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Proceedings, 2019, TropAg 2019

The Third International Tropical Agriculture Conference

Brisbane, Australia | 11–13 November 2019

Volume Editor: Leanne Mulheran, Expert Events, Australia

Number of Papers: 221
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Cover Story (view full-size image): This volume of Proceedings gathers abstracts of posters and symposium presentations that were presented at TropAg 2019. The third international TropAg conference was held on 11–13 November 2019 [...] Read more.
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1 pages, 145 KiB  
Abstract
Impact of Soil Water Stress at Seed Development Stage on Phenology, Fecundity and Seed Dormancy of Avena sterilis ssp. ludoviciana
Proceedings 2019, 36(1), 1; https://doi.org/10.3390/proceedings2019036001 - 24 Dec 2019
Viewed by 922
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  
Abstract
The Role of Leadership and Local Ownership in Research 4 Development (R4D) Projects
Proceedings 2019, 36(1), 2; https://doi.org/10.3390/proceedings2019036002 - 24 Dec 2019
Viewed by 818
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  
Abstract
Harnessing Asexual Seed Formation to Preserve Hybrid Vigour and Complex Yield Traits
Proceedings 2019, 36(1), 3; https://doi.org/10.3390/proceedings2019036003 - 24 Dec 2019
Viewed by 802
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  
Abstract
Integrating Crop Modelling, Physiology, Genetics and Breeding to Aid Crop Improvement for Changing Environments in the Australian Wheatbelt
Proceedings 2019, 36(1), 4; https://doi.org/10.3390/proceedings2019036004 - 24 Dec 2019
Viewed by 1019
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  
Abstract
Recent Trends in Drought, Heat and Frost-Induced Yield Losses Across the Australian Wheatbelt
Proceedings 2019, 36(1), 5; https://doi.org/10.3390/proceedings2019036005 - 24 Dec 2019
Cited by 4 | Viewed by 862
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 (Tmax > 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 ha1 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  
Abstract
Fall Armyworm Invasion and Impact in Africa
Proceedings 2019, 36(1), 6; https://doi.org/10.3390/proceedings2019036006 - 25 Dec 2019
Viewed by 787
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  
Abstract
Prepartum Supplementation to Improve Transfer of Passive Immunity and Growth
Proceedings 2019, 36(1), 7; https://doi.org/10.3390/proceedings2019036007 - 26 Dec 2019
Viewed by 960
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 (NaturSafeTM). 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  
Abstract
Foliar Nutrient Management on Potato Grown under Zero Tillage and Mulching in Coastal Saline Soil of West Bengal, India
Proceedings 2019, 36(1), 8; https://doi.org/10.3390/proceedings2019036008 - 26 Dec 2019
Viewed by 968
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  
Abstract
Clay Nanoparticles Facilitate Delivery of Antiviral RNA for Crop Protection
Proceedings 2019, 36(1), 9; https://doi.org/10.3390/proceedings2019036009 - 26 Dec 2019
Viewed by 774
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  
Abstract
RNAi-Mediated Management of Whitefly Bemisia tabaci by Oral Delivery of Double-stranded RNAs
Proceedings 2019, 36(1), 11; https://doi.org/10.3390/proceedings2019036011 - 27 Dec 2019
Viewed by 1196
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  
Abstract
The Effect of Water Stress Combined with a Heatwave on Reproduction and Yield of Roma-VF Tomatoes
Proceedings 2019, 36(1), 12; https://doi.org/10.3390/proceedings2019036012 - 27 Dec 2019
Viewed by 821
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  
Abstract
Drivers of Phosphorus Efficiency in Tropical and Subtropical Cropping Systems
Proceedings 2019, 36(1), 13; https://doi.org/10.3390/proceedings2019036013 - 30 Dec 2019
Viewed by 824
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  
Abstract
Diversity of Domestication Loci in Wild Rice Populations
Proceedings 2019, 36(1), 14; https://doi.org/10.3390/proceedings2019036014 - 30 Dec 2019
Viewed by 775
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  
Abstract
Farmers’ Perceptions of Salinity for Ensuring Food Security: Evidence from Coastal Rice-Growing Areas of Bangladesh
Proceedings 2019, 36(1), 15; https://doi.org/10.3390/proceedings2019036015 - 30 Dec 2019
Viewed by 882
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  
Abstract
Differential Gene Expression Among Genotypes of the Genus Saccharum Contrasting in Biomass Production
Proceedings 2019, 36(1), 16; https://doi.org/10.3390/proceedings2019036016 - 30 Dec 2019
Viewed by 875
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  
Abstract
Determination of Phylogenetic Relationships of the Genus Sorghum Using Nuclear and Chloroplast Genome Assembly
Proceedings 2019, 36(1), 17; https://doi.org/10.3390/proceedings2019036017 - 30 Dec 2019
Viewed by 945
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  
Abstract
Evaluation of Mungbean Varieties for Northwest Cambodian Lowland Rice Systems
Proceedings 2019, 36(1), 18; https://doi.org/10.3390/proceedings2019036018 - 30 Dec 2019
