Integrated Management of Important Soybean Pathogens of the United States in Changing Climate

Abstract

Soybean (Glycine max L.) is a major crop grown in the United States but is susceptible to many diseases that cause significant yield losses each year. Consistent threats exist across both northern and southern production regions and include the soybean cyst nematode, charcoal rot, and seedling diseases. In contrast, significant soybean diseases like Phytophthora stem and root rot, sudden death syndrome, and Sclerotinia stem rot (white mold) are intermittent threats that can be heavily influenced by environmental factors. Additional threats to soybean production that have emerged in recent years as more common problems in soybean production include root-knot and reniform nematodes, frogeye leaf spot, and Diaporthe diseases. Disease in any crop will only occur when the three components of the disease triangle are present: a susceptible host, a virulent pathogen, and a conducive environment. If an environment is becoming more conducive for a particular disease, it is important that farmers and practitioners are prepared to manage the problem. The information in this review was compiled to help assist agriculturalists in being proactive in managing new soybean diseases that may be emerging in new areas. To do this, we provide: 1) an overview of the impact and disease cycle for major soybean diseases currently causing significant yield losses in the United States, 2) a comprehensive review of the current management strategies for each soybean disease, and 3) insights into the epidemiology of each pathogen, including the likelihood of outbreaks and expansion to additional geographic regions based on current trends in climate change.

The fungal pathogen Corynespora cassiicola: A review and insights for target spot management on cotton and Soya bean

“…As demand for food and fibre to a growing world population increases, crop yields must increase on existing farmable land while protecting the environment (CropLife International, 2014). Thereby, the importance of using IPM is not just for the disease discussed here but for every pest population as stated in the FAO definition of IPM (Vetek et al, 2017 (Roth et al, 2020). Additionally, cultural practices are included in IPM adjusting tillage, row spacing, plant population and irrigation (Roth et al, 2020).…”

“…We discussed here some disease management strategies to improve and to better understand target spot management, but there is a need of more applied research (Molina et al, 2019). In addition, there is a need for research on developing disease prediction tools to anticipate possible pathogen threats and disease outbreaks (Dutta et al, 2020;Roth et al, 2020). If farmers and researchers could anticipate the optimum environmental conditions for target spot development, management practices could be implemented in time to reduce the risk of the disease.…”

“…Genetic resistance, crop rotation, fungicide, and nematicide seed treatments, mid‐season fungicide sprays and biocontrol were included in the IPM strategies recommended to manage diseases on Soya bean (Roth et al., 2020). Additionally, cultural practices are included in IPM adjusting tillage, row spacing, plant population and irrigation (Roth et al., 2020).…”

“…Genetic resistance, crop rotation, fungicide, and nematicide seed treatments, mid‐season fungicide sprays and biocontrol were included in the IPM strategies recommended to manage diseases on Soya bean (Roth et al., 2020). Additionally, cultural practices are included in IPM adjusting tillage, row spacing, plant population and irrigation (Roth et al., 2020). The integration of crop rotation with non‐hosts, destruction of plant residues, sanitary practices of seeds, germplasm genetic resistant to target spot and fungicide applications help with disease management and reduction of yield losses on cotton and Soya bean (Galbieri et al., 2014; Hartman et al., 2011).…”

A Bacillus thuringiensis Cry protein controls soybean cyst nematode in transgenic soybean plants

“…H. glycines can reduce yield by 30-50%, even in fields with little or no visible above-ground symptoms 4,5 . In the U.S. control of nematodes has relied on the use of varieties incorporating native resistance 6 , crop rotation, and nematicidal seed treatments 7 . One source of native resistance, derived from plant introduction (PI) accession 88788, results from a high copy number of the rhg1-b allele 8 .…”