F2] and grass pea [F3]) following rice crop to enhance grain production was studied in a paddy field in the northern Timor-Leste. A split plot design was used with three water treatments [...] Read more.

Growth, development and yield of three-grain legumes (mung bean [F1], soybean [F2] and grass pea [F3]) following rice crop to enhance grain production was studied in a paddy field in the northern Timor-Leste. A split plot design was used with three water treatments (well-watered [W0], water withheld at flowering [W1] and after germination [W2]). Interaction between water treatments and species on dry matter production (p < 0.001) and seed yield (p = 0.005) was observed. In control, the highest seed yield was F1 (1.2 t/ha) followed by F2 (1.1 t/ha) and F3 (0.4 t/ha) respectively. There was a steady reduction in seed yield in F1 from W0 to W2, but almost fifty percent reduction in F2 under W1 and W2 compared to W0. F3 had little difference between water treatments. The W1 and W2 reduced number of filled pods per plant in all species compared to control (W0). Between the species, F3 had the highest filled pods per plant followed by F2 and F3. The W1 and W2 reduced seeds per pod of F1; however, it did not effect F2 and F3. There were interactions between water treatment and species on 100 seeds weight. The heaviest seeds were in F2 in the control plants, but in the F2 drought treatments (W1 and W2) seed weight were less than F3. The lowest seed weight was in F1, but there was no impact of the terminal droughts on its seed weight. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 139 KiB

Open AccessAbstract

Yield Response of Sunflower to Sowing Dates and NPK Rates under Zero Tillage in Wet Soil of Southwestern Coastal Bangladesh

by Bidhan Chandro Sarker, Md. Enamul Kabir, Md. Yasin Ali and Richard W. Bell

Proceedings 2019, 36(1), 202; https://doi.org/10.3390/proceedings2019036202 - 8 Apr 2020

Viewed by 1032

Abstract

The low cropping intensity in the southwestern coastal Bangladesh is constrained by excess wetness of soil, low fertility and scarcity of fresh irrigation water. Fallow-fallow-T. aman is the main cropping pattern in this region. In the recent years some winter (dry season) crops [...] Read more.

The low cropping intensity in the southwestern coastal Bangladesh is constrained by excess wetness of soil, low fertility and scarcity of fresh irrigation water. Fallow-fallow-T. aman is the main cropping pattern in this region. In the recent years some winter (dry season) crops (wheat, sunflower, maize etc.) have been introduced. Among them sunflower is best suited as it can be established in wet soil and also having the capacity to tolerate salinity and drought to some extent. The fertility of soil of this area is low particularly nitrogen (N). There is no fertilizer recommendation for sunflower in this area. Thus it is necessary to develop a fertilizer recommendation for sunflower. To develop this, a set of field experiments were carried out during winter season (2018–19). In these experiments, the major nutrients [nitrogen (N), phosphorus (P) and potassium (K)] were varied in early (by November) and late (end of December) sown (dibbled) sunflower. Results showed that early sown sunflower produced higher seed yield with lower amount of N than that of late one. In case of P, unlike N, yield increase was not at par with the increase of P rates indicated residual P that applied to previous rice crop supported the sunflower. Potassium rates have little effect on yield increase. Based on the average yield (~3.5 t/ha) of the variety (Hysun-33) N, P and K @ 120–150, 40–50 kg/ha and 50–60 kg/ha was produced highest yield in early sown sunflower in excessively wet soil of southwestern coastal Bangladesh. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Improving Light Use Efficiency in C₄ Plants by Increasing Electron Transport Rate

by Maria Ermakova, Robert T. Furbank and Susanne von Caemmerer

Proceedings 2019, 36(1), 203; https://doi.org/10.3390/proceedings2019036203 - 8 Apr 2020

Viewed by 1199

Abstract

C₄ plants play a key role in world agriculture and strategies to manipulate and enhance C₄ photosynthesis have the potential for major agricultural impacts. The C₄ photosynthetic pathway is a biochemical CO₂ concentrating mechanism that requires the coordinated functioning [...] Read more.

C₄ plants play a key role in world agriculture and strategies to manipulate and enhance C₄ photosynthesis have the potential for major agricultural impacts. The C₄ photosynthetic pathway is a biochemical CO₂ concentrating mechanism that requires the coordinated functioning of mesophyll and bundle sheath cells of leaves. Chloroplast electron transport in C₄ plants is shared between the two cell types; it provides resources for CO₂ fixation therefore underpinning the efficiency of photosynthesis. Using the model monocot C₄ species Setaria viridis (green foxtail millet) we demonstrated that the Cytochrome (Cyt) b₆f complex regulates the electron transport capacity and thus the rate of CO₂ assimilation at high light and saturating CO₂. Overexpression of the Cyt b₆f in both mesophyll and bundle sheath cells results in a higher electron throughput and allows better light conversion efficiency in both photosystems. Importantly, increased Cyt b₆f abundance in leaves provides higher rates of C₄ photosynthesis without marked changes in Rubisco or chlorophyll content. Our results demonstrate that increasing the rate of electron transport is a viable strategy for improving the light conversion efficiency in C₄ crop species like maize and sorghum. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Control of Sugar and Fibre: Insights from Sugarcane Transcriptome Analyses

by Prathima Perumal Thirugnanasambandam, Lakshmi Kasirajan, Agnelo Furtado, Frikkie C. Botha and Robert J. Henry

Proceedings 2019, 36(1), 204; https://doi.org/10.3390/proceedings2019036204 - 8 Apr 2020

Viewed by 1090

Abstract

Sucrose and fibre in sugarcane share a very dynamic relationship depending largely upon the genetic makeup of the genotypes and growth environment. To investigate the molecular basis of carbon flux into sucrose and fibre that makes the genotypes high sugared or high fibred, [...] Read more.

