Brazilian Soybean Research Articles

Simulated soybean pod and flower injuries and economic thresholds for Spodoptera eridania (Lepidoptera: Noctuidae) management decisions

Although defoliation economic thresholds (ETs) in soybean are well-established, there are concerns about Spodoptera spp. and Helicoverpa spp. damaging soybean pods and flowers. Moreover, S. eridania is the most common species of its genus feeding on soybean in Brazil. On this account, we quantified the feeding of S. eridania larvae on leaves, pods and flowers of BRS388RR and BRS1001IPRO cultivars in the laboratory. In the field, trials were conducted testing artificial injuries for 3 consecutive crop seasons. Results indicated that third-instar S. eridania can grow when feeding on pods (from plants at R3 stage). However, the larval stage is lengthened (27.4 days) compared with larvae feeding on leaves (19.9 days). Tests with older pods (stages R5.1 and R5.5) resulted in 100% mortality. For neonates, 100% mortality was observed for both pod and pod + flower feeding. Also, soybean tolerated all tested injuries in the field, including 25% perforated pods with 16.7% defoliation or 100% flower removal, without yield reduction. Overall, S. eridania is a leaf feeder. Older larvae (from 3rd instar) can feed on pods at an early plant reproductive stage (R3 stage). However, soybean tolerance to pod and flower injuries is high, even when occurring in combination with defoliation. Therefore, an ET of 25% of injured pods or a general defoliation ET of 15% at the reproductive stage is safe. Flower removal at R2 reproductive stage by S. eridania should not trigger management because no reduction in yield was observed even when 100% of flowers were removed.

Development of a decision-making application for optimum soybean and maize fertilization strategies in Mato Grosso

Mato Grosso accounts for 25 and 31% of soybean and maize grain production in Brazil, respectively. Despite the importance of this region, there is limited information to optimize fertilization management decisions for these crops. Our objectives were to i) quantify soybean and maize yield response to fertilization, ii) develop prediction algorithms to prescribe recommendations based on site characteristics, and iii) incorporate these algorithms in a decision-making application. A total of 37 soybean and 27 maize field trials (year by site combinations) were conducted to test yield responses of soybean to phosphorus (P) and potassium (K), and maize responses to nitrogen (N) and K. Soybean and maize showed significant yield increments to applied P and N, respectively, but K fertilization showed minor yield effects in both crops (and was not considered further). Yield responses to P and N in soybean and maize, respectively, were highly variable across environments, and non-linear mixed model analysis was used to test co-variates to optimize yield response predictions. Including soil pH and initial soil P for soybean, and planting date and soil clay for maize, helped reduce a significant fraction of the site-to-site random variation. Soybean yield response to P increased in soils with higher pH values, agreeing with the concept of more mineral P retention in acidic soils. Maize showed lower N fertilization yield responses in later plantings dates, agreeing with higher water stress typical of late plantings. Out-of-sample relative root mean square error (rRMSE) of predictions were 15.9 and 19.5% for soybean and maize, respectively, showing the model has adequate accuracy to predict crop yield responses to nutrient fertilizations across the region. These algorithms were incorporated in a user-friendly web application to facilitate utilization, and dynamically calculates optimum fertilization rates including economic inputs such as grain and fertilizer prices. Our field results provide basic information to optimize fertilization rates for soybean and maize in Mato Grosso and are available for management decisions through a web application.

Methods to quantify Bacillus simplex-based inoculant and its effect as a seed treatment on field-grown corn and soybean in Brazil