Viewed by 690
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  
Abstract
Promoting Social Learning in Soil Water and Nutrients Management Using Farmer—Friendly Monitoring Technology
Proceedings 2019, 36(1), 19; https://doi.org/10.3390/proceedings2019036019 - 30 Dec 2019
Cited by 1 | Viewed by 957
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  
Abstract
Aflatoxin Contamination of Village Grains in Central Tanzania: Dietary and Agricultural Practices in Relation to Contamination and Exposure Risk
Proceedings 2019, 36(1), 20; https://doi.org/10.3390/proceedings2019036020 - 30 Dec 2019
Cited by 1 | Viewed by 859
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 (AFLACHECKTM -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  
Abstract
Genotypic Variation in Biomass Produced Is Linked to Differences in Radiation Acquisition in Mungbean
Proceedings 2019, 36(1), 21; https://doi.org/10.3390/proceedings2019036021 - 30 Dec 2019
Viewed by 1091
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 (Fi). 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 Fi. 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  
Abstract
Utilisation of Sludge from Ditches to Maintain Soil Nutrients and Increase Rice Yield in Rice-Shrimp Systems in Vietnam
Proceedings 2019, 36(1), 22; https://doi.org/10.3390/proceedings2019036022 - 30 Dec 2019
Viewed by 951
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  
Abstract
Quantifying Gas Emissions and Denitrifying Genes in a Salt-Affected Soil
Proceedings 2019, 36(1), 23; https://doi.org/10.3390/proceedings2019036023 - 30 Dec 2019
Viewed by 800
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  
Abstract
Relationships between Iraqi Rice Varieties at the Nuclear and Plastid Genome Levels
Proceedings 2019, 36(1), 24; https://doi.org/10.3390/proceedings2019036024 - 31 Dec 2019
Viewed by 646
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  
Abstract
SNPs Linked to Key Traits in Hybrids between African and Asian Rice
Proceedings 2019, 36(1), 25; https://doi.org/10.3390/proceedings2019036025 - 31 Dec 2019
Viewed by 773
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  
Abstract
Remobilisation and Fate of Sulphur in Indian Mustard (Brassica juncea. L)
Proceedings 2019, 36(1), 26; https://doi.org/10.3390/proceedings2019036026 - 31 Dec 2019
Viewed by 690
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  
Abstract
Investigation of Insect Resistance Components in Wild Pigeonpea Cajanus Scarabaeoides
Proceedings 2019, 36(1), 27; https://doi.org/10.3390/proceedings2019036027 - 31 Dec 2019
Viewed by 767
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  
Abstract
The Relationship Between Bulb Yield and Allicin Concentration in Garlic Varieties
Proceedings 2019, 36(1), 28; https://doi.org/10.3390/proceedings2019036028 - 31 Dec 2019
Cited by 1 | Viewed by 1609
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  
Abstract
Performance of Zero Tillage Potato Cultivation with Different Mulch Materials in the South-Western Saline Area of Bangladesh
Proceedings 2019, 36(1), 29; https://doi.org/10.3390/proceedings2019036029 - 31 Dec 2019
Cited by 2 | Viewed by 929
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  
Abstract
Effect of Mulch Materials and Nitrogen Source on the Performance of Tomato in the South-Western Coastal Area of Bangladesh
Proceedings 2019, 36(1), 30; https://doi.org/10.3390/proceedings2019036030 - 31 Dec 2019
Viewed by 711
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  
Abstract
System Identification of Linearized Rice Growth Dynamic for Precision Irrigation
Proceedings 2019, 36(1), 31; https://doi.org/10.3390/proceedings2019036031 - 31 Dec 2019
Cited by 1 | Viewed by 846
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  
Abstract
Rescheduling of Wet Season (T. Aman) Rice Planting for Cropping Intensification in Coastal Bangladesh
Proceedings 2019, 36(1), 32; https://doi.org/10.3390/proceedings2019036032 - 02 Jan 2020
Viewed by 1039
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  
Abstract
Air Temperature an Influential Climatic Factor for Growth and Reproduction of Dry Flower Pathogens of Macadamia
Proceedings 2019, 36(1), 33; https://doi.org/10.3390/proceedings2019036033 - 03 Jan 2020
Cited by 1 | Viewed by 1025
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  
Abstract
The Effect of Medium Type and Subculture Frequency on the Formation of Friable Embryogenic Callus for Coconut Cell Suspension Culture
Proceedings 2019, 36(1), 34; https://doi.org/10.3390/proceedings2019036034 - 03 Jan 2020
Cited by 1 | Viewed by 1280
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  
Abstract
Deploying New Technologies to Secure the Banana Industry
Proceedings 2019, 36(1), 35; https://doi.org/10.3390/proceedings2019036035 - 04 Jan 2020
Viewed by 728
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  
Abstract
Climate Change Impacts, Adaptation and Mitigation for Tropical Agriculture
Proceedings 2019, 36(1), 36; https://doi.org/10.3390/proceedings2019036036 - 04 Jan 2020
Cited by 1 | Viewed by 796
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  
Abstract
