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Agriculture, Volume 11, Issue 6 (June 2021) – 104 articles

Cover Story (view full-size image): How would lettuce grown in vertical farming compare with those grown in hydroponic greenhouses under Mediterranean climatic conditions?
Lettuce (Lactuca sativa L.) is one of the most important leafy vegetables worldwide and a model crop for studying the effect of lighting. Low light intensity during winter can increase the nitrate concentration in lettuce and other leafy greens to harmful levels for humans.
Two different light intensity levels were used in the vertical farm to study morphological, physiological, and commercial characteristics and compare them with those of plants cultivated in a standard hydroponic glasshouse during winter. The plants can be morphologically identical if an appropriate light intensity is applied, but vertical farms can guarantee safety when it comes to nitrate content. View this paper.
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Article
IoFarm in Field Test: Does a Cost-Optimal Choice of Fertilization Influence Yield, Protein Content, and Market Performance in Crop Production?
Agriculture 2021, 11(6), 571; https://doi.org/10.3390/agriculture11060571 - 21 Jun 2021
Viewed by 487
Abstract
Decision-support system (DSS) IoFarm was developed to identify economically optimal fertilizer strategies on the farm level. The average cost savings are 66 EUR ha−1. This study aimed to determine whether this approach impacts yield, protein content, and market performance in crop [...] Read more.
Decision-support system (DSS) IoFarm was developed to identify economically optimal fertilizer strategies on the farm level. The average cost savings are 66 EUR ha−1. This study aimed to determine whether this approach impacts yield, protein content, and market performance in crop production compared to usual farm-fertilization strategies. Few DSSs for fertilizer optimization consider multiple nutrients. DSSs with a clear focus on both fertilizer intensity and the least-cost combination of fertilizers are even rarer. To the best of our knowledge, there is no information in the literature on the impact of such DSSs on yield, protein content, and market performance for cereal–maize crop rotation. This study determines for the first time whether the financial benefits of using such an optimization tool are in conflict with important agronomic goals. In a three-year field trial, IoFarm was compared to standard farm-fertilization strategies. Results were evaluated with an analysis of variance followed by post hoc tests. No significant differences in yield, protein content, and market performance were found for comparable fertilization variants (with or without organic fertilization). However, differences exist in the selection of fertilizers and the timing of fertilization. Results show the agronomic comparability of IoFarm and usual farm-fertilizer strategies. Full article
(This article belongs to the Section Crop Production)
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Article
Equipment Performance, Costs and Constraints of Packaging and Transporting Rice Straw for Alternative Uses to Burning in the “Parc Natural l’Albufera de València” (Spain)
Agriculture 2021, 11(6), 570; https://doi.org/10.3390/agriculture11060570 - 21 Jun 2021
Viewed by 339
Abstract
Rice straw is a residue that causes significant environmental problems, as burning it causes CO2 and ash emissions, while buried waste can cause issues associated with eutrophication. The extraction of straw from fields for alternative uses may contribute to solving these problems, [...] Read more.
Rice straw is a residue that causes significant environmental problems, as burning it causes CO2 and ash emissions, while buried waste can cause issues associated with eutrophication. The extraction of straw from fields for alternative uses may contribute to solving these problems, but research into its economic viability is necessary. The straw can be used for crop mulching, biofuel, bedding for livestock, and so on. In this study, we analyse the work carried out by straw harvesting machines (rakes, balers, bundlers, and loaders) and calculate the costs of packing, road-siding, and transportation of the straw from the rice fields to stockage points in the producer area, as well as to locations outside of the rice production area, in order to assess the viability. The costs of all elemental operations were calculated. The costs of all the operations included between raking and unloading in the producer area stocking point ranged between 28.1 and 51 EUR t−1. These costs were compared with the price of rain-fed cereal straw (wheat and barley), which is the most abundant, noting that the years in which rain-fed cereal straw reached high prices, rice straw could serve as a competitive product; however, in years when the former is cheap, it would be necessary to subsidise the harvesting of rice straw. Full article
(This article belongs to the Special Issue Agricultural Structures and Mechanization)
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Article
Impact of Climate Change on Rice Yield in Malaysia: A Panel Data Analysis
by , , , and
Agriculture 2021, 11(6), 569; https://doi.org/10.3390/agriculture11060569 - 21 Jun 2021
Viewed by 398
Abstract
Climate change is a global problem since many countries worldwide are becoming increasingly vulnerable to natural disasters. Numerous climate models in various studies project a decline in agricultural productivity that will mainly be due to excessive heat in tropical and subtropical regions, especially [...] Read more.
Climate change is a global problem since many countries worldwide are becoming increasingly vulnerable to natural disasters. Numerous climate models in various studies project a decline in agricultural productivity that will mainly be due to excessive heat in tropical and subtropical regions, especially in Southeast Asia. As a Southeast Asian country, Malaysia is no exception to this problem. Hence, the present study aimed to examine the impact of climate change on rice yields in Malaysia. A panel data approach was adopted using data from 1987 to 2017 on eight granary areas in Peninsular Malaysia. The main objectives were to assess the impact of climate variables (i.e., minimum and maximum temperature and precipitation) on rice yield and the variance of the impact during the main season and off-season. Our regression results indicate that precipitation was not statistically significant in all model specifications for both the main and off-season. While the maximum temperature was found to be negatively associated with yield during the off-season, the minimum temperature showed a positive effect in both cropping seasons. We used the HadGEM3-GC31 N512 resolution model based on the high-emission Shared Socioeconomic Pathways 8.5 scenario (SSPs-8.5) from the High-Resolution Model Intercomparison Project (HighResMIP) of the Coupled Model Intercomparison Project Phase 6 (CMIP6) to project future climate change in 2030 and 2040. The projected results indicate that rice yield would show a more positive trend by 2040 when compared to the previous decade, ranging from −0.02 to 19.85% during the main season and −2.77 to 7.41% during the off-season. Although rice yield is likely to increase in certain areas, other areas are projected to experience negative effects. Hence, adaptation at the farm level remains crucial, specifically during the off-season, since climate change could widen the gaps in rice yields between cropping seasons and among granary areas. Full article
(This article belongs to the Section Ecosystem, Environment and Climate Change in Agriculture)
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Article
Techno-Economic Analysis of a Crossflow Column Dryer for Maize Drying in Ghana
Agriculture 2021, 11(6), 568; https://doi.org/10.3390/agriculture11060568 - 21 Jun 2021
Viewed by 360
Abstract
In Ghana, smallholder maize farmers continue to serve as the primary contributor to maize production. These farmers, however, still face challenges of access to appropriate, effective, and efficient drying systems. They continue to depend on open sun drying, which leads to high post-harvest [...] Read more.
