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The objective of this study was to evaluate the performance of four machine learning models, as well as multitask learning, to predict soybean root variables from simpler variables, under two water availability conditions. In order to do so, 100 soybean cultivars were conducted in a greenhouse under a control condition and a stress condition. Aerial part and root variables were evaluated. The machine learning models used to predict complex root variables were artificial neural network (ANN), random forest (RF), extreme gradient boosting (EGBoost) and support vector machine (SVM). A linear model was used for comparison purposes. Multitask learning was employed for ANN and RF. In addition, feature importance was defined using RF and XGBoost algorithms. All the machine learning models performed better than the linear model. In general, SVM had the greatest potential for the prediction of most of the root variables, with better values of RMSE, MAE and R2. Dry weight of the aerial part and root volume exhibited the greatest importance in the predictions. The models developed using multitask learning performed similarly to the ones conventionally developed. Finally, it is concluded that the machine learning models evaluated can be used to predict root variables of soybean from easily measurable variables, such as dry weight of the aerial part and root volume.

The development of a rational and efficient control strategy against Asian rust caused by Phakopsora pachyrhizi requires knowledge of the pathogenicity and local variability of the pathogen. The general objective of this study was to phenotypically characterize some isolates of P. pachyrhizi in Cameroon. In five agro-ecological zones (AEZ), 34 isolates of P. pachyrhizi were collected from diseased leaflet samples of soybean taken in the field. The length (L) and width (w) of the phenotypic forms of different uredospores of the isolates obtained were observed and measured under the light microscope. The length to width ratio (L/w) was calculated and the isolates aggressiveness was evaluated. Microscopic observation revealed seven different uredospore shapes including two new ones (seedlike and angular). Uredospore lengths ranged from 25.40 to 27.64 μm; widths from 16.64 to 19.61 μm; and L/w ratio from 1.45 to 1.57. The pathogenicity test on detached leaflets showed that the P. pachyrhizi isolates obtained were pathogenic with varying degrees of aggressiveness at 14 days after inoculation (DAI). The most aggressive isolates were obtained in AEZ II (GA1, WA and MB with aggressiveness of 84; 84.33 and 76.67 % respectively), AEZ III (BAM, 84 %) and AEZ V (MF2, 79.33 %). These morphological characters and different degrees of aggressiveness reveal a great variability of P. pachyrhizi uredospores in Cameroon. [ABSTRACT FROM AUTHOR]

Weathering deterioration in the pre-harvest phase impairs high-quality soybean seed production. The performance of several tests to infer seed quality is common in genotype selection, and multivariate statistics can assist in the interpretations. This study aimed to assess the efficiency of the principal component analysis (PCA) and canonical discriminant analysis (CDA) multivariate statistical methods in assessing the tolerance of seeds of different soybean cultivars to weathering deterioration in the pre-harvest phase under greenhouse conditions. Seeds of six soybean cultivars (DM 6563, BMX Apolo, BMX Potência, NA 5909, NS 5959, and TMG 1175) were produced. Different simulated precipitation levels (0, 60, 120, and 180 mm) were applied in the pre-harvest phase. The seeds were collected and assessed for physiological, physical, and biochemical analyses and the data were analyzed by PCA and CDA techniques. The results showed that PCA and CDA are efficient for assessing the tolerance to weathering deterioration in soybean seeds. PCA and CDA assisted in the recommendation of the tests first germination count, accelerated aging, tetrazolium, percentage of seeds with seed coat wrinkling, protein content, and protease activity in the pre-selection of genotypes for weathering deterioration. PCA and CDA also helped to identify the cultivars DM 6563 and BMX Potência as more susceptible and NA 5909 and TMG 1175 as more tolerant to weathering deterioration in the pre-harvest phase. [ABSTRACT FROM AUTHOR]

The selection of soybean genotypes with seeds of high physiological quality is key to increasing the likelihood of establishment and success in the field and thus reaping higher yields. The aim of this study was to evaluate the genetic control of the physiological quality of soybean seeds from a partial diallel cross. Six previously selected soybean cultivars, group 1 (CD 201, CA 115, MS 8400) and group 2 (CD 202, Syn 1263, Syn 1279), were intercrossed by a partial diallel cross, totalizing 24 treatments. Seeds from these cultivars and crosses were evaluated for seed physiological quality based on germination tests, first germination count, accelerated aging, seedlings emergence, and emergence speed index. The lignin content in the soybean seed coat was evaluated. The effects on general and specific combining ability and reciprocal effects were analyzed. There were significant additive and non-additive effects of the genes on the seed quality traits and pronounced effects on the reciprocal traits, which suggest the presence of a maternal effect. Lignin content was not correlated with the physiological test results in the studied genotypes. [ABSTRACT FROM AUTHOR]

Representative seed lot sampling is important in analyzing seed quality. This study aimed to determine whether sampling during processing and after packaging using samplers interferes in analyzing the physiological quality and health of soybean seed lots. The study was conducted with six and twelve soybean seed lots produced in the 2017/2018 and 2018/2019 growing seasons, respectively. Two sampling methods were used, according to the Rules for Seed Testing: a) sampling during processing; b) sampling of seed lots stored in bags using a sampler. Seed quality was assessed by germination percentage, accelerated aging, and tetrazolium tests to determine vigor, and seed health using the blotter test. Sampling during processing and after storage in bags differ in the expression of seed vigor and health. Seed lot homogeneity is essential to determine the difference between sampling methods. Sampling in the processing flow is more representative and may be indicated for the germination test. [ABSTRACT FROM AUTHOR]

The size of soybean seeds needs further study because its relationships with physiological quality, field establishment, and yield are controversial. The aim of this study was to evaluate the effects of seed size on soybean establishment and seed physiological quality. In the field, a 2x3x3 factorial design was used, with two cultivars (M 5947 IPRO and 59HO124 IPRO), three seed sizes (5.5, 6.0, and 6.5 mm), and three sowing densities (280,000, 320,000, and 360,000 plants.ha-1). Agronomic traits and grain yield were evaluated. After harvest, only seeds from plots with a population of 320,000 plants were classified by size using circular sieves with 5.5-mm, 6.0-mm, 6.5-mm, and 7.0-mm mesh sizes. For the evaluation of physiological quality, a 2x4 factorial design was applied, with two cultivars and four seed sizes. Germination, seedling emergence, accelerated aging, seedling dry matter, and emergence speed index were evaluated. Smaller seeds gave rise to shorter plants with a lower first pod insertion height. Larger seeds had higher physiological quality. The M 5947 IPRO cultivar showed better seed performance and quality. [ABSTRACT FROM AUTHOR]

