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Agronomy, Volume 12, Issue 3 (March 2022) – 211 articles

Cover Story (view full-size image): Laurel wilt, a new fungal disease vectored by ambrosia beetles is causing mortality among avocado trees in south Florida. The effect of canopy cover on ambrosia beetle abundance was evaluated. Orchards with a dense canopy cover harbored large populations of these beetles. Reducing canopy cover, thus increasing light intensity, suppresses ambrosia beetle abundance, especially for species associated with the pathogen. Canopy management alters the microclimate in avocado orchards, affecting ambrosia beetle abundance and flight activity. Sanitation (e.g., pruning, stumping, and removing LW-affected trees) and replanting with young trees are cultural practices currently used by avocado growers to reduce the incidence of laurel wilt in their orchards. View this paper
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Article
The Adenine at the 4th Exon of the DRO1 Gene Provides Drought-Tolerance Capacity to Hybrid Rice Deyou4727 and Its Maintainer Line Dexiang074B
Agronomy 2022, 12(3), 752; https://doi.org/10.3390/agronomy12030752 - 21 Mar 2022
Viewed by 725
Abstract
Extreme weather and global warming are drastic agricultural issues causing water scarcity. Under these conditions, it is vital to select drought-tolerant hybrid super rice breeds to enhance the rice yield in dry areas. In the current study, a dry-shed experiment was carried out [...] Read more.
Extreme weather and global warming are drastic agricultural issues causing water scarcity. Under these conditions, it is vital to select drought-tolerant hybrid super rice breeds to enhance the rice yield in dry areas. In the current study, a dry-shed experiment was carried out in 2019–2020 to analyze the root growth, gene expression, and enzyme activity of hybrid rice Deyou4727, its parent (Dexiang074B * Chenghui727), taking IR64 as a universal control. Results showed that Deyou4727 and its maintainer line Dexiang074B produced more roots (30–50 cm soil) and higher enzymatic activity than IR64 during the drought stress period, indicating a good drought-tolerant capacity for Deyou4727. The distribution and morphology of the root system in Deyou4727 were inherited by the maintainer line Dexiang074B, which was confirmed by the high upregulation of DRO1 and OsPIN1b gene expression and the sharing of the same ORF region in both the hybrid rice varieties. However, the DRO1 gene ORF study showed that, in the case of the control IR64, ‘A’ was missing at the 4th exon of the DRO1 gene, which may explain the shallow and weak root architecture system of IR64. The drought-tolerance capacity of Deyou4727 can be used in the future as a drought-resistant germplasm for breeding more drought-tolerant hybrid rice varieties. Full article
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Communication
The ‘Pick-Your-Own’ Model of Production and Marketing of Ethnic Crops in Central New Jersey, USA
Agronomy 2022, 12(3), 751; https://doi.org/10.3390/agronomy12030751 - 21 Mar 2022
Viewed by 524
Abstract
Specca Farms Pick Your Own (SFPYO) operates a 125-acre (50 ha) farm in Bordentown, Central New Jersey, USA, which attends to customers from many different ethnic regions such as Africa, the Americas, Asia, the Mediterranean region, Eastern Europe, and the Caribbean. The company [...] Read more.
Specca Farms Pick Your Own (SFPYO) operates a 125-acre (50 ha) farm in Bordentown, Central New Jersey, USA, which attends to customers from many different ethnic regions such as Africa, the Americas, Asia, the Mediterranean region, Eastern Europe, and the Caribbean. The company produces more than 100 ethnic crops that require unique agronomic and management practices tailored to central New Jersey’s ecosystem and the unique quality of produce demanded by various ethnic nationalities. This paper reviews the ethnic crop classifications at the farm, the agronomic and crop protection practices applied to different crop groups, and the factors that guide produce marketing to meet the unique quality demanded by different ethnic nationalities. Full article
(This article belongs to the Special Issue Ethnic Crops in the United States of America)
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Article
Ontology-Based IoT Middleware Approach for Smart Livestock Farming toward Agriculture 4.0: A Case Study for Controlling Thermal Environment in a Pig Facility
Agronomy 2022, 12(3), 750; https://doi.org/10.3390/agronomy12030750 - 21 Mar 2022
Viewed by 738
Abstract
Integrated farm management (IFM) is promoted as a whole farm approach toward Agriculture 4.0, incorporating smart farming technologies for attempting to limit livestock production’s negative impacts on the environment while increasing productivity with regard to the economic viability of rural communities. The Internet [...] Read more.
Integrated farm management (IFM) is promoted as a whole farm approach toward Agriculture 4.0, incorporating smart farming technologies for attempting to limit livestock production’s negative impacts on the environment while increasing productivity with regard to the economic viability of rural communities. The Internet of Things (IoT) may serve as an enabler to ensure key properties—such as interconnectivity, scalability, agility, and interoperability—in IFM systems so that they could provide object-based services while adapting to dynamic changes. This paper focuses on the problem of facilitating the management, processing, and sharing of the vast and heterogeneous data points generated in livestock facilities by introducing distributed IoT middleware as the core of a responsive and adaptive service-oriented IFM system, specifically targeted to enable smart livestock farming in view of its unique requirements. The proposed IoT middleware encompasses the context-awareness approach via the integration of a flexible ontology-based structure for modeling and reasoning. The IoT middleware was assessed in actual conditions on the grounds of a case study for smart control of the thermal environment in a medium-sized pig farming facility. As derived from the obtained evaluation results, the system appears to perform quite satisfactorily in terms of computational performance as well as ontology coherence, consistency, and efficiency. Full article
(This article belongs to the Special Issue Smart Farming in Service of Modernizing Agriculture)
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Article
Transcriptome Analysis Reveals Genetic Factors Related to Callus Induction in Barley
Agronomy 2022, 12(3), 749; https://doi.org/10.3390/agronomy12030749 - 21 Mar 2022
Viewed by 639
Abstract
Barley is an important cereal crop worldwide. Its genetic transformation is now limited to very few cultivars because of the high genotype dependence of embryogenic callus. To reveal the key genes or factors controlling the callus induction and plantlet regeneration in barley, we [...] Read more.
Barley is an important cereal crop worldwide. Its genetic transformation is now limited to very few cultivars because of the high genotype dependence of embryogenic callus. To reveal the key genes or factors controlling the callus induction and plantlet regeneration in barley, we compared the transcriptomic profiles of immature embryos of Golden Promise and ZU9, which differed dramatically in the efficiency of the genetic transformation. The samples were taken at 0, 5, 10 and 20 days of the culture, respectively. In total, 5386 up-regulated and 6257 down-regulated genes were identified in Golden Promise. Several genes, identified exclusively in GP callus, were selected for further investigation. These genes were mainly involved in protein metabolism, energy metabolism, stress response, detoxification and ubiquitin–proteasome. Four YUCCA flavin monooxygenases, one PIN-FORMED, one tryptophan aminotransferase related, three small auxin up RNA, three indole-3-acetic acid and one adenylate isopentenyl transferase, seven cytokinin oxidase/dehydrogenase, three Arabidopsis histidine kinase, three Arabidopsis histidine phosphotransfer protein, and one Arabidopsis response regulator were differentially expressed in the calli of the two barley genotypes, suggesting that biosynthesis, response and transport of auxin and cytokinin might be associated with cell reprogramming during callus induction. The current results provide insights into molecular mechanisms of callus induction at an early developmental stage and are helpful for optimizing the tissue culture system in barley. Full article
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Review
Challenges to Use Machine Learning in Agricultural Big Data: A Systematic Literature Review
Agronomy 2022, 12(3), 748; https://doi.org/10.3390/agronomy12030748 - 21 Mar 2022
Cited by 1 | Viewed by 1066
Abstract
Agricultural Big Data is a set of technologies that allows responding to the challenges of the new data era. In conjunction with machine learning, farmers can use data to address problems such as farmers’ decision making, water management, soil management, crop management, and [...] Read more.