In Ghana, smallholder maize farmers continue to serve as the primary contributor to maize production. These farmers, however, still face challenges of access to appropriate, effective, and efficient drying systems. They continue to depend on open sun drying, which leads to high post-harvest losses. In this study, a 500 kg portable column dryer with a biomass burner heat source was evaluated using maize. Indicators such as drying rate, drying efficiency, and moisture extraction rate were used to assess its technical performance. The economic performance of the drying system was appraised using Net Present Value (NPV), Internal Rate of Return (IRR), Benefit-Cost Ratio (BCR), and Payback Period (PBP). The results showed that the moisture content of maize was reduced from 22.3% to 13.4 ± 2.6% in 5 h at an average drying rate of 1.81%/h and drying efficiency of 64.7%. Utilization of the column dryer for the provision of drying services in a maize-growing community over a 10-year utilization period proved viable with an NPV and IRR of $1633 and 71%, respectively, PBP of less than two years, and BCR of 2.82. Adoption of such low-capacity mobile grain dryers in sub-Saharan Africa would be beneficial in providing timely drying services and improve the socio-economic status of smallholder maize farmers in the region. Full article
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Article
A Stability Analysis Using AΜΜΙ and GGE Biplot Approach on Forage Yield Assessment of Common Vetch in Both Conventional and Low-Input Cultivation Systems
Agriculture 2021, 11(6), 567; https://doi.org/10.3390/agriculture11060567 - 20 Jun 2021
Viewed by 408
Abstract
Common vetch (Vicia sativa L.) is a widespread legume crop in the Mediterranean mega-environment, due to its versatile uses and its compatibility with organic and low-input farming systems. However, its adaptation to various such environments should be studied and varieties suitable for [...] Read more.
Common vetch (Vicia sativa L.) is a widespread legume crop in the Mediterranean mega-environment, due to its versatile uses and its compatibility with organic and low-input farming systems. However, its adaptation to various such environments should be studied and varieties suitable for forage yield must be selected. This study aimed to explore forage yield stability of common vetch varieties based on the stability index, with a specific target to explore common vetch variety behavior in various environments. Six Greek varieties of common vetch were used over four environments for two years. The cultivation was conducted using a strip plot with the varieties randomized within each plot in both conventional and low-input cultivation systems. (Alexandros) and (Tempi) varieties showed stability for days to 50% of flowering (index >4000), while (Pigasos) and (Zefyros) for fresh forage yield (>200) across environments. Combined estimations, also showed stability of (Pigasos) and (Zefyros) for fresh forage yield. Comparisons between the conventional and low-input farming systems generally showed minor differences but revealed varieties that exhibit stable performance even in the low-input farming systems, where stability is generally a little higher. The AMMI and GGE biplot analysis depicted the stability performance of the varieties regarding the traits under experimentation. As far as the fresh forage and dry matter yield, (Zefyros) was the most stable and productive variety over all others. Correlations between traits displayed the positive relation of fresh forage yield with days for 50% flowering and dry forage yield. Positive correlations may be proved useful for indirect breeding through traits with high stability leading to the selection of traits that show low stability. Full article
(This article belongs to the Special Issue Crop Breeding and Genetics)
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Article
Optimization Design of Spray Cooling Fan Based on CFD Simulation and Field Experiment for Horticultural Crops
Agriculture 2021, 11(6), 566; https://doi.org/10.3390/agriculture11060566 - 20 Jun 2021
Viewed by 427
Abstract
In recent years, horticultural plants have frequently suffered significant heat damage due to excessive temperatures. In this study, a horticultural spray cooling system was designed, consisting mainly of a jet fan and spraying system. CFD simulation technology and response surface methodology were used [...] Read more.
In recent years, horticultural plants have frequently suffered significant heat damage due to excessive temperatures. In this study, a horticultural spray cooling system was designed, consisting mainly of a jet fan and spraying system. CFD simulation technology and response surface methodology were used to optimize the design of the jet fan, which improved the thrust of the fan. The length of the inlet section was 300 mm, the length of the outlet section was 300 mm, the length of the cone section was 450 mm, and the diameter of the outlet was 950 mm, where the thrust of the jet fan was 225.06 N. By establishing the CFD model of spray cooling in a tea field and designing a L9 (34) orthogonal experiment, the effect of the spray parameters on the maximum temperature drop and effective cooling distance was studied, and the best parameters were selected. The simulation results show that the optimum parameters are a spray flow rate of 4.5 kg/s, a droplet diameter of 15–45 μm, a droplet temperature of 298.15 K, and a nozzle double circle layout. Based on the simulation results of the optimized jet fan and spray parameters selected, a spray cooling test bench was established. Field test results show that when the initial ambient temperature was 310.05 K–310.95 K, the maximum temperature drop of the spray cooling fan was 9.1 K, and the cooling distance was approximately 36.0 m. The temperature drop decreased with increasing distance from the fan. This study is of great significance to protect horticultural plants from extremely high temperatures. Full article
(This article belongs to the Section Agricultural Technology)
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Article
QTL Analysis of Rice Grain Size Using Segregating Populations Derived from the Large Grain Line
Agriculture 2021, 11(6), 565; https://doi.org/10.3390/agriculture11060565 - 20 Jun 2021
Viewed by 394
Abstract
Grain size affects the yield and quality of rice. The large grain line (LGL), showing a large grain size and japonica-like genome, was selected in the breeding field. The 94 F2 plants derived from a cross between LGL and Hanareum (a [...] Read more.