The quality of the seed directly impacts the agronomic characteristics and the final yield of the soybean crop. Therefore, the objective of the study was to evaluate different phytotechnical parameters and the final productivity for different soybean cultivars obtained in a certified way and saved by the rural producer. The study was carried out in the Experimental Area of the University of Cruz Alta. During the 2017/2018 harvest, the plant breeding parameters were evaluated: plant height, stem diameter, number of branches, number of pods, lodging and final yield for cultivars NA5909RG, NS5959IPRO, NS5445IPRO and NS6909IPRO under different ways of obtaining, being these, "saved seeds" and "certified seeds". The phytotechnical parameters evaluated were influenced by the way of obtaining the seed for cultivars NS5445IPRO and NS6909IPRO. Among the evaluated cultivars, it was found that the yield of NS5445IPRO and NS6909IPRO were higher in plants from certified seeds. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the quality and health safety of fermented milk, soya fermented by different lactic acid bacteria (LAB) was used. It was found that soya fermented by solid state (SSF) and submerged (SmF) fermentation can be used for the processing of innovative fermented milk, because the final product is enriched with soya proteins and LAB. Lactobacillus sakei in milk-soya samples, treated with submerged fermentation, was responsible as the strain for low active acidity (pH 4.62), high titratable acidity (99.0 T) and degradation of lactose (up to 4.18%) P ≤ 0.05, lower amounts of D(-) lactic acid isomers, biogenic amines and high acceptability of the final product. The results showed a possibility for innovations to use LAB, especially L. sakei, in soya fermentation and production of fermented milk products of valuable composition.

The soya seed was treated before sowing with the following biological active substances: Lignohumate B, Lexin, Lexenzym, brassinosteroid, and "Complex treatment" (a mixture of saturated sugar solution, Lexin, fungicide treatment Maxim XL 035 FS and remedial pinolen substance Agrovital). During growing, the influence of biological active substances on root biomass formation and the activity of bacteria for nitrogen fixation was observed. Evaluated parameters were shoot biomass formation and dry mass formation of plants. Harvest values were considered an important output of the whole year soya growth process. As can be observed from the results, the most effective seed treatments were Lexenzym, Lexin, and "Complex treatment", where the yields were high. Moreover, the "Complex treatment" in comparison with the control variant (not treated) improved statistically conclusively not only the final yield but was helpful also for bacteria nodulation and nitrogen fixation (N2). All biologically active compounds supported the root and shoot biomass formation and the whole plant growth.

Abstract Background Shortage of water is a major problem facing Egypt; thus, it becomes necessary to use non-traditional sources of water such as saline water in irrigation. Overcoming the adverse effects of saline water and enhancing plant tolerance to salinity stress is the main challenge for increasing plant growth and productivity. Using a natural compound such as cysteine amino acid has an important effect in alleviating the adverse effect of salinity stress on different plant crops. Materials and methods Two pot experiments were carried out during two successive summer seasons to study the beneficial role of cysteine (0, 20, and 40 mg/l) in enhancing growth, some metabolic process, and seed yield quality and quantity of soybean plant grown under salinity stress (0, 3000, and 6000 mg/l). Results Salinity stress (3000 and 6000 mg/l) caused decreases in soybean growth criteria (plant height, number of branches and leaves/plant, dry weight of leaves and stem/plant), photosynthetic pigments and some element contents (nitrogen (N), phosphorus (P), and potassium (K)), and seed yield and yield components (number of pods/plant, weight of pods/plant and number of seeds/plant) as well as oil%. Meanwhile, proline, H2O2 and MDA contents, and superoxide dismutase activity were gradually increased by increasing salinity level. On the other hand, cysteine treatments improved growth and yield of soybean plant either irrigated with tap water or saline water. Cysteine treatments could alleviate the adverse effect of salinity stress on growth and yield of soybean plant through increasing photosynthetic pigments; proline content; N, P, and K contents; superoxide dismutase and catalase activities; and oil% accompanied by decreases in H2O2 and MDA contents as compared with their corresponding controls. In addition, cysteine treatments and/or salinity stress exhibited differences in protein pattern from 112 to 19 kD molecular weight. The appearance of new protein bands reflected the expression of cysteine treatments and salinity stress. Conclusion Cysteine treatments had a beneficial role in alleviating the adverse effect of salinity stress on soybean plant. Forty milligrams per liter of cysteine was the most effective treatment in enhancing salinity tolerance of soybean plant.

ABSTRACT A good soil fertility management for soybean production must consider the amount of nutrients that are exported by seeds. In recent decades, soybean yield has increased due to better crop management and genetic improvements, which may affect the amount of nutrients removed. Therefore, this study aimed (i) to analyze the relationship between the concentration of macronutrients in soybean seeds in Brazil with soybean yield and genotypes, and (ii) to update nutrient concentration values in soybean seeds for fertilizer recommendation purposes, comparing them with the values described in the main official fertilization recommendation systems used in Brazil. For this purpose, we used 3,017 observations obtained from 67 studies evaluating at least one macronutrient concentration [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] in soybean seeds in the last 45 years in Brazil (from 1974 to 2019). Results indicate that the concentration of macronutrients in soybean seed is affected by both soybean yield and genetic material. Modern genotypes of the Intacta Roundup Ready-2 group remove 15, 21, 18, 17, and 23 % more K, P, Ca, Mg, and S and 4 % less N compared to non-Roundup Ready genotypes. The increase in soybean yield was followed by an increase in the concentration of N and a decrease in the concentration of P and K in soybean seed. Data obtained from studies published between 2015 and 2019 indicates that soybean removes, on average, 57.2, 17.6, 5.5, 2.9, 2.6, and 2.5 kg Mg-1 of N, K, P, S, Ca, and Mg, respectively. These macronutrient concentrations in soybean seeds are in disparity with most reference values described in the official fertilization recommendation systems in Brazil, highlighting an urgent need to review the standard values for replacement fertilization of soybeans. Moreover, future studies should focus on the influence of genetics on soybean seeds composition to ensure high soybean productivity with rational use of fertilizers.

Abstract: Chemical treatment of soybean seeds is very important to ensure successful crop establishment. However, problems such as phytotoxicity of product combinations that can reduce seed physiological performance require attention. The use of computational resources has shown potential in identifying phytotoxic effects and contributing to the steps of quality control of treated seeds. The aim of this study was to determine if computerized image analysis of seedlings enables the phytotoxicity of chemical treatment of soybean seeds to be assessed in an effective and simplified manner. Samples from two soybean seed lots were treated with fungicides, insecticides, micronutrients, and their combinations, as well as with polymer and drying powder (coatings). After chemical treatment, the seeds were evaluated for germination, first germination count, seedling emergence in sand, accelerated aging, and seedling performance with and without the correction of regions not automatically demarcated (Vigor-S). We found high correlation of the Vigor-S parameters with the traditional tests for detection of phytotoxic effects of chemical treatment, regardless of correction made in the system. Computerized image analysis of seedlings is an effective and highly sensitive resource for evaluating possible phytotoxicity effects due to chemical treatment of soybean seeds.

