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Agronomy, Volume 13, Issue 11 (November 2023) – 186 articles

Cover Story (view full-size image): Solanum orbiculatum ssp. orbiculatum is an edible bush tomato endemic to Australia. Plants of this species are potentially self-compatible but are unable to carry out spontaneous autogamy. The flowers are protogynous with a floral structure and morphology that can encourage cross pollination as the stigma is exserted above the anther’s tips. This study will contribute to understanding the evolution and systematic relationships of species. Furthermore, understanding the reproductive biology of this species is also of interest for cultivated tomato breeding. View this paper
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14 pages, 7277 KiB  
Article
A Proposal for Lodging Judgment of Rice Based on Binocular Camera
Agronomy 2023, 13(11), 2852; https://doi.org/10.3390/agronomy13112852 - 20 Nov 2023
Viewed by 569
Abstract
Rice lodging is a crucial problem in rice production. Lodging during growing and harvesting periods can decrease rice yields. Practical lodging judgment for rice can provide effective reference information for yield prediction and harvesting. This article proposes a binocular camera-based lodging judgment method [...] Read more.
Rice lodging is a crucial problem in rice production. Lodging during growing and harvesting periods can decrease rice yields. Practical lodging judgment for rice can provide effective reference information for yield prediction and harvesting. This article proposes a binocular camera-based lodging judgment method for rice in real-time. As a first step, the binocular camera and Inertial Measurement Unit (IMU) were calibrated. Secondly, Census and Grayscale Level cost features are constructed for stereo matching of left and right images. The Cross-Matching Cost Aggregation method is improved to compute the aggregation space in the LAB color space. Then, the Winner-Takes-All algorithm is applied to determine the optimal disparity for each pixel. A disparity map is constructed, and Multi-Step Disparity Refinement is applied to the disparity map to generate the final one. Finally, coordinate transformation obtains 3D world coordinates corresponding to pixels. IMU calculates the real-time pose of the binocular camera. A pose transformation is applied to the 3D world coordinates of the rice to obtain its 3D world coordinates in the horizontal state of the camera (pitch and roll angles are equal to 0). Based on the distance between the rice and the camera level, thresholding was used to determine whether the region to be detected belonged to lodging rice. The disparity map effect of the proposed matching algorithm was tested on the Middlebury Benchmark v3 dataset. The results show that the proposed algorithm is superior to the widely used Semi-Global Block Matching (SGBM) stereo-matching algorithm. Field images of rice were analyzed for lodging judgments. After the threshold judgment, the lodging region results were accurate and could be used to judge rice lodging. By combining the algorithms with binocular cameras, the research results can provide practical technical support for yield estimation and intelligent control of rice harvesters. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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17 pages, 3243 KiB  
Article
Soil Moisture Contribution to Winter Wheat Water Consumption from Different Soil Layers under Straw Returning
Agronomy 2023, 13(11), 2851; https://doi.org/10.3390/agronomy13112851 - 20 Nov 2023
Viewed by 569
Abstract
To study the contribution of moisture from different straw-treated and irrigated soil layers to the water consumption of winter wheat in dry farming, a 2-year straw treatment and regulated deficit irrigation experiment was implemented. The field experiment was carried out with 0% (S0), [...] Read more.
To study the contribution of moisture from different straw-treated and irrigated soil layers to the water consumption of winter wheat in dry farming, a 2-year straw treatment and regulated deficit irrigation experiment was implemented. The field experiment was carried out with 0% (S0), 1% (S1), and 2% (S2) straw returning amounts, and 75 mm (V3), 60 mm (V2), and 45 mm (V1) irrigation volumes. This experiment involved nine treatments, used to quantitatively analyze the ratio and variation of soil water use from different soil layers via the direct contrast method (DCM) and the multiple linear mixed model (MLMM). The results show the following: (1) The distribution of precipitation isotope compositions displayed a repeated trend of first decreasing and then increasing during the study period. Regression analysis showed that the local meteoric water line (LMWL): δD = 6.37δ18O − 3.77 (R2 = 0.832). (2) With increasing soil depth, the δ18O value decreased gradually, and the maximum δ18O value of the soil water within each growth period was distributed at 10 cm. (3) Under the same irrigation amount, δ 18O increased with increasing straw return at 0–20 cm and decreased with increasing straw return at 20–80 cm. (4) The comparison results of the DCM and MLMM were consistent. During the jointing and flowering stages, 0–30 cm soil water was the main source of water for winter wheat. The contribution of soil water below 30 cm had a decreasing trend from the jointing stage to the flowering stage. The average contribution rates of the 0–30 cm soil layer during the jointing and flowering stages were 23.07% and 23.15%, respectively. These findings have important implications for studying the soil water cycle in the context of farming. Full article
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14 pages, 3120 KiB  
Article
Nutritional Composition, Antioxidant Activity, Cytotoxicity, and Enzymatic Potential of Ficus nitida-Associated Tomophagus colossus
Agronomy 2023, 13(11), 2850; https://doi.org/10.3390/agronomy13112850 - 20 Nov 2023
Viewed by 581
Abstract
A fruiting body of a basidiomycete fungus was discovered growing on chopped Ficus nitida tree trunks in the student housing on the Assiut University campus during the course of this inquiry and a normal collecting operation in the Assiut Governorate, Egypt. Following the [...] Read more.
A fruiting body of a basidiomycete fungus was discovered growing on chopped Ficus nitida tree trunks in the student housing on the Assiut University campus during the course of this inquiry and a normal collecting operation in the Assiut Governorate, Egypt. Following the growth of the basidioma’s inner tissue on PDA, fungal mycelial growth was achieved. Internal transcribed spacer region (ITS) sequencing has allowed for the identification of the fungus as Tomophagus colossus. On the dry weight basis, chemical analysis of T. colossus AUMC 14536 basidioma revealed that it contains 28.81% carbohydrates, 25.34% crude fats, 23.44% crude fibers, 20.64% crude proteins, and 3.02% ash, in addition to potassium, phosphorus, calcium, selenium, iron, and zinc (133.59, 114.46, 6.27, 3.08, 1.28, and 0.73 mg/100 g dry weight, respectively). The total phenolic compounds (39.26 mg/g) and total flavonoids (5.62 mg/g) were also evaluated. The basidioma extract’s antioxidant activity was assessed as %DPPH radical scavenging activity with an IC50 of 4.15 µg/mL compared with a 1.89 µg/mL IC50 of ascorbic acid. In solid-state fermentation (SSF), the fungus could ferment broad bean straw, palm leaf hay, rice husk, rice straw, sugarcane bagasse, and wheat bran to produce endoglucanase, exoglucanase, laccase, pectinase, and xylanase in substantial amounts. Specific activity exhibited the highest values for endoglucanase (81.48 U/mg), exoglucanase (114.35 U/mg), pectinase (81.94 U/mg), and xylanase (70.18 U/mg) on the rice husk, while the peak of laccase activity (94.27 U/mg) was gained on bean straw. This is the first assessment of the organism’s nutritional value, amino acid content, antioxidant activity, and enzymatic capabilities in Egypt. Full article
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12 pages, 2187 KiB  
Article
Simulation of Irrigation Strategy Based on Stochastic Rainfall and Evapotranspiration
Agronomy 2023, 13(11), 2849; https://doi.org/10.3390/agronomy13112849 - 20 Nov 2023
Viewed by 504
Abstract
The North China Plain plays a pivotal role in China’s crop production, contributing to 30% of the maize yield. Nevertheless, summer maize in this region faces challenges due to climatic constraints characterized by concurrent high temperatures and rainfall during the growing season, resulting [...] Read more.