Grain size affects the yield and quality of rice. The large grain line (LGL), showing a large grain size and japonica-like genome, was selected in the breeding field. The 94 F2 plants derived from a cross between LGL and Hanareum (a high-yielding tongil-type variety) were used for the quantitative trait loci (QTL) analysis of grain length (GL), grain width (GW), and grain thickness (GT). A linkage map of the F2 population, covering 1312 cM for all 12 chromosomes, was constructed using 123 Fluidigm SNP markers. A total of nine QTLs for the three traits were detected on chromosomes two, three, four, six, and seven. Two QTLs for GL on chromosomes two and six explained 17.3% and 16.2% of the phenotypic variation, respectively. Two QTLs were identified for GW on chromosomes two and three, and explained 24.3% and 23.5% of the phenotypic variation, respectively. The five QTLs for GT detected on chromosomes two, three, five, six and seven, explained 13.2%, 14.5%, 16.6%, 10.9%, and 10.2% of the phenotypic variation, respectively. A novel QTL for GT, qGT2, was validated on the same region of chromosome two in the selected F3 population. The QTLs identified in this study, and LGL, could be applied to the development of large-grain rice varieties. Full article
(This article belongs to the Special Issue Rice Breeding and Genetics)
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Article
Pigment Production under Cold Stress in the Green Microalga Chlamydomonas reinhardtii
Agriculture 2021, 11(6), 564; https://doi.org/10.3390/agriculture11060564 - 20 Jun 2021
Viewed by 518
Abstract
Microalgae have long been used for the commercial production of natural colorants such as carotenoids and chlorophyll. Due to the rising demand for carotenoids and other natural products from microalgae, strategies to increase production efficiency are urgently needed. The production of microalgal biorefineries [...] Read more.
Microalgae have long been used for the commercial production of natural colorants such as carotenoids and chlorophyll. Due to the rising demand for carotenoids and other natural products from microalgae, strategies to increase production efficiency are urgently needed. The production of microalgal biorefineries has been limited to countries with moderate climates. For countries with cooler climates and less daylight, methodologies for the efficient production of microalgal biorefineries need to be investigated. Algal strains that can be safely consumed as whole cells are also attractive alternatives for developing as carotenoid supplements, which can also contain other compounds with health benefits. Using such strains helps to eliminate the need for hazardous solvents for extraction and several other complicated steps. In this study, the mesophilic green alga Chlamydomonas reinhardtii was employed to study the effects of cold stress on cell physiology and the production of pigments and storage compounds. The results showed that temperatures between 10 and 20 °C induced carotenoid and chlorophyll accumulation in the wild-type strain of C. reinhardtii. Interestingly, the increased level of carotenoids suggested that they might play a crucial role in cold stress acclimation. A temperature of 15 °C resulted in the highest carotenoid and chlorophyll productivity. At this temperature, carotenoid and chlorophyll productivity was 2 times and 1.3 times higher than at 25 °C, respectively. Subjecting a mutant defective in lutein and zeaxanthin accumulation to cold stress revealed that these two carotenoids are not essential for cold stress survival. Therefore, cold temperature could be used as a strategy to induce and increase the productivity of pigments in C. reinhardtii. Full article
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Article
Impact of Camera Viewing Angle for Estimating Leaf Parameters of Wheat Plants from 3D Point Clouds
Agriculture 2021, 11(6), 563; https://doi.org/10.3390/agriculture11060563 - 20 Jun 2021
Viewed by 438
Abstract
Estimation of plant canopy using low-altitude imagery can help monitor the normal growth status of crops and is highly beneficial for various digital farming applications such as precision crop protection. However, extracting 3D canopy information from raw images requires studying the effect of [...] Read more.
Estimation of plant canopy using low-altitude imagery can help monitor the normal growth status of crops and is highly beneficial for various digital farming applications such as precision crop protection. However, extracting 3D canopy information from raw images requires studying the effect of sensor viewing angle by taking into accounts the limitations of the mobile platform routes inside the field. The main objective of this research was to estimate wheat (Triticum aestivum L.) leaf parameters, including leaf length and width, from the 3D model representation of the plants. For this purpose, experiments with different camera viewing angles were conducted to find the optimum setup of a mono-camera system that would result in the best 3D point clouds. The angle-control analytical study was conducted on a four-row wheat plot with a row spacing of 0.17 m and with two seeding densities and growth stages as factors. Nadir and six oblique view image datasets were acquired from the plot with 88% overlapping and were then reconstructed to point clouds using Structure from Motion (SfM) and Multi-View Stereo (MVS) methods. Point clouds were first categorized into three classes as wheat canopy, soil background, and experimental plot. The wheat canopy class was then used to extract leaf parameters, which were then compared with those values from manual measurements. The comparison between results showed that (i) multiple-view dataset provided the best estimation for leaf length and leaf width, (ii) among the single-view dataset, canopy, and leaf parameters were best modeled with angles vertically at −45° and horizontally at 0° (VA −45, HA 0), while (iii) in nadir view, fewer underlying 3D points were obtained with a missing leaf rate of 70%. It was concluded that oblique imagery is a promising approach to effectively estimate wheat canopy 3D representation with SfM-MVS using a single camera platform for crop monitoring. This study contributes to the improvement of the proximal sensing platform for crop health assessment. Full article
(This article belongs to the Special Issue Crop Monitoring and Weed Management Based on Sensor-Actuation Systems)
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Article
The Possibilities of Using Common Buckwheat in Phytoremediation of Mineral and Organic Soils Contaminated with Cd or Pb
Agriculture 2021, 11(6), 562; https://doi.org/10.3390/agriculture11060562 - 19 Jun 2021
Viewed by 417
Abstract
The results of this study provided accurate guidance on the possibility of using common buckwheat (Fagopyrum esculentum Moench) in phytoremediation practices for mineral soil or organic soils contaminated with Cd or Pb. Based on a model pot experiment, the tolerance of buckwheat [...] Read more.
The results of this study provided accurate guidance on the possibility of using common buckwheat (Fagopyrum esculentum Moench) in phytoremediation practices for mineral soil or organic soils contaminated with Cd or Pb. Based on a model pot experiment, the tolerance of buckwheat to elevated contents of cadmium and lead in organic and mineral soils was examined. The soils were differentiated into neutral and acidic, and amended with metals at doses of 10 mg Cd kg−1 DM and 100 mg Pb kg−1 DM of soil. The growth, development, biomass, translocation coefficient, and tolerance index (TI) of the tested plants were examined. The use of metals caused a weakening of plant growth and development, as well as intensified chlorotic and necrotic changes to the buckwheat leaves. The application of Cd caused a statistically significant decrease in shoot biomass. The plants growing in organic acidic soil were most vulnerable to Cd toxicity. The (TI) values confirm the generally low tolerance of buckwheat to Cd, except for the treatment in organic neutral soil, and the high tolerance of this plant to Pb in all the studied soils. Full article
(This article belongs to the Special Issue Bioremediation in Agricultural and Urban Soils)
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Article
Effects of Short-Term Rice Straw Return on the Soil Microbial Community
Agriculture 2021, 11(6), 561; https://doi.org/10.3390/agriculture11060561 - 18 Jun 2021
Viewed by 383
Abstract
Rice straw is a byproduct of agricultural production and an important agricultural resource. However, rice straw has not yet been effectively used, and incorrect treatment methods (such as burning in the field) can cause serious damage to the environment. Studies have shown that [...] Read more.