Increasing the Diversity of Crops That Can Be Grown in Urban and Vertical Farms
Proceedings 2019, 36(1), 37; https://doi.org/10.3390/proceedings2019036037 - 05 Jan 2020
Viewed by 1072
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  
Abstract
Effects of Pesticides on Nitrous Oxide Production in Sugarcane Cropping Soil
Proceedings 2019, 36(1), 38; https://doi.org/10.3390/proceedings2019036038 - 06 Jan 2020
Viewed by 1301
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  
Abstract
Nanobubbles in Hydroponics
Proceedings 2019, 36(1), 39; https://doi.org/10.3390/proceedings2019036039 - 06 Jan 2020
Cited by 1 | Viewed by 1222
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  
Abstract
Sorghum (Sorghum bicolour L.) Germination Dynamics at Extreme Temperatures
Proceedings 2019, 36(1), 40; https://doi.org/10.3390/proceedings2019036040 - 10 Jan 2020
Viewed by 1074
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  
Abstract
Dynamics of Mango Seedlings and Mango Varieties: A Case Study of Nurseries in Mango Production Center in Majalengka, West Java, Indonesia
Proceedings 2019, 36(1), 41; https://doi.org/10.3390/proceedings2019036041 - 11 Jan 2020
Cited by 1 | Viewed by 938
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  
Abstract
Assessing Food Safety and Quality Compliance: An Evidence from Vegetable Industry
Proceedings 2019, 36(1), 42; https://doi.org/10.3390/proceedings2019036042 - 12 Jan 2020
Viewed by 818
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  
Abstract
Low Cost Glad Wrap Film Packaging Delays Postharvest Senescence and Maintains Fruit Quality of Green Chilies
Proceedings 2019, 36(1), 43; https://doi.org/10.3390/proceedings2019036043 - 12 Jan 2020
Viewed by 932
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  
Abstract
Economic, Environmental, and Social Sustainability Assessment of Queensland Industries
Proceedings 2019, 36(1), 45; https://doi.org/10.3390/proceedings2019036045 - 13 Jan 2020
Viewed by 866
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  
Abstract
The Economic Benefits of Improvements in Online Licensing of The Chemical Use in Queensland Crop Industries
Proceedings 2019, 36(1), 46; https://doi.org/10.3390/proceedings2019036046 - 13 Jan 2020
Viewed by 839
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  
Abstract
Analysis of the Temporal and Spatial Distribution Patterns of Abnormal Vertical Growth in Commercial Macadamia Orchards in Australia
Proceedings 2019, 36(1), 47; https://doi.org/10.3390/proceedings2019036047 - 14 Jan 2020
Viewed by 877
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  
Abstract
Analysis of Gross Margins in Queensland Tomatoes
Proceedings 2019, 36(1), 48; https://doi.org/10.3390/proceedings2019036048 - 16 Jan 2020
Viewed by 1327
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  
Abstract
Alternative Diagnostic Tools for White Spot Disease
Proceedings 2019, 36(1), 49; https://doi.org/10.3390/proceedings2019036049 - 16 Jan 2020
Viewed by 817
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  
Abstract
Cropping Systems Modelling: Past, Present and Future
Proceedings 2019, 36(1), 50; https://doi.org/10.3390/proceedings2019036050 - 16 Jan 2020
Viewed by 699
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  
Abstract
Suitability Evaluation of Underutilized Crops Under Future Climate Change Using Ecocrop Model: A Case of Bambara Groundnut in Nigeria
Proceedings 2019, 36(1), 53; https://doi.org/10.3390/proceedings2019036053 - 16 Jan 2020
Cited by 1 | Viewed by 1070
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  
Abstract
Developing Plantain for Resistance to Banana Aphids by RNA Interference
Proceedings 2019, 36(1), 54; https://doi.org/10.3390/proceedings2019036054 - 16 Jan 2020
Cited by 2 | Viewed by 1625
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  
Abstract
Optimization of Coconut Micropropagation via Somatic Embryogenesis
Proceedings 2019, 36(1), 55; https://doi.org/10.3390/proceedings2019036055 - 16 Jan 2020
Cited by 1 | Viewed by 1462
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  
Abstract
Innovation in Plant Protection in the Citrus Industry
Proceedings 2019, 36(1), 57; https://doi.org/10.3390/proceedings2019036057 - 16 Jan 2020
Viewed by 710
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  
Abstract
Strategic Supplementation Enhances Rumen Microbiome Efficiency in Pregnant Tropical Beef Cows
Proceedings 2019, 36(1), 58; https://doi.org/10.3390/proceedings2019036058 - 16 Jan 2020
Viewed by 745
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  
Abstract
Intelligent Systems for Commercial Application in Perennial Horticulture
Proceedings 2019, 36(1), 59; https://doi.org/10.3390/proceedings2019036059 - 17 Jan 2020
Cited by 1 | Viewed by 1408
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  
Abstract
Collaborative Planning and Shared Decision Making in Biosecurity Emergency Management
Proceedings 2019, 36(1), 60; https://doi.org/10.3390/proceedings2019036060 - 17 Jan 2020
Viewed by 929
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  
Abstract
Discerning Wine Astringency Sub-Qualities by Tribological Approaches in a Model System—What Is the Role of Saliva?
