Brazilian Soybean Research Articles

Annual 30 m soybean yield mapping in Brazil using long-term satellite observations, climate data and machine learning

Long-term spatially explicit information on crop yield is essential for understanding food security in a changing climate. Here we present a study that combines twenty-years of Landsat and MODIS data, climate and weather records, municipality-level crop yield statistics, random forests and linear regression models for mapping crop yield in a multi-temporal, multi-scale modeling framework. The study was conducted for soybean in Brazil. Using a recently developed 30 m resolution, annual (2001–2019) soybean classification map product, we aggregated multi-temporal phenological metrics derived from Landsat and MODIS data over soybean pixels to the municipality scale. We combined phenological metrics with topographic features, long-term climate data, in-season weather data and soil variables as inputs to machine learning models. We trained a multi-year random forests model using yield statistics as reference and subsequently applied linear regression to adjust the biases in the direct output of the random forests model. This model combination achieved the best performance with a root-mean-square-error (RMSE) of 344 kg/ha (12% relative to long-term mean yield) and an r2 of 0.69, on the basis of 20% withheld test data. The RMSE of the leave-one-year-out model assessment ranged from 259 kg/ha to 816 kg/ha. To eliminate the artifacts caused by the coarse-resolution climate and weather data, we developed multiple models with different categories of input variables. Employing the per-pixel uncertainty estimates of different models, the final soybean yield maps were produced through per-pixel model composition. We applied the models trained on 2001–2019 data to 2020 data and produced a soybean yield map for 2020, demonstrating the predictive capability of trained machine learning models for operational yield mapping in future years. Our research showed that combining satellite, climate and weather data and machine learning could effectively map crop yield at high resolution, providing critical information to understand yield growth, anomaly and food security.

Genetic diversity and interaction between the maintainers of commercial soybean cultivars using self‐organizing maps

AbstractInformation on the genetic diversity of commercial cultivars is of fundamental importance for crop improvement. In addition, information about possible interactions between the maintainers developing these cultivars can help design a breeding program. The objective of this work was to study the genetic diversity of soybean [Glycine max (L.) Merr.] cultivars released in Brazil from 1998 to 2017 and compare the similarity between maintainers of these cultivars based on the phenotypic information disclosed. Data was collected on 1,587 soybean cultivars registered in the National Register of Cultivars of the Ministry of Agriculture, Livestock, and Supply belonging to 59 different maintainers. Among these cultivars, 12 agromorphological traits were evaluated. To perform the grouping and select the main discriminating traits of the cultivars, the Random Forest method was used. Multiple correspondence analysis was performed to obtain the variance explanation percentage of the traits evaluated in each dimension and coordinates among the maintainers. The maintainers were organized through Kohonen self‐organizing map (SOM) through the respective coordinates. There is a wide variety of maintainers of soybean cultivars in Brazil with different objectives for launching new cultivars. Among the maintainers, Soymax presented the most restricted genetic base. The other private companies showed more remarkable similarities and a broader genetic base. The public institution EMBRAPA presented the greatest genetic diversity in its population base. Federal University of Uberlândia and Federal University of Viçosa can be partners to launch soybean cultivars given the proximity between neurons in Kohonen analysis. The high diversity of traits shows that the genetic base of soybean in Brazil is large.

Molecular and biological characterization of an isolate of the potyvirus passiflora virus Y naturally infecting soybean (Glycine max) in Brazil.

Passiflora virus Y was detected naturally infecting soybean (Glycine max) for the first time in Brazil. Here, we report the nearly complete genome sequence and molecular and biological properties of the PaVY-Br isolate. The nearly complete genome sequence is 9679 nt long and shares 84.4% nt sequence identity with a previously reported PaVY isolate from Passiflora sp. PaVY-Br induced chlorotic spots and systemic mosaic on soybean and chlorotic local lesions on yellow passion fruit (Passiflora edulis) and sesame (Sesamum indicum). The virus was successfully transmitted by Myzus persicae, indicating that this aphid vector can contribute to the spread of PaYV from passion fruit to soybean plants. Additional epidemiological research is in progress to investigate the distribution of PaVY in soybean production areas in Brazil.