Rice straw is a byproduct of agricultural production and an important agricultural resource. However, rice straw has not yet been effectively used, and incorrect treatment methods (such as burning in the field) can cause serious damage to the environment. Studies have shown that straw returning is beneficial to soil, but there have been few studies focused on the effect of the amount of short-term straw returned on the soil microbial community. This study evaluates 0%, 50%, 75%, and 100% rice straw returned to the field on whether returning different amounts of straw in the short term would affect the diversity and composition of the soil microbial community and the correlation between bacteria and fungi. The results show that the amount of straw returned to the field is the main factor that triggers the changes in the abundance and composition of the microbial community in the paddy soil. A small amount of added straw (≤50% straw added) mainly affects the composition of the bacterial community, while a larger amount of added straw (>50% straw added) mainly affects the composition of the fungal community. Returning a large amount of straw increases the microbial abundance related to carbon and iron cycles in the paddy soil, thus promoting the carbon and iron cycle processes to a certain extent. In addition, network analysis shows that returning a large amount of straw also increases the complexity of the microbial network, which may encourage more microbes to be niche-sharing and comprehensively improve the ecological environment of paddy soil. This study may provide some useful guidance for rice straw returning in northeast China. Full article
(This article belongs to the Special Issue Advanced Research of Soil Microbial Functional Diversity)
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Article
Effects of Different Organic Fertilizers on Improving Soil from Newly Reclaimed Land to Crop Soil
Agriculture 2021, 11(6), 560; https://doi.org/10.3390/agriculture11060560 - 18 Jun 2021
Viewed by 469
Abstract
The rapid development of cities in the recent 10 years caused a reduction in the cultivated land area, which only accounts for 14% of the total land area in China. Land development and reclamation have been regarded as an effective way to compensate [...] Read more.
The rapid development of cities in the recent 10 years caused a reduction in the cultivated land area, which only accounts for 14% of the total land area in China. Land development and reclamation have been regarded as an effective way to compensate farmland occupation. However, most of the newly reclaimed land has poor soil fertility and suitability; in some cases, the production capacity is only 10–30% of the occupied farmland. In order to ameliorate the soil quality of the newly reclaimed land, this study evaluated the effects of commercial organic fertilizer (0.75, 1.50, and 2.25 kg/m2), mushroom residue (1.50, 2.25, and 3.00 kg/m2), biogas slurry (150, 225, and 300 kg/m2), vegetable cake (0.30 and 0.60 kg/m2), and chemical compound fertilizer (37.50 g/m2) on the pH, moisture content and organic matter content (OMC), available phosphate, total nitrogen, alkaline hydrolysis nitrogen, microbial biomass carbon and nitrogen, and number of total bacteria and phosphate-solubilizing bacteria, as well as the growth of maize seedlings. The results from this study indicate that the soil quality (OMC is an indicator) was ameliorated by chemical and organic fertilizers, in particular commercial organic fertilizers, which caused a 9.35–16.35% increase in moisture content, a 11.56–18.72% increase in pH, a 1.73–2.15 fold increase in OMC, a 338.44–491.41% increase in available P, a 36.80–48.14% increase in total N, a 95.32–128.34% increase in alkaline hydrolysis N, a 92.57–178.38% increase in total bacterial numbers, and a 7.57–20.87 fold increase in microbial biomass carbon compared with the control. The pot experiment further indicated that soil amended with commercial organic fertilizers caused a 20.35–30.55% increase in the height and a 12.50–16.67% increase in the total dry weight of maize seedlings. In addition, representative strains with the ability to dissolve phosphorus and fix nitrogen were successfully isolated using the culture method, and were then identified based on colony morphological observation and 16S rDNA sequence analysis, which help us to not only understand why organic fertilizer has great effect on soil improvement, but also provides beneficial microbial resources for further study. Full article
(This article belongs to the Special Issue Fertilizer Use, Soil Health and Agricultural Sustainability)
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Communication
First Report on the Mechanisms of Insecticide Resistance in Field Populations of the Small Hive Beetle in Florida
Agriculture 2021, 11(6), 559; https://doi.org/10.3390/agriculture11060559 - 18 Jun 2021
Viewed by 459
Abstract
The small hive beetle (Aethina tumida Murray) is a serious threat to beekeeping and crops that rely on honeybees for pollination. The small hive beetle not only causes significant damage to honeybees by feeding on pollen and honey, attacking bee brood and [...] Read more.
The small hive beetle (Aethina tumida Murray) is a serious threat to beekeeping and crops that rely on honeybees for pollination. The small hive beetle not only causes significant damage to honeybees by feeding on pollen and honey, attacking bee brood and causing stored honey to ferment, but also might serve as a vector of diseases. In addition, the small hive beetle has developed resistance to the pyrethroid and organophosphate insecticides registered for control of honeybee pests in the United States. The development of resistance in small hive beetle populations is a great concern to the beekeeping industry; thus, there is an urgent need for strategies to manage that resistance. Therefore, we used synergist probes to determine the mechanisms of resistance in a small hive beetle population to these insecticides. Our studies on the toxicity of insecticides alone or with the synergists piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithionate (DEF) suggested that mixed-function oxidases and esterases were the major resistance factors to these insecticides in a studied population of the small hive beetle. In contrast, there was no synergism with diethyl maleate (DEM), triphenyl phosphate (TPP) and formamidine. Therefore, glutathione-S-transferase, carboxylesterase and target site were not involved in insecticide resistance in the small hive beetle. Rotation of classes of insecticides (with different modes of action) and metabolic synergists were suggested for the development of successful resistance management programs. To the best of our knowledge, this is the first study of the mechanisms of resistance in small hive beetle populations in Florida and suggests an urgent need for alternative control strategies for these serious pests of honeybee colonies. Full article
(This article belongs to the Section Crop Protection, Diseases, Pest and Weeds)
Article
Evaluating Genotype × Environment Interactions of Yield Traits and Adaptability in Rice Cultivars Grown under Temperate, Subtropical and Tropical Environments
Agriculture 2021, 11(6), 558; https://doi.org/10.3390/agriculture11060558 - 18 Jun 2021
Viewed by 394
Abstract
Rice yield is a complex trait that is strongly affected by environment and genotype × environment interaction (GEI) effects. Consideration of GEI in diverse environments facilitates the accurate identification of optimal genotypes with high yield performance, which are adaptable to specific or diverse [...] Read more.