Proceedings 2019, 36(1), 61; https://doi.org/10.3390/proceedings2019036061 - 17 Jan 2020
Cited by 1 | Viewed by 920
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  
Abstract
Impacts of Heat Stress on the Physiological and Production Responses of Lactating Dairy Cows Grazing Pastures over Hot Summer Months
Proceedings 2019, 36(1), 62; https://doi.org/10.3390/proceedings2019036062 - 19 Jan 2020
Viewed by 874
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  
Abstract
Association of Thermotolerance with Milk Production, Feed Saver, Fertility and Fat Percentage Breeding Values in Holstein Friesian Dairy Cattle
Proceedings 2019, 36(1), 63; https://doi.org/10.3390/proceedings2019036063 - 19 Jan 2020
Viewed by 1034
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  
Abstract
Understanding the Metabolic Fate and Bioactivity of Dietary Anthocyanins
Proceedings 2019, 36(1), 64; https://doi.org/10.3390/proceedings2019036064 - 19 Jan 2020
Cited by 1 | Viewed by 824
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  
Abstract
Pregnancy Nutrition Affects Calf Survival in the Tropics
Proceedings 2019, 36(1), 66; https://doi.org/10.3390/proceedings2019036066 - 19 Jan 2020
Cited by 1 | Viewed by 732
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  
Abstract
Phylogenetic Relationship among Macadamia integrifolia and Macadamia tetraphylla Wild Accessions
Proceedings 2019, 36(1), 67; https://doi.org/10.3390/proceedings2019036067 - 19 Jan 2020
Viewed by 977
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  
Abstract
Start Clean, Stay Clean
Proceedings 2019, 36(1), 68; https://doi.org/10.3390/proceedings2019036068 - 19 Jan 2020
Viewed by 654
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  
Abstract
Rice Biofortification—Progress and Challenges in Improving the Nutritional Value of Rice
Proceedings 2019, 36(1), 69; https://doi.org/10.3390/proceedings2019036069 - 19 Jan 2020
Viewed by 966
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  
Abstract
Autoencoding Genetic Markers to Predict the Value of Ecophysiological Model Parameters - Proof of Concept Using a Sorghum Diversity Panel
Proceedings 2019, 36(1), 70; https://doi.org/10.3390/proceedings2019036070 - 19 Jan 2020
Viewed by 924
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  
Abstract
Nutritional Programming of Beef Heifers
Proceedings 2019, 36(1), 71; https://doi.org/10.3390/proceedings2019036071 - 20 Jan 2020
Viewed by 686
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  
Abstract
Drought Impacts on Grassland Productivity: The Role of Plant-Soil Feedbacks
Proceedings 2019, 36(1), 72; https://doi.org/10.3390/proceedings2019036072 - 20 Jan 2020
Viewed by 877
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  
Abstract
New Technologies for Weed Eradication—Invasive Plants Have No Place to Hide When DNA Is Involved
Proceedings 2019, 36(1), 73; https://doi.org/10.3390/proceedings2019036073 - 20 Jan 2020
Viewed by 853
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  
Abstract
Differences in the Anthocyanin Profile of Different Tissues of the Strawberry Fruit
Proceedings 2019, 36(1), 74; https://doi.org/10.3390/proceedings2019036074 - 20 Jan 2020
Viewed by 853
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  
Abstract
In-Plant Insect-Proofing by Trans-Kingdom RNAi
Proceedings 2019, 36(1), 75; https://doi.org/10.3390/proceedings2019036075 - 20 Jan 2020
Viewed by 865
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  
Abstract
Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management
Proceedings 2019, 36(1), 76; https://doi.org/10.3390/proceedings2019036076 - 21 Jan 2020
Cited by 1 | Viewed by 1132
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  
Abstract
Brassica Biofumigants for Improved Soil Health
Proceedings 2019, 36(1), 77; https://doi.org/10.3390/proceedings2019036077 - 21 Jan 2020
Cited by 2 | Viewed by 1061
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  
Abstract
Do GAP Practices Improve Market Access for Vegetable Farmers? A Case Study from Vientiane Capital, Laos
Proceedings 2019, 36(1), 78; https://doi.org/10.3390/proceedings2019036078 - 21 Jan 2020
Viewed by 1154
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  
Abstract
Buffalo Flies Receptive to Wolbachia Infection: An Opportunity for Population Control?
Proceedings 2019, 36(1), 79; https://doi.org/10.3390/proceedings2019036079 - 21 Jan 2020
Viewed by 1065
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  
Abstract
Impact of Photosensitization on Physicochemical Properties in Strawberries
Proceedings 2019, 36(1), 80; https://doi.org/10.3390/proceedings2019036080 - 21 Jan 2020
Viewed by 969
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  
Abstract
Antimicrobial Activity and Ellagitannins from Terminalia Ferdinandiana
Proceedings 2019, 36(1), 81; https://doi.org/10.3390/proceedings2019036081 - 21 Jan 2020
Cited by 1 | Viewed by 1405
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  
Abstract
High-amylose Rice: Starch Molecular Structural Features Controlling Cooked Rice Texture and Preference
Proceedings 2019, 36(1), 82; https://doi.org/10.3390/proceedings2019036082 - 21 Jan 2020
Cited by 1 | Viewed by 1407
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  
Abstract
Exploring the Nutritional Profile and Bioactive Potential of Australian Grown Saltbush (Atriplex sp.)