This work aims to highlight the best soybean genotypes for specific environments in the Northwest Region of the State of Rio Grande do Sul. The experiment was carried out in the 2018/19 crop season in fifteen cultivation environments in the Northwest region of the state of Rio Grande do Sul, using 52 soybean genotypes in 15 growing environments. The experimental design used was lattice with treatments (growing environments) arranged in three replications. In each useful area of the experimental unit, the grain productivity of the genotypes was evaluated. Then, the Restricted Maximum Likelihood (REML) method was applied to estimate the variance components and genetic parameters. The following variance components were estimated: Genetic variation (Vg) and phenotypic variation (Vp). The genetic parameters estimated were: broad sense heritability (H²), coefficient of genotypic variation (CVg), coefficient of residual variation (CVe), ratio between genetic and residual coefficient (CVr) and selective accuracy (Ac). The phenotypic expression of grain yield is determined by 17% due to genetic effects and 83% by the environment. The NS 6909 RR IPRO, NS 5445 IPRO, DM 5958 IPRO and DM 6563 IPRO genotypes showed greater genetic gains for grain yield. The environments Doutor Maurício Cardoso (RS), Nova Ramada (RS) and Independência (RS) are characterized as favorable environments. [ABSTRACT FROM AUTHOR]

Nitrogen is the element most demanded by the soybean crop, and the biological fixation of atmospheric nitrogen is the main means to supply it. In contrast, micronutrients and chemical treatments applied on seeds together with the inoculant can alter the phenomenon of biological fixation of atmospheric nitrogen. This work aimed to evaluate the effect of chemical products, micronutrients, and nitrogen fertilization on the nodulation, development, and yield of soybean. The experiment was developed in a field and a greenhouse in the municipality of Toledo, Brazil. A randomized block with four repetitions was used as an experimental design. This design had eight treatments, namely: T1 - Control (seeds treated with insecticide); T2 - Seeds treated with insecticides and inoculated with Bradyrhizobium; T3 - Untreated seeds inoculated with Bradyrhizobium; T4 - Seeds treated with insecticides and cobalt-molybdenum (CoMo), inoculated with Bradyrhizobium; T5 - Seeds with CoMo inoculated with Bradyrhizobium; T6 - Seeds treated with insecticides, inoculated with Bradyrhizobium and with foliar application of CoMo; T7 - Seeds treated with insecticides, inoculated with Bradyrhizobium and with the application of nitrogen in cover; T8 - Seeds treated with nitrogen by broadcast. No significant differences were observed between treatments on the nodules numbers, stem diameter, plant height, root length, the mass of 1000 grains, and yield. The application of nitrogen at the R2 stage (a plant with an open flower in one of the two uppermost nodes of the main stem with a fully developed leaf) and in association with the inoculant + CoMo without seed treatment provided a greater number of nodes, pods, and grains per plant. [ABSTRACT FROM AUTHOR]

BACKGROUND: The environmental risk of the application of synthetic chelates has furthered the implementation of biodegradable complexes to correct manganese (Mn)-deficient plants. This study used the biodegradable ligands of heptagluconate (G7) and gluconate (G6) to test the influence of the Mn2+:ligand ratio on their fertilizers' capacity to provide Mn to plants. The efficacy of these complexes to correct Mn-deficient soybean was evaluated in hydroponics and calcareous soil conditions and compared with the synthetic chelate EDTA (ethylenediaminetetraacetic acid). RESULTS: This study demonstrated that G7 was a biodegradable alternative to EDTA for supplying Mn, maintaining an adequate nutritional balance compared with G6, which reduced iron (Fe) uptake by the plants. The efficacy of the Mn complexes depended on both the ligand and the Mn:ligand ratio, with the 1:1 and 1:2 molar ratios of Mn2+:G7 being the most effective complexes in the short term on the basis of their chemical structure and stability. CONCLUSION: The Mn2+:G7 (1:1 and 1:2) complexes were found to be effective Mn sources for plant nutrition due to their chemical structures providing adequate stability in alkaline solution and their fast-action effect. [ABSTRACT FROM AUTHOR]

The occurrence of powdery mildew (Microsphaera diffusa) in soybean (Glycine max L.) has increased in the last harvests. In order to study the efficiency of powdery mildew control due to the application of alternative products and conventional fungicide, trials were conducted in Ponta Grossa, PR, Brazil, during the 2013/2014 and 2014/2015 growing seasons. The design used was randomized blocks with four replications. The treatments for the experiments were: 1 - control; 2 - acibenzolar-S-methyl (Bion 500 WG®); 3 - calcium (Max Fruit®); 4 - Micronutrients: copper, manganese and zinc (Wert Plus®); 5 - Micronutrients: manganese, zinc and molybdenum (V6®); 6 - NK fertilizer (Hight Roots®); 7 - Ascophyllum nodosum (Acadian®) and 8 - fungicide (azoxystrobin + cyproconazole) (Priori XTRA®) with the addition of the adjuvant. Four applications of alternative products (phenological stages V3, V6, R1 and R5.1) and two of fungicide (phenological stages R1 and R5.1) were carried out. The parameters evaluated were powdery mildew severity and productivity. The severity data made it possible to calculate the area under the disease progress curve (AUDPG). Alternative products didn’t reduce powdery mildew in the two harvests. The conventional fungicide treatment was the only one that controlled powdery mildew and didn’t reduce the productivity in both experiments.

ABSTRACT: In the last crop seasons, the complex of late season diseases (CLSD) of soybean (Glycine max L. (Merrill)), has been causing considerable reductions in the crop yield. Currently, there are no cultivars resistant to all pathogens that causes CLSD. The present study evaluated the effect of applying the acibenzolar-S-methyl resistance inducer, alternative products and fungicide on the severity of CLSD in the soybean cultivar BMX Potência RR during the 2013/2014 and 2014/2015 crops, in the field. The treatments for the experiments were: 1 - control (water); 2 - acibenzolar-S-methyl; 3 - calcium; 4 - micronutrients: copper, manganese and zinc; 5 - micronutrients: manganese, zinc and molybdenum; 6 - nitrogen-potassium fertilizer; 7 - Ascophyllum nodosum and 8 - azoxystrobin + cyproconazole with the addition of the adjuvant. Four applications of alternative products and two of fungicide were carried out in both harvests. A diagrammatic scale assessed the severity of CLSD at the phenological stage R7.1. The acibenzolar-S-methyl resistance inducer, alternative products (macro and micronutrients) and A. nodosum had no effect on the severity of CLSD in the two harvests. The fungicide (azoxystrobin + cyproconazole) reduced the severity of CLSD and prevented damage to productivity in both experiments.