Genetic improvement of soybeans in Brazil: South and Midwest regions

AbstractSoybean [Glycine max (L.) Merril] is one of the main crops produced worldwide, and on‐farm yields have increased considerably in the last decades in Brazil. We evaluated the genetic gain for agronomic, phenological, and end‐use quality traits in 29 cultivars in the South Region, and in 38 cultivars in the Midwest Region in Brazil, released from 1966 to 2011. Field trials were conducted in Macroregions 1, 2, and 4, in 2016–2017, 2017–2018, and 2018–2019 crop seasons. The best linear unbiased predictors (BLUP) of the cultivars were obtained for each trait using a linear model. The BLUPs were regressed with the year of release using linear and quadratic regression models. The rates of genetic gain for seed yield ranged from 11.98 to 15.31 kg ha–1 yr–1 (0.33 to 0.42% yr–1) in the South Region, and from 13.58 to 21.84 kg ha–1 yr–1 (0.47 to 0.77% yr–1) in the Midwest Region. New cultivars presented taller plants and more seed oil content, oil and protein yield, and lower seed weight, days to flowering, days to maturity, and seed protein content than old cultivars in the South Region, although with differences between the Macroregions. In the Midwest Region, new cultivars showed higher seed oil content, oil and protein yield, and lower bottom pod height and seed protein content than old cultivars. Our results showed that breeding programs have been efficient to improve soybean yield and other traits across the years, without yield plateaus in sight.

Identification of Functional Genetic Variations Underlying Flooding Tolerance in Brazilian Soybean Genotypes.

Flooding is a frequent environmental stress that reduces soybean (Glycine max) growth and grain yield in many producing areas in the world, such as, e.g., in the United States, Southeast Asia and Southern Brazil. In these regions, soybean is frequently cultivated in lowland areas by rotating with rice (Oryza sativa), which provides numerous technical, economic and environmental benefits. Given these realities, this work aimed to characterize physiological responses, identify genes differentially expressed under flooding stress in Brazilian soybean genotypes with contrasting flooding tolerance, and select SNPs with potential use for marker-assisted selection. Soybean cultivars TECIRGA 6070 (flooding tolerant) and FUNDACEP 62 (flooding sensitive) were grown up to the V6 growth stage and then flooding stress was imposed. Total RNA was extracted from leaves 24 h after the stress was imposed and sequenced. In total, 421 induced and 291 repressed genes were identified in both genotypes. TECIRGA 6070 presented 284 and 460 genes up- and down-regulated, respectively, under flooding conditions. Of those, 100 and 148 genes were exclusively up- and down-regulated, respectively, in the tolerant genotype. Based on the RNA sequencing data, SNPs in differentially expressed genes in response to flooding stress were identified. Finally, 38 SNPs, located in genes with functional annotation for response to abiotic stresses, were found in TECIRGA 6070 and absent in FUNDACEP 62. To validate them, 22 SNPs were selected for designing KASP assays that were used to genotype a panel of 11 contrasting genotypes with known phenotypes. In addition, the phenotypic and grain yield impacts were analyzed in four field experiments using a panel of 166 Brazilian soybean genotypes. Five SNPs possibly related to flooding tolerance in Brazilian soybean genotypes were identified. The information generated from this research will be useful to develop soybean genotypes adapted to poorly drained soils or areas subject to flooding.