Agricultural Big Data is a set of technologies that allows responding to the challenges of the new data era. In conjunction with machine learning, farmers can use data to address problems such as farmers’ decision making, water management, soil management, crop management, and livestock management. Crop management includes yield prediction, disease detection, weed detection, crop quality, and species recognition. On the other hand, livestock management considers animal welfare and livestock production. The purpose of this paper is to synthesize the evidence regarding the challenges involved in implementing machine learning in agricultural Big Data. We conducted a systematic literature review applying the PRISMA protocol. This review includes 30 papers published from 2015 to 2020. We develop a framework that summarizes the main challenges encountered, machine learning techniques, and the leading technologies used. A significant challenge is the design of agricultural Big Data architectures due to the need to modify the set of technologies adapting the machine learning techniques as the volume of data increases. Full article
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Article
Chemical Composition of Plant Residues Regulates Soil Organic Carbon Turnover in Typical Soils with Contrasting Textures in Northeast China Plain
Agronomy 2022, 12(3), 747; https://doi.org/10.3390/agronomy12030747 - 21 Mar 2022
Viewed by 707
Abstract
Soil organic carbon (SOC) turnover plays a pivotal role in achieving C neutrality, promoting C retention and increasing soil fertility. Residue biochemistry and soil texture essentially determine SOC distribution (including CO2 mineralization and stock in soil) in farmland. However, less is known [...] Read more.
Soil organic carbon (SOC) turnover plays a pivotal role in achieving C neutrality, promoting C retention and increasing soil fertility. Residue biochemistry and soil texture essentially determine SOC distribution (including CO2 mineralization and stock in soil) in farmland. However, less is known about allocation of residue-C with contrasting biochemistry and the fate of residue-C in soil under two different textures. This study was conducted in a 61-day aerobic incubation with two Black soils with distinct texture (clay loam vs. sandy loam) in Northeast China. Chemical composition of seven residue parts (soybean roots, leaves, and stems and maize roots, leaves and top and bottom stem parts) was characterized using solid-state 13C nuclear magnetic resonance spectroscopy. The results showed that leaves of both two crops contained significantly higher nitrogen (N), carbonyl and aryl concentrations and lower carbon (C) and lignin concentrations than other parts, resulted in faster decomposition in soils, especially in the clay loam. Stems contained higher O-alkyl and di-O-alkyl concentrations, C/N and lignin/N, while roots contained higher aromaticity. Maize top stem parts with larger slow C pool and longer half-life had higher contribution to SOC accumulation than other parts. Soil textures also induced great impact on SOC turnover. The clay loam favored SOC sequestration due to significantly longer half-life of slow C pool than the sandy loam. Generally, the alkyl/O-alkyl ratio showed the most significant correlation with SOC, CO2 emission and soil biochemical factors in the clay loam; whereas in sandy loam, the lignin/N was the pivotal indicator for SOC accumulation. This study provides insights into the differences in chemical composition among various residue parts, and highlights the significant effects of both residue chemical composition and soil texture on residue decomposition and SOC accumulation. Full article
(This article belongs to the Special Issue Applied Research and Extension in Agronomic Soil Fertility)
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Article
Household Attitudes and Behavior towards the Food Waste Generation before and during the COVID-19 Pandemic in Romania
Agronomy 2022, 12(3), 746; https://doi.org/10.3390/agronomy12030746 - 21 Mar 2022
Viewed by 759
Abstract
Food waste represents an important aspect with social, economic, and environmental implications. As previous studies underlined, the COVID-19 pandemic led to changes in the food consumption patterns among consumers. The aim of the study was to investigate the main changes in household food [...] Read more.
Food waste represents an important aspect with social, economic, and environmental implications. As previous studies underlined, the COVID-19 pandemic led to changes in the food consumption patterns among consumers. The aim of the study was to investigate the main changes in household food waste management during the COVID-19 pandemic in Romania compared with the period before the COVID-19 pandemic. Factors affecting food waste were also analyzed. Data were collected among Romanian households using an online administrated questionnaire. The 784 usable questionnaires were analyzed using descriptive statistics and Cluster analysis. Consumers’ food shopping habits have become more sustainable during the pandemic, with a positive impact on waste management. The amount of the food losses decreased, people found ways to valorize the food scraps. The Cluster analysis of 25 food waste behavior factors lead to a 3 clusters solution: “wasters” (n = 264), “careless consumers” (n = 227), “careful consumers” (n = 359). While the “wasters” group was represented by consumers who chose to plan the shopping and the menu for the next period, were represented mainly by males with a lower level of education, the “careless consumers” did not choose to plan before going shopping, they discharge lower quantities of food compared with the first group. The “careful consumers” proved to be the most organized one, being preoccupied about the menu planning and reuse of leftovers. People became more conscious about their shopping habits; however, not all groups greatly improved their habits. The results indicate that more actions are needed to increase the awareness at the household level regarding food waste management and sustainable consumption during changing times. Full article
(This article belongs to the Special Issue COVID-19 Crises & Implications to Agri-Food Sector)
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Article
Subsurface Drip Irrigation with Emitters Placed at Suitable Depth Can Mitigate N2O Emissions and Enhance Chinese Cabbage Yield under Greenhouse Cultivation
Agronomy 2022, 12(3), 745; https://doi.org/10.3390/agronomy12030745 - 20 Mar 2022
Cited by 1 | Viewed by 762
Abstract
Agricultural practices, such as applying excessive water and nitrogen fertilizer to increase the crop yield, can be a significant source of greenhouse gas emissions (GHGs). Therefore, techniques and proper management are needed to mitigate these emissions without yield reduction. The experiment used three [...] Read more.
Agricultural practices, such as applying excessive water and nitrogen fertilizer to increase the crop yield, can be a significant source of greenhouse gas emissions (GHGs). Therefore, techniques and proper management are needed to mitigate these emissions without yield reduction. The experiment used three subsurface drip irrigation (SDI) depths with emitters buried at 0.05, 0.10, and 0.15 m below the soil surface, along with two nitrogen fertilizer (Urea, N > 46.2%) application levels of 300 kg N ha−1 (N300) and 240 kg N ha−1 (N240) to investigate the effect of vertical and horizontal water and fertilizer distribution on N2O emissions under different SDI techniques in greenhouse conditions. The results indicated that soil N2O emissions from SDI10 and SDI15 decreased by 7.06% and 10.69%, respectively, compared to SDI5. N2O, WFPS, NH4+-N, and NO3-N were significantly reduced with the increased radial distance from the emitter. N2O was positively correlated to WFPS and NH4+-N while negatively correlated to NO3-N. The NH4+-N and NO3-N concentrations decreased with depth and increased with fertilization events. Furthermore, N2O, WFPS, NH4+-N, and NO3-N were increased under N300 compared to N240 (p > 0.05). The findings demonstrated that the Chinese cabbage yield was significantly enhanced under SDI15 compared to SDI5 and SDI10. Furthermore, N300 can increase the cabbage yield more than N240 among all treatments. Full article
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Article
Evaluation and Comparative Analysis of Meteorological Data, Moisture Content, and Rice Panicle Threshability
Agronomy 2022, 12(3), 744; https://doi.org/10.3390/agronomy12030744 - 20 Mar 2022
Viewed by 760
Abstract
Harvesting and threshing are crucial processes that influence the quantity, quality, and economic efficiency of rice production. Therefore, the threshability of rice varieties is an important agronomic trait for breeding programs. However, selection for threshability is hardly standardized. With the application of an [...] Read more.