Chitinases are enzymes catalyzing the hydrolysis of chitin that are present on the cell wall of fungal pathogens. Here, we identified and characterized the chitinase gene family in cultivated soybean (Glycine max L.) across the whole genome. A total of 38 chitinase genes were identified in the whole genome of soybean. Phylogenetic analysis of these chitinases classified them into five separate clusters, I–V. From a broader view, the I–V classes of chitinases are basically divided into two mega-groups (X and Y), and these two big groups have evolved independently. In addition, the chitinases were unevenly and randomly distributed in 17 of the total 20 chromosomes of soybean, and the majority of these chitinase genes contained few introns (≤2). Synteny and duplication analysis showed the major role of tandem duplication in the expansion of the chitinase gene family in soybean. Promoter analysis identified multiple cis-regulatory elements involved in the biotic and abiotic stress response in the upstream regions (1.5 kb) of chitinase genes. Furthermore, qRT-PCR analysis showed that pathogenic and drought stress treatment significantly induces the up-regulation of chitinase genes belonging to specific classes at different time intervals, which further verifies their function in the plant stress response. Hence, both in silico and qRT-PCR analysis revealed the important role of the chitinases in multiple plant defense responses. However, there is a need for extensive research efforts to elucidate the detailed function of chitinase in various plant stresses. In conclusion, our investigation is a detailed and systematic report of whole genome characterization of the chitinase family in soybean.

The Brazilian Savanna presents a complex agricultural dynamic and cloud cover issues; therefore, there is a need for new strategies for more detailed agricultural monitoring. Using a hierarchical classification system, we explored the Harmonized Landsat Sentinel-2 (HLS) dataset to detect soybean in western Bahia, Brazil. Multispectral bands (MS) and vegetation indices (VIs) from October 2021 to March 2022 were used as variables to feed Random Forest models, and the performances of the complete HLS time-series, HLSS30 (harmonized Sentinel), HLSL30 (harmonized Landsat), and Landsat 8 OLI (L8) were compared. At Level 1 (agricultural areas × native vegetation), HLS, HLSS30, and L8 produced identical models using MS + VIs, with 0.959 overall accuracies (OA) and Kappa of 0.917. At Level 2 (annual crops × perennial crops × pasturelands), HLS and L8 achieved an OA of 0.935 and Kappa > 0.89 using only VIs. At Level 3 (soybean × other annual crops), the HLS MS + VIs model achieved the best performance, with OA of 0.913 and Kappa of 0.808. Our results demonstrated the potential of the new HLS dataset for medium-resolution mapping initiatives at the crop level, which can impact decision-making processes involving large-scale soybean production and agricultural sustainability.

ABSTRACT The decision-making capability of the machine to harvest grains must consider a lower fuel consumption with a higher operating velocity allied to a greater performance of the grain cleaning system, along with lower rates of the damage and waste produced. This study aimed at evaluating the operational performance and the energy efficiency of two axial harvesters, having different trail and separation systems in the soybean seed harvest. The experiment was carried out in a completely randomized block design in 500-m bands, consisting of two factors, namely two axial harvesters (single and double rotor) and six target velocities (3, 4, 5, 6, 7, and 8 km h-1). Regarding the operational energy performance, the hourly fuel consumption, operational speed, operational field capacity, fuel consumption per area and mass of the harvested grain, and the handling capacity of the harvest were evaluated. The harvesting performance parameters, such as the percentage losses in the platform and the trail system, broken grains, impurities, and the pods, which did not undergo threshing, were evaluated. The results obtained showed that the single-rotor harvester had a better energy efficiency, while the double-rotor harvester had a better operational performance. The double-rotor harvester was agronomically more efficient.

The search for time and human subjectivity reduction in the analysis of the physiologic potential of seeds has brought forward the use of computerized systems as an alternative. The goal of this research was to assess the effectiveness of the GroundEye equipment in the characterization of soybean seeds vigor by using the image analysis technique in comparison to the information provided by vigor tests recommended to soybean seeds. Sixteen lots of two soybean varieties were used -- variety 98Y12 and P98Y70, characterized by the following tests: germination test, accelerated ageing test, cold test, tetrazolium test, and seedling emergence in the field. The image analysis was performed using the GroundEye software to obtain the vigor index and the average length of seedlings and roots for a later comparison with the results of the accelerated ageing test and the manual measurement of the average length of seedlings and roots. GroundEye has demonstrated efficiency in the determination of vigor of soybean seeds and has reduced the time needed to obtain the results in six days, being indicated in the quality control programs established by soybean seeds production companies. [ABSTRACT FROM AUTHOR]

Seed companies use vigor tests in their internal seed quality control procedures. Therefore, it is necessary to choose effective methods to obtain quick responses for making decisions related to the handling, disposal and marketing of seed lots. Thus, the objective of this work was to adapt a methodology for the accelerated aging test in soybean seeds. Sixty-nine lots were used and the experimental design used was completely randomized, with four replications. For the initial characterization of the lots, water content was determined, germination test and field emergence. The soybean seed lots selected based on the initial characterization, were submitted to the standard accelerated aging methodology and twenty-one adapted methodologies. After the physiological characterization of the 69 lots, 24 lots with similar germination with different levels of vigor were selected. For adapted methodologies that used only distilled water inside the gerbox box, there was an increase in the water content of the seeds of all analyzed lots. However, all methodologies with the use of saline solution had a lower water content. The adapted methodologies N (pre-treatment in forced air oven at 35-40°C for two hours, BOD 42°C for 24 hours, using saline) and S (pretreatment in forced air oven at 35-40°C for two hours, BOD 45°C for 12 hours, with the use of distilled water) are the most suitable for use in the accelerated aging test for soybean crops, as they present relevant results in a shorter evaluation period. [ABSTRACT FROM AUTHOR]

Aims: Crop residue amendment is likely to stimulate symbiotic N2 fixation, and clarifying its effect on N2-fixing bacteria, i.e., diazotrophs in the rhizosphere of legume crops, is important for sustainable N management in legume-cereal cropping systems. Therefore, this study aimed to reveal the diazotrophic community composition in the rhizosphere of soybean in response to maize residue amendment. Methods: Being designed with treatments of maize residue, chemical fertilizer, and non-fertilizer applications, this study deployed the 15N-labeling technology combined with high-throughput sequencing of the nifH gene as a molecular marker for diazotrophs to quantify the symbiotically-fixed N2 in soybean plants and link symbiotically fixed N2 to the diazotrophic community diversity in the rhizosphere. Results: Residue amendment increased the abundance of diazotrophs and fundamentally altered the composition of its community in the rhizosphere. It increased the relative abundances of Bradyrhizobium and Azohydromonas compared to the chemical fertilizer treatment. The copy number of nifH in the rhizosphere was associated with dissolved organic carbon and N2 fixation. Conclusions: Residue-induced increase in dissolved organic carbon may provide sufficient carbon sources for diazotroph enrichment and thus enhance nodulation. The maize residue amendment may enrich N2 fixers to facilitate nodulation and subsequent N2 fixation of soybean, highlighting the eco-functional importance of diazotrophs fixing extra N into the rotation system. [ABSTRACT FROM AUTHOR]