The North China Plain plays a pivotal role in China’s crop production, contributing to 30% of the maize yield. Nevertheless, summer maize in this region faces challenges due to climatic constraints characterized by concurrent high temperatures and rainfall during the growing season, resulting in a relatively high evapotranspiration rate. In this study, we explored eight soil moisture-based threshold irrigation strategies, consisting of two upper limits and four lower limits, along with a rainfed mode (E). The upper and lower irrigation limits are expressed as a percentage of the field’s water-holding capacity (sfc). For the four full irrigation modes (A1, A2, A3, A4), the lower limits were set at 0.6 sfc, 0.6 sfc, 0.5 sfc, and 0.5 sfc, respectively. The upper limits were defined at two levels: 0.8 sfc for A1 and A2 and sfc for A3 and A4. Similarly, for the four deficit irrigation modes (B1, B2, B3, B4), the lower limits were established at 0.4 sfc, 0.4 sfc, 0.3 sfc, and 0.3 sfc, respectively, with the upper limits set at two levels: 0.8 sfc for B1 and B2 and the full sfc for B3 and B4. To investigate the impact of rainfall and potential evapotranspiration on these irrigation modes under long-term fluctuations, we employed a stochastic framework that probabilistically linked rainfall events and irrigation applications. The Monte Carlo method was employed to simulate a long-term series (4000a) of rainfall parameters and evapotranspiration using 62 years of meteorological data from the Xinxiang region, situated in the southern part of the North China Plain. Results showed that the relative yield and net irrigation water requirement of summer maize decreased with decreasing irrigation lower limits. Additionally, the interannual variation of rainfall parameters and evapotranspiration during the growing season were remarkable, which led to the lowest relative yield of the rainfed mode (E) aligned with a larger interannual difference. According to the simulation results, mode A4 (irrigation lower limit equals 0.5 sfc, irrigation upper limit equals 0.8 sfc) could be adopted for adequate water resources. Conversely, mode B2 is more suitable for a lack of water resources. Full article
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14 pages, 3980 KiB  
Article
Adaptability of Millets and Landscapes: Ancient Cultivation in North-Central Asia
Agronomy 2023, 13(11), 2848; https://doi.org/10.3390/agronomy13112848 - 20 Nov 2023
Cited by 1 | Viewed by 1841
Abstract
Millet is a highly adaptable plant whose cultivation dramatically altered ancient economies in northern Asia. The adoption of millet is associated with increased subsistence reliability in semi-arid settings and perceived as a cultigen compatible with pastoralism. Here, we examine the pace of millet’s [...] Read more.
Millet is a highly adaptable plant whose cultivation dramatically altered ancient economies in northern Asia. The adoption of millet is associated with increased subsistence reliability in semi-arid settings and perceived as a cultigen compatible with pastoralism. Here, we examine the pace of millet’s transmission and locales of adoption by compiling stable carbon isotope data from humans and fauna, then comparing them to environmental variables. The Bayesian modelling of isotope data allows for the assessment of changes in dietary intake over time and space. Our results suggest variability in the pace of adoption and intensification of millet production across northern Asia. Full article
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15 pages, 3148 KiB  
Article
Effects of Fertilizer Application Patterns on Foxtail Millet Root Morphological Construction and Yield Formation during the Reproductive Stage in the Loess Plateau of China
Agronomy 2023, 13(11), 2847; https://doi.org/10.3390/agronomy13112847 - 20 Nov 2023
Viewed by 651
Abstract
With crop yields continually increasing, chemical fertilizer consumption in China is increasing in parallel. The excessive use of synthetic fertilizer can lead to soil compaction, acidification, and degeneration, which can all be mitigated through additional organic manure application. The combined application of organic [...] Read more.
With crop yields continually increasing, chemical fertilizer consumption in China is increasing in parallel. The excessive use of synthetic fertilizer can lead to soil compaction, acidification, and degeneration, which can all be mitigated through additional organic manure application. The combined application of organic manure and inorganic fertilizer plays crucial roles in the root morphology and yield formation of dryland crops. In this study, foxtail millet (Chang Sheng 07) was used as the experimental material and sown in a dry farming area with five different fertilizing patterns, which were composed of chemical N, P, organic manure, and microbial manure. These patterns included a single application of 45 kg·ha−1 of nitrogen fertilizer as the control (N45), the combined application of 60 kg·ha−1 of nitrogen fertilizer with 30 kg·ha−1 of phosphorus fertilizer (N60P30), the combined application of 90 kg·ha−1 of nitrogen fertilizer with 45 kg·ha−1 of phosphorus fertilizer (N90P45), 60 kg·ha−1 of nitrogen fertilizer and 40 kg·ha−1 of phosphorus fertilizer with 2000 kg·ha−1 of organic manure (N60P40-O), and 60 kg·ha−1 of nitrogen fertilizer and 40 kg·ha−1 of phosphorus fertilizer with 5 kg·ha−1 of microbial manure (N60P40-M). Each treatment was performed with four repeats. The results show that (1) the different fertilization patterns had significant effects on the morphological construction of foxtail millet roots, and the root length (RL) with N60P40–O underwent a significant increase of 88.23% and 61.59% in the two stages, respectively, (2) as confirmed by the correlation analysis, the root surface area (RSA) was positively correlated with the RL and root volume (RV), (3) the yields with N90P45 and N60P30 exhibited a significant increase of 54.43% and 59.86%, and those with N60P40–O and N60P40–M stably increased by 13.12–24.11% compared to those with N45, and (4) the water use efficiency (WUE) of foxtail millet under the N60P30 and N90P45 patterns significantly increased by 33.40–62.39%, while that under the N60P40–O and N60P40–M patterns increased by 12.89–29.20%. In summary, the application of additional organic matter and microbial manure promoted the morphological construction of foxtail millet roots, led to better stability in grain production, and is an ecofriendly option in terms of sustainable land use. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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18 pages, 2012 KiB  
Article
Long-Term Maize Intercropping with Peanut and Phosphorus Application Maintains Sustainable Farmland Productivity by Improving Soil Aggregate Stability and P Availability
Agronomy 2023, 13(11), 2846; https://doi.org/10.3390/agronomy13112846 - 20 Nov 2023
Viewed by 777
Abstract
The intercropping of maize (Zea mays L.) and peanuts (Arachis hypogaea L.) (M||P) significantly enhances crop yield. In a long-term M||P field experiment with two P fertilizer levels, we examined how long-term M||P affects topsoil aggregate fractions and stability, organic carbon [...] Read more.
The intercropping of maize (Zea mays L.) and peanuts (Arachis hypogaea L.) (M||P) significantly enhances crop yield. In a long-term M||P field experiment with two P fertilizer levels, we examined how long-term M||P affects topsoil aggregate fractions and stability, organic carbon (SOC), available phosphorus (AP), and total phosphorus (TP) in each aggregate fraction, along with crop yields. Compared to their respective monocultures, long-term M||P substantially increased the proportion of topsoil mechanical macroaggregates (7.6–16.3%) and water-stable macroaggregates (>1 mm) (13.8–36.1%), while reducing the unstable aggregate index (ELT) and the percentage of aggregation destruction (PAD). M||P significantly boosted the concentration (12.9–39.9%) and contribution rate (4.1–47.9%) of SOC in macroaggregates compared to single crops. Moreover, the concentration of TP in macroaggregates (>1 mm) and AP in each aggregate fraction of M||P exceeded that of the respective single crops (p < 0.05). Furthermore, M||P significantly increased the Ca2-P, Ca8-P, Al-P, and Fe-P concentrations of intercropped maize (IM) and the Ca8-P, O-P, and Ca10-P concentrations of intercropped peanuts (IP). The land equivalent ratio (LER) of M||P was higher than one, and M||P stubble improved the yield of subsequent winter wheat (Triticum aestivum L.) compared with sole-crop maize stubble. P application augmented the concentration of SOC, TP, and AP in macroaggregates, resulting in improved crop yields. In conclusion, our findings suggest that long-term M||P combined with P application sustains farmland productivity in the North China Plain by increasing SOC and macroaggregate fractions, improving aggregate stability, and enhancing soil P availability. Full article
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15 pages, 2517 KiB  
Article
The Purple leaf (Pl) Alleles, Plw and Pli, Regulate Leaf Color Development Independently from the Pb Gene of Purple pericarp (Prp) in Rice
Agronomy 2023, 13(11), 2845; https://doi.org/10.3390/agronomy13112845 - 19 Nov 2023
Viewed by 706
Abstract
Color development in various rice organs results from the complementary expression of genes involved in anthocyanin biosynthesis. The Purple pericarp (Prp) trait and the Purple leaf (Pl) trait both display epistasis, relying on the complement of the Pb and [...] Read more.