Rice yield is a complex trait that is strongly affected by environment and genotype × environment interaction (GEI) effects. Consideration of GEI in diverse environments facilitates the accurate identification of optimal genotypes with high yield performance, which are adaptable to specific or diverse environments. In this study, multiple environment trials were conducted to evaluate grain yield (GY) and four yield-component traits: panicle length, panicle number, spikelet number per panicle, and thousand-grain weight. Eighty-nine rice varieties were cultivated in temperate, subtropical, and tropical regions for two years. The effects of both GEI (12.4–19.6%) and environment (23.6–69.6%) significantly contributed to the variation of all yield-component traits. In addition, 37.1% of GY variation was explained by GEI, indicating that GY performance was strongly affected by the different environmental conditions. GY performance and genotype stability were evaluated using simultaneous selection indexing, and 19 desirable genotypes were identified with high productivity and broad adaptability across temperate, subtropical, and tropical conditions. These optimal genotypes could be recommended for cultivation and as elite parents for rice breeding programs to improve yield potential and general adaptability to climates. Full article
(This article belongs to the Section Genotype Evaluation and Breeding)
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Article
A Biostimulant Based on Seaweed (Ascophyllum nodosum and Laminaria digitata) and Yeast Extracts Mitigates Water Stress Effects on Tomato (Solanum lycopersicum L.)
Agriculture 2021, 11(6), 557; https://doi.org/10.3390/agriculture11060557 - 17 Jun 2021
Viewed by 503
Abstract
Water deficit is one of the most problematic stressors worldwide. In this context, the use of biostimulants represents an increasingly ecological practice aimed to improve crop tolerance and mitigate the negative effects on the productivity. Here, the effect derived from the foliar application [...] Read more.
Water deficit is one of the most problematic stressors worldwide. In this context, the use of biostimulants represents an increasingly ecological practice aimed to improve crop tolerance and mitigate the negative effects on the productivity. Here, the effect derived from the foliar application of ERANTHIS®®, a biostimulant based on seaweed (Ascophyllum nodosum and Laminaria digitata) and yeast extracts, was tested on tomato plants grown under mild water-stress conditions. The potential stress mitigation action was evaluated by monitoring morphometric (fresh weight and dry matter content), physiological (stem water potential) and biochemical (ROS scavenger enzymes activity, proline, abscisic acid, hydrogen peroxide and photosynthetic pigment content) parameters closely related to the occurrence and response to stress at both flowering and fruit-set timing. In general, we observed that plants grown under drought conditions and treated with the biostimulant had a lower amount of ABA, and MDA and proline correlated to a lower activity of ROS scavenger enzymes compared to untreated plants. These data, together with the higher stem water potential and photosynthetic pigment levels recorded for the treated plants, suggest that ERANTHIS®® may mitigate water stress effects on tomato. Full article
(This article belongs to the Special Issue Impact of Biostimulants on Crops)
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Article
Field Decomposition of Corn Cob in Seasonally Frozen Soil and Its Intrinsic Influencing Factors: The Case of Northeast China
Agriculture 2021, 11(6), 556; https://doi.org/10.3390/agriculture11060556 - 17 Jun 2021
Viewed by 386
Abstract
Returning corn cobs to the field during corn kernel harvesting is an effective way to improve soil properties and increase crop yield. However, seasonally frozen soil seriously hinders the field decomposition process of corn cobs. To explore the decomposition characteristics and promote field [...] Read more.
Returning corn cobs to the field during corn kernel harvesting is an effective way to improve soil properties and increase crop yield. However, seasonally frozen soil seriously hinders the field decomposition process of corn cobs. To explore the decomposition characteristics and promote field decomposition, in this study, the nylon mesh bag method was used to perform field decomposition tests for 150 days. Fiber composition analysis and microstructure observation were carried out. The results showed that the field decomposition of corn cob was influenced by temperature, precipitation, and frozen soil environment. The 150-day cumulative decomposition rates of the pith, woody ring, and glume were 40.0%, 24.2%, and 36.3%, respectively. Caused by the difference in fiber compositions, the decomposition speeds of pith and glume were much higher than that of the woody ring. The complex microstructures of the pith, woody ring, and glume led to differences in the accessibility of cellulose, which indirectly influenced the field decomposition characteristics. The homogeneous sponge-like structure of the pith and glume increased the accessibility of cellulose and ultimately accelerated the field decomposition, while the compact lignocellulosic structure of the woody ring hindered the decomposition process. Compared with corn stalk, corn cob had similar or even better field decomposition characteristics and excellent application prospects. Full article
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Article
Antioxidant Activity of Elderberry Fruits during Maturation
Agriculture 2021, 11(6), 555; https://doi.org/10.3390/agriculture11060555 - 17 Jun 2021
Viewed by 365
Abstract
Antioxidant activity (AOA) in fruits of Sambucus nigra and several new elderberry interspecific hybrids involving S. javanica (JA), S. nigra subsp. nigra (NI), S. nigra subsp. nigra ‘Black Beauty’ (BB), S. nigra subsp. cerulea (CER) and S. racemosa (S. racemosa subsp. racemosa [...] Read more.