Harvesting and threshing are crucial processes that influence the quantity, quality, and economic efficiency of rice production. Therefore, the threshability of rice varieties is an important agronomic trait for breeding programs. However, selection for threshability is hardly standardized. With the application of an improved threshing meter, the threshability of four local temperate japonica rice varieties was determined during the ripening phase (DAF 37–60) in three consecutive years. Panicle threshing force (TF in N) was measured parallel with seed moisture content (MC) to describe differences in ripening habits of the genotypes. Shapes of the separation pilei were observed and the relationship with the different types of grain shattering was found. The different threshability patterns of the genotypes were found as quite stable along these periods. Moreover, correlation among TF, MC, and 5-day averages of meteorological parameters during the ripening phase was determined. Precipitation, Tmean, Tmax, and relative humidity had a significant influence on the MC. Based on our results, the MC had a low but significant positive correlation with the TF (0.312 *). Full article
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Article
Responses of N2O Production and Abundances of Associated Microorganisms to Soil Profiles and Water Regime in Two Paddy Soils
Agronomy 2022, 12(3), 743; https://doi.org/10.3390/agronomy12030743 - 20 Mar 2022
Cited by 1 | Viewed by 579
Abstract
Soil moisture is one of the critical factors affecting N2O emissions. The water regime affects the physical and chemical properties of paddy soil in different soil layers, which, in turn, affects N2O emissions and microbial growth. However, there are [...] Read more.
Soil moisture is one of the critical factors affecting N2O emissions. The water regime affects the physical and chemical properties of paddy soil in different soil layers, which, in turn, affects N2O emissions and microbial growth. However, there are few reports on the effects of different soil layers and soil moisture conditions on N2O emission characteristics and microbial mechanisms. A 21-day microcosm experiment was performed to research the effects of soil moisture levels (60%, 100%, and 200% water holding capacity, WHC) and different soil layers (0–10, 10–20, and 20–40 cm) on N2O emissions in hydromorphic and gleyed paddy soils. Function microbes involved in nitrification and denitrification were determined by quantitative PCR. Moreover, the abiotic variables pH, Eh, and exchangeable Fe2+, Fe3+, NH4+-N, and NO3-N were also analyzed. Results showed that N2O emissions of gleyed paddy soil were significantly higher than that of hydromorphic paddy soil, which was consistent with the result of the abundance of nitrifier and denitrifier in the two paddy soils. Soil depth, water content, and their interaction significantly affected N2O emission (p < 0.05). Cumulative emissions of N2O from each layer of the two paddy soils at 100% and 200% WHC were significantly higher than that under 60% WHC (p < 0.05). N2O emissions decreased significantly with the increase of soil depth (p < 0.05), which was consistent with the change in the abundance of soil nitrifier (AOB and AOA) and denitrifier (nirK and nosZ) function genes with soil depth. The abundance of AOB, AOA, and nirK and nosZ genes decreased significantly with soil depth (p < 0.05), but did not respond significantly to the water regime. Based on the results of redundancy analysis, the contents of Fe2+ and Fe3+ were positively correlated with N2O emissions and the abundance of AOB, AOA, and nirK and nosZ genes. These results indicate that N2O emissions and the abundance of associated microbes are selectively affected by soil moisture and soil layers in the two paddy soils. Full article
(This article belongs to the Special Issue Nitrogen Cycle in Farming Systems)
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Article
Application of the Nitrogen Nutrition Index to Estimate the Yield of Indica Hybrid Rice Grown from Machine-Transplanted Bowl Seedlings
Agronomy 2022, 12(3), 742; https://doi.org/10.3390/agronomy12030742 - 20 Mar 2022
Viewed by 563
Abstract
The purpose was to comprehensively compare the prediction accuracy of different nitrogen nutrition indexes (NNILAI and NNIDM) derived from critical nitrogen concentration (Nc) models established by the leaf area index (LAI) and dry matter (DM) in [...] Read more.
The purpose was to comprehensively compare the prediction accuracy of different nitrogen nutrition indexes (NNILAI and NNIDM) derived from critical nitrogen concentration (Nc) models established by the leaf area index (LAI) and dry matter (DM) in estimating the grain yield of indica hybrid rice grown from machine-transplanted bowl seedlings. Therefore, field experiments were conducted with two high-yielding indica hybrid rice varieties and five nitrogen application rates in 2018 and 2019. The results show that NNIDM peaked in the stem elongation stage, while NNILAI had its maximal value in the mid-tillering stage during the growth stages. The NNILAI had the highest correlation with the relative effective panicle number in the tillering stage when compared with the NNIDM, and the threshold points of the NNI were 0.971 (active tillering stage) and 1.106 (mid-tillering stage). Moreover, the NNILAI had the highest correlation with the relative seed setting rate in the stem elongation–panicle initiation stage compared with the NNIDM, and its threshold points were 1.116 (stem elongation stage) and 1.053 (panicle initiation stage). In contrast, the NNIDM had the highest correlation with the relative seed setting rate in the heading stage compared with the NNILAI, and its threshold point was 1.050 (heading stage). Therefore, the NNILAI in the tillering–panicle initiation stage and NNIDM in the heading stage should be merged to effectively improve the nitrogen nutrition status and its evaluation in addition to the prediction accuracy of the yield of indica hybrid rice grown from machine-transplanted bowl seedlings. This study provides a theoretical basis for improved understanding of the nitrogen status and yield prediction of indica hybrid rice grown from machine-transplanted bowl seedlings. Full article
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Article
Carbohydrate Partitioning, Growth and Ionic Compartmentalisation of Wheat Grown under Boron Toxic and Salt Degraded Land
Agronomy 2022, 12(3), 740; https://doi.org/10.3390/agronomy12030740 - 20 Mar 2022
Cited by 1 | Viewed by 723
Abstract
Cultivation of crops in salt-affected soils is a major challenge for growers. Despite the use of multiple amendments, salinity stresses adversely affect the crops to some extent. On the other hand, imbalance in the use of boron (B) as a nutrient also creates [...] Read more.