The impact of the cost of road transport on the price of Brazilian soybean: the case of Mato Grosso do Sul and the practice of collaborative logistics

Of vital importance to the economy of Mato Grosso do Sul, soybean held the second position in the overview of the products exported in 2020, however, the state is distant from the main export terminals and with high dependence on the road modal. In view of this, the present study sought to evaluate the impact of the average cost of transportation on the price of Mato Grosso do Sul state soybean and the adoption of the practice of collaborative logistics as an alternative to reduce transportation costs. In order to calculate the average cost of road transport, the criteria established in the National Policy of Minimum Costs of Road Cargo Transport (PNPM – TRC) were followed as a guide. Analyzes were made for the vehicle compositions with 7 axles and 9 axles, originating in the municipalities of Maracaju, Ponta Porã and São Gabriel do Oeste and as destinations the port of Santos, Paranaguá and São Francisco do Sul. The results indicate that the vehicle compositions with 9 axles presented the lowest cost per ton transported for all routes analyzed and that, in the comparison between the current scenario and the ideal scenario that considers the adoption of the practice of collaborative logistics with the aggregate of routes Santos (route 1a), Paranaguá (route 1b) and São Francisco do Sul (route 1d) the reduction in the total financial cost for 7-axle compositions was R$ 49,936,261.64, representing a reduction of 5.24% and for 9-axle compositions the reduction in the total financial cost between the current scenario and the ideal scenario of the same aggregate route was R$ 43,462,818.45, representing also a reduction of 5.24%.

Missing data estimates related to soybean production in the state of Mato Grosso, Brazil, from 1990 to 2018

PurposeThe state of Mato Grosso represents the largest producer and exporter of soybeans in Brazil; given this importance, it was aimed to propose to use the univariate imputation tool for time series, through applications of splines interpolations, in 46 of its municipalities that had missing data in the variables soybean production in thousand tons, production value and soy derivatives in R$ thousand, and also to assess the differences between the observed series and those with imputed values, in each of these municipalities, in these variables.Design/methodology/approachThe proposed methodology was based on the use of the univariate imputation method through the application of cubic spline interpolation in each of the 46 municipalities, for each of the 3 variables. Then, for each municipality, the original series were compared with each observed series plus the values imputed in these variables by the Quenouille test of correlation of time series.FindingsIt was observed that, after imputation, all series were compared with those observed and are equal by the Queinouille test in the 46 municipalities analyzed, and the Wilcoxon test also showed equality for the accumulated total of the three variables involved with the production of soybeans. And there were increases of 5.92%, 3.58% and 2.84% for soy production, soy production value and soy derivatives value accumulated in the state after imputation in the 46 municipalities.Originality/valueThe present research and its results facilitate the process of estimates and monitoring the total soy production in the state of Mato Grosso and its municipalities from 1990 to 2018.

Regional pest suppression associated with adoption of Cry1Ac soybean benefits pest management in tropical agriculture.

Bacillus thuringiensis (Bt) crops have been adopted worldwide, providing high-level protection from insect pests. Furthermore, Bt crops preserve natural enemies, promote higher yield, and economically benefit farmers. Although regional pest suppression by widespread Bt crop adoption has been observed in temperate regions, this possibility remains uncertain in tropical areas due to the high diversity of alternative hosts and mild winters. Evidence of regional reduction in insecticide use across areas was observed in Brazil where Cry1Ac soybean has been grown since 2013, with up to 50% reduction in the number of insecticide sprays for managing lepidopteran pests on non-Bt soybean observed at specific locations from 2012 to 2019. Pest monitoring data from four mesoregions across 5 years of commercial plantings of Cry1Ac soybean from December 2014 to July 2019 showed reduced numbers of Chrysodeixis includens moths captured in pheromone traps across years at all locations. The number of Helicoverpa spp. moths captured also was reduced at three locations. We provide evidence for regional suppression of lepidopteran pests and reduced insecticide use with the widespread adoption of Cry1Ac soybean in Brazil, bringing economic, social and environmental benefits. © 2022 Society of Chemical Industry.