The objective of this study was to verify the separation of soybean seed lots according to vigor levels by the rapid ethanol test following the adapted ethylometer method. The design used was entirely randomized with four repetitions. The treatments consisted of five soybean seed lots submitted to germination tests, first germination count, accelerated aging, field emergence, electrical conductivity, and ethanol test. To measure ethanol, 50 soybean seeds were placed in plastic bottles containing 50 mL of distilled water and placed in a BOD incubator for different temperatures and exposure times. After the imbibition period, measurements were performed with the aid of an adapted ethylometer. It is possible to quantify ethanol in soybean seed lots using the adapted ethylometer equipment. However, the equipment is not efficient in ranking soybean seed lots at different vigor levels. [ABSTRACT FROM AUTHOR]

The incidence of soybean anthracnose reduces yields and leads to financial losses. Among several management practices to control this disease, use of phosphites (Phi) can act by providing mineral nutrition, inducing resistance in the host and causing direct toxicity to the pathogen. The aim of this study was to investigate the effectiveness of phosphites in the management of anthracnose in soybean pods, in the transmission of the pathogen and the activities of plant defense enzymes. Soybean plants were sprayed with potassium (KPhi), manganese (MnPhi), zinc (ZnPhi), copper (CuPhi) phosphites and fungicide epoxiconazole + piraclostrobin at V4, R1 and R3 stages and inoculated with Colletotrichum truncatum isolate in the R3 stage. The anthracnose severity, the incidence of C. truncatum in soybean seeds, activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes and contents of soluble lignin and total soluble phenols were evaluated. KPhi, CuPhi and MnPhi reduced the severity of anthracnose, the transmission of the C. truncatum, increased lignin content and SOD, POX and CAT enzymatic activity. Phosphites can be utilized in the management of anthracnose in soybean. [ABSTRACT FROM AUTHOR]

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O objetivo desse trabalho foi avaliar o efeito de culturas de entressafra e fertilização com N mineral na implantação da soja sobre os teores de nitrato e amônio no solo durante a entressafra e a safra da soja. O delineamento experimental foi de blocos completos casualizados, com cinco repetições e em esquema de parcelas subdivididas. Nas parcelas foram alocados seis tratamentos de entressafra: pousio, milho segunda safra com 0 ou 80 kg de N ha-1 em cobertura, trigo, braquiária ruziziensis e crotalária spectabilis, sendo as duas últimas destinadas à cobertura do solo. Nas subparcelas foram alocados dois níveis de N na implantação da soja (0 e 30 kg de N ha-1). De abril de 2016 a fevereiro de 2017 foram realizadas 26 coletas de solo na camada de 0,0-0,1 m, sendo avaliados os teores de nitrato e amônio nas amostras. Durante o período de entressafra da soja, os maiores teores de nitrato no solo foram observados no milho segunda safra adubado com 80 kg de N ha-1, enquanto os teores de amônio variaram menos entre os tratamentos de entressafra. As culturas de entressafra não influenciaram os teores de nitrato e amônio no solo durante o ciclo da soja em sucessão. Na fase vegetativa da soja, os teores de nitrato no solo foram superiores quando a soja foi adubada com 30 kg de N ha-1, em relação à ausência de adubação, mas nas fases de formação de vagens e de grãos essa diferença não ocorreu.

Entre os métodos para diagnóstico nutricional das plantas, destaca-se o Sistema Integrado de Diagnose e Recomendação (DRIS), que utiliza o conceito do balanço de nutrientes. A pesquisa foi realizada com a cultura da soja, cultivar Monsoy 8210, semeada em área anteriormente cultivada com milho por três anos em sistema de plantio direto (SPD) localizada no Instituto Federal do Triângulo Mineiro, Uberaba-MG. O objetivo foi estabelecer padrões foliares para avaliação o estado nutricional da soja fertilizada com micronutrientes em área de SPD estabelecida na região do Cerrado, pelo método DRIS. O delineamento experimental utilizado foi em blocos casualizados em esquema fatorial 4 x 2 + 1 com quatro repetições, correspondente quatro doses de adubação com micronutrientes: 0, 140, 200, 240 e 280 g ha-1 do NiCoMo e dois modo de aplicação: tratamento de sementes e via foliar, além da testemunha. A amostragem foliar e estabelecimento dos índices DRIS foram feitos através da coleta da primeira folha madura a partir dos trifólios superiores, realizada no estádio fenológico R1. Calculou-se o índice de balanço nutricional (IBN) pelo somatório em módulo, dos índices nutricionais DRIS e do Índice de Balanço Nutricional médio (IBNm). Para a interpretação do estado nutricional, adotaram-se três classes: insuficiente, equilibrado ou excesso. Realizou-se a colheita dos grãos por parcela, estimando as produtividades em t ha-1. A aplicação de micronutrientes via foliar no estádio vegetativo (V3), 24 dias após a semeadura proporciona maior equilíbrio nutricional às plantas em comparação ao tratamento de sementes, sendo que a dose de 280 g ha-1 do níquel, cobalto e molibdênio no tratamento vegetativo é a que resulta em maior produtividade de grãos de soja.

Estudos recentes demonstram que a adubação potássica em áreas adeptas do sistema de plantio direto resultam uma boa correlação com a produção de fitomassa de coberturas utilizadas em processo de rotação. O presente trabalho teve como objetivo avaliar os efeitos da adubação potássica em três diferentes gramíneas e a eficácia residual para a cultura da soja em sucessão em sistema de plantio direto. O experimento foi conduzido em área experimental pertencente a UNESP – FEIS, nos anos agrícolas de 2012/13 e 2013/14. O delineamento experimental utilizado foi o de blocos casualizados, sendo os tratamentos quatro doses de K (0, 35, 70, 120 kg ha-1) com quatro repetições. Cada cobertura foi avaliada isoladamente totalizando três subprojetos. O solo da área é classificado como LATOSSOLO VERMELHO Distrófico de textura argilosa. O segundo ano de experimento foi negativamente influenciado pelas questões climáticas problemáticas na época do estudo. Em função dos tratamentos aplicados, maiores produções de fitomassa foram vistas para a sucessão com milho. A maior média para teor de K foliar na soja foi observada em função na sucessão com sorgo. O teor de K na palhada destacou-se para as plantas de milheto. A maior produtividade de grãos de soja foi observada em área de sorgo.

The practices of soil amendment and fertilization carried out over the years have allowed the improvement of the fertility in some of them in the Brazilian soils. The objective of this study was to evaluate the performance of soybean in response to phosphate fertilization in soil with improved fertility. The research was carried out during the 2015-2016 harvest season in a dry-land area in the municipality of São Desidério, Bahia. The experiment was arranged in randomized blocks, with five treatments and four replicates. Treatments were composed by doses of phosphate fertilizer (0, 70, 140, 210 and 280 kg P2O5 ha-1). The following variables were evaluated: plant height, height of insertion of the first pod, number of stems per plant, number of pods per plant, thousand grain weight, productivity, and the analysis of macro and micronutrients in the leaf. Soybean plants did not respond to phosphorus applied to soil with built fertility. Under the conditions of this study, phosphorus fertilization in soil with improved fertility did not promote productivity. Although the plants did not respond to foliar macro and micronutrients as a function of phosphate fertilization, there was no reduction of these in response to high doses.