Antioxidant activity (AOA) in fruits of Sambucus nigra and several new elderberry interspecific hybrids involving S. javanica (JA), S. nigra subsp. nigra (NI), S. nigra subsp. nigra ‘Black Beauty’ (BB), S. nigra subsp. cerulea (CER) and S. racemosa (S. racemosa subsp. racemosa (RAC), S. racemosa subsp. racemosa var. miquelii (MIQ), S. racemosa subsp. tigranii (TIG), S. racemosa subsp. kamtschatica—coreana (KOR) at five maturity stages were investigated by applying DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric reducing antioxidant power) and ORAC (oxygen radical absorption capacity) assays. The aim of the study was to compare different assays for estimating AOA in elderberries, to plan the appropriate harvest time and to determine whether the most promising genotypes could be predicted in advance. All assays used showed that AOA increased significantly during maturation. All assays were significantly correlated with each other and could be reliably used for the AOA determination of elderberries. In fully mature berries, significant correlations were also found between total phenolic (TP) content and AOA by all assays, but no significant correlations were found between total ascorbic acid (TAA) content and AOA by all assays. At the fully mature stage, (the most appropriate stage for harvesting), berries of (JA × NI) × BB and (JA × NI) × MIQ were found to be superior in AOA and TP content. Genotypes with higher/lower AOA and TP content could not be predicted in advance, while TAA showed the opposite. Full article
(This article belongs to the Special Issue Bioactive Compounds in Fruits)
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Article
Enhanced Ruminal Fermentation Parameters and Altered Rumen Bacterial Community Composition by Formulated Rumen Buffer Agents Fed to Dairy Cows with a High-Concentrate Diet
Agriculture 2021, 11(6), 554; https://doi.org/10.3390/agriculture11060554 - 17 Jun 2021
Viewed by 443
Abstract
The effects of rumen buffer agents on ruminal fermentation parameters and bacterial community composition were determined using in vitro and in vivo experiments in three rumen-cannulated, high-concentrate fed Holstein Friesian dairy cows. Experiment 1 in vitro treatments included bentonite, calcium carbonate, calcium oxide, [...] Read more.
The effects of rumen buffer agents on ruminal fermentation parameters and bacterial community composition were determined using in vitro and in vivo experiments in three rumen-cannulated, high-concentrate fed Holstein Friesian dairy cows. Experiment 1 in vitro treatments included bentonite, calcium carbonate, calcium oxide, sodium bicarbonate, sodium sesquicarbonate, and processed coral, and unbuffered samples served as the control. Experiment 2 in vitro treatments were based on the formulation of various combinations of the buffer agents used in Experiment 1. Combinations were selected for the in vivo study based on their buffering ability. Calcium oxide, sodium bicarbonate, and sodium sesquicarbonate stabilized the ruminal pH and improved in vitro rumen fermentation. The combined buffer agents had a significant effect on pH, buffering capacity, total gas, and total volatile fatty acids. Firmicutes and Bacteroidetes were the dominant phyla in both treatments and the control. Ruminococcus and Prevotella were found to be the dominant genera. Ruminococcus bromii was predominant in the treatment group. Prevotella jejuni was more abundant in the control group compared to the treatment group, in which its abundance was very low. Ruminococcus flavefaciens and Intestinimonas butyriciproducens gradually increased in abundance as cows received treatment. Overall, a high-concentrate diet administered to cows induced adverse changes in ruminal pH; however, buffer supplementation enhanced ruminal fermentation characteristics and altered bacterial community, which could contribute to preventing ruminal acidosis. Full article
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Article
Efficiency of Recycled Biogas Digestates as Phosphorus Fertilizers for Maize
Agriculture 2021, 11(6), 553; https://doi.org/10.3390/agriculture11060553 - 17 Jun 2021
Viewed by 326
Abstract
Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy [...] Read more.
Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy of phosphorus fertilizers recycled from biogas digestates in maize shoots grown under controlled greenhouse conditions, in two soils, in a pot experiment. Variables investigated were plant-available phosphorus in soil, plant biomass production, and concentration of phosphorus, calcium, and magnesium in shoots. Soils were treated with three different fertilizer fractions, separated from biogas digestates, at equivalent phosphorus concentrations, using different combinations and application techniques, isolated or in combination, and compared to triple superphosphate (TSP) as a reference. One of the fractions (P-Salt) had effects on biomass production and plant phosphorus concentration equivalent to TSP in agricultural surface soil. In the second soil (with less active soil life and nutrient content), equivalence to TSP was achieved with combinations of two recycled fractions (P-Salt and dried solids). The enhancement of the phosphorus fertilizing effect by the solids was synergistic, indicating that the solids had a soil conditioning effect. The results show that biogas digestates are a valuable source for phosphorus recycling of fractions that have equivalent or even superior fertilizing properties compared to TSP. Full article
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Article
Are Chilean Pasture Seed End-Users Adopting New Species? Trends and Joinpoint Regression Analysis of the Last 19 Years of Seed Imports
Agriculture 2021, 11(6), 552; https://doi.org/10.3390/agriculture11060552 - 17 Jun 2021
Viewed by 302
Abstract
Pastures are important for the agricultural sector as forage, recreational and sports systems. The Chilean pasture seed market is highly dependent on introduced genetics; however, the effect of climate change and market conditions can modify pasture options. The objective of this study was [...] Read more.
Pastures are important for the agricultural sector as forage, recreational and sports systems. The Chilean pasture seed market is highly dependent on introduced genetics; however, the effect of climate change and market conditions can modify pasture options. The objective of this study was to quantify changes of the pasture seeds sown by Chilean end-users, as metric tons (Mt) or proportion of the total (PT), based on 19 years of imported seed. The Mann–Kendall test and joinpoint regression analysis were used to estimate the overall trends and the average annual percent change (AAPC) for the whole period, respectively. The total imported Mt had an increasing trend and AAPC (+5.7%), wherein a large PT corresponded to ryegrasses (Lolium spp.) (0.681), with increasing trends for Mt and PT. Clovers (Trifolium spp.) had decreasing trends and AAPC (−2.9% for Mt and −9.6% for PT). For PT, the main species was perennial ryegrass (L. perenne L.) (0.357), with increasing trends for Mt. As Mt, a positive AAPC was found for plantain (P. lanceolata L.) (+17.4%) and chicory (C. intybus L.) (+63.2%). Over a period of 19 years, based on Mt but not PT, Chilean end-users have been adopting new pasture species with a decreasing use of Trifolium spp. Full article
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Article
Effect of Inorganic Zinc on Selected Immune Parameters in Chicken Blood and Jejunum after A. galli Infection
Agriculture 2021, 11(6), 551; https://doi.org/10.3390/agriculture11060551 - 16 Jun 2021
Viewed by 381
Abstract
Ascaridiosis in poultry results in a reduction in body weight gain, egg production, as well as microelement levels. Infected poultry have higher demands on feed with the addition of essential elements including zinc. The effects of the infection by Ascaridia galli and the [...] Read more.