Cultivation of crops in salt-affected soils is a major challenge for growers. Despite the use of multiple amendments, salinity stresses adversely affect the crops to some extent. On the other hand, imbalance in the use of boron (B) as a nutrient also creates toxicity. Mismanagement of B fertilizer application decreases the growth and yield of crops. It is necessary to study in depth the adverse effects of salinity and B toxicity. This is why the current research work was conducted in a glass house at Murdoch University, Perth, Australia. The aim of study was to investigate the influence of salinity and B toxicity on carbohydrate partitioning, growth, and ionic composition of two Australian wheat varieties. There were four treatments, i.e., control, high B (15 kg ha−1), salinity (15 dS m−1), and B + salinity. The results showed that the salt-tolerant Halberd (HB) variety accumulated more Na+, B, and Cl in their leaf sheath and kept the leaf blades free of these toxic ions as compared to the sensitive variety Westonia (WS). Water-soluble carbohydrate (WSC; i.e., glucose, sucrose, fructose, and fructans) concentration increased in response to individual as well as combined constrains of soil salinity and toxic B in the leaf blade of both tolerant and sensitive wheat varieties, but the increase was higher in the tolerant variety as compared to the sensitive one. The concentration of WSCs in leaf sheath of the salt-tolerant wheat variety was increased in response to stress conditions, but those remained low in salt-sensitive ones. Therefore, the salt-tolerant HB genotype was found to be a good source for future wheat breeding programs or to be grown by farmers in B toxic, saline, and B toxic–saline conditions. Full article
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Article
The Influence of Different Nitrogen Fertilizer Rates, Urease Inhibitors and Biological Preparations on Maize Grain Yield and Yield Structure Elements
Agronomy 2022, 12(3), 741; https://doi.org/10.3390/agronomy12030741 - 19 Mar 2022
Cited by 1 | Viewed by 730
Abstract
The field experiment was performed in 2019–2021 at the Experimental Station of Vytautas Magnus University Agriculture Academy (54°52′ N, 23°49′ E). The soil of the experimental field was Endohipogleyic-Eutric Planasol. The studied factors were: Factor A—different nitrogen fertilizer rates: (1) 100 kg N [...] Read more.
The field experiment was performed in 2019–2021 at the Experimental Station of Vytautas Magnus University Agriculture Academy (54°52′ N, 23°49′ E). The soil of the experimental field was Endohipogleyic-Eutric Planasol. The studied factors were: Factor A—different nitrogen fertilizer rates: (1) 100 kg N ha−1; (2) 140 kg N ha−1; (3) 180 kg N ha−1; Factor B—the use of urease inhibitors (UI) and biological preparations (BP): (1) urease inhibitors (UI) and biological preparations (BP) were not used; (2) Urease inhibitor (UI ATS)—ammonium thiosulfate—[(NH4)2S2O3 12-0-0-26S]; (3) Urease inhibitor (UI URN)—N-butyl-thiophosphorus triamide (NBPT) and N-propyl-thiophosphorus triamide (NPPT); (4) Biological preparation (BP HUM)—suspension of humic and fulvic acids; (5) Biological preparation (BP FIT)—Ascophyllum nodosum suspension. Our studies showed that the highest yield of maize grain (8.9–12.0 t ha−1) was obtained by fertilizing with N180 and using the urease inhibitor ammonium thiosulfate (ATS). ATS significantly increased corn grain yield in all backgrounds of nitrogen fertilization. The investigated urease inhibitors and biologics had a higher and more significant (p < 0.05) effect on maize grain yield when fertilized with N100 nitrogen. The increase in nitrogen fertilizer rates had an effect on maize grain yield, with the largest increase in yield being found in the increase in nitrogen rate from N100 to N140, and the increase in rate to N180 was less effective. The maximum mass of 1000 grains (323.5 g) was determined in 2019 by fertilization with N180 and use of the urease inhibitor UI URN. The urease inhibitor UI ATS was more effective when fertilized with lower rates of N100 and N140. Positive, moderate, strong and very strong, statistically significant correlations (r2 = 0.48–0.91) were most often found between the latter indicators and nitrogen fertilizer rates throughout the study year. The largest amount of grain (497 units) in the cob was determined in 2019, using fertilization with N140 and UI ATS, but no significant differences were found between the different fertilizer rates and the tested preparations. These results suggest that urease inhibitors and biologics can reduce dependence on nitrogen fertilizers and increase maize yield, a technology that should be practiced by maize growers. Full article
(This article belongs to the Special Issue Agricultural Automation and Innovative Agricultural Systems)
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Article
Leaf Pigments, Surface Wax and Spectral Vegetation Indices for Heat Stress Resistance in Pea
Agronomy 2022, 12(3), 739; https://doi.org/10.3390/agronomy12030739 - 19 Mar 2022
Viewed by 699
Abstract
Pea is a grain legume crop commonly grown in semi-arid temperate regions. Pea is susceptible to heat stress that affects development and reduces yield. Leaf pigments and surface wax in a crop canopy make the primary interaction with the environment and can impact [...] Read more.
Pea is a grain legume crop commonly grown in semi-arid temperate regions. Pea is susceptible to heat stress that affects development and reduces yield. Leaf pigments and surface wax in a crop canopy make the primary interaction with the environment and can impact plant response to environmental stress. Vegetation indices can be used to indirectly assess canopy performance in regard to pigment, biomass, and water content to indicate overall plant stress. Our objectives were to investigate the contribution of leaf pigments and surface wax to heat avoidance in pea canopies, and their associations with spectral vegetation indices. Canopies represented by 24 pea cultivars varying in leaf traits were tested in field trials across six environments with three stress levels in western Canada. Compared with the control non-stress environments, heat stress reduced leaf lamina and petiole chlorophyll a, chlorophyll b, and carotenoid concentrations by 18–35%, and increased leaf lamina chlorophyll a/b ratio, anthocyanin and wax concentrations by 24–28%. Generally, greater leaf pigment and wax concentrations were associated with cooler canopy temperature and high heat tolerance index (HTI) values. Upright cultivars had higher HTI values, whereas the lowest HTI was associated with normal leafed vining cultivars. Vegetation indices, including photochemical reflectance index (PRI), green normalized vegetation index (GNDVI), normalized pigment chlorophyll ratio index (NPCI), and water band index (WBI), had strong correlations with HTI and with heat avoidance traits. This study highlights the contribution of pigments and wax as heat avoidance traits in crop canopies, and the potential application of spectral measurements for selecting genotypes with more heat resistant vegetation. Full article
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Article
Yields and Nitrogen Dynamics in Ley-Arable Systems—Comparing Different Approaches in the APSIM Model
Agronomy 2022, 12(3), 738; https://doi.org/10.3390/agronomy12030738 - 18 Mar 2022
Viewed by 690
Abstract
Nitrogen (N) dynamics in ley-arable cropping systems require better understanding in order to assess the potential of such systems to contribute to improved productivity and reduced nutrient losses in crop production. Large inputs of organic matter after termination of the ley phase result [...] Read more.