Proceedings 2019, 36(1), 83; https://doi.org/10.3390/proceedings2019036083 - 21 Jan 2020
Cited by 1 | Viewed by 1345
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  
Abstract
Optimizing Planting Method and Fertilizer Application Rate for Producing High Quality Nursery of Onion cv. Phulkara
Proceedings 2019, 36(1), 84; https://doi.org/10.3390/proceedings2019036084 - 21 Jan 2020
Viewed by 1113
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−2 at 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  
Abstract
Jatropha Curcas Development as Intervention Potential to Tackling Land, Energy and Food Challenges of Rural Communities in Dryland Sub-Saharan Africa
Proceedings 2019, 36(1), 85; https://doi.org/10.3390/proceedings2019036085 - 21 Jan 2020
Viewed by 954
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  
Abstract
The Inside and out of Folate in Strawberries and Avocados
Proceedings 2019, 36(1), 86; https://doi.org/10.3390/proceedings2019036086 - 02 Feb 2020
Viewed by 1084
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  
Abstract
Comparative Analysis and Evaluation of Handheld X-ray Fluorescence Spectrometry to Measure Silicon in Crop Plants
Proceedings 2019, 36(1), 87; https://doi.org/10.3390/proceedings2019036087 - 02 Feb 2020
Viewed by 879
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  
Abstract
Utilization of Forgoing Coastal Rice Fallow Lands of Bangladesh with Zero Tillage Potato Cultivation using Different Rates of Residues
Proceedings 2019, 36(1), 88; https://doi.org/10.3390/proceedings2019036088 - 02 Feb 2020
Viewed by 762
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  
Abstract
Modelling the Controlled Release of Toxins in a Rumen Environment
Proceedings 2019, 36(1), 89; https://doi.org/10.3390/proceedings2019036089 - 12 Feb 2020
Viewed by 1127
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  
Abstract
Adsorbents for the Sequestration of the Pimelea Toxin, Simplexin
Proceedings 2019, 36(1), 90; https://doi.org/10.3390/proceedings2019036090 - 12 Feb 2020
Viewed by 927
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  
Abstract
High Level of Energy and Protein Supplementation Effect on Feed Intake and Liveweight Gain of Bali Bulls Fed Elephant Grass
Proceedings 2019, 36(1), 91; https://doi.org/10.3390/proceedings2019036091 - 12 Feb 2020
Viewed by 743
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  
Abstract
Digital Twin for the Future of Orchard Production Systems
Proceedings 2019, 36(1), 92; https://doi.org/10.3390/proceedings2019036092 - 12 Feb 2020
Cited by 8 | Viewed by 2667
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  
Abstract
Exploring the Nutritional and Functional Properties of Two Understudied Australian Endemic Plants: Diploglottis bracteata and Syzigium aqueum
Proceedings 2019, 36(1), 93; https://doi.org/10.3390/proceedings2019036093 - 01 Feb 2020
Viewed by 804
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  
Abstract
Optimizing the Antimicrobial Activity of Tasmanian Pepper Leaf Oil Emulsion as a Natural Preservative for Capsicum
Proceedings 2019, 36(1), 94; https://doi.org/10.3390/proceedings2019036094 - 01 Feb 2020
Viewed by 900
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  
Abstract
Shoot Borer Earias Vittella—A Threat to the Indigenous Vegetable Pele Abelmoschus Manihot in the Pacific
Proceedings 2019, 36(1), 95; https://doi.org/10.3390/proceedings2019036095 - 13 Feb 2020
Viewed by 917
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  
Abstract
Effect of Feeding Different Cultivars of Leucaena leucocephala on Rumen-Based in vitro Anaerobic Fermentations
Proceedings 2019, 36(1), 96; https://doi.org/10.3390/proceedings2019036096 - 13 Feb 2020
Viewed by 862
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  
Abstract
Biopolymer Composites for Slow Release to Manage Pimelea Poisoning in Cattle
Proceedings 2019, 36(1), 97; https://doi.org/10.3390/proceedings2019036097 - 13 Feb 2020
Viewed by 888
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  
Abstract
DNA Testing and Genetic Evaluation for Poll Breeding in Tropically Adapted Beef Cattle
Proceedings 2019, 36(1), 98; https://doi.org/10.3390/proceedings2019036098 - 13 Feb 2020
Viewed by 942
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  
Abstract
The Effect of Post-Harvest Storage on the Physicochemical Properties and Phytochemical Content of Queen Garnet Plum
Proceedings 2019, 36(1), 99; https://doi.org/10.3390/proceedings2019036099 - 13 Feb 2020
Viewed by 913
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  
Abstract
Nutritional Characteristics of Australian Grown Feijoa (Acca sellowiana) and Its Antimicrobial Activity
Proceedings 2019, 36(1), 100; https://doi.org/10.3390/proceedings2019036100 - 13 Feb 2020
Cited by 1 | Viewed by 734
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  
Abstract
Analysis of Environmental Contaminants in Australian Honey and Comparison to Stingless Bee Honey from Queensland and Malaysia
Proceedings 2019, 36(1), 101; https://doi.org/10.3390/proceedings2019036101 - 13 Feb 2020
Viewed by 1026
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  
Abstract
Purple Sweetcorn—An innovative Horticultural Product—Consumer Views
Proceedings 2019, 36(1), 102; https://doi.org/10.3390/proceedings2019036102 - 13 Feb 2020
Viewed by 774
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  
Abstract
Breeding for Resistance to Husk Spot Disease in Macadamia
Proceedings 2019, 36(1), 103; https://doi.org/10.3390/proceedings2019036103 - 13 Feb 2020
Viewed by 835
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  
Abstract
Determinants of Food Inflation in Pakistan: Empirical Evidences
Proceedings 2019, 36(1), 104; https://doi.org/10.3390/proceedings2019036104 - 13 Feb 2020
Viewed by 2688
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  
Abstract
Aligning Pacific Cocoa Genetics to Productivity and Quality for the Craft Speciality Chocolate Market
Proceedings 2019, 36(1), 105; https://doi.org/10.3390/proceedings2019036105 - 14 Feb 2020
Viewed by 1139
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  
Abstract
Nutritional Composition of Solid-State Fermented Camelina Meal (An Enriched Protein Source for Broiler Chickens)
Proceedings 2019, 36(1), 106; https://doi.org/10.3390/proceedings2019036106 - 14 Feb 2020
Cited by 2 | Viewed by 1084
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 30oC 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  
Abstract
Benefits and Challenges for Expanding Protected Cropping in the Australian Tropics
Proceedings 2019, 36(1), 107; https://doi.org/10.3390/proceedings2019036107 - 19 Feb 2020
Viewed by 826
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  
Abstract
Detection of Stephanofilaria (Nematoda: Filariidae) in Buffalo Fly Lesions
Proceedings 2019, 36(1), 108; https://doi.org/10.3390/proceedings2019036108 - 20 Feb 2020
Viewed by 972
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  
Abstract
Variations in macadamia varietal susceptibility to Phytophthora multivora and P. cinnamomi
Proceedings 2019, 36(1), 109; https://doi.org/10.3390/proceedings2019036109 - 21 Feb 2020
Viewed by 833
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  
Abstract
How Can Protected Cropping Ensure an Export Supply of High Quality Melons in the Tropics?