Genetic relationships and genome selection signatures between soybean cultivars from Brazil and United States after decades of breeding

Soybean is one of the most important crops worldwide. Brazil and the United States (US) are the world’s two biggest producers of this legume. The increase of publicly available DNA sequencing data as well as high-density genotyping data of multiple soybean germplasms has made it possible to understand the genetic relationships and identify genomics regions that underwent selection pressure during soy domestication and breeding. In this study, we analyzed the genetic relationships between Brazilian (N = 235) and US soybean cultivars (N = 675) released in different decades and screened for genomic signatures between Brazilian and US cultivars. The population structure analysis demonstrated that the Brazilian germplasm has a narrower genetic base than the US germplasm. The US cultivars were grouped according to maturity groups, while Brazilian cultivars were separated according to decade of release. We found 73 SNPs that differentiate Brazilian and US soybean germplasm. Maturity-associated SNPs showed high allelic frequency differences between Brazilian and US accessions. Other important loci were identified separating cultivars released before and after 1996 in Brazil. Our data showed important genomic regions under selection during decades of soybean breeding in Brazil and the US that should be targeted to adapt lines from different origins in these countries.

CADEIAS MERCANTIS E CONTRIBUIÇÕES CONCEITUAIS À GEOGRAFIA HUMANA

This article proposes that the conceptual parameters of the focus on "Commodity Chains" offer fertile resources for the formulation, exploration, and unraveling of problems in human geography. To this end, an exploratory study was carried out, beginning with a bibliographical, documentary, and data survey followed by a concise case analysis of the productive-commercial system of Brazilian soybean production. The "Geoeconomic Web" concept was formulated to highlight socio-institutional factors in the geopolitical dimension of the economy. It is understood that these conceptual frameworks are suitable to problematize issues about the dynamics of insertion and positioning of substructures in national economies, of these economies in the world economy, and power relations in these spaces. Keywords: Commodity Chains, Conceptualization, Web Geoeconomic.

Work accidents in agriculture: a study of Brazilian soybean production

Soybean cultivation has great economic and social impacts, meaning it offers many job opportunities. Studying the number of accidents in this field is essential for a better understanding of the quality of work related to it. Therefore, the purpose of this article is to verify if, in the field of soybean cultivation, there are correlations between productivity, product price, and the number of accidents, between the years of 1999 and 2018, in Brazil. For that, Pearson’s method was applied, allowing for a bivariate analysis that can quantify a degree of strength between different variables. As a result, it was found that soybean production and price are linearly related to the number of work-related accidents in cultivation. Therefore, it is concluded that, if an increase in price or production occurs, it will lead to an increase in accidents, and the opposite will also happen.

Characterization and genomic analyses of a novel alphabaculovirus isolated from the black armyworm, Spodoptera cosmioides (Lepidoptera: Noctuidae)

The black armyworm Spodoptera cosmioides is a pest of increasing importance in Cry1Ac-Bt toxin crops and non-Bt crops of soybean and cotton in Brazil. Here we characterized a baculovirus isolated from extracts of S. cosmioides that died with symptoms of nuclear polyhedrosis. The putative novel virus exhibited polyhedral occlusion bodies (OBs) with virions containing multiple rod-shaped nucleocapsids, characteristic of alphabaculoviruses. The virus isolate was named Spodoptera cosmioides nucleopolyhedrovirus isolate CNPSo-72 (SpcoNPV-CNPSo-72). SpcoNPV-CNPSo-72 was lethal to third-instar S. cosmioides caterpillars but not to S. frugiperda under the tested viral concentrations. Moreover, SpcoNPV-CNPSo-72 contained a circular 147,763 bp long genome and a G + C content of 44.8% with 151 annotated ORFs (10 unique for baculovirus) and five homologous regions (hrs). The 38 currently defined baculovirus core genes were found in the SpcoNPV-CNPSo-72 genome. After phylogenetic analysis, the novel virus was found to be closely related to other members of Alphabaculovirus, especially to the Spodoptera-infecting viruses, which included Spodoptera eridania nucleopolyhedrovirus isolate 251, Spodoptera litura nucleopolyhedrovirus isolate II, Spodoptera exigua multiple nucleopolyhedrovirus isolate US-1, Spodoptera eridania nucleopolyhedrovirus isolate CNPSo-165, and Spodoptera frugiperda multiple nucleopolyhedrovirus isolate 19. Surprisingly, the new baculoviral genome was found to code for a putative arginine-associated tRNA gene with a predicted intronic sequence of 105 nt. The gene was found inside the bjdp CDS. Overall, baculoviruses are pathogens that lethally infect insect larvae and their study allows a better understanding of large DNA virus evolution, which provides important insights for the development and improvement of biological control agents.