Color development in various rice organs results from the complementary expression of genes involved in anthocyanin biosynthesis. The Purple pericarp (Prp) trait and the Purple leaf (Pl) trait both display epistasis, relying on the complement of the Pb and Pp genes for pericarp coloration and the Pl and Pp genes for leaf coloration, respectively. However, there is still genetic uncertainty in identifying the genes responsible for the various color expressions and intensities of rice grain pericarp and leaves. In this study, we characterized the inheritance patterns of color development and the mode of anthocyanin pigments in rice by crossing two parental mutant lines. YUM051, exhibiting dark purple leaves (Plw) and purple pericarp (Prp), was crossed with YUM144, which displayed light purple leaves (Pli) and a white pericarp (prp). The F1 plants exhibited dark purple leaves with purple pericarps, indicating the dominant nature of the purple leaf (Pl) and purple pericarp (Prp) traits. The rice Prp traits display a complementary interaction, reflected in a 9:7 ratio of purple to white pericarp. However, the Prp trait followed Mendelian segregation with a 3:1 ratio of purple to white pericarp in this cross, indicating homozygous dominant Pp alleles in both parental plants. Meanwhile, the segregation of the purple leaf color in the F2 generation of this cross followed complementary inheritance, exhibiting a 9:7 segregation ratio between purple leaves and greenish leaves with purple leaf margins. Moreover, the co-segregation of Prp and Pl traits in the cross between YUM051 (Plw) and YUM144 (Pli) plants did not adhere to the Mendelian 9:3:3:1 independent assortment ratio, confirming that the Pl gene and Pb gene are linked on the same chromosome. Cyanidin-3-O-glucoside (C3G) was detected in the leaves of all progeny resulting from the Plw and Pli cross. However, C3G was exclusively identified in the seeds of offspring carrying the dominant Pb gene. Therefore, the Plw and Pli alleles are Pl genes responsible for purple leaf color, while the Pb gene is responsible for purple pericarp color in rice; these genes function independently of each other. Full article
(This article belongs to the Special Issue Genetic Analysis in Crops)
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27 pages, 8754 KiB  
Article
A Comprehensive Step-by-Step Guide to Using Data Science Tools in the Gestion of Epidemiological and Climatological Data in Rice Production Systems
Agronomy 2023, 13(11), 2844; https://doi.org/10.3390/agronomy13112844 - 19 Nov 2023
Cited by 1 | Viewed by 698
Abstract
The application of data science (DS) techniques has become increasingly essential in various fields, including epidemiology and climatology in agricultural production systems. In this sector, traditionally large amounts of data are acquired, but not well-managed and -analyzed as a basis for evidence-based decision-making [...] Read more.
The application of data science (DS) techniques has become increasingly essential in various fields, including epidemiology and climatology in agricultural production systems. In this sector, traditionally large amounts of data are acquired, but not well-managed and -analyzed as a basis for evidence-based decision-making processes. Here, we present a comprehensive step-by-step guide that explores the use of DS in managing epidemiological and climatological data within rice production systems under tropical conditions. Our work focuses on using the multi-temporal dataset associated with the monitoring of diseases and climate variables in rice in Colombia during eight years (2012–2019). The study comprises four main phases: (I) data cleaning and organization to ensure the integrity and consistency of the dataset; (II) data management involving web-scraping techniques to acquire climate information from free databases, like WordClim and Chelsa, validation against in situ weather stations, and bias removal to enrich the dataset; (III) data visualization techniques to effectively represent the gathered information, and (IV) a basic analysis related to the clustering and climatic characterization of rice-producing areas in Colombia. In our work, a process of evaluation and the validation of climate data are conducted based on errors (r, R2, MAE, RSME) and bias evaluation metrics. In addition, in phase II, climate clustering was conducted based on a PCA and K-means algorithm. Understanding the association of climatic and epidemiological data is pivotal in predicting and mitigating disease outbreaks in rice production areas. Our research underscores the significance of DS in managing epidemiological and climatological data for rice production systems. By applying a protocol responsible for DS tools, our study provides a solid foundation for further research into disease dynamics and climate interactions in rice-producing regions and other crops, ultimately contributing to more informed decision-making processes in agriculture. Full article
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17 pages, 30436 KiB  
Article
Increase in Soil Carbon Pool Stability Rather Than Its Stock in Coastal Saline—Alkali Ditches following Reclamation Time
Agronomy 2023, 13(11), 2843; https://doi.org/10.3390/agronomy13112843 - 19 Nov 2023
Viewed by 878
Abstract
Extensive drainage ditches are constructed to reduce soil salinity in reclaimed saline–alkali farmland, consequently forming plant growth hotspots and impacting soil carbon stocks therein. However, the investigation into changes in soil carbon stocks remains limited in these ditches. To address this, soil samples [...] Read more.
Extensive drainage ditches are constructed to reduce soil salinity in reclaimed saline–alkali farmland, consequently forming plant growth hotspots and impacting soil carbon stocks therein. However, the investigation into changes in soil carbon stocks remains limited in these ditches. To address this, soil samples were collected from drainage ditches, which originated from the reclamation of saline–alkali farmland, at different reclamation years (the first, seventh, and fifteenth year). Moreover, fractions were separated from soil samples; a particle size separation method (particulate organic matter, POM; mineral–associated organic matter, MAOM) and a spatio–temporal substitution method were conducted to analyze the variations in soil carbon components and the underlying mechanisms. The results indicate that there were no significant variations in the contents and stocks of soil organic carbon (SOC) and soil inorganic carbon (SIC) following the increase in reclamation time. However, in the POM fraction, the SOC content (SOCPOM) and stock significantly decreased from 2.24 to 1.12 g kg−1 and from 19.02 to 12.71 Mg ha−1, respectively. Conversely, in the MAOM fraction, the SOC content (SOCMAOM) and stock significantly increased from 0.65 to 1.70 g kg−1 and from 5.30 to 12.27 Mg ha−1, respectively. The different changes in SOCPOM and SOCMAOM, as well as the result of the structural equation model, showed a possible transformation process from SOCPOM to SOCMAOM in the soil carbon pool under the driving force of reclamation time. The results in terms of the changes in soil carbon components demonstrate the stability rather than the stock of the soil carbon pool increase in coastal saline–alkali ditches following the excavation formation time. Although more long time series and direct evidence are needed, our findings further provide a case study for new knowledge about changes in the soil carbon pool within saline–alkali ditches and reveal the potential processes involved in the transformation of soil carbon components. Full article
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15 pages, 3578 KiB  
Article
OpenToolFlux: An Open-Source Software for Estimating Gas Fluxes from Automatic Chamber Data
Agronomy 2023, 13(11), 2842; https://doi.org/10.3390/agronomy13112842 - 18 Nov 2023
Viewed by 695
Abstract
OpenToolFlux 1.0 is an open-source software designed to estimate soil gas fluxes from gas concentration time-series data generated by automatic chamber systems. This paper describes the physical equipment used as well as the software design and workflow. The software is a command-line application [...] Read more.