Abstract: Growth-promoting bacteria in agriculture have become an important tool to improve crop performance and productivity in the face of climate change and deteriorating soil conditions. Bacillus simplex is a recently developed active ingredient for the growth promotion of corn and soybean in Brazil. This study compared three methods to quantify B. simplex colony-forming units in the inoculant product and evaluated the treatment effects of four different concentrations of a B. simplex-based inoculant on corn and soybean root and shoot dry weight, the Normalized Difference Vegetation Index (NDVI), and yield. Field trials were performed at four different locations for each crop, in Mato Grosso do Sul and Paraná for corn, and in Mato Grosso do Sul, Minas Gerais, and Paraná for soybean. The performance of B. simplex was compared to an Azospirillum brasilense-based inoculant, a polymer seed treatment, and untreated controls. The results showed that the official MAPA method for quantifying microbes in inoculants recovered the highest number of B. simplex colonies. However, all three evaluated quantification methods recovered over 100 million colony-forming units per mL (108 CFU.mL-1). The field results showed that the B. simplex inoculant generally increased corn and soybean yields as much or more as the A. brasilense product and that the polymer seed treatment had no impact on yield. The treatment effect on root and shoot weight, and NDVI, was inconsistent. This research shows that B. simplex is quantifiable with three different methods and that it can improve yield in corn and soy. The Bacillus simplex-based inoculant has the potential to become widely used in Brazil.

Impacts of El Niño southern oscillation on hedge strategies for Brazilian corn and soybean futures contracts

Abstract: Climate influences the variations in soybean and corn prices; thus, we assessed the relationship between the El Niño Southern Oscillation (ENSO) with soybean-to-corn price ratio to determine potential impacts on price risk management. The commercial areas of Passo Fundo (RS), Cascavel (PR), Maringá (PR), Uberlândia (Triângulo Mineiro), and Sorriso (MT) covered in the study were chosen according to the MAPA edaphoclimatic classification. To estimate the effectiveness and optimal hedge ratio, the static and generalized model by Myers and Thompson (1989), adapted by Lien and Tse (2000), was used to include the cointegration approach in the analysis. The innovation of this study is the inclusion of the climate variable ENSO in this hedging approach. The findings showed that ENSO, especially La Niña, affects soybean-to-corn price ratio and hedge strategies. These results highlight the need to expand the use of futures contracts to reduce the price risk during the occurrence of ENSO events.

A Review and Analysis of Life Cycle Assessment Tendencies in the Brazilian Soybean Supply Chain

A Review and Analysis of Life Cycle Assessment Tendencies in the Brazilian Soybean Supply Chain

Food Loss and Waste from Farm to Gate in Brazilian Soybean Production

Food Loss and Waste from Farm to Gate in Brazilian Soybean Production

Bundled Contracts and Technological Diffusion Evidence from the Brazilian Soybean Boom

Bundled Contracts and Technological Diffusion Evidence from the Brazilian Soybean Boom

Analyzing complexities in the Brazilian soybean supply chain: a systems thinking and modeling approach

Purpose This study aims to analyze the complexities of the Brazilian soybean supply chain (SSC) and develop strategic interventions to improve the origin system’s performance. Design/methodology/approach This study used stakeholder interviews to identify the SSC bottlenecks and determine and assess drivers of competitiveness. A methodological framework based on the systems thinking approach for developing long-term structural changes was used. The problem was structured using behavior over time graph and causal loop modeling to propose three investment strategies to solve the logistics problem in SSC. Findings This study highlights the gaps in coordination between stakeholders and the public sector regarding the public policy for infrastructure investment. Three strategic interventions were developed to address the agro-industrial logistical problem, namely, investment in storage, multimodal transport systems and improvements in existing transport infrastructure. To overcome transport and storage logistics limitations, the authors suggest different forms of partnerships, including public-private partnerships. Research limitations/implications This research is limited to evaluating an agricultural commodity (soybean) and does not include its by-products. The sample of stakeholders was limited and the boundary of analysis was Brazil. Nevertheless, the study showed how strategic interventions could be developed following a holistic analysis. Practical implications The proposed integrated approach illustrates the development of three strategic initiatives. It can be implemented by stakeholders, including the public sector, which is the basis for providing assertive long-term investments in Brazilian logistics. Social implications The SSC analysis could promote the implementation of systemically determined interventions and strategies. It could significantly improve the performance of agricultural systems and help the formulation of public policies aimed at rural development. Originality/value The use of system dynamics to identify intervention points is an essential contribution to mitigating the SSC’s hindrances. Moreover, the combining methodologies resulted in comprehensive intervention strategies.