Ascaridiosis in poultry results in a reduction in body weight gain, egg production, as well as microelement levels. Infected poultry have higher demands on feed with the addition of essential elements including zinc. The effects of the infection by Ascaridia galli and the supplementation of inorganic zinc on the immune status of broilers were monitored through evaluation of the relative expression of selected genes (interleukins, IFN-γ, and TNF-α) by real-time PCR, haematology parameters by microscopy, and quantitative changes of lamina propria lymphocytes by flow cytometry in day 7 and day 14 of the study. We observed that the enrichment of the diet with inorganic zinc has a positive effect on the relative percentage of CD4+ lamina propria lymphocytes in the jejunum and on heterophil counts in blood. In addition, it was concluded that inorganic zinc has an anti-inflammatory effect (downregulation of TNF-α and IL-17) and activates IgA-producing cells in the jejunum of chicks infected with A. galli. Full article
(This article belongs to the Special Issue Poultry: Breeding, Health, Nutrition, and Management)
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Article
Recent Patterns of Exposure, Sensitivity, and Adaptive Capacity of Selected Crops in Cameroon
Agriculture 2021, 11(6), 550; https://doi.org/10.3390/agriculture11060550 - 16 Jun 2021
Viewed by 345
Abstract
In most parts of sub-Saharan Africa, precipitation is impacted by climate change. In some countries like Cameroon, it is still not clear how maize, millet and rice will respond to changes in growing season precipitation. This work examines the exposure, sensitivity, and adaptive [...] Read more.
In most parts of sub-Saharan Africa, precipitation is impacted by climate change. In some countries like Cameroon, it is still not clear how maize, millet and rice will respond to changes in growing season precipitation. This work examines the exposure, sensitivity, and adaptive capacity of the above crops to droughts at both the national and sub-national scale. Crop yield data were culled from FAOSTAT while growing season precipitation data were culled from the database of UNDP/Oxford University and the climate portal of the World Bank. Adaptive capacity proxies (literacy, and poverty rate) were collected from KNOEMA and the African Development Bank. The analysis was performed using the vulnerability index equation. Nationally, millet has the lowest vulnerability and rice has the highest. At the sub-national scale, northern maize has the highest vulnerability followed by western highland rice. It is observed that when scales change, the crops that are vulnerable also change. However, at both levels vulnerability has an inverse relationship with adaptive capacity. Full article
(This article belongs to the Special Issue Agricultural Food Security and Economic Analysis)
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Addendum
Addendum: Grenda et al. Clostridia in Insect Processed Animal Proteins—Is an Epidemiological Problem Possible? Agriculture 2021, 11, 270
Agriculture 2021, 11(6), 549; https://doi.org/10.3390/agriculture11060549 - 16 Jun 2021
Viewed by 361
Abstract
The following should be added to the Acknowledgments section of this paper [...] Full article
Article
(Re)Commoning Food and Food Systems. The Contribution of Social Innovation from Solidarity Economy
Agriculture 2021, 11(6), 548; https://doi.org/10.3390/agriculture11060548 - 15 Jun 2021
Viewed by 442
Abstract
The need for a transition to sustainable food systems is widely recognised. Over the last three decades, movements have been demanding and proposing a radical transformation, foregrounding the social values of food. Experiences inspired by solidarity economy have given rise to highly innovative [...] Read more.
The need for a transition to sustainable food systems is widely recognised. Over the last three decades, movements have been demanding and proposing a radical transformation, foregrounding the social values of food. Experiences inspired by solidarity economy have given rise to highly innovative pathways, grounded on the redefinition of the food-related values and practices and the reconstruction of local, community-based food systems by referring to social and ecological sustainability. One can usefully draw from these experiences for identifying challenges, opportunities and benefits and for analysing the most effective modes of action leading to the creation of alternatives. Capturing and supporting this innovation is particularly important when looking at the opportunities offered by local food policies. This significantly involves the meanings, goals and forms that food governance takes on. The paper aims at investigating these aspects, reading the initiatives inspired by SE principles as an example of social innovation. Their engagement in re-signifying food in terms of “commons” and in “commoning” food systems constitutes a complementary key of analysis. Focusing on the Italian context, the paper draws on many years of qualitative research and direct involvement in these initiatives. The analysis provides useful insights about the potential for change existing in society and invites us to develop reflexivity on how local food policies capture the opportunity for a re-politicisation of food-related issues. Full article
(This article belongs to the Special Issue Sustainable Food Systems in Italy: Policies, Movements and Markets)
Article
The Response of Soil pH and Exchangeable Al to Alum and Lime Amendments
Agriculture 2021, 11(6), 547; https://doi.org/10.3390/agriculture11060547 - 15 Jun 2021
Viewed by 415
Abstract
Intensive cultivation and unprecedented utilization of ammoniacal fertilizer has accelerated soil acidification in the southern Great Plains and many other parts of the world. During a two-year study that evaluated the impact of soil pH and aluminum (Al) toxicity on winter wheat yield [...] Read more.
Intensive cultivation and unprecedented utilization of ammoniacal fertilizer has accelerated soil acidification in the southern Great Plains and many other parts of the world. During a two-year study that evaluated the impact of soil pH and aluminum (Al) toxicity on winter wheat yield potential, we observed a variance in the edaphic responses of the two study sites (Stillwater and Chickasha) to two soil amendments, Alum [Al2(SO4)3] and lime [Ca(OH)2]. We found that AlKCl values at Stillwater were 223% and 150% higher than Chickasha during Year 1 and Year 2, respectively, with similar soil pH. Additionally, Alsat values at Stillwater were 30.6% and 24.9% higher than Chickasha during Year 1 and Year 2, respectively. Surprisingly, when treated as a bivariate of Alsat, soil buffer indices differed in graphical structure. While Chickasha was identified with a cubic polynomial (p < 0.0001), Stillwater was characterized by linear regression (p < 0.0001). We have reason to believe that this divergence in edaphic response might be attributed to the organically bound Al, dissolved organic carbon (DOC), spatio-temporal variance, and adsorption reactions regulated by the solubility of Al(OH)+2 species in acidic soils. Full article
(This article belongs to the Section Agricultural Soils)
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Article
Nitrogen Dynamics in Tropical Soils Treated with Liquid and Granular Urea Fertilizers
Agriculture 2021, 11(6), 546; https://doi.org/10.3390/agriculture11060546 - 14 Jun 2021
Viewed by 615
Abstract
The mineralization of urea fertilizer mostly regulates the nitrogen dynamics in the soil. A laboratory-scale study was conducted to compare the nitrogen dynamics in two tropical soil series incubated with either liquid urea (LU) or granular urea (GU) at 0, 300, 400 or [...] Read more.