OpenToolFlux 1.0 is an open-source software designed to estimate soil gas fluxes from gas concentration time-series data generated by automatic chamber systems. This paper describes the physical equipment used as well as the software design and workflow. The software is a command-line application that imports tabular time-series data from the analyzer following the instructions specified in a configuration file by the user, performs configurable data-cleaning operations, and outputs a data file with volumetric flux estimates as well as diagnostic plots. The software can be configured according to the specifics of the physical equipment and experimental setups, and it is, therefore, applicable to a wide range of studies. Full article
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21 pages, 4559 KiB  
Article
Introducing Autochthonous Bacterium and Fungus Composition to Enhance the Phytopathogen-Suppressive Capacity of Composts against Clonostachys rosea, Penicillium solitum and Alternaria alternata In Vitro
Agronomy 2023, 13(11), 2841; https://doi.org/10.3390/agronomy13112841 - 18 Nov 2023
Viewed by 773
Abstract
Given their numerous positive characteristics, composts are widely used agriculturally in sustainable development and resource-saving technologies. The management of phytopathogen-suppressive potential and the fertilizing capacity of composts are of great interest. This study examines the impact of introducing the autochthonous compost species Bacillus [...] Read more.
Given their numerous positive characteristics, composts are widely used agriculturally in sustainable development and resource-saving technologies. The management of phytopathogen-suppressive potential and the fertilizing capacity of composts are of great interest. This study examines the impact of introducing the autochthonous compost species Bacillus subtilis, B. amyloliquefaciens, Pseudomonas aeruginosa, and Aspergillus corrugatus, both individually and in combination, to composts containing dry matter comprising 36% solid compost and 7% compost suspensions to study their phytopathogen-suppressive and phytostimulation activity. The test phytopathogens were Clonostachys rosea, Penicillium solitum, and Alternaria alternata. This is the first report on compost’s potential to biologically control C. rosea and P. solitum. Classical microbiological and molecular biological methods were used to evaluate the survival rate of microorganisms in compost and validate these results. Test plant (Raphanus sativus) germination indexes were determined to evaluate the phytotoxic/phytostimulation effects of the substrates. To assess the effectiveness of biocontrol, mycelial growth inhibition was measured using in vitro tests. The introduction of composition increased the composts’ fertilizing properties by up to 35% and improved antagonistic activity by up to 91.7%. Autochthonous bacterial–fungal composition can promote resistance to fungal root and foliar phytopathogens and raise the fertilizing quality of compost. Full article
(This article belongs to the Section Pest and Disease Management)
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17 pages, 2990 KiB  
Article
Economic Evaluation and Risk Premium Estimation of Rainfed Soybean under Various Planting Practices in a Semi-Humid Drought-Prone Region of Northwest China
Agronomy 2023, 13(11), 2840; https://doi.org/10.3390/agronomy13112840 - 18 Nov 2023
Viewed by 758
Abstract
Economic benefits and risk premiums significantly affect the production system decision making of farmers and government departments. This study evaluated the economic feasibility and estimated the risk premium of 12 rainfed soybean production systems with various planting densities, fertilization rates and planting patterns [...] Read more.
Economic benefits and risk premiums significantly affect the production system decision making of farmers and government departments. This study evaluated the economic feasibility and estimated the risk premium of 12 rainfed soybean production systems with various planting densities, fertilization rates and planting patterns by considering the impact of soybean price fluctuation. There were two planting densities (D1: 160,000 plants ha−1 and D2: 320,000 plants ha−1), two fertilization rates (F1: 20 kg ha−1 N, 30 kg ha−1 P, 30 kg ha−1 K; F2: 40 kg ha−1 N, 60 kg ha−1 P, 60 kg ha−1 K) and three planting patterns (F+W0: flat cultivation with no irrigation; R+W0: plastic-mulched ridge-furrow cultivation (PMRF) with no irrigation; R+W1: PMRF with supplemental irrigation of 30 mm at the pod-filling stage). Based on the two-year (2019–2020) field data in a semi-humid drought-prone region of northwest China and soybean price fluctuation from January 2014 to June 2021, the net income (NI) was calculated by considering the impact of soybean price fluctuation and assuming constant soybean production costs. The net present value (NPV) method and the stochastic efficiency with respect to a function (SERF) method were used to evaluate the profitability of protective alternatives and the risk of these alternatives. The results showed that the 12 proposed soybean production systems were economically feasible. Reducing the fertilization rate reduced the input costs, but it did not necessarily result in a decrease in soybean yield and NI. The payback period of all production systems was within two years for farmers investing through loans. High-fertilizer and high-density production systems made personal investment obtain the highest economic benefit in this study, which was not the best investment strategy from the perspective of production-to-investment ratio and environmental protection departments. The preferences of farmers with various risk aversion and environmental protection departments in terms of risk premium were also proposed. The economic and risk assessment framework of this study can enhance the understanding of the adjustment of production systems from different perspectives, and provide strategies for promoting the protection of economic, environmental and socially sustainable agricultural systems. Full article
(This article belongs to the Special Issue Economy and Sociology in Sustainable Agriculture)
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16 pages, 3436 KiB  
Article
Suppression of Monilinia Brown Rot by Bacillus spp. Strains
Agronomy 2023, 13(11), 2839; https://doi.org/10.3390/agronomy13112839 - 18 Nov 2023
Viewed by 605
Abstract
Brown rot caused by Monilinia spp. is one of the main causes of pre- and postharvest losses in stone and pome fruit production. The use of beneficial microorganisms is considered one of the most promising, safe and effective alternative methods for controlling these [...] Read more.
Brown rot caused by Monilinia spp. is one of the main causes of pre- and postharvest losses in stone and pome fruit production. The use of beneficial microorganisms is considered one of the most promising, safe and effective alternative methods for controlling these pathogens. This study aimed to investigate the antagonistic potential of 33 Bacillus spp. strains, in order to identify the best candidate for brown rot biocontrol. Strains identified as Bacillus amyloliquefaciens B-241 and Bacillus subtilis B-313 and B-358 were chosen for further ex situ studies on detached apple fruit. The efficacy of B-241 (87.1–93.7%) did not differ significantly from a commercially available synthetic fungicide (p > 0.05). The putative mode of action of B. amyloliquefaciens B-241 against Monilinia species is competition for nutrients and antibiosis. The ethyl acetate extract of the strain, applied at 5 and 12.5 mg/mL, was bioactive in vitro and ex situ. A HPLC analysis confirmed the presence of surfactin and bacillomycin D in the extract. However, before developing a shelf-stable product and commercial production, the spectrum and efficacy on a larger scale of the B-241 strain should be determined, and its efficacy in combination with commercial biofungicides and fungicides tested in vivo. Full article
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16 pages, 9057 KiB  
Article
Condition of Young Japanese Knotweed (Reynoutria japonica Houtt.) Offshoots in Response to Microwave Radiation of Their Rhizomes
Agronomy 2023, 13(11), 2838; https://doi.org/10.3390/agronomy13112838 - 18 Nov 2023
Viewed by 733
Abstract
Invasive Japanese knotweed is one of Poland’s most aggressive and difficult-to-control species. New methods of control are of utmost importance. This study aimed to analyze young knotweed offshoots’ regeneration and physiological condition after treatment of their rhizomes with microwaves of high frequency. The [...] Read more.