NemaNet: A convolutional neural network model for identification of soybean nematodes

Phytoparasitic nematodes (or phytonematodes) are causing severe damage to crops and generating large-scale economic losses worldwide. In soybean crops, annual losses are estimated at 10.6% of the world production. Besides, the identification of these species through microscopic analysis by an expert with taxonomic knowledge is often laborious, time-consuming, and susceptible to failure. From this perspective, robust and automatic approaches are necessary for identifying phytonematodes that are capable of providing correct diagnoses for the classification of species and subsidizing of all control and prevention measures. This work presents a new public data set called NemaDataset containing 3063 microscopic images from five nematode species with the most significant damage relevance for the soybean crop. Additionally, we propose a new Convolutional Neural Network (CNN) model defined as NemaNet and present a comparative assessment with thirteen popular models of CNNs, all of them representing state-of-the art classification and recognition. The general average was calculated for each model, on a from-scratch training; the NemaNet model reached 96.76% accuracy, while the best evaluation fold reached 98.04%. When training with transfer learning was performed, the average accuracy reached 98.82%. The best evaluation fold reached 99.35%, and overall accuracy improvements of over 6.83% and 4.1%, for from-scratch and transfer learning training, respectively, compared to other popular models were achieved. • Detect phytonematodes in soybean crops in Brazil using convolutional neural network. • A new dataset with five main species of phytonematodes from Brazil's soybean culture. • Evaluation of thirteen most popular CNN's architectures and new model (NemaNet). • Results describe NemaNet reaches best results in identifying nematodes overall.

First Report of Colletotrichum cliviae Causing Anthracnose of Rubber Tree in China.

Rubber tree (Hevea brasiliensis) is the most important species producing commercially viable natural rubber latex, which is an important raw material for many industrial uses. Anthracnose caused by Colletotrichum is one of the most severe diseases of rubber tree, especially in China. However, the diversity of Colletotrichum from rubber trees is complex and needs further identification (Liu et al. 2018). In January 2021, anthracnose-like lesions were observed on the leaves of rubber seedlings at a plantation in Qiongzhong City (19.08 N, 109.54E), Hainan Province, China. The lesions initially produced dark brown spots on the leaves of rubber trees, and then gradually evolved into larger necrotic spots. The diseased leaves shrank and died until they fell off. Small pieces of symptomatic leaf tissues were soaked in 0.5% mercuric chloride for 40 s, washed with sterile water for three times, and plated on potato dextrose ager (PDA). The plates were incubated at 28°C with 12-h light/dark regime for 10 days. Two isolate HN16 and HN18 from different leaves were subcultured on PDA using the single-spore method. The center of the colony is brown or grayish brown with the leading edge of growth in culture being white. Conidia were hyaline, septate, and cylindrical, with obtuse ends (14-20 μm × 4-6 μm).These morphological features confirmed the identity of the two isolated fungi as Colletotrichum cliviae (Yang et al. 2009). To confirm the morphological identification, five loci informative for identification of Colletotrichum spp. were amplified and sequenced, including the 5.8S nuclear ribosomal gene with the two flanking internal transcribed spacers (ITS), beta-tubulin (TUB), actin (ACT), an intron of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and chitin synthase (CHS-1), using the primer pairs ITS-1F/ITS4,T1/Bt-2b, ACT-512F/ACT-783R, GDF/GDR and CHS-79F/CHS-345R, respectively (Weir et al 2012). Sequences were deposited in NCBIs GenBank database (MW971911-MW971920). A multilocus phylogenetic analysis revealed that the sequences of the two isolates and published sequences of C. cliviae S37 clustered into one clade with a 100% confidence level. The two isolates were determined as C. cliviae by combining morphological and molecular characteristics. To verify pathogenicity, six leaves of rubber plants at the light green phase were sprayed with drop of spore suspension (106 conidia/ml) and sterile distilled water as control. After inoculation, all leaves were maintained in a climate box at 28°C with 100% relative humidity. After 3 days, lesions similar to those observed with dark brown spots in the field appeared on the inoculated leaves, while the controls remained symptomless. The fungus was reisolated from inoculated leaves and confirmed as C. cliviae by morphological and molecular identification, fulfilling Koch's postulates. The pathogen has been mainly reported on soybean in Brazil and China. To our knowledge, this is the first report of anthracnose on rubber tree caused by C. cliviae in China. However, Colletorrichum gloeosporioides and Colletorrichum acutatum are the two major causatives agent of anthracnose of rubber trees in China (Cai et al. 2016; Shi et al. 2019). The disease caused by C. cliviae was observed only at one rubber plantation with its distribution needing further investigation.