Sucrose and fibre in sugarcane share a very dynamic relationship depending largely upon the genetic makeup of the genotypes and growth environment. To investigate the molecular basis of carbon flux into sucrose and fibre that makes the genotypes high sugared or high fibred, or dual purposed, an extensive transcriptomics study was undertaken using a set of sugarcane genotypes differing in sugar and fibre contents. Differential gene expression analyses were performed using 50 transcriptomes revealing a complex network of transcripts associated with growth, defence, vacuole, sucrose and fibre. Rather than merely being a storage sugar of the culms, sucrose might play a significant regulatory role in controlling the expression of several thousand genes including those related to fibre. The high sugar genotypes were not always low in fibre and the fibre might to an extent provide structural framework for maintaining high sugar levels as seen by the high expression of fibre related genes. The study suggests that there could exist certain threshold levels of sugar or fibre contents beyond which an inverse relation would occur. In addition, analysis of the transcriptomes resulted in the identification of a new isoform of sucrose synthase genes, SuSy 7 that was not reported earlier. With the availability of a monoploid reference genome, there is a need for in-depth transcriptome studies to understand and identify finer details of genes, and their transcripts in entirety and regulatory elements of sugarcane genome which is challenging the current capabilities of sequencing technologies unlike any other plant genomes sequenced thus far. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 137 KiB

Open AccessAbstract

Preliminary Investigations in Giant Taro (Alocasia macrorrhiza L.) Corm Meal as Energy Source in Poultry Diets

by Siaka Diarra

Proceedings 2019, 36(1), 205; https://doi.org/10.3390/proceedings2019036205 - 8 Apr 2020

Viewed by 1536

Abstract

Giant taro (Alocasia macrorrhiza var. Tonga) grows wild in Pacific Island countries and has become invasive in most countries. Proximate analysis of giant taro (GT) corm at USP Alafua Central Laboratory showed ~12 MJ ME/kg, 127 g crude protein/kg DM. Currently however, the [...] Read more.

Giant taro (Alocasia macrorrhiza var. Tonga) grows wild in Pacific Island countries and has become invasive in most countries. Proximate analysis of giant taro (GT) corm at USP Alafua Central Laboratory showed ~12 MJ ME/kg, 127 g crude protein/kg DM. Currently however, the crop has low food value in the region and its use in poultry feeding is still limited because of the acrid taste due to the presence of calcium (Ca) oxalate. Two preliminary studies (PS) were conducted to evaluate the feeding value of GT for poultry. Study 1 investigated the effect of coconut oil addition on the utilsation of GT corm meal by layers and broilers. Replacing dietary maize with whole GT corm meal at 200 g/kg adversely affected performance of broilers and layers (P < 0.05). Addition of coconut oil at 9:1 (corm meal: oil) improved utilisation of the meal by laying hens but not in broilers. Study 2 investigated the effect of peeling and inorganic calcium addition on the utilisation of GT corm meal by laying hens. Results showed that feeding whole GT corm meal at 200 g/kg diet had adverse effects on egg production and egg qualities (P < 0.05) but peeling or increasing dietary Ca carbonate level from 40 to 60 g/kg improved the utilisation of whole or peeled corm in terms of egg production and egg qualities. In view of the ready availability and low food value, more research is recommended into processing and diet formulation to improve the utilsation of GT corm meal by poultry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 149 KiB

Open AccessAbstract

Integrated High-Throughput Phenotyping with High Resolution Multispectral, Hyperspectral and 3D Point Cloud Techniques for Screening Wheat Genotypes on Sodic Soils

by Malini Roy Choudhury, Jack Christopher, Armando Apan, Scott Chapman, Neal Menzies and Yash Dang

Proceedings 2019, 36(1), 206; https://doi.org/10.3390/proceedings2019036206 - 8 Apr 2020

Cited by 1 | Viewed by 1446

Abstract

Wheat production in southern Queensland, Australia is adversely affected by soil sodicity. Crop phenotyping could be useful to improve productivity in such soils. This research focused on adapting high-throughput phenotyping of crop biophysical attributes to monitor crop health, nutrient deficiencies and plant moisture [...] Read more.

Wheat production in southern Queensland, Australia is adversely affected by soil sodicity. Crop phenotyping could be useful to improve productivity in such soils. This research focused on adapting high-throughput phenotyping of crop biophysical attributes to monitor crop health, nutrient deficiencies and plant moisture availability. We conducted an aerial and ground-based campaign during several wheat growing stages to capture crop information for 18 wheat genotypes at a moderately sodic site near Goondiwindi in southern Queensland. Three techniques were employed (multispectral, hyperspectral, and 3D point cloud) to monitor crop characteristics and predict biomass and yield. Spectral information and vegetation indices (VI) such as, normalized different vegetation index (NDVI), modified soil adjusted vegetation index (MSAVI), and leaf area index (LAI) were derived from multispectral imagery and compared with ground-based agronomic data for biomass, leaf area, and yield. Significant correlations were observed between NDVI and yield (R² = 0.81), LAI (R² = 0.74), and biomass (R² = 0.65). Partial least square regression (PLS-R) modelling using hyperspectral spectroscopy data provided crop yield predictions that correlated significantly with observed yield (R² = 0.65). The 3D point cloud technique was effective with comparison to in field manual measurements of crop architectural traits height and foliage cover (e.g., for height R² = 0.73). For, this study multispectral techniques showed a greater potential to predict biomass and yield of wheat genotypes under moderately sodic soils than hyperspectral and 3D point cloud techniques. In future, the genotypes will be tested under more severely sodic soils to monitor crop performance and predicting yield. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 162 KiB

Open AccessAbstract

Flight Zone as an Alternative Temperament Assessment to Predict Animal Efficiency

by Mariano Parra, Tia Breed, Alana Connolly, Emily Janz, Sarah Kennedy, Jonathan Reid, Andre Palma, Diogo Fleury Azevedo Costa and Luis Felipe Prada e Silva Silva

Proceedings 2019, 36(1), 207; https://doi.org/10.3390/proceedings2019036207 - 8 Apr 2020

Viewed by 1363

Abstract

Animal temperament evaluation can be included in the cattle selection program also because of an existing correlation with performance. However, there are different assessment methods such as flight speed (time and speed that an animal takes to leave the crush) and exit score [...] Read more.