Invasive Japanese knotweed is one of Poland’s most aggressive and difficult-to-control species. New methods of control are of utmost importance. This study aimed to analyze young knotweed offshoots’ regeneration and physiological condition after treatment of their rhizomes with microwaves of high frequency. The fresh rhizomes were microwaved in the laboratory once for different times (from 5 to 60 s, interval 5 s). Next, in the greenhouse, the growth of offshoots and their biochemical state (spectrophotometry of leaves) were recorded in three measurement series. It was shown that the microwave treatment for 35 s directly destroys knotweed rhizomes of a diameter of 1–3 cm, so it does not produce new offsprings. The treatment times from 5–25 s delay offspring regeneration and growth and development of leaves. The leaves initiate the mechanisms of protection against microwave stress in offshoots grown from the rhizomes exposed to microwaves for 10 s (increase in the anthocyanin index) and the 5 or 20 s treatments (higher values of the photochemical reflectance index). Based on the effective dose (ED50) analysis, the threshold of harmful effects of microwaves on the growth and development of Reynoutria japonica rhizomes was assumed to be 17–19 s. Full article
(This article belongs to the Special Issue New Trends in Crop Production Management Practices)
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25 pages, 3281 KiB  
Article
Soil Chemical Properties and Microbial Behavior under Short-Term Organic and Mineral Fertilization within Different Crops
Agronomy 2023, 13(11), 2837; https://doi.org/10.3390/agronomy13112837 - 17 Nov 2023
Viewed by 688
Abstract
Agronomic practices can have a negative impact on soil health and quality and ecosystem resilience. The objectives of the study were (1) to evaluate the soil chemical properties and microbial abundance under short-term application of organic and mineral fertilizers and different cultivated crops [...] Read more.
Agronomic practices can have a negative impact on soil health and quality and ecosystem resilience. The objectives of the study were (1) to evaluate the soil chemical properties and microbial abundance under short-term application of organic and mineral fertilizers and different cultivated crops and (2) to observe the antifungal efficacy of microorganisms isolated from the studied soil. A field trial was conducted in the 2021–2022 period on a preluvosoil-type soil in four randomized blocks with eight fertilizer treatments based on manure compost (MC) and MC + mineral fertilizer (V1—control-soil; V2—NPK only; V3—15 t/ha MC; V4—15 t/ha MC + NPK; V5—30 t/ha MC; V6—30 t/ha MC + NPK; V7—60 t/ha MC; and V8—60 t/ha MC +NPK) and four crops (winter wheat—Triticum aestivum L., maize—Zea mays L., soybean—Glycine max L., and a mixture of perennial grasses and legumes). In almost all treatments, the soil pH decreased during the summer–autumn period. The organic carbon (Corg) and humus contents increased compared to the initial state of the soil after the application of different doses of MC and MC + NPK fertilization in almost all treatments. The microbial load of the soil was influenced by the fertilization regime and crop species, but there were no significant differences between the variants. The highest bacterial load was recorded in soil cultivated with a mixture of perennial grasses and grain legumes, i.e., in the variant with 15 t/ha MC, followed by soil cultivated with maize and fertilized with 30 t/ha and 60 t/ha MC. A higher number of fungi was observed in the mixture of perennial grasses and legumes, and Rhizobium population was higher, especially in the winter wheat plots, despite the fertilization regime. The antifungal efficacy of the microorganisms isolated from the samples was medium to low, except in the winter wheat experiment, where the efficacy against Fusarium culmorum was medium to high and against other pathogens was medium. In the other crops within the experiment, the antagonistic activity of the soil microorganisms was medium to low. Full article
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17 pages, 4059 KiB  
Article
The Impact of Mechanical Compression on the Postharvest Quality of ‘Shine Muscat’ Grapes during Short-Term Storage
Agronomy 2023, 13(11), 2836; https://doi.org/10.3390/agronomy13112836 - 17 Nov 2023
Viewed by 763
Abstract
Mechanical stress induced by compression during preharvest and postharvest handling of fresh fruit is a major factor influencing the quality of fresh fruit. The degree of compression primarily governs the extent of quality deterioration. However, research on the damage mechanisms of mechanical compression [...] Read more.
Mechanical stress induced by compression during preharvest and postharvest handling of fresh fruit is a major factor influencing the quality of fresh fruit. The degree of compression primarily governs the extent of quality deterioration. However, research on the damage mechanisms of mechanical compression in table grapes remains scarce. This investigation evaluated the impact of varying compression levels (0%, 20%, 40%, 60%, and 80%) on the postharvest quality attributes of table grapes. Changes in postharvest physical properties (overall appearance and color), structural properties (firmness, springiness, cohesiveness, and chewiness), physiological qualities (total soluble solids, titratable acidity, ascorbic acid, malonaldehyde content, and relative electrical conductivity), and cell microstructure of the berries was determined at 4 °C during 15 d of storage. Mechanical compression contributed to the deterioration of the quality of table grapes during storage, resulting in increased weight loss, decay rate, malonaldehyde content, and relative electrical conductivity; and decreased total soluble solids, titratable acidity, and ascorbic acid content. Furthermore, as compared to the control group, mechanical compression resulted in substantial yellowing and diminished textural qualities of grapes. In particular, compression treatment caused significant deformation of grape cell microstructure. In conclusion, mechanical compression stress significantly affects the physical and physiological properties of postharvest table grapes, as well as the internal cellular organization. As compression levels increase, the quality of table grapes progressively deteriorates, leading to a substantial reduction in storage life and commercial value. This study offers essential information for devising damage prevention strategies in preharvest and postharvest handling of table grapes. Full article
(This article belongs to the Section Agricultural Biosystem and Biological Engineering)
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17 pages, 2719 KiB  
Article
Modeling Callus Induction and Regeneration in Hypocotyl Explant of Fodder Pea (Pisum sativum var. arvense L.) Using Machine Learning Algorithm Method
Agronomy 2023, 13(11), 2835; https://doi.org/10.3390/agronomy13112835 - 17 Nov 2023
Cited by 2 | Viewed by 733
Abstract
A comprehensive understanding of genetic diversity and the categorization of germplasm is important to effectively identify appropriate parental candidates for the goal of breeding. It is necessary to have a technique of tissue culture that is both effective and reproducible to perform genetic [...] Read more.
A comprehensive understanding of genetic diversity and the categorization of germplasm is important to effectively identify appropriate parental candidates for the goal of breeding. It is necessary to have a technique of tissue culture that is both effective and reproducible to perform genetic engineering on fodder pea genotypes (Pisum sativum var. arvense L.). In this investigation, the genetic diversity of forty-two fodder pea genotypes was assessed based on their ability of callus induction (CI), the percentage of embryogenic callus by explant number (ECNEP), the percentage of responding embryogenic calluses by explant number (RECNEP), the number of somatic embryogenesis (NSE), the number of responding somatic embryogenesis (RSE), the regeneration efficiency (RE), and the number of regenerated plantlets (NRP). The findings of the ANOVA showed that there were significant differences (p < 0.001) between the genotypes for all in vitro parameters. The method of principal component analysis (PCA) was used to study the correlations that exist between the factors associated with tissue culture. While RE and NRP variables were most strongly associated with Doğruyol, Ovaçevirme-4, Doşeli-1, Yolgeçmez, and Incili-3 genotypes, RECNEP, NSE, RDE, and RECNEP variables were strongly associated with Avcılar, Ovaçevirme-3, and Ardahan Merkez-2 genotypes. The in vitro process is a complex multivariate process and more robust analyses are needed for linear and nonlinear parameters. Within the scope of this study, artificial neural network (ANN), random forest (RF), and multivariate adaptive regression spline (MARS) algorithms were used for RE estimation, and these algorithms were also compared. The results that we acquired from our research led us to the conclusion that the employed ANN-multilayer perceptron (ANN-MLP) model (R2 = 0.941) performs better than the RF model (R2 = 0.754) and the MARS model (R2 = 0.214). Despite this, it has been shown that the RF model is capable of accurately predicting RE in the early stages of the in vitro process. The current work is an inquiry regarding the use of RF, MARS, and ANN models in plant tissue culture, and it indicates the possibilities of application in a variety of economically important fodder peas. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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19 pages, 1955 KiB  
Article
Linking Conventional and Organic Rainfed Almond Cultivation to Nut Quality in a Marginal Growing Area (SE Spain)
Agronomy 2023, 13(11), 2834; https://doi.org/10.3390/agronomy13112834 - 17 Nov 2023
Viewed by 646
Abstract
The need to improve agroecosystem sustainability to secure yields, minimize environmental impacts and improve soil health is widely recognized. Organic production systems are one of the strategies that may be used to alleviate the negative environmental repercussions of conventional agriculture. In the present [...] Read more.