Proceedings 2019, 36(1), 110; https://doi.org/10.3390/proceedings2019036110 - 21 Feb 2020
Viewed by 924
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  
Abstract
Australian Native Plant Foods and Their Contribution to Diet Diversity
Proceedings 2019, 36(1), 111; https://doi.org/10.3390/proceedings2019036111 - 03 Mar 2020
Viewed by 1240
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  
Abstract
A New Method for the Authentication of Australian Honey
Proceedings 2019, 36(1), 112; https://doi.org/10.3390/proceedings2019036112 - 03 Mar 2020
Viewed by 1315
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  
Abstract
Ensiling Unsalable Vegetables with Crop Sorghum to Produce High Quality Feed
Proceedings 2019, 36(1), 113; https://doi.org/10.3390/proceedings2019036113 - 03 Mar 2020
Viewed by 1106
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  
Abstract
Kakadu Plum (Terminalia Ferdinandiana)—A Native Australian Fruit with Functional Properties
Proceedings 2019, 36(1), 114; https://doi.org/10.3390/proceedings2019036114 - 03 Mar 2020
Viewed by 3568
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  
Abstract
Linking Smallholder Farmers to Potential Beef Markets: A Case Study of Livestock Farmers in Pakistan
Proceedings 2019, 36(1), 115; https://doi.org/10.3390/proceedings2019036115 - 03 Mar 2020
Viewed by 1196
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  
Abstract
Effect of Photosensitization on Inactivation of Aspergillus flavus in Maize
Proceedings 2019, 36(1), 116; https://doi.org/10.3390/proceedings2019036116 - 05 Mar 2020
Viewed by 1002
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  
Abstract
Farmer Perception and Resources for Calf Fattening Under Smallholder Production System
Proceedings 2019, 36(1), 117; https://doi.org/10.3390/proceedings2019036117 - 05 Mar 2020
Viewed by 1053
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  
Abstract
The Small Trees High Productivity Initiative: Principles and Practice in High Density Orchard Design
Proceedings 2019, 36(1), 118; https://doi.org/10.3390/proceedings2019036118 - 06 Mar 2020
Viewed by 998
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  
Abstract
Improving Crop Adaptation through Improved Phenology Prediction: A Case Study with Chickpea
Proceedings 2019, 36(1), 119; https://doi.org/10.3390/proceedings2019036119 - 06 Mar 2020
Viewed by 766
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  
Abstract
The Effect of Heat Treatments and Drip Line Placements on The Yield and Quality of Garlic
Proceedings 2019, 36(1), 120; https://doi.org/10.3390/proceedings2019036120 - 07 Mar 2020
Viewed by 806
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  
Abstract
Introgression of Large Grain Size from Australian Wild Rice and Its Agronomical Importance
Proceedings 2019, 36(1), 121; https://doi.org/10.3390/proceedings2019036121 - 07 Mar 2020
Viewed by 771
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  
Abstract
Light Relation in Intensive Mango Orchards
Proceedings 2019, 36(1), 122; https://doi.org/10.3390/proceedings2019036122 - 08 Mar 2020
Cited by 1 | Viewed by 1030
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  
Abstract
Advancing Brewing Science
Proceedings 2019, 36(1), 123; https://doi.org/10.3390/proceedings2019036123 - 08 Mar 2020
Viewed by 730
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  
Abstract
Comparison of Antioxidant Properties of Coconut Testa Flour of Selected Local Coconut Cultivars of Sri Lanka
Proceedings 2019, 36(1), 124; https://doi.org/10.3390/proceedings2019036124 - 14 Mar 2020
Viewed by 1005
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  
Abstract
Women Empowerment and Poverty Reduction in Rural Okara, Punjab Pakistan
Proceedings 2019, 36(1), 125; https://doi.org/10.3390/proceedings2019036125 - 15 Mar 2020
Viewed by 386
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  
Abstract
Milk Delivery in Tropically-Adapted Neonatal Beef Calves
Proceedings 2019, 36(1), 126; https://doi.org/10.3390/proceedings2019036126 - 16 Mar 2020