How Communication Affects the Adoption of Digital Technologies in Soybean Production: A Survey in Brazil

Technology adoption has contributed to developing efficient food production throughout the history of modern agriculture. In the last decades, several technologies have positively affected yields globally, and, more recently, digital solutions are leading the way. This article presents the results of a survey carried out with 461 Brazilian soybean farmers about the use of technologies and the level of influence of mass media, social media, and interpersonal meetings on the decision to adopt new technologies. We surveyed farmers in Brazil’s top five soybean-producing states, which represent 75% of production in the world’s largest soybean producer. Spearman’s rank correlations showed an association between communication and the use of precision and digital technologies. LinkedIn had the highest positive correlation between precision and digital tools. Conferences, forums, and seminars had the highest positive correlation with the perceived benefits of using technologies on-farm. The results suggest that in-person activities still have relevance, but social media platforms, such as WhatsApp, have grown increasingly important to farmers. In addition, the correlations indicate that adopters of established technologies tend to prioritize in-person connections as a reference for their decision making. The results reinforce that superior knowledge and information are decisive in the process of adopting technologies in agriculture.

Monitoring Complex Integrated Crop–Livestock Systems at Regional Scale in Brazil: A Big Earth Observation Data Approach

Due to different combinations of agriculture, livestock and forestry managed by rotation, succession and intercropping practices, integrated agriculture production systems such as integrated crop–livestock systems (iCL) constitute a very complex target and a challenge for automatic mapping of cropping practices based on remote sensing data. The overall objective of this study was to develop a classification strategy for the annual mapping of integrated Crop–Livestock systems (iCL) at a regional scale. This strategy was designed and tested in the six agro-climatic regions of Mato Grosso, the largest Brazilian soybean producer state, using MODIS satellite time-series images acquired between 2012 and 2019, ground data with heterogeneous distribution in space and time and a Random Forest classifier. The results showed that: 1. the use of unbalanced training samples with a class composition close to the real one was the right classifier training strategy; 2. the use of a single training database (pooling samples from different years and regions) to classify each region and year individually proved to be robust enough to provide similar classification accuracies in comparison to those based on the use of a database acquired for each region and for each year. The final hierarchical classification overall accuracy was 0.89 for Level 1, the cropping pattern level (single and double crops DC); 0.84 for Level 2, the DC category level (integrated system iCL soy-pasture/brachiaria, soy-cotton and soy-cereal); 0.77 for Level 3, the iCL level (iCL1 soy-pasture and iCL2 soy-pasture mixed with corn). The F-scores for DC, iCL and iCL1 cropping systems presented high accuracy (0.89, 0.85 and 0.84), while iCL2 was more difficult to classify (0.63). This approach will next be applied across the entire Brazilian soybean corridor, leading to an operational tool for monitoring the adoption of sustainable intensification practices recognized by Brazil’s Agriculture Low Carbon Plan (ABC PLAN).

Genetic Diversity and Selection Footprints in the Genome of Brazilian Soybean Cultivars.