The mineralization of urea fertilizer mostly regulates the nitrogen dynamics in the soil. A laboratory-scale study was conducted to compare the nitrogen dynamics in two tropical soil series incubated with either liquid urea (LU) or granular urea (GU) at 0, 300, 400 or 500 mg/kg of soil. The soils samples used in the experiment were the Bungor and Selangor soil series which have a sandy clay loam and clay texture, respectively. The NH4+-N, NO3-N concentration in the soils were measured for four weeks to determine the urea-N mineralization while ten pore volumes of water were used for the NH4+-N and NO3-N leaching loss. At the same application rate, higher NH4+-N and NO3-N concentrations were recorded in the LU applied soils throughout the incubation period in case of N mineralization. Urea-N recovery was higher in GU than LU treated soils in the first two weeks while no urea-N was present in both GU and LU treated soils after the third week of incubation. The leaching of N (NH4+-N and NO3-N) was higher in GU treated soils than that of LU and leaching was increased with increased application rate in both LU and GU in both soils. The NH4+-N and NO3-N concentrations were higher in the Selangor soil whereas the total N leaching loss was higher in Bungor soil. The results suggest that the LU was a better N fertilizer source than GU for rapid mineralization, quicker N availability and lower N leaching loss. Full article
(This article belongs to the Section Agricultural Systems and Management)
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Article
Effect of Storage Conditions on Storability and Antioxidant Potential of Pears cv. ‘Conference’
Agriculture 2021, 11(6), 545; https://doi.org/10.3390/agriculture11060545 - 13 Jun 2021
Viewed by 530
Abstract
Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere [...] Read more.
Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere + 1-MCP—on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and were found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment; at the same time, it is profitable to store ‘Conference’ pears in controlled atmosphere for the same period, no matter whether 1-MCP was applied or not. Full article
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Article
Almond Fruit Drop Patterns under Mediterranean Conditions
Agriculture 2021, 11(6), 544; https://doi.org/10.3390/agriculture11060544 - 12 Jun 2021
Viewed by 538
Abstract
Almond is an important tree nut crop worldwide, and planted areas have been increasing year after year. While self-fertility is one of the key factors when it comes to improved almond productivity of new cultivars, yield is also affected by the number of [...] Read more.
Almond is an important tree nut crop worldwide, and planted areas have been increasing year after year. While self-fertility is one of the key factors when it comes to improved almond productivity of new cultivars, yield is also affected by the number of flowers produced, pollination, fruit set, fruit drop, and fruit weight. Almond fruit drop patterns of 20 Mediterranean almond cultivars were studied over three years. In addition, fruit drop patterns of two scion cultivars ‘Marinada’ and ‘Vairo’ budded onto eight to 10 different rootstocks managed with three different pruning strategies were studied for two years. Cumulative flower and fruit drop ranged from 50% to 90% among cultivars and treatments, and there were up to four fruit drop events during the growing season, the main one occurring from 20–60 days from full bloom (DFFB). Subsequent drops were at 100 DFFB, 120–140 DFFB, and the last one at 160–180 DFFB. The later drops were less apparent. In general, about half of the cumulative drop was comprised of buds and flowers, and the remaining percentage was fruit that dropped 20 or more days after full bloom. Furthermore, different fruit drop patterns were observed depending on the cultivar. For late- and extra-late flowering cultivars, cumulative fruit drop began to decrease earlier, with most of the drops occurred already at full bloom, whereas the opposite was observed for the early flowering cultivars. Rootstocks also had an important effect on the fruit drop pattern, with different effects depending on the scion cultivar. Tree management, such as type of pruning, also had an important effect on the rate of fruit drop and cumulative drop. Therefore, each combination of cultivar × rootstock × pruning type will require different strategies in order to reduce the fruit drop and optimize crop loads. Full article
(This article belongs to the Special Issue Development and Cultivar Improvement of Nut Crops)
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Article
The Effect of Herbage Availability, Pregnancy Stage and Rank on the Rate of Liveweight Loss during Fasting in Ewes
Agriculture 2021, 11(6), 543; https://doi.org/10.3390/agriculture11060543 - 12 Jun 2021
Viewed by 508
Abstract
Sheep liveweight and liveweight change are vital tools both for commercial and research farm management. However, they can be unreliable when collection procedures are not standardized or when there are varying time delays between sheep removal from grazing and weighing. This study had [...] Read more.
Sheep liveweight and liveweight change are vital tools both for commercial and research farm management. However, they can be unreliable when collection procedures are not standardized or when there are varying time delays between sheep removal from grazing and weighing. This study had two stages with different objectives: (1) A liveweight loss study to determine the effect of herbage availability (Low and High) on the rate of liveweight loss of ewes at different pregnancy stages (approximately 100 days of pregnancy: P100 and 130 days: P130) and ranks (single and twin); (2) A follow-up liveweight loss study to develop and validate correction equations for delayed liveweights by applying them to data sets collected under commercial conditions. Results from each stage showed that the rate of liveweight loss varied by herbage availability and stage of pregnancy (p < 0.05) but not pregnancy-rank (p > 0.05). Further, the rate of liveweight loss differed by farm (p < 0.05). Applying liveweight correction equations increased the accuracy of without delay liveweight estimates in P100 ewes by 56% and 45% for single-bearing and twin-bearing ewes, respectively, when offered the Low-level diet. In ewes offered the High-level diet, accuracies of without delay liveweight estimates were increased by 53% and 67% for single-bearing and twin-bearing ewes, respectively. Among P130 ewes, accuracy was increased by 43% and 37% for single-bearing and twin-bearing ewes, respectively, when offered the Low herbage level and by 60% and 50% for single-bearing and twin-bearing ewes, respectively, when offered the High herbage level. In conclusion, a short-term delay of up to 8 hours prior to weighing, which is commonly associated with practical handling operations, significantly reduced the liveweight recorded for individual sheep. Using delayed liveweights on commercial farms and in research can have consequences for management practices and research results; thus, liveweight data should be collected without delay. However, when this is not feasible, delayed ewe liveweights should be corrected and, in the absence of locally devised correction equations, the ones generated in the current study could be applied on farms with similar management conditions and herbage type. Full article
(This article belongs to the Section Farm Animal Production)
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Article
Application of Plant Extracts in Micropropagation and Cryopreservation of Bleeding Heart: An Ornamental-Medicinal Plant Species
Agriculture 2021, 11(6), 542; https://doi.org/10.3390/agriculture11060542 - 12 Jun 2021
Viewed by 495
Abstract
Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts [...] Read more.
Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis. Full article
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