Animal temperament evaluation can be included in the cattle selection program also because of an existing correlation with performance. However, there are different assessment methods such as flight speed (time and speed that an animal takes to leave the crush) and exit score (indicating in which pace it does). Flight zone (FZ) refers to the distance that an animal allows human proximity without signs of fear (e.g., moving away and/or aggression) and it was used in this study as an alternative approach to measure temperament without putting cattle through the crush. Apparently, there is no study correlating FZ with performance. Therefore, a pilot trial was conducted to evaluate the correlation between average daily gain (ADG), dry matter intake (DMI) and feed conversion ratio (FCR) of ten Brahman steers. Steers were classified into temperament groups (Docile < 2 m; Moderate between 2 to 2.9 m; and Lively ≥ 3 m). Even though no significant differences were found for ADG (P = 0.65), DMI (P = 0.36), and FCR (P = 0.46), the docile group gained 133 grams/day more than lively counterparts, most likely because of the extra 50 grams consumed. Furthermore, lively steers required an extra 1 kg of feed per kg of gain in comparison to docile animals, 8.24 vs. 7.28 kg FCR, respectively. These results are promising and indicate that FZ could be an efficient way to measure temperament in cattle. Thus, in order to confirm these findings, a new experiment with a more representative number of steers (n = 30) will be conducted. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 136 KiB

Open AccessAbstract

How Do Crops Balance Water Supply and Demand when Water Is Limiting?

by Andrew Borrell, Barbara George-Jaeggli, Erik van Oosterom, Graeme Hammer, Emma Mace, Ian Godwin, Guoquan Liu, Albert Wong, Temesgen Matiwos, Kassahun Bantte, Jack Christopher, Lee Hickey, Cecile Richard, Hannah Robinson and David Jordan

Proceedings 2019, 36(1), 208; https://doi.org/10.3390/proceedings2019036208 - 9 Apr 2020

Viewed by 1590

Abstract

Plants are sessile organisms requiring mechanisms that enable them to balance water supply and demand in dry environments. Demand (D) is largely driven by canopy size (transpirational leaf area), although differences in transpiration per unit leaf area also occur. Supply (S) is primarily [...] Read more.

Plants are sessile organisms requiring mechanisms that enable them to balance water supply and demand in dry environments. Demand (D) is largely driven by canopy size (transpirational leaf area), although differences in transpiration per unit leaf area also occur. Supply (S) is primarily driven by water capture via the root system. Drought stress can be defined as the situation where supply of water cannot meet demand of the crop, such that water availability is the limiting factor for biomass accumulation. Under such conditions, plants will need to reduce D in order to meet the limited S, access more water to increase S, or increase the efficiency with which water is utilised. We used sorghum, a model C4 crop species, to demonstrate how the stay-green trait can modulate canopy development and root architecture to enhance adaptation. We show how stay-green positively impacts the balance between S and D under post-flowering drought, including insights at the molecular level. We provide examples of how canopy and root traits impact the S/D balance in other cereals under water limitation. For example, on the supply side, the extent of genetic variation for root angle (RA) has been evaluated in sorghum, wheat and barley, and genomic regions associated with RA have been mapped. Furthermore, the relationship between RA and grain yield has been explored in barley and sorghum field trials. The capacity to manipulate components of S and D to optimise the S/D balance should assist crop improvement programs to develop enhanced ideotypes for dry environments. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 121 KiB

Open AccessAbstract

Integrating Gene Editing Techniques into Modern Cereal Breeding

by Ian Godwin, Karen Massel and Guoquan Liu

Proceedings 2019, 36(1), 209; https://doi.org/10.3390/proceedings2019036209 - 9 Apr 2020

Viewed by 1103

Abstract

New breeding technologies are revolutionizing plant and animal improvement programs [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 116 KiB

Open AccessAbstract

Investigating Capacities to Change Soil and Irrigation Practices in Vegetable Production in Two Provinces in Cambodia

by Ann Starasts, Tech Ratana, Yin Putheavy and Ratan Kay

Proceedings 2019, 36(1), 210; https://doi.org/10.3390/proceedings2019036210 - 10 Apr 2020

Viewed by 1194

Abstract

Improving vegetable production in Cambodia offers a pathway to grow domestic consumption and exports, and improve nutrition, profits, and livelihoods. Interviews with 120 growers and 5 focus group discussions within 5 villages investigated growers’ capacity to change soil and irrigation management in their [...] Read more.

Improving vegetable production in Cambodia offers a pathway to grow domestic consumption and exports, and improve nutrition, profits, and livelihoods. Interviews with 120 growers and 5 focus group discussions within 5 villages investigated growers’ capacity to change soil and irrigation management in their Chinese cabbage, Petsai, Cucumber, Cauliflower, Lettuce and other vegetable crops. Low or no profitability (34% participants), insect pests (59%) and dry periods (18%) were growers’ major limitations, with small farm size (0.08 ha) and limited schooling (21–36% had no schooling) contributing to the scenario. High cost of inputs is a limitation to making farming system changes, with most growers using their own funds and less than 10% borrowing funds to pay for crop inputs. Communication and planning for vegetable growing occurred almost exclusively within families (93%), with 7.5% of participants discussing with other farmers. Lack of time (43%) and knowledge about farmer group activities (30%) limited ongoing group learning opportunities. Although very traditional, 28% of participants had tried new practices; 42% of participants indicated they will try new practices after exposure to a soil and irrigation research trial. The participants were keen learners, and after exposure to the research, 58% believed that liming improves yields and 18% prefer to evaluate this on their farms. Information sources about vegetable growing are limited, and growers had complex information needs. Facilitating and mentoring ongoing local support and technical information networks, and enhancing capacity and communication are seen as key strategies for empowering long term ability to change. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 171 KiB

Open AccessAbstract

Metabolism and Endocrinology of Cattle in High Environmental Temperatures

by Gene Wijffels, Megan Sullivan, Stephen Anderson, Sally Stockwell, Suzie Briscoe, Russell McCulloch, Judy Cawdell-Smith and John Gaughan

Proceedings 2019, 36(1), 211; https://doi.org/10.3390/proceedings2019036211 - 10 Apr 2020

Viewed by 1121

Abstract

Close-to-market weight grain fed cattle experience high heat loads during summer. There are health, welfare and production impacts on these high value animals. Two cohorts of 600 kg Black Angus steers (n = 12) were subjected to heatwave conditions during a thermal [...] Read more.