Soybean yield depends on the choice of cultivar, soil fertility, cultivation practices, and weather conditions in different years. Ploughing down crop residues increases the content of soil organic matter, and thereby positively affects soil fertility. The use of crop residues as an energy source has been promoted in recent years. It would be wrong to refer to this as a renewable energy source as the removal of crop residues from agricultural fields reduces and ultimately damages soil fertility, which in turn leads to reduced yield and a crop residue decrease in the future. Due to the reduced application of manure and organic fertilisers, it is necessary to return crop residues to the soil to preserve soil structure and prevent soil fertility decline. The effect of ploughing down crop residues of preceding crops on soybean yield has been the focus of studies for eleven years. Ploughing down maize crop residues resulted in the soybean yield increase by about 11.69%, i.e. the annual yield increase ranged from 2.89% to 15.94%.

O sistema agroflorestal com eucalipto e soja é uma opção de uso do solo em regiões com solo arenoso e clima quente. O objetivo desse trabalho foi avaliar o desempenho da cultura da soja associada a renques simples de eucalipto maculata (Corymbia maculata) na região Noroeste do Paraná. O sistema agroflorestal foi implantado em outubro de 2009, usando a sucessão soja/ Urochloa ruziziensis nos entre renques simples de eucalipto. O desempenho da cultura da soja foi avaliado na safra 2015/16, em dois experimentos, um com espaçamento entre renques de 14 m e outro com 28 m. Como testemunha, foi considerada uma área contígua, sem a presença de árvores. O crescimento e o acúmulo de nitrogênio na massa seca da soja, avaliados no pleno florescimento, foram reduzidos em função da interferência do eucalipto, com maior intensidade no menor espaçamento entre os renques. A redução de produtividade de grãos de soja causada pelas árvores foi de 65 e 44% em relação à testemunha, nos espaçamentos de 14 e 28 m entre renques, respectivamente. Os teores de nitrogênio na massa seca e de proteína e óleo nos grãos de soja não foram alterados pela interferência das árvores.

The interest in cultivation of vegetable soybeans, also known as edamame, in the North Europe region has increased during the last years due to their high nutritional value and excellent taste properties. During the last decade the possible growing area for soybeans has expanded towards the north due to changes in climate as well as breeding efforts. In order to adopt vegetable soybean growing technology for commercial cultivation in the North Europe region, independent experiments were carried out in Latvia and Norway. This study shows that vegetable soybean is a crop with potential for successful cultivation at higher latitudes, such as the Nordic–Baltic region in North Europe, with yield levels comparable to other regions of the world. We observed that hydrothermal conditions had the most significant impact on soybean plant development. Sowing or planting as early as possible is a key to obtaining sufficient yield levels. In the study, the vegetation period needed to be at least 123 to 127 days, with growing degree days (GDD) at least 650, and hydrothermal coefficient (HTC) above 1. Under such conditions, the obtained marketable yield in Latvia ranged between 3 to 10 t ha−1 during the period of 2017–2019, and 1.2 to 10.5 t ha−1 in Norway. Planting density of 20–25 plants per m2 appeared to be optimal. The variety ‘Midori Giant’ showed the most stable yield outcome, but ‘Chiba Green’ also gave a satisfactory yield.

The spatial variability of soil physical attributes is important to indicate management practices that best suit agricultural areas. This study aimed to analyze spatial correlations between soybean grain yield and soil mass-volume relationships, in order to select which attribute is correlated with yield, as well as to evaluate the spatial variability of soil attributes and yield components of this crop, in an Oxisol under no-tillage system. The soil attributes analyzed (0.0-0.10 m and 0.10-0.20 m) were the following ones: soil bulk density (paraffin-coated clod and volumetric ring methods), particle density (volumetric flask and modified volumetric flask methods) and total porosity. The soybean yield components were evaluated as it follows: grain yield, number of pods per plant, number of grains per pod, mass of 100 grains, grain mass per plant, plant population and plant height. The total soil porosity, calculated by the relations between the bulk density (volumetric ring method) and particle density (volumetric flask), in the 0.10-0.20 m layer, was the best indicator of soybean grain yield under no-tillage conditions.

ABSTRACT: Successive cycles of water absorption and loss favor weathering deterioration, one of the main factors that affect the quality of soybean seeds. This study evaluated the physiological, physical, and morpho-anatomical changes in soybean seeds under weathering deterioration at the pre-harvest phase. Six soybean cultivars (BMX Apolo, DM 6563, NS 5959, NA 5909, BMX Potência, and TMG 1175) were produced in a greenhouse and underwent weathering deterioration through a rainfall simulation system, applying 0, 60, 120, and 180 mm of precipitation at pre-harvest phase. Each rainfall level was divided into two applications at an interval of 72 h: 60 mm (30 + 30), 120 mm (60 + 60), and 180 mm (90 + 90). After harvest, the seeds were evaluated for germination, vigor, physical and morpho-anatomical properties. Weathering deterioration induced by simulated rainfall at the pre-harvest phase contributes to the reduction in soybean seed germination and vigor and is conditioned by the soybean genotype. The increase in intensity of simulated rainfall led to a more significant weathering damage in seeds, as evidenced by the X-ray and tetrazolium test. Cultivars DM 6563 and BMX Potência were more susceptible, while NA 5909 was less susceptible to weathering deterioration (especially at the highest level; 120 mm and 180 mm). Anatomical changes caused by weathering deterioration lead to cell compaction and rupture, mainly in the cell layers of the hourglass and parenchyma, forming intracellular spaces. The presence of weathering damage caused a reduction in physiological soybean seed quality.

Background: High and stable production requires quality seed. Seed quality is the basis of efficient crop production and farmers need such seeds for optimum yield production. Therefore, various procedures are applied in seed production technology that aim to improve not only the germination of seeds but also the speed of its germination. These methods can reduce of seed aging and the effects of different agroecological factors. Methods: For research the impact of priming used seed aged seven months (fresh seeds) and seed was nineteen months old (aged seed). The seed was treated with following solutions: potassium nitrate (1%), ascorbic acid (100mgl-1) and potassium chloride (1%) for 6 hours and then germinated at 25°C in 8 days. Result: The analysis showed that seed aging resulted in a decrease in its germination energy and germination. Moreover, time required for germination is prolonged, the lipid peroxidation intensity and content of free proline are increased and the amount of vitamin C is reduced. The results showed that the effect of priming is dependable on variety selection, seed age and treatments. Therefore, we can conclude that there is no universal use of one only primer, as it may not be suitable for each particular cultivar and can ultimately lead to a decrease in the germination energy and germination. [ABSTRACT FROM AUTHOR]