Nitrogen (N) dynamics in ley-arable cropping systems require better understanding in order to assess the potential of such systems to contribute to improved productivity and reduced nutrient losses in crop production. Large inputs of organic matter after termination of the ley phase result in increased mineralization and N availability to subsequent crops. The description and quantification of this residual N effect in ley-arable systems remains a major scientific challenge due to its variability and many influencing factors. Simulation modeling could contribute to improved understanding of N dynamics in ley-arable systems. The aim of this study was to evaluate the robustness of the Agricultural Production Systems Simulator (APSIM) to predict biomass yield, N yield, and N leaching of different forage maize systems in northwest Europe, while using two different approaches to predict the residual N effect. The evaluation was based on three field experiments covering plant phenology, biomass, N yield, and N leaching over several years. Model adjustments were necessary to describe mineralization of organic matter and release of N after ploughing of the grass leys. For this purpose, three scenarios were investigated by accounting for either (1) aboveground grass residues; (2) above- and belowground grass residues, both with the generic turnover approach in the model; or (3) N release depending on the carbon-to-N ratio of the residue compiled in a simple mineralization model (SMM). The results showed that APSIM-simulated biomass and N yield of maize were reasonable to poor across the different systems and sites, regardless of using the residue-related approach. The SMM performed more accurately compared to the generic turnover approach in predicting N leaching in a maize following a grass-clover ley. However, for all scenarios, APSIM had difficulties to predict a delay of N leaching observed in the experimental data after a pure ryegrass ley. In conclusion, the process description in APSIM related to organic matter mineralization in ley-arable systems under northwest European pedo-climatic conditions needs improved accounting of belowground grass residues, while the SMM is of added value to improve N mineralization patterns and leaching after a ley phase. Full article
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Article
The Effect of Various Foliar Treatments and Nitrogen Nutrition Levels on the Yield and Physicochemical Parameters of Flowering Chinese Cabbage
Agronomy 2022, 12(3), 737; https://doi.org/10.3390/agronomy12030737 - 18 Mar 2022
Viewed by 698
Abstract
Flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) is an original leafy vegetable from China, and it is a valuable source of bioactive compounds. In the literature, there are no practical recommendations for the cultivation and fertilization [...] Read more.
Flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) is an original leafy vegetable from China, and it is a valuable source of bioactive compounds. In the literature, there are no practical recommendations for the cultivation and fertilization of this species. Our study aimed to investigate the effect of nitrogen nutrition levels (70 and 90 mg N per dm3) and various foliar treatments (Se, Si, Li, V, and SA—salicylic acid) on the quantity of the yield and the quality of flowering Chinese cabbage grown in two varied soilless cultivation systems: under pot cultivation (mixture of peat and sand) and hydroponic culture. In conducted studies, we have confirmed the hypothesis that the intensity of nitrogen nutrition and the application of foliar spraying modify the yield of plants, both the quantity and the quality aspects. The factors under analysis had a diversified and multidirectional influence on the yield, growth, and quality of the plants. The results varied between the two cultivation systems. This was proved by the PCA (principal component analysis). Generally, the plants grown in the hydroponic system were characterized by higher yields than those grown in pot cultivation. This was found to be a stimulating effect of N nutrition on the content of that nutrient in the aerial parts of the plants. Plants sprayed with Si and Se were characterized by a high content of Chl a, Chl b, carotenoids, and relatively high antioxidant activity. Finally, the samples subjected to different foliar spray treatments could be classified into appropriate groups based on the quality parameters. Full article
(This article belongs to the Section Horticultural and Floricultural Crops)
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Article
Phenology and Population Differentiation in Reproductive Plasticity in Feathertop Rhodes Grass (Chloris virgata Sw.)
Agronomy 2022, 12(3), 736; https://doi.org/10.3390/agronomy12030736 - 18 Mar 2022
Cited by 2 | Viewed by 685
Abstract
An understanding of phenology and reproductive plasticity of a weed species can provide valuable information to manage it precisely. This study evaluated the phenotypic plasticity of feathertop Rhodes grass (Chloris virgata Sw.) where cohorts of four different populations (two from cropping and [...] Read more.
An understanding of phenology and reproductive plasticity of a weed species can provide valuable information to manage it precisely. This study evaluated the phenotypic plasticity of feathertop Rhodes grass (Chloris virgata Sw.) where cohorts of four different populations (two from cropping and two from roadside situations) were initiated in early spring (4 September), late spring (4 November), mid-summer (4 January), and early autumn (4 March) in southern New South Wales (NSW), Australia. The team grew individual plants in the absence of competition under natural conditions. Life-history and fitness-related traits of both phenology and morphology were measured, and dry biomass of vegetative and reproductive parts were determined at physiological maturity. Among the four sowing times, the late-spring sowing treatment took the longest time from emergence to the first seed head emergence (70–110 days), while it had the shortest seed maturity period (8–16 days). Length of reproductive and total life period of the four populations differed across the four sowing-time treatments. The plants that emerged in mid-summer had the longest reproductive period (30 days) whereas the early-autumn emerging plants died before the reproductive stage because of the cold temperatures during winter. The mid-summer cohort required slightly longer time (63–85 days) to achieve seed head formation and less time (19–24 days) for seed maturity than those plants that emerged in early or late spring. All the reproductive features were varied by sowing times and population. The number of seed heads (12–15 per plant) and spikelets (12–13 per seed head), as well as the seed head biomass, re-productive biomass allocation pattern, and seed production, generally increased in the mid-summer-emerged cohort. Seed production in the mid-summer (9942 seeds/plant) cohort was 10% and 70% higher than the late spring (8000 seeds/plant) and early spring (3240 seeds/plant) cohorts, respectively. The ratio of reproductive biomass to vegetative biomass increased in the mid-summer sowing times in all populations, and this species displayed true plasticity in reproductive allocation. Additionally, the four populations of feathertop Rhodes grass differed significantly in phenological, vegetative, and reproductive traits, depending on the sowing time. The reproductive fitness of the four populations varied, with the two roadside populations (FELT 04/20 and STURT/16–17) appearing to be better adapted than the two cropping populations (PARK 01/20 and GLEN 03/18). The results from our study could help construct a basic framework for a variety of weed-management tactics to achieve successful control. Full article
(This article belongs to the Special Issue Pests, Pesticides and Food Safety in a Changing Climate)
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Article
The Potential Use of Citrus aurantifolia L. Essential Oils for Decay Control, Quality Preservation of Agricultural Products, and Anti-Insect Activity
Agronomy 2022, 12(3), 735; https://doi.org/10.3390/agronomy12030735 - 18 Mar 2022
Cited by 1 | Viewed by 687
Abstract
The primary objective of the study was to evaluate the biological activity of Citrus aurantifolia essential oil (CAEO) with emphasis on antioxidant, antimicrobial, and insecticidal activity, chemical composition, and the antimicrobial effect of its vapor phase in situ on various food models. We [...] Read more.
The primary objective of the study was to evaluate the biological activity of Citrus aurantifolia essential oil (CAEO) with emphasis on antioxidant, antimicrobial, and insecticidal activity, chemical composition, and the antimicrobial effect of its vapor phase in situ on various food models. We determined the main volatile components of CAEO as α-phellandrene (48.5%) and p-cymene (16.5%). The antioxidant activity was high and reached 74.5 ± 0.5%, which corresponds to 442 ± 2.3 TEAC. The antimicrobial activity in the contact phase was most pronounced against Gram-negative bacteria, with inhibition zones of 12.66–15.33 mm and a minimal inhibition concentration of 2.36–8.26 µL/mL. The antimicrobial activity of the CAEO vapor phase was high at the highest concentration tested (500 µL/mL), but the inhibitory effect was seen at all concentrations tested. The effect was observed on all types of microorganisms and all types of model foods. Based on the findings, CAEO could find use in storing and extending the shelf life of agricultural products. Insecticidal activity reached 10–90% depending on the concentration used. The significant insecticidal effect provides the possibility of using CAEO as a natural insecticidal, larvicidal, or repellent preparation. Full article
Article
Exogenous Application of Zinc Sulphate at Heading Stage of Wheat Improves the Yield and Grain Zinc Biofortification
Agronomy 2022, 12(3), 734; https://doi.org/10.3390/agronomy12030734 - 17 Mar 2022
Cited by 1 | Viewed by 724
Abstract
Wheat is the leading staple food in the world, particularly in developing countries, which lacks a mechanism of zinc absorption; when compared to pulses, more attention is consequently important to be given to the wheat crop. Micronutrient deficiencies and especially zinc deficiency influences [...] Read more.