The need to improve agroecosystem sustainability to secure yields, minimize environmental impacts and improve soil health is widely recognized. Organic production systems are one of the strategies that may be used to alleviate the negative environmental repercussions of conventional agriculture. In the present study, we compared the impact of conventional and organic production systems on the almond (Prunus dulcis (Mill.) D.A. Webb) yield and quality of nuts of two cultivars (Marcona and Desmayo largueta), with both systems being managed on marginal hillslopes in the southeast of Spain. Our findings show that the organic production system in rainfed almond trees has positive effects on certain nut quality parameters, with a slight decrease in almond yield, specifically 9.5% for cv. D. largueta and 1.3% for cv. Marcona, with respect to the conventional system. The results obtained have varied depending on the cultivar. Statistically significant differences have been obtained for cv. Marcona in the sugar content (54.4 and 49.8 g kg−1 in organic and conventional, respectively) and the total phenol content (3.41 and 2.46 g GAE kg−1 for organic and conventional, respectively). In the case of cv D. largueta, statistically significant differences were found between the organic and conventional systems for antioxidant activity (14.8 vs. 8.68 mmol Trolox kg−1, DPPH), fatty acid content (229 vs. 188 g kg−1 dw), saturated fatty acids (36 vs. 28.7 g kg−1 dw), monounsaturated fatty acids (113 vs. 110 g kg−1 dw) and polyunsaturated fatty acids (60.3 vs. 49.6 g kg−1 dw). Here, we show for the first time how a rainfed organic system allows for higher-quality almonds, specifically with a higher content of phytochemicals beneficial for health, which, together with the higher price compared to conventional almonds, could compensate for the yield losses while preserving the sustainability of marginal agroecosystems. Full article
(This article belongs to the Section Water Use and Irrigation)
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29 pages, 6358 KiB  
Review
Biomass Waste Conversion Technologies and Its Application for Sustainable Environmental Development—A Review
Agronomy 2023, 13(11), 2833; https://doi.org/10.3390/agronomy13112833 - 17 Nov 2023
Viewed by 1308
Abstract
With the global population continuing to increase, the demand for food and energy has escalated, resulting in severe environmental pressures. Traditional methods of food and energy production have left a significant footprint on the environment, primarily due to the emission of greenhouse gases [...] Read more.
With the global population continuing to increase, the demand for food and energy has escalated, resulting in severe environmental pressures. Traditional methods of food and energy production have left a significant footprint on the environment, primarily due to the emission of greenhouse gases and a notable surge in waste production. Nevertheless, scientists have recently focused on developing sustainable solutions by managing biomass waste and converting it into useful products. Various biomass conversion technologies, including pyrolysis, gasification, and fermentation, have emerged to transform waste materials into valuable commodities like biofuels, fertilizers, and chemicals. These technologies present an alternative to conventional energy production methods and decrease reliance on non-renewable resources. Furthermore, the by-products generated through biomass conversion, such as biochar, possess utility as valuable soil amendments. This review emphasizes the potential of biomass conversion technologies in providing sustainable solutions for waste management, food and energy production, and reducing negative environmental impacts while providing valuable by-products for agricultural use. The focus is on Lebanon, which is facing a waste and energy crisis, with an aim to encourage and promote sustainable practices by highlighting different green waste management technologies. Focusing on the application of biochar in soil, our goal is to provide cost-effective and eco-friendly solutions to various agricultural and environmental challenges in Lebanon. This includes using biochar from biomass waste as a soil amendment to boost crop yields, remediate soil pollution, reduce soil drought stress, and address other related issues. Full article
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24 pages, 4366 KiB  
Review
Field Phenotyping Monitoring Systems for High-Throughput: A Survey of Enabling Technologies, Equipment, and Research Challenges
Agronomy 2023, 13(11), 2832; https://doi.org/10.3390/agronomy13112832 - 17 Nov 2023
Viewed by 787
Abstract
High-throughput phenotype monitoring systems for field crops can not only accelerate the breeding process but also provide important data support for precision agricultural monitoring. Traditional phenotype monitoring methods for field crops relying on artificial sampling and measurement have some disadvantages including low efficiency, [...] Read more.
High-throughput phenotype monitoring systems for field crops can not only accelerate the breeding process but also provide important data support for precision agricultural monitoring. Traditional phenotype monitoring methods for field crops relying on artificial sampling and measurement have some disadvantages including low efficiency, strong subjectivity, and single characteristics. To solve these problems, the rapid monitoring, acquisition, and analysis of phenotyping information of field crops have become the focus of current research. The research explores the systematic framing of phenotype monitoring systems for field crops. Focusing on four aspects, namely phenotyping sensors, mobile platforms, control systems, and phenotyping data preprocessing algorithms, the application of the sensor technology, structural design technology of mobile carriers, intelligent control technology, and data processing algorithms to phenotype monitoring systems was assessed. The research status of multi-scale phenotype monitoring products was summarized, and the merits and demerits of various phenotype monitoring systems for field crops in application were discussed. In the meantime, development trends related to phenotype monitoring systems for field crops in aspects including sensor integration, platform optimization, standard unification, and algorithm improvement were proposed. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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14 pages, 2952 KiB  
Article
The Differentiations in the Soil Nematode Community in an Agricultural Field after Soil Amendment Using Composted Coffee Waste in Various Concentrations
Agronomy 2023, 13(11), 2831; https://doi.org/10.3390/agronomy13112831 - 17 Nov 2023
Viewed by 601
Abstract
In a field experiment, composted coffee waste (CW) was used as soil amendment at three different rates (2%, 4%, and 8%) in plots cultivated with wheat; the effects on the soil nematode community and plant growth were studied. By sampling twice, i.e., three [...] Read more.
In a field experiment, composted coffee waste (CW) was used as soil amendment at three different rates (2%, 4%, and 8%) in plots cultivated with wheat; the effects on the soil nematode community and plant growth were studied. By sampling twice, i.e., three and six months after the application of treatments (3MAA and 6MAA), the duration of these effects was also evaluated. Treatment using composted coffee waste (CW) led to an increased abundance of all soil nematodes, especially of bacterivores and fungivores, probably via a bottom-up effect of CW on the soil community. The most-affected genera were the enrichment opportunists Panagrolaimus and Rhabditis, which increased after CW addition in a dosage-dependent way at 3MAA, while at 6MAA they were replaced by general opportunists, mainly bacterivorous and fungivorous genera; a nematotoxic effect of CW was also observed in the 6MAA condition. The nematode indices and the metabolic footprint indicated an enriched and vigorous soil three months after CW addition and a lower enrichment status of the soil together with a higher fungal participation in the decomposition pathway six months after treatments. However, in the 6 MAA condition, the soil nutrient values were higher in the CW-treated plots. None of our treatments inhibited or enhanced plant growth. Full article
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20 pages, 13589 KiB  
Article
Optimal Plant Density Improves Sweet Maize Fresh Ear Yield without Compromising Grain Carbohydrate Concentration
Agronomy 2023, 13(11), 2830; https://doi.org/10.3390/agronomy13112830 - 17 Nov 2023
Viewed by 613
Abstract
It is crucial to synergistically improve the yield and quality of sweet maize by implementing precise and strategic planting methods. However, a comprehensive understanding of how increasing plant density affects the sweet maize fresh ear yield, grain-filling rate, and grain carbohydrate concentration is [...] Read more.