The agribusiness industry and the Brazilian soybean producers’ internationalization patterns

The Brazilian soybean producers, seeking competitive advantage and success in their business, understand that the foreign market becomes an alternative to diversify their activities, to seek new sources of income and to reduce dependence on their domestic market. However, the Brazilian context of international trade includes tariff and non-tariff barriers, which may jeopardize any deal, just because a simple price of goods increases or the withdrawal of a closing deal. This study analyzes three soybean exporting companies in the northern region of Rio Grande do Sul, through a multiple case study, more specifically about the barriers encountered in their internationalization process. All three cases demonstrated a development path toward internationalization, in view of gaining more competitiveness. However, there is still a large intervention by intermediaries, such as trading companies and brokers, in the export of soybean from Rio Grande do Sul. Even though exports are predominant among the soybean producers, the results show elements of hurdling about technical, logistics, sanitary and phytosanitary matters and subsidies.

Soybean crops cultivated with dacite rock by-product: A proof of a cleaner technology to soil remineralization

Soybean crops cultivated with dacite rock by-product: A proof of a cleaner technology to soil remineralization

The chitinolytic activity of the Curtobacterium sp. isolated from field-grown soybean and analysis of its genome sequence.

Curtobacterium sp. GD1 was isolated from leaves of conventionally grown soybean in Brazil. It was noteworthy that among all bacteria previously isolated from the same origin, only Curtobacterium sp. GD1 showed a strong chitinase activity. The enzyme was secreted and its production was induced by the presence of colloidal chitin in the medium. The chitinase was partially purified and characterized: molecular weight was approximately 37 kDa and specific activity 90.8 U/mg. Furthermore, Curtobacterium sp. GD1 genome was sequenced and analyzed. Our isolate formed a phylogenetic cluster with four other Curtobacterium spp. strains, with ANIb/ANIm ≥ 98%, representing a new, still non described Curtobacterium species. The circular genome visualization and comparison of genome sequences of strains forming new cluster indicated that most regions within their genomes were highly conserved. The gene associated with chitinase production was identified and the distribution pattern of glycosyl hydrolases genes was assessed. Also, genes associated with catabolism of structural carbohydrates such as oligosaccharides, mixed polysaccharides, plant and animal polysaccharides, as well as genes or gene clusters associated with resistance to antibiotics, toxic compounds and auxin biosynthesis subsystem products were identified. The abundance of putative glycosyl hydrolases in the genome of Curtobacterium sp. GD1 suggests that it has the tools for the hydrolysis of different polysaccharides. Therefore, Curtobacterium sp. GD1 isolated from soybean might be a bioremediator, biocontrol agent, an elicitor of the plant defense responses or simply degrader.

Resistance status of lepidopteran soybean pests following large-scale use of MON\xa087701\u2009\xd7\u2009MON\xa089788 soybean in Brazil

Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil. A proactive program was implemented to phenotypically and genotypically monitor Cry1Ac resistance in Chrysodeixis includens (Walker). Recent cases of unexpected injury in MON 87701 × MON 89788 soybean were investigated and a large-scale sampling of larvae on commercial soybean fields was performed to assess the efficacy of this technology and the distribution of lepidopteran pests in Brazil. No significant shift in C. includens susceptibility to Cry1Ac was observed eight years after commercial introduction of this technology in Brazil. F2 screen results confirmed that the frequency of Cry1Ac resistance alleles remains low and stable in C. includens. Unexpected injury caused by Rachiplusia nu (Guenée) and Crocidosema aporema (Walsingham) in MON 87701 × MON 89788 soybean was detected during the 2020/21 season, and studies confirmed a genetically based alteration in their susceptibility to Cry1Ac. MON 87701 × MON 89788 soybean remains effective against Anticarsia gemmatalis (Hübner), C. includens, Chloridea virescents (Fabricius) and Helicoverpa armigera (Hübner) in Brazil. However, there is evidence of field-evolved resistance to MON 87701 × MON 89788 soybean by the secondary soybean pests R. nu and C. aporema.