Wheat is the leading staple food in the world, particularly in developing countries, which lacks a mechanism of zinc absorption; when compared to pulses, more attention is consequently important to be given to the wheat crop. Micronutrient deficiencies and especially zinc deficiency influences one-third of the world population. In addition to this, it is also essential for the growth and development of plants and animals. A pot and field experiment was conducted to check the effect of foliar application of zinc sulphate on three different wheat varieties at the same time. Treatment consisted of three zinc levels (control, 4%, 6%) in the form of zinc sulphate (21% Zn) applications were applied on various wheat varieties (Zincol, Fakher-e-Bhakkar, Faisalabad-2008) at different growth stages (tillering, booting and heading). Different zinc levels showed different results on wheat varieties in both experiments. Results revealed that var. Fakher-e-Bhakkar was best at 6% zinc application for more plant height, the number of spikelets, spike length, 100-grain weight, biological and grain yield per plant as compared to other varieties and treatments. Antioxidants and nutritional quality (protein, gluten, starch and zinc contents) showed variable behavior both on wheat varieties and zinc application. It is concluded that Fakher-e-Bhakkar was found to be the most responsive cultivar at 6% zinc application for improvement in growth, yield-related traits and nutritional quality. So it is recommended for achieving maximum yield and yield components and grain zinc contents of wheat under agro-climatic conditions of Layyah, Punjab-Pakistan. Full article
(This article belongs to the Special Issue Biofortification of Field Crops)
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Article
Humic Substances as Indicator of Degradation Rate of Chernozems in South-Eastern Poland
Agronomy 2022, 12(3), 733; https://doi.org/10.3390/agronomy12030733 - 17 Mar 2022
Cited by 2 | Viewed by 556
Abstract
Unfavourable quantitative and qualitative changes of soil organic matter result from degradation processes, such as water erosion connected with intense arable land use. In order to take adequate preventive action, the proper indicators of soil quality or degradation are urgently needed. In particular, [...] Read more.
Unfavourable quantitative and qualitative changes of soil organic matter result from degradation processes, such as water erosion connected with intense arable land use. In order to take adequate preventive action, the proper indicators of soil quality or degradation are urgently needed. In particular, tests considering the soil organic matter quality seem to be beneficial for soil monitoring. In this paper, we performed organic matter fractionation using the Tyurin and IHSS procedures on eight profiles of chernozemic soils (non-degraded, eroded, forest and accumulative soils). The study conducted confirmed the applicability of using humic and fulvic fractions in order to determine the pedogenesis processes and degradation rates of chernozemic soils. For example, the HA/FA ratio was higher in non-eroded and accumulative soils, compared with eroded or forest profiles. These findings were supported by statistical discrimination performed on the mid-infrared spectra of humic acids extracted from the selected profiles. Groups of samples were divided into classes depending on land usage or degradation rate. Considering the results, fractions of humic substances can be recommended as useful tools for the assessment of soil transformation. Full article
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Article
Response of the Five Highbush Blueberry Cultivars to In Vitro Induced Drought Stress by Polyethylene Glycol
Agronomy 2022, 12(3), 732; https://doi.org/10.3390/agronomy12030732 - 17 Mar 2022
Cited by 2 | Viewed by 662
Abstract
Stress caused by drought is an important factor that affects the growth and development of highbush blueberry plants. In vitro screening for drought stress tolerance is of major importance in identifying cultivars that have optimal stress tolerance and productivity. The aim of this [...] Read more.
Stress caused by drought is an important factor that affects the growth and development of highbush blueberry plants. In vitro screening for drought stress tolerance is of major importance in identifying cultivars that have optimal stress tolerance and productivity. The aim of this study was to evaluate the responses of five in vitro-grown highbush blueberry cultivars (Bluecrop, Brigitta Blue, Duke, Goldtraube and Hortblue Petite) under drought stress. Five concentrations of polyethylene glycol (PEG 6000), 0 g/L, 10 g/L, 20 g/L, 30 g/L, 40 g/L, 50 g/L, were applied to induce drought stress in the culture media. Significant differences were found in shoot length and number, proliferation rate, fresh weight, dry weight, water content, chlorophyll, and carotenoid content. Drought stress had a negative impact on shoots length, chlorophyll, and carotenoid content for all highbush blueberry varieties. The conclusion of the study highlights that Goldtraube had the highest drought tolerance efficiency, followed by Bluecrop, Hortblue Petite, Duke, and Brigitta Blue. Full article
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Article
Cerium Oxide Salicylic Acid Nanoparticles’ (CeO2: SA-NPs) Foliar Application and In-Soil Animal Manure Use Influence the Growth and Physiological Responses of Aloe vera L.
Agronomy 2022, 12(3), 731; https://doi.org/10.3390/agronomy12030731 - 17 Mar 2022
Cited by 1 | Viewed by 643
Abstract
Aloe vera is an economic crop due to the presence of a gel-like substance inside the leaves, which contains polysaccharides, vitamins, proteins, fats, and amino acids. There is an ongoing need for this plant and its products for diverse food and pharmaceutical industries. [...] Read more.
Aloe vera is an economic crop due to the presence of a gel-like substance inside the leaves, which contains polysaccharides, vitamins, proteins, fats, and amino acids. There is an ongoing need for this plant and its products for diverse food and pharmaceutical industries. To meet good agricultural practices, we studied the effect of manure application (0%, 10%, and 20% of v/v of soil) and foliar application with distilled water, salicylic acid (SA, 13.8 mg L−1 equivalent to 100 µM), cerium oxide nanoparticles (CeO2-NPs, 50 mg L−1), and cerium oxide salicylic acid nanoparticles (CeO2: SA-NPs; 100 µM + 50 mg L−1) on the growth and physiological responses of Aloe vera, and a factorial experiment was arranged based on a completely randomized design with three replications at Azarbaijan Shahid Madani University, Iran. The results showed that foliar application of CeO2: SA-NPs with the soil-based application of 10% and 20% manure increased plant dry weight and aloin content. The highest harvest index, economic yield, shoots-to-roots ratio, gel dry weight, chlorophyll a and b content, phenolics content of gel, and leaf and gel flavonoids’ content, as well as potassium, magnesium, zinc, and iron content, were obtained by the CeO2: SA-NPs × 20% manure treatment combination. The 10% and 20% manure and foliar application with CeO2-NPs, SA, and CeO2: SA-NPs increased the phenolics content of leaves compared to the control. Manure application (20%) positively affected the plant’s phosphorus content. The results revealed that co-application of soil-based cow manure and foliar CeO2: SA-NPs stimulated the growth and physiological responses of Aloe vera, and the results would be helpful to the agricultural extension sections and pioneer farmers. Full article
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Article
Assessment of Indicators in a Human Liver Cell Line HL-7702 for Tetracycline Toxicity in Farm Soil
Agronomy 2022, 12(3), 730; https://doi.org/10.3390/agronomy12030730 - 17 Mar 2022
Viewed by 552
Abstract
Tetracycline (TC) contamination has become hot research topic, but little attention has been paid to its ecotoxicological monitoring. The primary objective of this study is to investigate the impact of TC on human normal liver cells (HL-7702) and find indicators for monitoring their [...] Read more.