It is crucial to synergistically improve the yield and quality of sweet maize by implementing precise and strategic planting methods. However, a comprehensive understanding of how increasing plant density affects the sweet maize fresh ear yield, grain-filling rate, and grain carbohydrate concentration is not fully understood. Thus, a field experiment was performed using a split-plot design in Southeast China in 2021 and 2022, involving four sweet maize varieties (MT6855 and WT2015 were compact-type varieties, XMT10 and YZ7 were flat-type varieties) and three plant densities (D1: 4.5 plants m−2; D2: 6.0 plants m−2; and D3: 7.5 plants m−2). The results showed that an increasing plant density markedly increased the fresh ear yield of sweet maize varieties (MT6855 and WT2015) over the two years. However, it did not influence the fresh ear yield of XMT10 and YZ7. Across all four varieties in 2021 and 2022, the increasing plant density decreased the sweet maize filled ear length, while it did not affect the grain soluble solid concentration and grain residue ratio. The sweet maize grain weight, the maximum grain-filling rate, and the mean grain-filling rate decreased significantly with the increase in planting density across all four varieties. However, plant density did not significantly affect the grain soluble sugar, sucrose, fructose, and starch concentrations across different varieties at most stages during the grain filling. The current study also found that the sweet maize fresh ear yield was dramatically positively correlated with ears ha−1, grains per ear, grain-filling rate, and grain starch concentration but negatively correlated with the bare plant rate. Notably, a parabolic relationship existed between the fresh ear yield and 100-grain weight. These findings suggest that optimizing the plant density, particularly with compact-type varieties, can improve the sweet maize fresh ear yield without decreasing its quality. Full article
(This article belongs to the Section Innovative Cropping Systems)
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3 pages, 202 KiB  
Editorial
CERNAS—Current Evolution and Research Novelty in Agricultural Sustainability
Agronomy 2023, 13(11), 2829; https://doi.org/10.3390/agronomy13112829 - 16 Nov 2023
Viewed by 692
Abstract
Climate changes have overwhelming impacts on primary production and, consequently, on agricultural and animal farming [...] Full article
14 pages, 2198 KiB  
Article
Fixed Spraying Systems Application in Citrus Orchards: Nozzle Type and Nozzle Position Effects on Droplet Deposition and Pest Control
Agronomy 2023, 13(11), 2828; https://doi.org/10.3390/agronomy13112828 - 16 Nov 2023
Viewed by 606
Abstract
Pesticide application is an essential means of controlling plant diseases and pests in citrus orchards. In recent years, fixed spraying systems have gradually been used as alternatives to traditional sprayers and manual sprayers in some hilly citrus orchards. In this paper, influences of [...] Read more.
Pesticide application is an essential means of controlling plant diseases and pests in citrus orchards. In recent years, fixed spraying systems have gradually been used as alternatives to traditional sprayers and manual sprayers in some hilly citrus orchards. In this paper, influences of fixed system spraying parameters, such as droplet size and spraying height, on spraying quality were elucidated and analyzed. The performances of two nozzle types, pressure-swirl nozzles and fixed spray plate sprinklers, were assessed and compared by effective droplet coverage ratio (DCR), droplet distribution uniformity coefficient of variation (CV), and droplet penetration ratio (DPR). The results showed that appropriately increasing droplet size and spraying height could improve the DCR and distribution uniformity of pressure-swirl nozzles. The DCR and distribution uniformity of fixed spray plate sprinklers had a positive correlation with droplet size, while spraying height had no significant effect on these variables. Additionally, with the increase in droplet size, DPR initially increased and then gradually decreased. The optimized results showed that the optimal parameters for pressure-swirl nozzles were a droplet size of 240 μm and spraying height of 100 cm, while for fixed spray plate sprinklers, the results were a droplet size of 240 μm and spraying height of 50 cm. Comparison results showed that the spraying quality of fixed spray plate sprinklers was better overall, with values of DCR, CV, and DPR being 37.15%, 24.20%, and 71.67%, respectively, while the corresponding values for pressure-swirl nozzles were 39.65%, 35.41%, and 56.02%. Based on the above results and the occurrence rule of citrus pests and disease, the optimal spraying parameters of fixed spraying systems were selected to control the Asian citrus psyllid Diaphorina citri. Furthermore, the effect of fixed spraying systems on controlling Diaphorina citri reached the maximum at 3 days after spraying, which was 97.83%, and the effect declined at 14 days after spraying, which was 85.47%. This study provides valuable scientific references for guiding the application of fixed spraying systems in hilly citrus orchards. Full article
(This article belongs to the Section Precision and Digital Agriculture)
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15 pages, 1089 KiB  
Article
Can Soil Improvers (Biochar, Compost, Insect Frass, Lime, and Zeolite) Achieve Phytostabilization of Potentially Toxic Elements in Heavily Contaminated Soil with the Use of Purslane (Portulaca oleracea)?
Agronomy 2023, 13(11), 2827; https://doi.org/10.3390/agronomy13112827 - 16 Nov 2023
Viewed by 612
Abstract
In soil with extremely high contents of Cd (101.87), Pb (26,526.44), and Zn (17,652.63 mg kg−1), we aimed to test the phytostabilization capacity of purslane (Portulaca oleracea) with the use of various soil improvers, both organic (biochar, compost, insect [...] Read more.
In soil with extremely high contents of Cd (101.87), Pb (26,526.44), and Zn (17,652.63 mg kg−1), we aimed to test the phytostabilization capacity of purslane (Portulaca oleracea) with the use of various soil improvers, both organic (biochar, compost, insect frass) and inorganic (lime and zeolite). Thus, in a 60-day pot experiment, we amended this heavily contaminated soil with the five materials at two rates, 2% and 4%, resulting in 11 treatments (control plus five materials × two rates) replicated 10 times. We found that soil extractions of Cd with DTPA (diethylenetriaminepentaacetic acid) were not affected by any of the amendments, as there was no recorded significant reduction in soil Cd. In the case of Pb, there were even significant increases in its extractability with added biochar, and so was the case for compost at 4%. The reason may be the formation of organometallic complexes with organic substances of low molecular weight eluted by the organic amendments. Similarly, Zn extractability increased significantly compared to the control in the compost and frass treatments. As for purslane shoots, Cd decreased from 61 μg kg−1 fresh weight (FW) at control to 39 at biochar 4%, but the reduction was non-significant. As for Pb, it decreased with biochar but not significantly, while it exhibited a significant decrease in all other treatments. However, in all cases the content of Pb in purslane was well above the European regulation limit of 0.100 mg kg−1 FW (fresh weight) for vegetables and fresh herbs, while Cd fell below the regulation limit of 50 μg kg−1 FW at biochar 4%, compost 4%, and frass 2% and 4% (with control being 62.5 μg kg−1 FW). We conclude that in heavily contaminated soils, although biochar, along with compost and frass, was not entirely unsuccessful, the tested amendments did not reduce satisfactorily toxic elements to sufficiently low levels both in soil and in the test plant (here, purslane) in order to achieve phytostabilization. However, further research is necessary to identify exact mechanisms and to elucidate the role of different biochars. Full article
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14 pages, 952 KiB  
Article
Evaluation of Soil Suppressiveness of Various Japanese Soils against the Soybean Cyst Nematode Heterodera glycines and Its Relation with the Soil Chemical and Biological Properties
Agronomy 2023, 13(11), 2826; https://doi.org/10.3390/agronomy13112826 - 16 Nov 2023
Viewed by 691
Abstract
This study aimed to evaluate the suppressive potential of different soils on soybean cyst nematodes (SCN) and to estimate the suppressive mechanism. Fifteen soils (designated as soil A to O) from different agricultural fields with varying organic inputs were added with SCN-infested soil [...] Read more.
