This article was written by Angie Peltier, UMN Extension educator-crops. Figure. Soybean roots, with yellow arrows pointing to swollen female SCN and the white arrow to a much larger nitrogen fixing nodule. Photo: Angie Peltier Soybean cyst nematode (SCN) is a microscopic worm that is attracted to and infests soybean roots where it uses for its own growth and development the water and sugars that the soybean plant takes up to develop leaves, flowers, pods and beans (Figure). Capable of causing significant yield loss without alerting a producer of its presence, SCN caused an estimated $7.32 million in lost yield in 2023 in Minnesota (Crop Protection Network, 2024), making it the top yield-limiting pathogen of soybean in Minnesota and throughout the Midwest. One of the most sickening feelings is to visit a field to assist a farmer or crop consultant with diagnosing a soybean production issue only to have to break the news to the unsuspecting that the field is infested with SCN
This article was written by Angie Peltier. The 2024 growing season couldn't have been any more ideal for sudden death syndrome (SDS) symptoms to appear in soybeans during reproductive growth stages, provided your field was infested with Fusarium virguliforme , the fungus that causes SDS. If you encounter soybeans in northwest Minnesota, please send me an email (apeltier@umn.edu) or give me a call {(218) 281-8692} as I would like to come and check out your field and collect isolates for further study. Wet weather this spring lead some to 'mud in' their soybeans, likely lead to both side wall and general compaction and wet weather after planting all favor infection by F. virguliforme. Infection can take place just as soon as the radicle breaks through the seed coat. While SDS can cause root rot, it is most often much later in the growing season that the most conspicuous symptoms of SDS become evident. While the fungus remains below ground, plenty of rain during the reproduct