Close-to-market weight grain fed cattle experience high heat loads during summer. There are health, welfare and production impacts on these high value animals. Two cohorts of 600 kg Black Angus steers (n = 12) were subjected to heatwave conditions during a thermal challenge in climate chambers. Frequent blood sampling enabled a detailed description of the metabolic and endocrine trajectories during high heat load and recovery in feedlot cattle. In high heat load ruminants, blood flow is diverted from the major organs impacting metabolic rate and cellular functions. The metabolic rate will slow with falls in the thyroid hormone plasma concentrations. Insulin and the adipokines gave an indifferent response. The high heat load cattle were hypoglycaemic and oxidising fatty acids. Liver involvement was evidenced by the build-up of bilirubin in plasma, and reduced release of cholesterol and ALP. Thermal challenge saw markedly increased plasma creatinine and urea implicating reduced glomerular filtration; although the kidneys were working to retain chloride ions to balance the loss of bicarbonate from the increased respiration rate. As heat load reduced during recovery, rumen temperature and respiration rate normalised and feed intake gradually returned. Plasma glucose levels increased also. With increased blood supply to the organs, there was a rise in liver enzymes into the blood, although liver function had not fully restored during the recovery period; plasma bilirubin concentrations were still high, and ALP and cholesterol levels low. Twelve days after the thermal challenge, most blood parameters had returned to normal and the steers had gained weight. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 130 KiB

Open AccessAbstract

Characterizing Genetic Variation in Late, Deep Wheat Root Architecture to Improve Yield and Yield Stability under Terminal Water Stress

by Kanwal Shazadi, Karine Chenu and Jack Christopher

Proceedings 2019, 36(1), 212; https://doi.org/10.3390/proceedings2019036212 - 10 Apr 2020

Viewed by 1287

Abstract

Root systems play an important role in crop performance particularly under rain fed conditions. Root architecture is key in determining the ability of crops to extract water at various soil depths. In many rain fed production regions, opportunities to improve yield through changes [...] Read more.

Root systems play an important role in crop performance particularly under rain fed conditions. Root architecture is key in determining the ability of crops to extract water at various soil depths. In many rain fed production regions, opportunities to improve yield through changes in management practices are limited. Thus, genetic solutions to improve yield under water limitation are required. We postulate that in drought-prone environments, genotypes with greater yield and yield stability can be developed by breeding for genotypes with favorable root systems. We studied wheat root architecture late in the developmental cycle. Narrow and deep root systems may help wheat to extract more water at depth late in the season and give an advantage to yield and yield stability where crops rely on stored moisture deep in the soil. To improve yield stability in rain fed regions, an effective phenotypic method is needed. However, studying root traits in mature field-grown crops is extremely challenging. A PVC tube method was developed and has been used to identify genotypic differences in root architecture late in crop development. Identification of root traits to improve deep water uptake late in crop development and the development of phenotypic methods to identify genetic sources of such traits will assist breeders to improve yield and yield stability in water-limited environments. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Low Cost Protective Structures Providing Suitable Growing Conditions for Vegetable Crops Year-Round in the Tropics

by Thongkhoun Sisaphaithong, Phathana Sengounkeo, Sengdala Mounnalath, Gerard Kelly and Jeremy Badgery-Parker

Proceedings 2019, 36(1), 213; https://doi.org/10.3390/proceedings2019036213 - 10 Apr 2020

Viewed by 1155

Abstract

Vegetable production is an important activity, source of food and income for farmers. Vegetables are grown in many regions in Lao PDR. There is a large range of agro-climatic conditions between the two seasons - wet and dry. The dry season is suitable [...] Read more.

Vegetable production is an important activity, source of food and income for farmers. Vegetables are grown in many regions in Lao PDR. There is a large range of agro-climatic conditions between the two seasons - wet and dry. The dry season is suitable and favourable for vegetable production. However, the wet season has high temperature, high relative humidity, high soil moisture content and heavy rain. These conditions cause several negative impacts for vegetable production such as, low vegetable productivity and poor quality. Higher application of pesticides can also lead to food safety issues and high input cost of cultivation. These challenges could impact to inadequate domestic supply of vegetables in rainy season, low economic returns from vegetable production, and increased imports of vegetable from other countries. NAFRI and ACIAR have cooperated to research and develop a design of greenhouse structure that is economical and provides suitable growing conditions in the wet season to help farmers to mitigate the multiple constraints and successfully grow vegetables year-round. The new design was constructed and tested with several types of vegetable crops including coriander, lettuce, spring onion and tomato during 2015–2018. Evaluation was made against ambient conditions, crop needs and also a comparison with several other protected cropping designs was conducted. The new design provides improved, cooler and more suitable growing conditions for a range of crops, increasing productivity and quality of vegetable in the wet season. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 132 KiB

Open AccessAbstract

Cassava-Based Diets Increase Live Weight Gain of Cross Bred Bulls in Small Fattening Systems in Malang, East Java

by Deni Setiadi, Kasmiati Kasmiati, Abu Z. Zakariya, Karen Harper and Dennis Poppi

Proceedings 2019, 36(1), 214; https://doi.org/10.3390/proceedings2019036214 - 10 Apr 2020

Viewed by 1092

Abstract

Traditional farmers usually use local feed ingredient based on cheapest ingredients without considering the importance of feed conversion ratio to maximise cattle growth. The experiment was conducted to determine the growth of crossbred bulls fed on a cassava by-product based diet and a [...] Read more.

Traditional farmers usually use local feed ingredient based on cheapest ingredients without considering the importance of feed conversion ratio to maximise cattle growth. The experiment was conducted to determine the growth of crossbred bulls fed on a cassava by-product based diet and a local concentrate. Fifty cross bred bulls aged 1.5–2 years were used in this study. The bulls were divided into five groups and offered 1% and 2% local concentrate (T1 and T2), 1% and 2% cassava-based diet (T3 and T4) and the current feeding system (CFS) by farmers (T0) as the control. Local concentrate was bought from Blitar while cassava-based diets contained 50% cassava, 25% copra meal and 25% palm kernel cake. No interventions were made to the CFS, however, some farmers in T0 used local forages and agricultural by-products such as rice bran and pollard bran as a feed, and adopted the supplementation of local concentrates as used by T1 and T2 farmers. The average daily gain were 1.13 kg/head/day (T0), 1.09 kg/head/day (T1), 1.38 kg/head/day (T2), 0.8 kg/head/day (T3) and 1.23 kg/head/day (T4). The study found that local concentrates promoted high average daily gain and that traditional feeding systems (CFS) performed well when farmers saw other farmers feeding better diets. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 138 KiB

Open AccessAbstract

Analyzing the Climate Change Impact and Farmer’s Adaptability Strategies in Khyber Pakhtunkhwa, Pakistan

by Khuram Nawaz Sadozai, Munawar Raza Kazmi, Muhammad Israr Khan and Sonia Sonia

Proceedings 2019, 36(1), 215; https://doi.org/10.3390/proceedings2019036215 - 10 Apr 2020

Viewed by 1282

Abstract

The agriculture sector is deemed as more vulnerable to climate change as its variation can directly affect the crop’s productivity. However, climate change impact and farmers adaptation strategies were not figured out in Khyber Pakhtunkhwa Province, Pakistan by previous researchers and formed the [...] Read more.