Cited by 2 | Viewed by 948
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  
Abstract
Photosensitization, a Green Treatment for the Inactivation of Aspergillus Flavus in Peanuts Mediated by Curcumin
Proceedings 2019, 36(1), 127; https://doi.org/10.3390/proceedings2019036127 - 16 Mar 2020
Viewed by 1089
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  
Abstract
Maximising Reproduction under Extensive Grazing Conditions, Regardless of Rainfall
by
Proceedings 2019, 36(1), 129; https://doi.org/10.3390/proceedings2019036129 - 18 Mar 2020
Viewed by 666
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  
Abstract
Proteomics as a Potential Tool for Identifying Biomarkers for Host Resistance to Cattle Tick
Proceedings 2019, 36(1), 131; https://doi.org/10.3390/proceedings2019036131 - 21 Mar 2020
Viewed by 1023
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  
Abstract
Increasing Heat Tolerance in Wheat to Counteract Recent and Projected Increases in Heat Stress
Proceedings 2019, 36(1), 132; https://doi.org/10.3390/proceedings2019036132 - 28 Mar 2020
Cited by 3 | Viewed by 790
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  
Abstract
Northern Beef Industry Emerging Market, Supply Chain Gap Analysis & Sector Capacity Baseline Study
Proceedings 2019, 36(1), 133; https://doi.org/10.3390/proceedings2019036133 - 29 Mar 2020
Viewed by 807
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  
Abstract
Transcriptomics Analysis for the Detection of Novel Drought Tolerance Genes in Jojoba (Simmondsia Chinensis)
Proceedings 2019, 36(1), 135; https://doi.org/10.3390/proceedings2019036135 - 30 Mar 2020
Viewed by 928
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  
Abstract
Blood Phosphorus Concentration as an Indicator of Phosphorus Deficiency in Growing Cattle
Proceedings 2019, 36(1), 136; https://doi.org/10.3390/proceedings2019036136 - 01 Apr 2020
Viewed by 737
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  
Abstract
Adaptive and Productive Sheep Breed for Changing Climate
Proceedings 2019, 36(1), 137; https://doi.org/10.3390/proceedings2019036137 - 01 Apr 2020
Viewed by 803
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  
Abstract
Shining a Light on Haemonchus contortus in Sheep
Proceedings 2019, 36(1), 138; https://doi.org/10.3390/proceedings2019036138 - 02 Apr 2020
Viewed by 898
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  
Abstract
Demand Driven Common Bean Variety Development and Promotion for Enhanced Productivity and Production
Proceedings 2019, 36(1), 139; https://doi.org/10.3390/proceedings2019036139 - 02 Apr 2020
Viewed by 829
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  
Abstract
Wxlv, the Ancestral Allele of Rice Waxy Gene
Proceedings 2019, 36(1), 140; https://doi.org/10.3390/proceedings2019036140 - 02 Apr 2020
Cited by 4 | Viewed by 970
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 Wxlv 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 Wxlv of the Wx locus, which affects the mouthfeel of rice grains by modulating the size of amylose molecules. Using evolutionary analysis, we demonstrated that Wxlv originated directly from wild rice, and the three major Wx alleles in cultivated rice (Wxb, Wxa, and Wxin) differentiated after the substitution of one base pair at the functional sites. These data indicate that the Wxlv 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  
Abstract
Estimating Soil Organic Carbon Under Different Land-Use Types in Australia’s Northern Grains Region Using Mid-Infrared Spectroscopy
Proceedings 2019, 36(1), 141; https://doi.org/10.3390/proceedings2019036141 - 03 Apr 2020
Viewed by 980
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  
Abstract
Agroforestry Suitability Mapping for the Northwest Provinces of Vietnam
Proceedings 2019, 36(1), 142; https://doi.org/10.3390/proceedings2019036142 - 03 Apr 2020
Viewed by 912
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  
Abstract
Grain Oats—An Alternative Winter Cereal for the Australian Sub-Tropics?