Although Brazil is currently the largest soybean producer in the world, only a small number of studies have analyzed the genetic diversity of Brazilian soybean. These studies have shown the existence of a narrow genetic base. The objectives of this work were to analyze the population structure and genetic diversity, and to identify selection signatures in the genome of soybean germplasms from different companies in Brazil. A panel consisting of 343 soybean lines from Brazil, North America, and Asia was genotyped using genotyping by sequencing (GBS). Population structure was assessed by Bayesian and multivariate approaches. Genetic diversity was analyzed using metrics such as the fixation index, nucleotide diversity, genetic dissimilarity, and linkage disequilibrium. The software BayeScan was used to detect selection signatures between Brazilian and Asian accessions as well as among Brazilian germplasms. Region of origin, company of origin, and relative maturity group (RMG) all had a significant influence on population structure. Varieties belonging to the same company and especially to the same RMG exhibited a high level of genetic similarity. This result was exacerbated among early maturing accessions. Brazilian soybean showed significantly lower genetic diversity when compared to Asian accessions. This was expected, because the crop’s region of origin is its main genetic diversity reserve. We identified 7 genomic regions under selection between the Brazilian and Asian accessions, and 27 among Brazilian varieties developed by different companies. Associated with these genomic regions, we found 96 quantitative trait loci (QTLs) for important soybean breeding traits such as flowering, maturity, plant architecture, productivity components, pathogen resistance, and seed composition. Some of the QTLs associated with the markers under selection have genes of great importance to soybean’s regional adaptation. The results reported herein allowed to expand the knowledge about the organization of the genetic variability of the Brazilian soybean germplasm. Furthermore, it was possible to identify genomic regions under selection possibly associated with the adaptation of soybean to Brazilian environments.

Intra- and Interspecific Variation in the Susceptibility to Insecticides of Stink Bugs (Hemiptera: Pentatomidae) That Attack Soybean and Maize in Southern Brazil.

This study evaluated intra- and interspecific variation regarding the susceptibility to insecticides of key pentatomid pests of soybean (Glycine max L.) and maize (Zea mays L.) crops in Brazil. To perform bioassays, populations of Euschistus heros (F.), Diceraeus (=Dichelops) furcatus (F.), Nezara viridula (L.), and Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) were collected in soybean fields in Southern Brazil during the 2020/2021 crop season. Then, stink bugs were exposed to doses of commercial insecticides commonly applied for its control in dip-test bioassays using fresh green bean pods. In general, all stink bug species and populations studied were susceptible to acephate, acetamiprid + bifenthrin, imidacloprid + bifenthrin, and ethiprole, with mortality rates > 80%. Most populations of E. heros and D. furcatus, considered the main stink bugs that attack soybean and maize, respectively, presented low or intermediate susceptibility to acetamiprid + α-cypermethrin, ζ-cypermethrin + bifenthrin, dinotefuran + λ-cyhalothrin, and bifenthrin + carbosulfan. Except for bifenthrin + carbosulfan (mortality < 57%), secondary stink bugs species that attack soybean (N. viridula and P. guildinii) showed pronounced susceptibility to all insecticides tested, with mortality rates > 70%. In summary, the populations of E. heros and D. furcatus showed diminished susceptibility to various insecticides formulated with the mixture of neonicotinoids + pyrethroids, whereas N. viridula and P. guildinii were most susceptible to the insecticides evaluated. The implications of these findings to integrated and resistance management programs are discussed.

Glyphosate-resistant (GR) soybean and corn in Brazil: past, present, and future

Glyphosate-Resistant Crops (GR crops) have caused considerable changes in weed management worldwide. In Brazil, GR cultivars of soybean and corn were officially introduced in the 2005/06 and 2011/12 crops, respectively. This technology has radically changed the weed management system, having an enormous impact on national agriculture. The objective of this review was to analyze the general aspects that led to the adoption of this technology in Brazil and present its future consequences and challenges. The adoption of GR soybean [...]