The agriculture sector is deemed as more vulnerable to climate change as its variation can directly affect the crop’s productivity. However, climate change impact and farmers adaptation strategies were not figured out in Khyber Pakhtunkhwa Province, Pakistan by previous researchers and formed the rationale for this research endeavor. This research has assessed the Climate Change impact on wheat productivity and farmers adaptability strategies. The non-climatic variables (wheat yield and area under wheat cultivation) and climatic variables (temperature, precipitation and humidity) were taken into consideration. The Panel Data of thirty years (1985–2015) about non climatic and climatic variables was obtained from different secondary sources; however, primary data was collected from sampled farmers. The econometric diagnostic tests were encompassed to confirm the validity of the data. Chow test was used to underscore the structural breaks. Fixed Effect Model was adopted as suggested by Hausman Test. The salient findings express that temperature has inverse relationship with wheat productivity. This implies that by soaring one Celsius degree Centigrade (°C) temperature can plunge down the wheat productivity by 0.074 percent. Similarly, the association of precipitation was also observed negative with wheat. Contrary to this, humidity is observed as positively associated with wheat. The study concludes the substantial association of climate change with wheat crop, whereas, farmers had less awareness about the adoptability strategies. It is recommended that high temperature resistant wheat varieties may be provided to farmers and disseminates the exalted adaptation strategies with respect to climate change to overhaul their existing crop management practices. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 143 KiB

Open AccessAbstract

Nutritional Value of Black Soldier Fly Grown on Abattoir Waste

by Luis F. P. Silva, Geoff W. Brown and Peter J. James

Proceedings 2019, 36(1), 216; https://doi.org/10.3390/proceedings2019036216 - 10 Apr 2020

Viewed by 2137

Abstract

Meat processing plants generate a range of solid and liquid wastes, including manure, paunch solids, and biological solids from wastewater treatment. There is growing interest in alternative technologies for treating abattoir waste, including using insects to transform waste into high-value products. Black Soldier [...] Read more.

Meat processing plants generate a range of solid and liquid wastes, including manure, paunch solids, and biological solids from wastewater treatment. There is growing interest in alternative technologies for treating abattoir waste, including using insects to transform waste into high-value products. Black Soldier Fly (BSF) larvae may be a competitive source of digestible amino acids and, depending on the protein digestibility, can be used as a replacement for fish meal, soybean meal or cottonseed meal in livestock and aquaculture rations. The objective of this study was to evaluate the effect of using different substrates and substrate mixes from abattoir waste streams on the nutritional quality of BSF harvested at two growth stages (larvae and prepupae). Protein digestibility was evaluated using an adapted pepsin digestion. Averaged across all substrates, there was no difference between growth stages in total protein content (43.7%). However, protein digestibility was higher for larvae (86.5%) than for prepupae (65.1%). The substrate used greatly influenced the nutritional composition of BSF. Prepupae protein content varied from 42 to 48% and protein digestibility varied from 42 to 80%, according to the substrate. Variation in larvae across substrates was greater than prepupae for protein content (34% to 53%) but much lower for digestibility (80% to 91%). Both substrate and growth stage altered the mineral composition of BSF prepupae and larvae. Iron levels varied from 79 (paunch) to 453 mg/kg DM (substrate containing blood), illustrating the plasticity of BSF. In conclusion, BSF can be used to transform abattoir waste into high-value products. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 147 KiB

Open AccessAbstract

Biological Control of Rice Brown Spot by Bacillus Spp. in Thailand

by Wanporn Khemmuk, Doungkamon Boonchuay, Nuchjarin Jungkhun, Chonsirin Klinmanee and Angkana Kantachan

Proceedings 2019, 36(1), 217; https://doi.org/10.3390/proceedings2019036217 - 10 Apr 2020

Viewed by 1400

Abstract

Rice brown spot (BS), caused by Bipolaris oryzae (Breda de Haan) Shoemaker, is a serious disease causing infection in all growth stages of rice and significantly affect to yield and grain quality losses. This study aimed to find effective antagonistic microorganisms to control [...] Read more.

Rice brown spot (BS), caused by Bipolaris oryzae (Breda de Haan) Shoemaker, is a serious disease causing infection in all growth stages of rice and significantly affect to yield and grain quality losses. This study aimed to find effective antagonistic microorganisms to control BS, hundreds of microbial isolates were obtained from rice paddy fields across Thailand. A total number of 31 antagonistic microbes were selected and screened against B. oryzae by dual culture technique. The results showed that CRI_15183 has highly percentage of inhibition (67.35%) followed by ACKB03, CRI_15059, CRI_15010, No.33, CRI_15186 and BUDN027 with 57.25, 54.01, 53.28, 52.94, 52.65 and 51.26%, respectively. Then, sequencing of 16S rDNA confirmed two species of Bacillus amongst the isolates, B. subtilis and B. amyloliquefaciens. Three isolates including CRI_15183, CRI_15186 and ACKB03 were formulated with talcum based powder, stored at room temperature and sampled to test their shelf life monthly. In greenhouse experiment, the results revealed that CRI_15186 has highest effective with 14.08 percent of disease incidence followed by CRI_15183 and ACKB03 with 15.06 and 15.98%, respectively. The field experiments will be conducted in wet season this year. There have been only a few reports on the improvement of rice brown spot control involving biological control agents. However, the use of antagonistic microbes can reduced the used of fungicides and developed environmentally safe for the management of rice brown spot disease. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 176 KiB

Open AccessAbstract

Identification of New Single Cross Testers for CIMMYT Heterotic Group B Maize Germplasm Adapted to Mid-Altitudes

by Arisede Chisaka, Vivi Arief, Amsal Tarekegne and Mark Dieters

Proceedings 2019, 36(1), 218; https://doi.org/10.3390/proceedings2019036218 - 10 Apr 2020

Viewed by 1378

Abstract

The development of higher yielding maize (Zea mays L.) hybrids adapted to low input small-holder farming systems in sub-Saharan Africa is required. Three-way hybrids (i.e. F1 tester crossed to inbred line) can be produced at lower cost for smallholder farmers, but to [...] Read more.