Proceedings 2019, 36(1), 143; https://doi.org/10.3390/proceedings2019036143 - 03 Apr 2020
Viewed by 637
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  
Abstract
Effects of Fresh and Saline Water Irrigation for Maize in Coastal Areas of Bangladesh
Proceedings 2019, 36(1), 144; https://doi.org/10.3390/proceedings2019036144 - 04 Apr 2020
Viewed by 1129
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 (ECe) 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  
Abstract
Effect of Straw Mulch and Irrigation on Sunflower and Maize Cultivation in No Tillage Systems of Coastal Heavy Soils
Proceedings 2019, 36(1), 145; https://doi.org/10.3390/proceedings2019036145 - 04 Apr 2020
Cited by 1 | Viewed by 1182
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  
Abstract
Modelling Yield and Seasonal Soil Salinity Dynamics in Rice-Grasspea Cropping System for the Coastal Saline Zone of West Bengal, India
Proceedings 2019, 36(1), 146; https://doi.org/10.3390/proceedings2019036146 - 04 Apr 2020
Cited by 1 | Viewed by 1024
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  
Abstract
Zero Tilled-Paddy Straw Mulched Potato (Solanum tuberosum) Cultivation in the Coastal Saline Soils Reduce Soil Salinity, Increase Yield and Profitability
Proceedings 2019, 36(1), 147; https://doi.org/10.3390/proceedings2019036147 - 05 Apr 2020
Cited by 2 | Viewed by 1175
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  
Abstract
Pedigree Data Analysis of a Wheat Population
Proceedings 2019, 36(1), 148; https://doi.org/10.3390/proceedings2019036148 - 05 Apr 2020
Viewed by 746
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  
Abstract
Host Plant Resistance to Helicoverpa armigera Has Been Observed in Australian Wild Cajanus (Pigeonpea) Species
Proceedings 2019, 36(1), 149; https://doi.org/10.3390/proceedings2019036149 - 05 Apr 2020
Viewed by 695
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  
Abstract
Understanding Sclerotinia Risks Associated with Growing Peanuts in the South Burnett Area
Proceedings 2019, 36(1), 150; https://doi.org/10.3390/proceedings2019036150 - 06 Apr 2020
Viewed by 728
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  
Abstract
Genotypic Effects on the Response of Soybean (Glycine max (L.) Merrill) to Sulfonylurea Herbicides
Proceedings 2019, 36(1), 151; https://doi.org/10.3390/proceedings2019036151 - 06 Apr 2020
Viewed by 799
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  
Abstract
Land Situation and Sowing Date Effects Growth and Yield of Crops in the Rice-Pulse Based Cropping Systems of Coastal India
Proceedings 2019, 36(1), 152; https://doi.org/10.3390/proceedings2019036152 - 06 Apr 2020
Cited by 1 | Viewed by 807
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  
Abstract
Assessments of Lowland Rice-Based Farming Systems and Prospects for Future Research and Development Priorities
Proceedings 2019, 36(1), 153; https://doi.org/10.3390/proceedings2019036153 - 07 Apr 2020
Viewed by 1287
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  
Abstract
Exploring the Potential of High Resolution Satellite Imagery for Yield Prediction of Avocado and Mango Crops
Proceedings 2019, 36(1), 154; https://doi.org/10.3390/proceedings2019036154 - 07 Apr 2020
Cited by 1 | Viewed by 967
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  
Abstract
Differences in Thermoregulatory Responses between Dorper and Second Cross Lambs to Heat Stress Challenges
Proceedings 2019, 36(1), 155; https://doi.org/10.3390/proceedings2019036155 - 07 Apr 2020
Cited by 1 | Viewed by 905
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  
Abstract
A Novel Biomarker Test for Sugarcane Yellow Canopy Syndrome
Proceedings 2019, 36(1), 156; https://doi.org/10.3390/proceedings2019036156 - 07 Apr 2020
Viewed by 768
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  
Abstract
Building Farming Resilience to Climate Change: Upland Crop Production in Northwest Cambodia
Proceedings 2019, 36(1), 157; https://doi.org/10.3390/proceedings2019036157 - 07 Apr 2020
Viewed by 1032
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  
Abstract
Exploring Common Bean Fresh Pod Market in East African Region: A Case of Uganda
Proceedings 2019, 36(1), 158; https://doi.org/10.3390/proceedings2019036158 - 07 Apr 2020
Viewed by 732
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  
Abstract
Performance of Garlic (Allium sativum) Varieties under Zero Tillage Mulch Condition in Southern Coastal Region of Bangladesh
Proceedings 2019, 36(1), 159; https://doi.org/10.3390/proceedings2019036159 - 07 Apr 2020
Cited by 1 | Viewed by 937
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  
Abstract
Plant and Seed Mortality of Fireweed Senecio madagascariensis Following Herbicide Application
Proceedings 2019, 36(1), 160; https://doi.org/10.3390/proceedings2019036160 - 07 Apr 2020
Viewed by 911
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 (TordonTM 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  
Abstract
A Biocontrol Option to Control a Foodborne Pathogen; Using Campylobacter Bacteriophages to Control Campylobacter in Poultry
Proceedings 2019, 36(1), 162; https://doi.org/10.3390/proceedings2019036162 - 07 Apr 2020
Viewed by 927
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  
Abstract
Outcomes of Agroforestry and Monocropping—Comparison and Assessment
Proceedings 2019, 36(1), 163; https://doi.org/10.3390/proceedings2019036163 - 07 Apr 2020
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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 ha1, respectively. Meanwhile, five agroforestry options were provided the cumulative profit from 29 to 10,000 USD ha1. 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  
Abstract
Analysis of Differences in Gene Expression Associated with Variation in Biomass Composition in Sugarcane
Proceedings 2019, 36(1), 164; https://doi.org/10.3390/proceedings2019036164 - 07 Apr 2020
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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  
Abstract
The Genetics of Rumen Phage Populations
Proceedings 2019, 36(1), 165; https://doi.org/10.3390/proceedings2019036165 - 07 Apr 2020
Cited by 2 | Viewed by 929
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  
Abstract
Breaking and Flowering: The Budding Story of Macadamia
Proceedings 2019, 36(1), 166; https://doi.org/10.3390/proceedings2019036166 - 07 Apr 2020
Viewed by 923
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  
Abstract
Is Broadcasting Mung Bean into Rice Crops a Useful Practice in Timor-Leste?
Proceedings 2019, 36(1), 167; https://doi.org/10.3390/proceedings2019036167 - 07 Apr 2020
Viewed by 1059
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