Tetracycline (TC) contamination has become hot research topic, but little attention has been paid to its ecotoxicological monitoring. The primary objective of this study is to investigate the impact of TC on human normal liver cells (HL-7702) and find indicators for monitoring their ecotoxicity. The cytotoxicity of TC, at concentrations ranging from 0 to 1000 μg L−1, was assessed on HL-7702 cells. The results showed that TC significantly inhibited the cell viability at a high concentration (1000 μg L−1). The TC at exposure levels ≥ 50–100 μg L−1 significantly increased the levels of extracellular catalase (CAT), malondialdehyde (MDA), alanine transaminase (ALT), and aspartate transaminase (AST), and a significantly positive correlation between the TC concentrations and the values of the above parameters was observed. Swelling of the mitochondrial cristae (MC) and rough endoplasmic reticulum (RER) and the loss of ribosomes in HL-7702 cells, were observed at high TC levels. There was a positive correlation between soil TC concentration and ALT activities. The above results suggest that TC is cytotoxic to HL-7702 cells and that extracellular ALT activities can be used as a sensitive bioindicator for monitoring soil TC contamination. We, therefore, propose that the HL-7702 cell line can be a novel tool for early antibiotics toxicity monitoring. Full article
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Review
Milk Thistle (Silybum Marianum L.) as a Novel Multipurpose Crop for Agriculture in Marginal Environments: A Review
Agronomy 2022, 12(3), 729; https://doi.org/10.3390/agronomy12030729 - 17 Mar 2022
Cited by 2 | Viewed by 840
Abstract
Milk thistle (Silybum marianum (L.) Gaertn.) is a versatile crop that has adapted to the broadly different soil and environmental conditions throughout all continents. To date, the fruits (“seeds”) of the plant are the only reliable source of silymarin, which, given its [...] Read more.
Milk thistle (Silybum marianum (L.) Gaertn.) is a versatile crop that has adapted to the broadly different soil and environmental conditions throughout all continents. To date, the fruits (“seeds”) of the plant are the only reliable source of silymarin, which, given its recognized therapeutic effects and its many present and potential uses, has led to a significant re-discovery and enhancement of the crop in recent years. Overall, although many studies have been carried out globally on the bioactivity, phytochemistry, and genetics of milk thistle, few and discontinuous research activity has been conducted on its basic agronomy as well as on the farm opportunities offered by the cultivation of this species. However, the multiple potential uses of the plant and its reduced need for external inputs suggest that milk thistle can perfectly fit among the most interesting alternative crops, even for marginal environments. The growing interest in natural medicine, the increasing popularity of herbal dietary supplements, and the multiple possibilities for livestock feeding are all arguments supporting the idea that in many rural areas, this crop could represent a significant tool for enhancing and stabilizing farm income. However, several issues still have to be addressed. The species retains some morphological and physiological traits belonging to non-domesticated plants, which make the application of some common agronomic practices challenging. Furthermore, the lack of reliable field data devoted to the definition of suitable cropping protocols represents a major constraint on the spread of this crop among farmers. This review has therefore focused on updating information on the main morphological and phytochemical traits of the crop and its agronomic characteristics and novel uses. Several gaps in technical knowledge have been addressed, and further goals for experimental activity have been outlined in order to guide farmers eager to cope with the cultivation of such a challenging and resource-rich crop. Full article
(This article belongs to the Special Issue Feature Papers on Medicinal and Aromatic Plants)
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Article
New Biostimulants Screening Method for Crop Seedlings under Water Deficit Stress
Agronomy 2022, 12(3), 728; https://doi.org/10.3390/agronomy12030728 - 17 Mar 2022
Viewed by 764
Abstract
Biostimulants can be used in many crops growing under water deficit conditions at the seedling stage. This study used tomato, Solanum lycopersicum L., seedlings growing in commercial 150-cell trays as an experimental setup to reproduce mild drought stress effects. The method showed significant [...] Read more.
Biostimulants can be used in many crops growing under water deficit conditions at the seedling stage. This study used tomato, Solanum lycopersicum L., seedlings growing in commercial 150-cell trays as an experimental setup to reproduce mild drought stress effects. The method showed significant reductions in seedling growth and RGR (25%) after a seven-day experiment. Gas exchange parameters (Pn, Gs and E) had significantly lower values (30–50%) than the control seedlings. Stress-related metabolite, ABA, exhibited a significant accumulation in the tomato seedlings (24 h), consistent with SINCED2 gene expression. Proline levels were twice as high in the water-deficit treated seedlings, remaining at this level until the end of the experiment. However, total carbohydrates were significantly lower in water-deficit treated seedlings. Qualitative and quantitative analysis suggested that using the variable ‘seedling biomass accumulation’ could simplify the methodology. Twelve different biostimulants were assayed, implementing this simplification, and all of them showed higher biomass accumulation in the treated seedlings than in the non-treated ones under water deficit. Among them, putrescine, spermine and spermidine were the most effective. The method is adjustable to different biostimulant volumes (1, 3 and 5 mL; 1 mM BABA), with no significant differences between the treatments. Full article
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Article
Host and Tissue Affiliations of Culturable Endophytic Fungi Associated with Xerophytic Plants in the Desert Region of Northwest China
Agronomy 2022, 12(3), 727; https://doi.org/10.3390/agronomy12030727 - 17 Mar 2022
Viewed by 588
Abstract
Endophytic fungi isolated from plants under drought stress have been evidenced to confer hosts adaptive benefits to withstand drought. In this study, endophytic fungi associated with five typical desert shrubs in different tissue from extremely arid desert in Northwest China were investigated based [...] Read more.
Endophytic fungi isolated from plants under drought stress have been evidenced to confer hosts adaptive benefits to withstand drought. In this study, endophytic fungi associated with five typical desert shrubs in different tissue from extremely arid desert in Northwest China were investigated based on ITS sequence analysis. A total of 158 endophytic fungal stains were isolated from 1088 tissue segments of 12 samples, and 28 taxa represented by 25 species and 15 genera were identified as Ascomycetes. Alternaria sp. was the dominant genus with generic abundance ranging from 20% to 65%. The colonization rate of root was significantly lower, but the root-endophytic fungi (19 species) conversely presented a higher diversity than stem and leaf (11 and 7 species, respectively). Endophytic fungi had pronounced relative host and tissue preferences, while tissue explained more endophytic fungal variation than plant species. Additionally, soil pH, organic carbon, and phosphatase elicited significant responses from fungal species, which significantly affected the species richness of Fusarium redolens, Alternaria chlamydospore, Didymella glomerata, and Xylariales sp. This research provides a basis for the further understanding of the ecological distribution of endophytic fungi associated with xerophytic plants and their potential application for vegetative restoration and agricultural cultivation in drylands. Full article
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Article
Effect of Plant Growth-Promoting Bacteria Azospirillum brasilense on the Physiology of Radish (Raphanus sativus L.) under Waterlogging Stress
Agronomy 2022, 12(3), 726; https://doi.org/10.3390/agronomy12030726 - 17 Mar 2022
Viewed by 666
Abstract
Stress due to waterlogging is considered an abiotic factor that negatively affects crop production, which, together with the excessive fertilization of crops, reduces cost-effectiveness and generates the need to create sustainable alternatives economically and environmentally. The effect of inoculation with Azospirillum brasilense on [...] Read more.