The development of higher yielding maize (Zea mays L.) hybrids adapted to low input small-holder farming systems in sub-Saharan Africa is required. Three-way hybrids (i.e. F1 tester crossed to inbred line) can be produced at lower cost for smallholder farmers, but to achieve this it is crucial for CIMMYT-Zimbabwe maize breeding program to identify new high yielding single cross testers with high combining ability to support the development of new high yielding hybrids for this region. Data collected on the performance of F1 and three-way hybrids from a total of 25 multi-environment trials (METs) located in South Africa (three trials), Zambia (four trials) and Zimbabwe (eighteen trials) grown across two seasons during the period from 2015–2018 to: (i) identify new single cross testers for CIMMYT HG-B maize germplasm; (ii) identify stable and high yielding three-way hybrids. Analyses were conducted using a two-stage approach. Clustering based on yield data, grouped sites into three environment types (ET); low (LY) < 3 t ha⁻¹, medium (MY) 3–6 t ha⁻¹ and high (HY) 6–13 t ha⁻¹ yielding groups. Additive genetic effects of both inbred parents and selected F1 crosses used as parents were more important than non-additive genetic effects for grain yield across ETs. Strong genotype x environment interactions on yield and other traits were observed. It was concluded that F1 hybrids (entry 75, 85, 72 and 28) demonstrated high yield across all environment types, and it is recommended that these be also evaluated as potential three-way hybrids. Single crosses CZL15085/CML566 and CZL15085/CZL13102 from heterotic group B to be used as testers for ET 1 and ET 2 respectively. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 139 KiB

Open AccessAbstract

Perspective of Smallholder Farmers on Smart Farming Gadgets in Pakistan

by Nadia Jabeen and Sandra Heaney-Mustafa

Proceedings 2019, 36(1), 219; https://doi.org/10.3390/proceedings2019036219 - 13 Apr 2020

Viewed by 1773

Abstract

Abstract: In spite of its importance as a backbone for Pakistani economy, agriculture sector is technologically backward. The sustainability of agriculture depends upon promotion and adoption of new agricultural tools among farmers. As technology adoption is a complicated process because of production [...] Read more.

Abstract: In spite of its importance as a backbone for Pakistani economy, agriculture sector is technologically backward. The sustainability of agriculture depends upon promotion and adoption of new agricultural tools among farmers. As technology adoption is a complicated process because of production and technical factors. The increasing need and use of smart technology in the field of agriculture invites us to make an assessment of the behaviour of farming community about trusting on gadgets or protecting their own traditional knowledge. Participatory action research is appreciated method of promoting new gadgets among farmers as compare to linear model but factors like age, literacy level, shortage of money, family size could hinder the process of engagement of smallholder farmers. Simple random sampling will be used to choose farmers out of one forty-two farming families who are active users of agricultural tools in six districts of three provinces of Pakistan under a project related to enhancement of water management skills of farmers. A mix methodology including surveys and interviews will be used to collect data from the smallholder farmers involved in project activities. The data will be analysed in narrative and tabular form. This research will indicate the trends in adopting smart farming gadgets among smallholder farmers. It will catch the insights from farmers and methods to improve the existing system and ways to deal with challenges to get smart technology gadgets into the hands of farmers. It will provide suggestions for the practitioners of participatory action research. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 155 KiB

Open AccessAbstract

A Decade of Tropical Sweet Corn Breeding Using Conventional and Molecular Approaches in Malaysia

by Pedram Kashiani and Ghizan Saleh

Proceedings 2019, 36(1), 220; https://doi.org/10.3390/proceedings2019036220 - 21 Apr 2020

Viewed by 1705

Abstract

To increase self-sufficiency in sweet corn production in Malaysia, a long-term breeding study was conducted to develop merit inbred lines using conventional and molecular techniques toward production of superior local hybrid varieties. A germplasm consisting of 18 tropical source populations was established and [...] Read more.

To increase self-sufficiency in sweet corn production in Malaysia, a long-term breeding study was conducted to develop merit inbred lines using conventional and molecular techniques toward production of superior local hybrid varieties. A germplasm consisting of 18 tropical source populations was established and used for inbred line development. Forty tropical inbred lines were developed through continues self-pollination and selection. Agronomic performance of these newly developed inbred lines was evaluated in replicated blocks in two locations. Significant variations in agronomic performance indicated presence of high genetic diversity among the inbred lines for potential utilization towards hybrid production. In addition, the level of genetic homozygosity for each inbred line and genetic similarities among the inbred lines were estimated through amplification of 100 microsatellite loci. The 40 inbred lines were clustered into five main heterotic groups based on their agronomic and molecular characteristics. Eleven inbred lines were selected to conduct two sets of half-diallel cross (5 × 5 and 6 × 6), resulting a total of 25 single-cross hybrids. Greater estimates of GCA mean squares than SCA mean squares showed relatively more important effect of additive gene action in controlling yield and yield components in the hybrids. Genetic distances among the parental lines were used to predict hybrid performance, showing significant positive associations between genetic similarities and SCA estimates. Among the 25 hybrids produced, five hybrids exhibited high and competitive yield performance in comparison to those from the commercial imported hybrids and can be released as new hybrids in Malaysia after evaluation in large scale multi-locational trials. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 153 KiB

Open AccessAbstract

Performance and Genetic Diversity among a Collection of Stevia Rebaudiana Bertoni Accessions Using Microsatellite Markers in Malaysia

by Pedram Kashiani, Ghizan Saleh and Ridzwan Che Rus

Proceedings 2019, 36(1), 221; https://doi.org/10.3390/proceedings2019036221 - 21 Apr 2020

Viewed by 1061

Abstract

The plant Stevia rebaudiana Bertoni (2n = 22) is a native of certain regions of South America particularly in Paraguay. It is a short-term plant and needs three months to complete one cycle of vegetative growth and flowering. With days less than 13 [...] Read more.