This study aimed to evaluate the suppressive potential of different soils on soybean cyst nematodes (SCN) and to estimate the suppressive mechanism. Fifteen soils (designated as soil A to O) from different agricultural fields with varying organic inputs were added with SCN-infested soil and grown with a green soybean variety. The SCN density in the soil at 6 weeks of soybean growth was markedly different depending on the soils used, indicating a different level of disease suppressiveness. No significant correlation was observed between the SCN density and any of the soil physicochemical and biological characteristics tested. Then, to estimate a suppression mechanism, F-soil that showed the lowest density of SCN was added to the SCN-infested soil with or without streptomycin to kill bacteria and grown with soybean. SCN density was not increased by the addition of streptomycin, indicating that soil bacteria may not be involved in the suppressiveness of F-soil. In total, 128 fungal strains were isolated from the rhizosphere of F-soil and inoculated in a combination or singly in the SCN-infested soil. After repeated screenings, five strains were selected since the SCN density was consistently decreased by them. Sequence analysis showed that they were closest to Clonostachys rosea, Aspergillus niger, Aspergillus fumigatus, Fusarium oxysporum, and Cylindrodendrum alicantinum. All five strains significantly reduced the mobility of second-stage juveniles (J2). Further, C. rosea a2, A. niger a8, and F. oxysporum a25 significantly decreased hatching. Overall, the present study demonstrated that soil fungi played an important role in SCN suppression in F-soil. Full article
(This article belongs to the Special Issue Effects of Nematodes on Crops—2nd Edition)
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15 pages, 8749 KiB  
Article
Bacterial Community Structure in Rhizosphere of Barley at Maturity Stage
Agronomy 2023, 13(11), 2825; https://doi.org/10.3390/agronomy13112825 - 16 Nov 2023
Viewed by 538
Abstract
The crop rhizosphere is the main site of soil microbial activities. Understanding the structure and diversity of microbial communities in the crop rhizosphere will help us reveal interactions between rhizosphere microorganisms and plant growth. In this study, the rhizosphere soil was collected from [...] Read more.
The crop rhizosphere is the main site of soil microbial activities. Understanding the structure and diversity of microbial communities in the crop rhizosphere will help us reveal interactions between rhizosphere microorganisms and plant growth. In this study, the rhizosphere soil was collected from 35 cultivated barley varieties at the mature stage. To investigate the structure and diversity of bacterial communities in the rhizosphere of different barley varieties, the 16S rDNA gene of microorganisms from the soil was sequenced using Illumina MiSeq next-generation high-throughput sequencing technology. The results showed that 13, 25, 49, and 59 bacterial flora with relative abundance >1% were detected from 35 barley rhizosphere samples at the phylum, class, order, and family levels, respectively. The abundance of bacteria among varieties differed relatively little, but the abundance of the same bacteria in rhizospheres of different varieties was different. In addition, both the cluster analysis and principal component analysis (PCA) divided the 35 samples into three clusters at the phylum level. Groups III and IV showed significantly higher abundance than group II in Proteobacteria, while group II exhibited significantly higher abundance of Chloroflexi than groups III and IV. This finding provides a realistic basis for further using the relationship between barley rhizosphere microorganisms and barley growth to improve the resistance and quality of barley. Full article
(This article belongs to the Section Crop Breeding and Genetics)
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12 pages, 1961 KiB  
Article
Diversity and Characterization of Resistance to Pyraclostrobin in Colletotrichum spp. from Strawberry
Agronomy 2023, 13(11), 2824; https://doi.org/10.3390/agronomy13112824 - 16 Nov 2023
Viewed by 610
Abstract
Strawberry crown rot poses a significant menace to strawberry production during the seedling stage, and the main pathogen is Colletotrichum spp. Pyraclostrobin is one of the main fungicides that have been registered to control anthracnose caused by Colletotrichum spp. The diversity of pathogens [...] Read more.
Strawberry crown rot poses a significant menace to strawberry production during the seedling stage, and the main pathogen is Colletotrichum spp. Pyraclostrobin is one of the main fungicides that have been registered to control anthracnose caused by Colletotrichum spp. The diversity of pathogens and the risk of fungicide resistance may change from year to year. In order to explore the diversity of pathogens causing crown rot and evaluate the resistance risk of pathogens to pyraclostrobin in different years, crown rot samples were collected in Jiande, Zhejiang Province in 2019 and 2021, and the pathogens were identified. Based on the morphological identification and phylogenetic analysis based on ACT, CAL, CHS, GAPDH, and ITS, all 55 strains were identified as C. gloeosporioides species complexes, including 23 C. siamense isolates and 2 C. fructicola isolates in 2019, and all isolates were identified as C. siamense in 2021. C. siamense was the dominant pathogen of strawberry crown rot in 2019 and 2021. The resistance frequencies of the isolates collected in 2019 and 2021 to pyraclostrobin were 69.57% and 100%, respectively. In general, compared to that in 2019, the resistance frequencies of the pathogen to pyraclostrobin increased in 2021. In terms of fitness, there was no significant difference between resistant strains and sensitive strains in the mycelium growth rate, sporulation and spore germination rate. In addition, the resistant mutants exhibited positive cross-resistance to kresoxim-methyl and azoxystrobin. A sequential analysis of cytochrome b gene showed that C. siamense resistance to pyraclostrobin is linked to the G143A point mutation. Our study indicated that the risk of resistance a fungicide gradually increases with the increase in use years, and in order to reduce the emergence and spread of resistant populations, we should choose fungicides of different mechanisms of action for rotation to reduce the risk of resistance development. Full article
(This article belongs to the Special Issue Plant Anthracnose: Etiology and Current Management Options)
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11 pages, 2483 KiB  
Article
Establishment of Alfalfa Intercropped under Corn in Response to Varying Rates of Prohexadione with or without Fungicide Plus Insecticide
Agronomy 2023, 13(11), 2823; https://doi.org/10.3390/agronomy13112823 - 15 Nov 2023
Cited by 1 | Viewed by 610
Abstract
Establishment of interseeded alfalfa (Medicago sativa L.) under corn (Zea mays L.) silage is enhanced with foliar applications of prohexadione (PHD) followed by fungicide plus insecticide (FI), but the lowest effective rates must be determined. We evaluated stand characteristics of alfalfa [...] Read more.
Establishment of interseeded alfalfa (Medicago sativa L.) under corn (Zea mays L.) silage is enhanced with foliar applications of prohexadione (PHD) followed by fungicide plus insecticide (FI), but the lowest effective rates must be determined. We evaluated stand characteristics of alfalfa interseeded into corn at Arlington, Wisconsin, USA in response to PHD applied at 0 to 0.423 kg a.e. ha−1 followed two weeks later with FI (none vs. 0.147 kg a.i. ha−1 fluxapyroxad-pyraclostrobin plus 0.018 kg a.i. ha−1 lambda-cyhalothrin). Application of PHD reduced etiolation, while FI treatment increased plant health and vigor. Following corn harvest, non-treated alfalfa stands averaged 4.2 plants m−2 and 1.2% groundcover under wet growing conditions in 2019 compared with 71.3 plants m−2 and 15.9% groundcover under normal growing conditions in 2020. Stand density in 2019 reached 130 plants m−2 but failed to plateau with combined PHD-FI treatments, while in 2020, stand density averaged 177 plants m−2 with FI regardless of the PHD rate. Alfalfa groundcover plateaued at 63% in 2019 and 71% in 2020 when 0.16 to 0.30 kg a.e. PHD ha−1 was applied prior to FI. The results indicate that FI enables excellent alfalfa establishment under normal conditions, but both PHD and FI should be applied during wet growing conditions. Full article
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