The arrow-leaf sida (Sida rhombifolia), in addition to competing with soybeans, which causes productivity losses, is also host to the whitefly, which transmits viruses. The aim was to evaluate the competitive ability of soybean cultivars in the presence of an arrow-leaf sida biotype, with different proportions of plants in the association. The experiments were conducted in a completely randomized design, with four replications. Tested competitors included arrow-leaf sida with the four soybean cultivars in proportions crop:weed of 100:0; 75:25; 50:50; 25:75; and 0:100. Competitiveness analysis was carried out using diagrams applied to replacement series experiments in addition to the relative competitiveness indices. At 50 days after the emergence of the species, the variables height, diameter, leaf area, and dry mass of shoots were evaluated. Competition occurred between soybean cultivars in the presence of arrow-leaf sida, regardless of the plant proportion, causing reductions in all variables evaluated. Interspecific competition causes greater damage to al variables studied than intraspecific competition. There was competition for the same resources between soybean and arrow-leaf sida. [ABSTRACT FROM AUTHOR]

The study of the soybean yield variability influenced by the climate contributes to the planning of strategies to mitigate its negative effects. Thus, our aim was to calibrate agrometeorological models for soybean yield forecast and identify the weather variables that most influence soybean yield. This study used historical series of climate and soybean yield data from soybean-producing locations in the Mato Grosso do Sul state, Brazil. The historical climate series was 20 years (2000–2019). The soybean production, yield, and planted area data of the localities were in the period from 2009–2018. Multiple linear regression analysis was the statistical tool used for data modeling. The models from the north and central regions forecast of anticipation of 2 months since the final data necessary to apply the model were EXCJANc and PJANc, respectively. The models calibrated for the southern region reported anticipation of one month since the final data necessary to apply the model was EXCFEVc. The calibrated models used to forecast soybean yield as a function of climatic conditions have a high degree of significance (p < 0.05), high accuracy and errors lower. The models for the northern and central regions show a prevision of anticipation of 2 months before soybean harvest, a period that is essential for producers to be able to conduct pre- and post-harvest planning. The climate variable with the greatest negative influence (r = − 0.54) on soybean yield in Mato Grosso do Sul state was water stress in December. [ABSTRACT FROM AUTHOR]

In this study, the effects of zinc and iron treatments in different growth stages on yield and yield components of soybean (Glycine max L.) plants were evaluated by principal component analysis (PCA). Field experiments were conducted over during the second crop seasons of the years 2018 and 2019. The experiment was designed as a split-split plot design with three replications. Three varieties of Arisoy, Bravo, and Nazlican were placed in main plots, growth stages of the soybean (V3, R1, R3) in subplots and foliar fertilizers (Zn, Fe, Zn+Fe) in sub-sub plots. Variance analysis revealed that all parameters were significant except the first pod length (2019) and 1000-seed weight (2019). PC1, PC2, and PC3 explained 84.50% of the total variation in 2018 and 86.10% in 2019. Zn + Fe mixture treatment could be recommended for foliar spray because the highest seed yields were obtained from Zn + Fe in both years. [ABSTRACT FROM AUTHOR]

O sucesso da cultura da soja depende da qualidade fisiológica das sementes, a qual pode ser favorecida por microrganismos benéficos, mas prejudicada por fatores ambientais desfavoráveis. O objetivo desse estudo foi avaliar o efeito da coinoculação com Bradyrhizobium japonicum e Azospirillum brasilense na qualidade fisiológica de sementes de soja obtidas na safra 2017/2018, em ensaio de campo com 23 cultivares, submetidas à coinoculação via sulco de semeadura ou mantidas sem coinoculação. As plantas foram avaliadas quanto à nodulação em R1 e, após a colheita (R8), determinaram-se os teores de proteínas, massa de mil sementes e a qualidade fisiológica das sementes [Germinação, emergência em areia e índice de velocidade de emergência (IVE)]. Na média das cultivares, o número de nódulos aumentou de 36,9 no controle para 44,4 nódulos por planta com a coinoculação. Os aumentos nos teores de proteínas e na massa de mil sementes devido à coinoculação foram de 5,6% e 34,7%, respectivamente. As sementes das plantas coinoculadas apresentaram maior germinação na primeira contagem (50,0% vs. 45,3%) e na final (87,0% vs. 79,8%), além de maior taxa de emergência de plântulas em caixa de areia (83,3% vs. 80,0%) e maior IVE (18,5 vs. 17,4). Os benefícios da coinoculação foram observados em 17 das 23 das cultivares (74%), em pelo menos duas das sete variáveis avaliadas. Considerando apenas o critério de germinação mínima de 80%, as sementes de 10 cultivares não inoculadas não serviriam para uso, enquanto que para as coinoculadas esse número caiu para quatro.

The nutritional value of Glycine max L. (soybean) and its yield potential for improving sustainability of agricultural systems has resulted into its increased production. Soybean crop has potential to replace the rice crop in the rice-wheat cropping system. However, the crop has shown high sensitivity towards iron (Fe) deficiency, and thus recorded major yield and nutritional quality losses. Thus, a three-year field experiment was planned to compare the impact of the application rate (0.5% and 1.0%) and number of sprays of FeSO4 on yield, Fe nutrition, and economic outcomes of soybeans. The Fe application posed a beneficial impact on the studied parameters due to an increase in enzymatic activity of Fe-containing enzymes. Among various treatments, maximum increase in grain and straw yield (3064 and 9341 kg ha−1, respectively) was obtained with 0.5% FeSO4 application at 30, 60, and 90 DAS over the control (2397 and 6894 kg ha−1, respectively). Similar results were attained for grain Fe concentration (69.9 mg kg−1) and Fe uptake in grain and straw (214 and 9088 g ha−1, respectively). The results were statistically non-significant, with the treatment in which 0.5% FeSO4 was applied at 30 and 60 DAS. The economic returns of soybean cultivation were also highest with 0.5% FeSO4 application at 30, 60, and 90 DAS with highest benefit; the cost (3.02) followed by treatment in which 0.5% FeSO4 was applied at 30 and 60 DAS. Thus, 0.5% FeSO4 application at 30, 60, and 90 DAS can be recommended for soybeans grown on sandy loam soil followed by 0.5% FeSO4 application at 30and 60 DAS to harness maximum yield, Fe concentration, and profitability.