The plant Stevia rebaudiana Bertoni (2n = 22) is a native of certain regions of South America particularly in Paraguay. It is a short-term plant and needs three months to complete one cycle of vegetative growth and flowering. With days less than 13 hours in tropical countries, stevia plants flower early, resulting in low yield. In addition, the early bud emergence under the short-day length condition causes the sugar content in stevia leaves to reduce drastically, making them no longer valuable for commercial use. The stevia accessions available in Malaysia today are limited in number and poor in performance, emphasizing the necessity of varietal improvement programs. Assessment of genetic variability, diversity and intrarelationships is an essential step for such breeding programs. This study aims to evaluate agronomic performance of among 21 stevia accessions, namely SRBA-1 to SRBA-21, collected from different origins and to reveal genetic diversity utilizing 52 novel microsatellites. Evaluation of agronomic traits revealed wide range of variation in leaf weight, dry leaf weight, plant height, number of branches, stevioside; rebaudioside A (Reb A), rebaudioside C (Reb C) and total steviol glycosides (TSG). The total genetic diversity detected among the accessions through amplification of the 43 polymorphic microsatellites showed that almost all markers had deviation from Hardy–Weinberg equilibrium (Ho > He). Three distinct heterotic groups were identified among the accessions based on their agronomic performance and molecular characteristics. Crosses among different accessions coming from different heterotic groups can be further used to produce potential stevia variety for plantation in Malaysia. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 131 KiB

Open AccessAbstract

Super-Sweet Purple Sweetcorn: Breaking the Genetic Link

by Apurba Anirban and Tim O’Hare

Proceedings 2019, 36(1), 6134; https://doi.org/10.3390/proceedings2019036134 - 29 Mar 2020

Cited by 2 | Viewed by 1323

Abstract

Purple-pericarp supersweet sweetcorn currently does not exist as a horticultural product. Purple pericarp comprises the outer layers of the kernel, with the purple pigment being produced by anthocyanin. Unlike the aleurone layer which can also be pigmented, the pericarp is maternal tissue. Although [...] Read more.

Purple-pericarp supersweet sweetcorn currently does not exist as a horticultural product. Purple pericarp comprises the outer layers of the kernel, with the purple pigment being produced by anthocyanin. Unlike the aleurone layer which can also be pigmented, the pericarp is maternal tissue. Although standard purple sweetcorn based on mutations such as sugary1 (su1) and sugary enhancer (se1) are in existence, the development of purple supersweet sweetcorn based on the widely used shrunken2 (sh2) gene mutation is much more challenging. This is because there is an extremely close genetic linkage between the supersweet shrunken-2 mutation and the anthocyanin biosynthesis gene, anthocyaninless-1 (a1). As distance between these two genes is only 0.1 cM, the development of purple supersweet sweetcorn depends on breaking this close genetic link, which occurs at a very low frequency of 1 in 1000 meiotic crossovers. To make this possible, we crossed a white supersweet variety (a1a1sh2sh2) with a purple-pericarp Peruvian maize (A1A1Sh2Sh2) to obtain an initial heterozygous hybrid (A1a1Sh2sh2). The hybrid seed was sown and subsequently self-pollinated to produce seed segregating for the double recessive homozygote, sh2sh2 (1 in 4). These kernels present a visually distinctive phenotype, characterised by the seed’s shrunken appearance. Approximately 2760 sh2sh2 seeds were separated and resown. Due to the low frequency of linkage breakage, the majority of these plants (~99.9%) produced supersweet white cobs (a1a1sh2sh2). Three plants (0.1%) however, produced supersweet purple cobs (A1a1sh2sh2), due to a single low-frequency linkage break. These cobs will form the basis for a purple-pericarp supersweet sweetcorn breeding program. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

Other

Jump to: Research

1 pages, 125 KiB

Open AccessExtended Abstract

Iron Responsive Genes in Rice: The Multiple Roles of WRKY Factors

by Vivian E. Viana, Carlos Busanello, Camila Pegoraro and Antonio Costa de Oliveira

Proceedings 2019, 36(1), 10; https://doi.org/10.3390/proceedings2019036010 - 27 Dec 2019

Viewed by 972

Abstract

The rice crop is one of the most important worldwide. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 150 KiB

Open AccessExtended Abstract

Genetic Tolerance in Capsicum Chinense to Low pH Constraints on Root Growth

by Minguo Li and Stephen Harper

Proceedings 2019, 36(1), 44; https://doi.org/10.3390/proceedings2019036044 - 12 Jan 2020

Viewed by 1062

Abstract

Peppers (Capsicum spp.) are valuable cash crops in developing countries of the tropics and subtropics where acidic soils represent a substantial amount of arable land. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 158 KiB

Open AccessExtended Abstract

Machinery and Labour Requirements as Influenced by Diversified Farming Systems in The Australian Northern Grain Production Region

by Julius H. Kotir, Lindsay W. Bell, John A. Kirkegaard, Jeremy D. Whish and Kojo A. Aikins

Proceedings 2019, 36(1), 51; https://doi.org/10.3390/proceedings2019036051 - 16 Jan 2020

Viewed by 1033

Abstract

Farming systems in tropical regions of the world have been shown to be underperforming. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 123 KiB

Open AccessExtended Abstract

Investigating New Methods to Increase Adventitious Root Formation

by William Nak, Alice Hayward and Neena Mitter

Proceedings 2019, 36(1), 52; https://doi.org/10.3390/proceedings2019036052 - 16 Jan 2020

Viewed by 933

Abstract

Modern agricultural improvements rely on the planting of elite crop lines to maximise the [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

1 pages, 133 KiB

Open AccessExtended Abstract

Genetic Diversity and Population Structure of Field Isolates of Ganoderma Boninense from Oil Palm Plantation in Solomon Islands

by Agnieszka Mudge, Derick Rama, Carmel Pilotti and Ian Godwin

Proceedings 2019, 36(1), 56; https://doi.org/10.3390/proceedings2019036056 - 16 Jan 2020

Cited by 1 | Viewed by 1143

Abstract

Oil palm (Elaeis guineensis Jacq.) is a long-term perennial crop of great economic importance to [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 305 KiB