Morphological Characterization of Corynespora cassiicola Isolates in Culture Media

Corynespora cassiicola threatens soybean and cotton production in Brazil. The objective of this study was to evaluate cultural and morphological aspects of C. cassiicola isolated from soybean and cotton of different Brazilian regions, in culture media. The isolates were grown in PDA (Potato Dextrose Agar) and V8 juice agar media. The characteristics evaluated were: color, aspect, and growth rate of mycelia, as well as production and dimension of conidia, and number of septa per conidium. Culture media and isolates were compared using the Kruskal-Wallis or Tukey’s test at 5% significance level. The mycelia of the isolates were predominantly dark gray and light brown. C. cassiicola isolates grew better in V8 juice agar medium, presenting a higher mycelial growth rate. In PDA medium, the production of conidia was higher in isolates from cotton, compared with soybean isolates. There was great variation in the production of conidia in V8 juice agar medium, regardless of the host origin. Conidia length and width varied for isolate and culture medium. The isolates of C. cassiicola coming from cotton presented a higher number of septa per conidium when grown in PDA medium. The morphological aspects of C. cassiicola vary depending on the host of origin and the culture medium.

Resistance ofCorynespora cassiicolafrom soybean to QoI and MBC fungicides in Brazil

AbstractFungicide sprays on soybean in Brazil have contributed to the selection of less sensitive isolates ofCorynespora cassiicola. We collected 59 isolates ofC. cassiicolafrom three Brazilian states and two isolates from Paraguay. We investigated their EC50to quinone outside inhibitors (QoI) and methyl benzimidazole carbamate (MBC), any cross‐resistance to compounds within QoI and MBC groups, and characterized the polymorphisms in theircytbandβ‐tubulingenes. Local associations of polymorphisms identified in each gene were statistically correlated with assays results. In total, 79% and 74% of the isolates were classified as resistant to QoI and MBC fungicides, respectively. There was positive cross‐resistance to active ingredients within QoI and MBC groups. For QoI, all isolates presented heteroplasmy in G143A ofcytbgene; the mutations F129L and G137R were not found. For MBC, 63% of isolates possessed E198A and 21% possessed F200Y mutations, associated with reduced control by MBC fungicides. Heteroplasmy was identified in two and one isolates from Brazil with E198A and F200Y mutations, respectively. The resistance factor for isolates with E198A (10.9) was statistically similar to the isolate with F200Y (8.8) mutation. Genic association analysis of the in vitro assays using discriminatory doses proved them to be accurate. Reduced sensitivity ofC. cassiicolato QoI and MBC was also identified in isolates from Paraguay and resistance to QoI and MBC was widely present inC. cassiicolaisolates from the main soybean‐producing states in Brazil. Thus, integrated management measures should be adopted to manage soybean target spot in these countries.

Testes morphology and the identification of transcripts of the hormonal pathways of the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Erebidae)

Anticarsia gemmatalis is one of the main defoliating pests of soybeans in Brazil. In the current study, we characterized the histomorphology of the testes and the spermatogenesis process in A. gemmatalis. We also identified transcripts involved in the biosynthesis, metabolism, and signaling of juvenile and ecdysteroid hormones, in order to provide information about potential mechanisms of regulation of hormonal pathways in this species. Our analyses revealed that the A. gemmatalis larvae have a pair of kidney-shaped testicles. These are divided into four testicular follicles, where there are germ cell cysts at different stages of development. In the pupal stage, the testicles are fused, so adults have a single spherical testis, with a variable number of follicles. The A. gemmatalis has centripetal spermatogenesis and exhibits spermatic dimorphism. We identified 31 transcripts that encode proteins involved in juvenile hormone and ecdysteroid pathways, such as mevalonate kinase, CYP14A1, ecdysone receptor, among others. Our results on the morphology of the testes and spermatogenesis process, as well as identification of the genes involved in hormonal pathways in A. gemmatalis, provide important data for understanding the biology of this agricultural pest, which can be used as a basis for further research in other economically important lepidopterans.

Mapping the Available Water Capacity in tropical climate soils for soybean (Glycine max) cultivation in the state of Tocantins-Brazil

Brazilian soybean has undergone considerable economic growth. Its production depends on the demand for some inputs. One of these inputs is the soil water supply, which can be made artificially or obtained by natural rainfall. Knowledge of available water capacity (AWC), which depends on total water availability (TWA), is poorly accessible and difficult to measure in the field. This study aimed to map the AWC of the state of Tocantins, based on pedotransfer functions (PTFs), to evaluate the water availability of the soils of the microregions of that state. We used the Arya and Paris model, aided by a computer program, Qualisolo, made by Embrapa Instrumentação. One hundred fifty-seven tropical soil samples were extracted from the Embrapa Solos portal. Preliminarily, the soil water retention curve (SWRC) was obtained and, subsequently, the TWA and AWC for this oilseed were estimated. Multiple linear regressions show the correlation between TWA and clay (CL), Silt (ST) and total sand (TS) contents. The correlation established was TWA = 3.2993 – 0.0028TS – 0.0034CL. This main conclusion reflects a fruitful AWC for decision-making by the soybean agribusiness and exposes the regional weaknesses for this crop under a rainfed regime in some regions of Tocantins. We could observe that, in terms of water availability, agribusiness is a potential threat to the environment protection area (APA) of the Ilha do Bananal/Cantão, Formoso River microregion.

Assessing the temporal dynamics of Frankliniella schultzei (Thysanoptera: Thripidae) in commercial soybean crops in North Brazil

Abstract Thrips are considered a secondary pest of soybean in Brazil, but high densities have been noticed since the last harvests (2017/18 and 2018/19), yet no study has provided an initial hypothesis regarding the causes of such events. We aimed to identify some of the factors related to Frankliniella schultzei Trybom (Thysanoptera: Thripidae) temporal dynamics in commercial soybean crops located in Tocantins (Northern Brazil). We undertook evaluations during soybean vegetative, flowering, and fruiting stages on 200 plants per field in each sampling date (n = 22). Our results indicated that the densities of F. schultzei were similar among fields and soybean phenological stages. The density of thrips showed a significant negative relationship with rainfall, but it was not related to either air temperature, photoperiod, relative humidity, or wind speed. The predators' density was less than 170 individuals (summing all assessments), and it was not associated with thrips density. This study indicates rainfall as the leading factor associated with the temporal dynamics of F. schultzei in commercial soybean crops.

Mutual analyses of agriculture land use and transportation networks: The future location of soybean and corn production in Brazil.

CONTEXTGiven the need to expand food production to satisfy an increasing world population; regional land-use planners must direct this expansion to available, permitted areas (i.e., not legally protected forests) where production can be maximized and transportation costs, production costs and environmental impacts can be minimized. In this balancing act, the capabilities and layout of the current and future transport system are crucial in determining the spatial distribution of future agricultural production. OBJECTIVEThe objective of the present study was to develop a modeling framework to determine the optimal spatial distribution of new soybean and corn production areas in Brazil and transport flows needed to move these commodities to maximize economic gains and limit or reduce negative environmental impacts. METHODSInitially, we applied Data Envelopment Analysis (DEA) to classify regions suitable for expanding soybean and corn production according to an area's potential for superior agricultural performance. Subsequently, we used a Network Equilibrium Model (NEM) to determine the best spatial distribution of new soybean and corn production areas so that their production added to existing production meets the estimated 2050 demand and the optimal configuration of existing and proposed transportation infrastructure required to move this production to appropriate locations. RESULTS AND CONCLUSIONSWhen compared to a 2018 baseline, the complete operation of planned railroads and the positioning of future grain production to occupy regions indicated by the modeling could increase soybean and corn production by 66% without simultaneous deforestation, reduce carbon dioxide emissions due to interregional soybean and corn transport by about 14%, and reduce combined transport and production costs by about 2%. SIGNIFICANCEThe proposed modeling framework should be an extremely useful tool when determining sites for future agriculture production and the network matrix needed to transport this production, especially when considering the relationship between land use and transportation infrastructure.