Stress due to waterlogging is considered an abiotic factor that negatively affects crop production, which, together with the excessive fertilization of crops, reduces cost-effectiveness and generates the need to create sustainable alternatives economically and environmentally. The effect of inoculation with Azospirillum brasilense on the physiology of the Raphanus sativus var. Crimson Giant subjected to waterlogging, was evaluated. Stomatal conductance, chlorophyll concentration and chlorophyll a fluorescence were analyzed to establish this effect, corroborating the beneficial effect of inoculation with A. brasilense in radish under waterlogging stress. The stomatal conductance of inoculated and waterlogged treatments presented the same values as the control plants, and photosystem II efficiency was favored in inoculated and waterlogged treatments (0.6 Fv/Fm) compared to non-inoculated and waterlogged treatments (0.3 Fv/Fm). The results suggested that this increased efficiency was due to the preservation of photosynthetic pigments in the tissues, allowing the preservation of stomatal conductance and a reduction in the amount of energy dissipated in the form of heat (fluorescence) due to inoculation with A. brasilense. Therefore, plant growth-promoting bacteria are responsible for activating and improving some physiological mechanisms of the plant. Full article
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Article
Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (Astragalus sinicus L.)
Agronomy 2022, 12(3), 725; https://doi.org/10.3390/agronomy12030725 - 17 Mar 2022
Viewed by 582
Abstract
Chinese milk vetch (Astragalus sinicus L.) is an important leguminous green manure that frequently suffers from seasonal drought. To improve its drought tolerance, the effects of rhizobia inoculation on drought tolerance and the underlying physiological mechanism were investigated. Drought tolerance in combination [...] Read more.
Chinese milk vetch (Astragalus sinicus L.) is an important leguminous green manure that frequently suffers from seasonal drought. To improve its drought tolerance, the effects of rhizobia inoculation on drought tolerance and the underlying physiological mechanism were investigated. Drought tolerance in combination with nitrogen assimilation, free amino acids, and polyamines was investigated in milk vetch with active nodules (AN), with inactive nodules (LN), or without nodules (NN). AN plants had increased drought tolerance compared to LN and NN plants. Glutamine synthetase (GS), glutamine 2-oxoglutarate amino transferase (GOGAT), and glutamate dehydrogenase (GDH) activities were decreased after drought, with higher levels in AN plants than in LN and NN plants under both control and drought stress conditions. Higher levels of proline (Pro), arginine (Ala), alanine (Ala), and glutamate (Glu) were observed in AN plants compared with LN and NN plants. Putrescine (Put), spermidine (Spd), and spermine (Spm) levels were increased in response to drought, and higher levels of Put and Spd were maintained in AN plants. It is suggested that active nodulation leads to increased drought tolerance in milk vetch, which is associated with improved nitrogen fixation and ammonium assimilation, which in turn lead to the promotion of free amino-acid and polyamine synthesis. Full article
(This article belongs to the Special Issue Abiotic Stress Responses and Microbe-Mediated Mitigation in Plants)
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Article
First Report of Field Resistance to Afidopyropen, the Novel Pyropene Insecticide, on Bemisia tabaci Mediterranean (Q Biotype) from China
Agronomy 2022, 12(3), 724; https://doi.org/10.3390/agronomy12030724 - 17 Mar 2022
Cited by 3 | Viewed by 580
Abstract
Afidopyropen, a novel biopesticide, is derived from Aspergillus fumigatus, a fungus, and shows promise as a novel insecticidal agent for the management of the whitefly pest Bemisia tabaci in horticultural and economical crop production. In the present work, we monitored the susceptibilities [...] Read more.
Afidopyropen, a novel biopesticide, is derived from Aspergillus fumigatus, a fungus, and shows promise as a novel insecticidal agent for the management of the whitefly pest Bemisia tabaci in horticultural and economical crop production. In the present work, we monitored the susceptibilities of B. tabaci to afidopyropen in 18 field populations, sampled from 9 provinces of China, and found that, in comparison with the susceptible strain (MED-S), B. tabaci from most field populations were highly susceptible, except for the Haidian population (HD) which exhibited an approximately 40-fold increase in resistance. The HD population also displayed significant cross-resistance to sulfoxaflor (14.5-fold) but little cross-resistance to cyantraniliprole, flonicamid, imidacloprid, pymetrozine, and thiamethoxam. Afidopyropen resistance of the HD population was determined to be incomplete dominant and autosomal, and synergism assays demonstrated that P450 monooxygenases could contribute to the field-evolved afidopyropen resistance observed in the HD population. These results will further our understanding of the molecular underpinnings of insecticide resistance in B. tabaci and can inform the development of field-based pest control tactics to slow the development of afidopyropen resistance and to control whiteflies more sustainably. Full article
(This article belongs to the Special Issue Advances in Pesticide Discovery and Application)
Communication
Intercropping Winter Oilseed Rape (Brassica napus L.) Has the Potential to Lessen the Impact of the Insect Pest Complex
Agronomy 2022, 12(3), 723; https://doi.org/10.3390/agronomy12030723 - 16 Mar 2022
Viewed by 888
Abstract
Winter oilseed rape (Brassica napus) is a global major crop used for the production of vegetable oil. Typically sown in late summer and grown throughout winter and spring, it allows for interesting cultural practices, such as frost-sensitive intercropping with companion plants. [...] Read more.
Winter oilseed rape (Brassica napus) is a global major crop used for the production of vegetable oil. Typically sown in late summer and grown throughout winter and spring, it allows for interesting cultural practices, such as frost-sensitive intercropping with companion plants. This practice not only provides nitrogen resources much needed by the crop in the spring, but companion plants can also prevent weed growth in autumn, thereby reducing common herbicide use. Additionally, intercropping has the potential to protect the crop from insect pests. During winter 2019–2020, B. napus was grown alone (i.e., as a control) or intercropped with a mixture of faba bean (Vicia faba) and grass pea (Lathyrus sativus); because of the unusually clement weather conditions, the faba bean did not freeze, which allowed for the evaluation of the impact of these companion plants on the insect pest complex in spring. Insect damage by the beetles Psylliodes chrysocephala, Ceutorhynchus napi, and Brassicogethes aeneus was assessed in both treatments. The larval density of P. chrysocephala was significantly lower in the crop grown with service plants. Egg laying and damage by C. napi were significantly reduced when B. napus was intercropped, and the number of B. aeneus captured was significantly lower in the presence of service plants than in the control. Moreover, the yield from oilseed rape was significantly higher in the part of the field with service plants than in the pure crop control. The underlying mechanisms are only partially understood, but intercropping winter oilseed rape with frost-resistant service plants seems to be an ecologically sound practice with a very high level of potential to reduce insect pest pressure and increase crop yield. This may eventually reduce our reliance on chemical inputs in one of the most treated crops. Full article
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