Black soybean has been used in traditional medicine to treat inflammatory diseases, cancer, and diabetes and as a nutritional source since ancient times. We found that Korean black soybean cultivar A63 has more cyanidin-3-O-glucoside, (C3G), procyanidin B2 (PB2), and epicatechin (EPC) contents than other cultivars and has beneficial effects on cell viability and anti-oxidation. Given the higher concentration of anthocyanidins and their strong anti-oxidant activity, we predicted that A63 extract could relieve inflammatory disease symptoms, including those of atopic dermatitis (AD). Here, we evaluated the anti-AD activity of A63 extract in an oxazolone (OXA)-induced mouse model. A63 extract treatment significantly reduced epidermal thickness and inflammatory cell infiltration, downregulated the expression of AD gene markers, including Interleukin (IL)-4 and IL-5, and restored damaged skin barrier tissues. Furthermore, A63 extract influenced the activation of the signal transducer and activator of transcription (STAT) 3 and STAT6, extracellular regulatory kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which play a crucial role in the development of AD. Altogether, our results suggest that A63 can ameliorate AD-like skin inflammation by inhibiting inflammatory cytokine production and STAT3/6 and Mitogen-activated protein kinase (MAPK) signaling and restoring skin barrier function.

Aims: The aims of this study were to determine the occurrence of Fusarium graminearum species complex (FGSC) on soybean pods, seeds and roots, including rhizoplane, during the period of soybean crop in rotation with wheat and to evaluate the FGSC dynamics on wheat and soybean residues during two soybean growing seasons in rotation with wheat, particularly F. graminearum sensu stricto (FGss). Methods and Results: Soybean roots, pods and seeds were analysed during 2012/13 and 2013/14 seasons. The morphological identification of FGSC and mycotoxin analysis was done. Crop residues were taken in both soybean season in wheat rotation and FGss were quantificated by real‐time PCR. The results showed that Fusarium species, mainly FGSC, survive in a soybean crop in rotation with wheat. Isolation frequency of these species was higher on soybean pods than on seeds at R6 stage. Deoxynivalenol contamination on soybean seeds was higher in the 2013/14 season in comparison with the 2012/13 season. Low isolation levels of Fusarium species and species that did not belong to FGSC were observed in soybean root, whereas in rhizoplane a higher level was observed. Fusarium species inoculum on residues remained stable during crop succession and the FGSC were recovered from both wheat and soybean residues. Real time PCR data showed a higher DNA concentration of FGss in wheat residues in the first developmental stages of soybean plants, being the levels more significant during 2012/13 season. With regard to soybean residues collected during the wheat growing stages, an increase in DNA from anthesis until wheat harvest was observed. Conclusions: In a no‐till production system, the populations of FGSC can colonize wheat and soybean residues to become an inoculum source. Significance and Impact of the Study: This study provides new data on the occurrence of FGSC populations in soybean plant and FGss on residues in soybean–wheat rotation, a cultural practice commonly used in in Argentina. [ABSTRACT FROM AUTHOR]

Chemical treatment of soybean seeds is very important to ensure successful crop establishment. However, problems such as phytotoxicity of product combinations that can reduce seed physiological performance require attention. The use of computational resources has shown potential in identifying phytotoxic effects and contributing to the steps of quality control of treated seeds. The aim of this study was to determine if computerized image analysis of seedlings enables the phytotoxicity of chemical treatment of soybean seeds to be assessed in an effective and simplified manner. Samples from two soybean seed lots were treated with fungicides, insecticides, micronutrients, and their combinations, as well as with polymer and drying powder (coatings). After chemical treatment, the seeds were evaluated for germination, first germination count, seedling emergence in sand, accelerated aging, and seedling performance with and without the correction of regions not automatically demarcated (Vigor-S). We found high correlation of the Vigor-S parameters with the traditional tests for detection of phytotoxic effects of chemical treatment, regardless of correction made in the system. Computerized image analysis of seedlings is an effective and highly sensitive resource for evaluating possible phytotoxicity effects due to chemical treatment of soybean seeds. [ABSTRACT FROM AUTHOR]

Phytosociology is a set of ecological assessment methods that aim to provide a view of plant species distributions within a plant assemblage. The objective of the current study was to identify and quantify the plants designated as weeds in a glyphosate-resistant soybean crop, using a phytosociological survey of a conventional planting system on the Fazenda Agrosantos (09°27'4124.4" S and 45°01'00.4" O), Vale do Gurguéia, Monte Alegre municipality Piauí state, Brazil. The site lies at a mean altitude of 652 m. Field collections were made 15 days after initial soya planting. For sampling, a 0.40 x 0.40 m quadrat was used, thrown randomly twenty times within the experimental area. Weeds were identified and quantified using the sum of the samples obtained from the quadrat samples. Plants that lay within the quadrat were identified, counted and collected for identification, which was carried out by comparison with specialist bibliographies and weed identification manuals. Evaluated variables were: frequency, density, abundance, relative frequency, relative density, relative abundance and species importance value index. In the soybean cultivation area, 60% of the sampled species were Eudicotyledons, and a total of 8 botanical families and 10 weed species were identified. The species Cenchrus echinatus, Ipomoea asarifolia (Desr.) Roem. & Schult, Amaranthus retroflexus L. and Zea mays L showed the highest values for the analyzed variables, and should therefore be of special attention to soybean producers in the region of Vale da Gurguéia, Piauí, Brazil. [ABSTRACT FROM AUTHOR]

Seeds may undergo interference from chemical products that are applied to the mother-plant, either impairing or improving their features, and to determine if there was interference in the seeds, germination and vigor tests are carried out. This study aimed to assess the quality of soybean seeds subjected to pre- and post-emergence herbicides and post-emergence growth regulators. At experiment 1, pre-emergence soybean herbicides were applied, and seeds were sown at the same day of application, at experiment 2, herbicides and growth regulators were applied at post-emergence soybean (V4). Seeds were harvested and subjected to the necessary tests, namely 1,000-seed weight, moisture content, germination, seedling length, tetrazolium and electrical conductivity. In general, herbicides and growth regulators did not cause an adverse impact on soybean seeds quality. Application of flumioxazin or mepiquat chloride caused minimal effects on the soybean seeds quality, with minor reductions in vigor, and no effect on germination. [ABSTRACT FROM AUTHOR]

The reduction of sowing density is a strategy that aims to reduce production costs with no losses in grain yield. This study aimed to evaluate the yield components and contents of protein and oil in grains from branches and stems of two soybean cultivars as a function of the reduction in sowing density. The experiments were conducted in two growing seasons (2016/17 and 2017/18) in Londrina, PR, Brazil. Two soybean cultivars were evaluated: BRS 1010 IPRO and NS 5959 IPRO. The experimental design was completely randomized blocks in a split-plot scheme, with five replications. Plots consisted of five sowing densities (100, 80, 60, 40, and 20% of that indicated by the cultivar breeder) and subplots consisted of two plant strata (branches and stems). The number of pods m-2 and grain, protein, and oil yield increased in the branches and decreased in the stems with a decrease in sowing density. The number of grains per pod is higher in the stems than in the branches, regardless of the cultivar. The protein content in the grains is higher in the branches than in the stems for the cultivar BRS 1010 IPRO and decreased with a reduction in sowing density. The thousand-grain weight of the cultivar NS 5959 IPRO decreased with a reduction in sowing density. The oil content in the grains was not influenced by the studied factors. [ABSTRACT FROM AUTHOR]