Alfalfa is a significant crop in South Dakota that provides many different benefits for its growers. South Dakota plants the most acres of alfalfa in the United States. It is used as a protein-rich feed for livestock, a cover crop that protects against soil erosion, and a natural fertilizer because of its ability to fix nitrogen in the soil. However, alfalfa seedlings are susceptible to many diseases. Pythium root and seed rot is one disease known to have devastating effects on alfalfa field establishment and yield. Pythium species are oomycete pathogens that inhabit the soil and remain present and pathogenic as oospores. Pythium diseases of alfalfa cause reduced root systems, plant size, length, and growth rate. Pythium management is centered on fungicidal seed treatments. There have been recent reports of Pythium spp. infecting alfalfa across the world in places like Sudan and China, but current research in South Dakota is needed. In our research, we isolated Pythium spp. from Lake County South Dakota soils under commercial alfalfa production. We also characterized these isolates with a DNA sequencing analysis and evaluated the isolates for fungicide sensitivity. This summer, we will conduct a statewide Pythium disease survey and assess the collected isolates for fungicide sensitivity and pathogenicity towards various commercial lines of alfalfa. This research will provide growers with the information necessary to make educated decisions in order to increase yields and maximize their profits.
Giles, Jennifer M. and Sathoff, Andrew E., "Isolation and characterization of Pythium spp. from South Dakota soils under commerial alfalfa production" (2021). Faculty Research & Publications. 25.