Danillo Leite

Ph.D. Level Student
Southern Illinois University
Advised by Dr. Ahmad Fakhoury

Stem Diseases of Soybean: Identifying the Prevalent Causing Pathogens Across Illinois

Soybean (Glycine max) is one of the most important agronomic crops in the Fabaceae family. Soybean is used in a wide range of food products, animal feed, and industrial applications. In 2022, according to USDA, the estimated world production of soybeans was 370,109 million tons. Diseases of soybean impact production in all soybean-producing regions in the U.S. with yield varying from one production region to another. In 2022, the estimated loss attributed to diseases was 4.4% of the soybean produced in the U.S.; stem diseases were responsible for a significant portion of that loss. Soybean stem disease can have a negative impact on production, resulting from reduced yields, increased production costs, and lower seed quality. The main objective of this research is to identify the major stem diseases affecting soybeans across IL. The methodology used included sampling diseased plant stems in 2022 and 2023 from production fields across IL. Pathogens were isolated from diseased plant material and identified using morphological features and molecular techniques with DNA sequencing of specific genetic loci. In both years, the most prevalent soybean stem diseases were stem canker and charcoal rot. An increase in the incidence of red crown rot was noted in 2023.