Simulation of the soybean oil hydrotreating process for green diesel production

Renewable diesel, or green diesel, is the biofuel with the fastest growing use in the world. Its use as a replacement for fossil diesel is important to reduce the impact of carbon emissions. Green diesel is formed by a mixture of hydrocarbons with a chemical composition similar to that of fossil fuel, making it a drop-in biofuel. Commercial processing employs hydrotreatment of vegetable oil, which, in addition to producing green diesel, can also be used to produce biofuel for aviation, bionaphtha and biopropane. The present paper proposes a model for the hydrotreatment of soybean oil for the production of green diesel. The process was simulated in Aspen Plus® v10; the decarboxylation, decarbonylation and hydrodeoxygenation reactions were carried out in a stoichiometric reactor in the presence of an NiMo/Al2O3 catalyst. In addition to the cracking reactions and fractionation, the fuels produced green diesel, aviation biofuel, and light gases. Brazilian soybean oil was used as the raw material to produce the green diesel. Sensitivity analyses were performed to adjust the best fractionation conditions, considering the composition of the product and the distillation column energy. The best results were chosen when the distillation column was configured with 22 stages, feed at stage 12 and reflux ratio equal to 0.8. The hydrogen/soybean oil ratio was 0.031. The energy used in the process was 1181 kW/h. More than 80% of the soybean oil was converted to renewable fuels, with approximately 65% to green diesel. In addition, a prediction of the simulated physical chemical properties was made and compared with the current Brazilian legislation for green diesel obtaining values within the established specifications. The ASTM D86 distillation curve was compared with simulated results from green diesel obtained from experimental data and fossil diesel. The experimental and simulated distillation curves agreed, showing only a small difference between curves up to 25% of recovered volume. This can be explained by the lighter components present in the experimental green diesel. The proposed simulation supported the potential of Brazilian soybean oil for the production of quality renewable fuels.

Means, motive and opportunity for biological invasions: Genetic introgression in a fungal pathogen.

Invasions by fungal plant pathogens pose a significant threat to the health of agricultural ecosystems. Despite limited standing genetic variation, many invasive fungal species can adapt and spread rapidly, resulting in significant losses to crop yields. Here, we report on the population genomics of Colletotrichum truncatum, a polyphagous pathogen that can infect more than 460 plant species, and an invasive pathogen of soybean in Brazil. We study the whole-genome sequences of 18 isolates representing 10 fields from two major regions of soybean production. We show that Brazilian C. truncatum is subdivided into three phylogenetically distinct lineages that exchange genetic variation through hybridization. Introgression affects 2%-30% of the nucleotides of genomes and varies widely between the lineages. We find that introgressed regions comprise secreted protein-encoding genes, suggesting possible co-evolutionary targets for selection in those regions. We highlight the inherent vulnerability of genetically uniform crops in the agro-ecological environment, particularly when faced with pathogens that can take full advantage of the opportunities offered by an increasingly globalized world. Finally, we discuss "the means, motive and opportunity" of fungal pathogens and how they can become invasive species of crops. We call for more population genomic studies because such analyses can help identify geographical areas and pathogens that pose a risk, thereby helping to inform control strategies to better protect crops in the future.

Fighting off the sucking pests of soybean: managing stink bugs and whiteflies

Stink bugs and whiteflies are major concerns for pest management in Brazilian soybean fields, causing severe economic losses to soybean growers and leading to excessive insecticide applications per crop cycle. Despite biological differences, these two sap-sucking pests often co-occur in soybean fields and can be successfully managed with the same insecticide spray, reducing operational costs to the growers. The aim of this work was to evaluate the efficacy of eleven insecticides in the control of stink bugs and whiteflies. Two insecticide sprays were made with an interval of 14 days between them. The results from ANOVA and Tukey post-hoc test (P≤0.05) revealed significant differences among treatments. Acetamiprid + bifenthrin (75 + 75 g a.i. ha-1) was the most efficient treatment for the control of stink bugs, reaching 97.8% of insect mortality. Cyantraniliprole + bifenthrin (50 + 50 g a.i. ha-1) was the most efficient treatment for the control of whiteflies, reaching 78.8% of insect mortality. This treatment also presented the highest combined control of stink bugs and whiteflies, reaching 83.5% of insect mortality