Open AccessExtended Abstract

From Fields to Farms: Informing the Trade-Offs Across the Multiple Functions of Agriculture

by Daniel Rodriguez

Proceedings 2019, 36(1), 65; https://doi.org/10.3390/proceedings2019036065 - 19 Jan 2020

Viewed by 863

Abstract

Adapting the nature and extent of agriculture to fit expected increases in food and energy
demand, amid changes in climate and the environment, clearly requires the development and
application of new scientific approaches and innovative solutions. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

► Show Figures

Figure 1

1 pages, 136 KiB

Open AccessExtended Abstract

Risk Factors for Dystocia in Cattle

by Scott Norman

Proceedings 2019, 36(1), 128; https://doi.org/10.3390/proceedings2019036128 - 17 Mar 2020

Cited by 1 | Viewed by 1143

Abstract

The understanding and classification of the general causes of dystocia in cattle has changed little [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 6697 KiB

Open AccessExtended Abstract

Investigating the Sporulation of Metarhizium anisopliae Formulated in Calcium Alginate in Soil

by Sudhan Shah, Gavin Ash and Bree Wilson

Proceedings 2019, 36(1), 130; https://doi.org/10.3390/proceedings2019036130 - 19 Mar 2020

Viewed by 1036

Abstract

Wireworms have the potential to cause significant damage to sweetpotato, particularly late in the season. [...] Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

► Show Figures

Figure 1

1 pages, 136 KiB

Open AccessProceeding Paper

Orange Capsicums and Chillies as a Potential Source of Dietary Zeaxanthin, an Important Macular Carotenoid for Eye Health

by Rimjhim Agarwal, Hung Hong Trieu, Robyn Cave, Stephen Harper and Tim O’Hare

Proceedings 2019, 36(1), 161; https://doi.org/10.3390/proceedings2019036161 - 7 Apr 2020

Viewed by 3450

Abstract

Zeaxanthin is a dietary carotenoid accumulated in the macula in order to reduce photoreceptor oxidation by blue light. Damage caused to photoreceptor cells in the human eye leads to macular degeneration, which is the leading cause of blindness in developed countries. Zeaxanthin, an [...] Read more.

Zeaxanthin is a dietary carotenoid accumulated in the macula in order to reduce photoreceptor oxidation by blue light. Damage caused to photoreceptor cells in the human eye leads to macular degeneration, which is the leading cause of blindness in developed countries. Zeaxanthin, an orange pigment, is rarer in western diets as compared to the yellow pigment, lutein, the other important macular carotenoid. Orange capsicums (Capsicum annuum) have been reported to be an excellent source of zeaxanthin, but there are limited reports about its occurrence both within, and in other closely related species (C. baccatum, C. chinense). In the current investigation, yellow, orange and red coloured accessions of C. annuum, C. chinense and C. baccatum were analysed for their carotenoid profiles to identify high zeaxanthin accessions. A carotenoid extraction protocol and ultra-high-performance liquid chromatography-photometric diode array-mass spectrometry (UHPLC-PDA-MS) analysis was optimised to identify and quantify carotenoids in the capsicum accessions both before and after saponification. Interestingly, out of 22 varieties tested, only the ‘Orange Belle’ orange capsicum demonstrated a high accumulation of zeaxanthin. Other accessions exhibiting orange colour accumulated different orange carotenoid pigments to zeaxanthin, such as violaxanthin, beta-carotene, and beta-cryptoxanthin. Yellow coloured accessions accumulated a high concentration of lutein or alpha-carotene, while red cultivars were highest in capsanthin and capsorubin. The present findings suggests a need for further studies to identify high zeaxanthin germplasm which can be cross-bred with orange capsicums for future biofortification, in order to help increase the daily dietary intake of zeaxanthin in western diets. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

2 pages, 793 KiB

Open AccessExtended Abstract

Topical RNAi for Sustainable Animal Health

by Karishma T. Mody, Bing Zhang, Xun Li, Ritesh Jain, Peng Li, Peter James, Timothy J. Mahony, Zhiping Xu and Neena Mitter

Proceedings 2019, 36(1), 170; https://doi.org/10.3390/proceedings2019036170 - 7 Apr 2020

Viewed by 1874

Abstract

Animal health measures mainly rely on vaccination or chemical control for major pests and pathogens, causing issues of residue, toxicity and development of resistance. For example, control of Sheep flystrike and lice-infestation affecting the Australia’s sheep/wool industry (>3.5 B) have developed resistance to [...] Read more.

Animal health measures mainly rely on vaccination or chemical control for major pests and pathogens, causing issues of residue, toxicity and development of resistance. For example, control of Sheep flystrike and lice-infestation affecting the Australia’s sheep/wool industry (>3.5 B) have developed resistance to nearly all control chemicals used in the past. Topicals RNAi provides an innovative clean-green, non-toxic, environmentally sustainable biological control solution. Biodegradable clay particles as carriers can be used to deliver double stranded RNA (dsRNA), the key trigger molecule of RNA interference pathway. As an early proof of concept, we investigated the stability dsRNA loaded on two types of Clay particles: Clay 1 (releases dsRNA under acidic conditions) and Clay 2 (releases dsRNA under alkaline conditions) on cattle hide. Cattle skin was treated with Cy3 labelled dsRNA alone and Cy3 labelled dsRNA loaded on Clay1 or Clay2. The skin samples treated with the Cy3 formulations were imaged using confocal microscopy. Once imaged, the skin samples were washed and stored at room temperature for 5 days, later the samples were re-imaged to detect the fluorescent signal (Figure 1). The dsRNA loaded on clay particles was stable unlike naked Cy3-dsRNA which degraded and was not visible after washing. This increased inherent stability of the dsRNA molecules, combined with the environmental stability afforded by the Clay particles, offers promise to provide a sustainable solution for animal health. Topical RNAi can reduce reliance on trade withholding periods of meat/wool without chemical residues, enhance animal welfare and increase production of premium quality meat/wool, improve export potential, competitiveness and long-term profitability of livestock industry. Full article

(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))

► Show Figures

Figure 1

Journal Menu

Journal Browser

Proceedings, 2019, TropAg 2019

The Third International Tropical Agriculture Conference

Research

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI