Red crown rot, a soilborne fungal disease that can cut soybean yields by 70% in severe cases, warrants consideration as farmers in affected areas finalize their variety selections and management plans for next year, agronomic experts say.
Historically prevalent in the southern U.S., red crown rot (RCR) is now moving northward with confirmations in at least seven key soybean-producing states since 2018, including Illinois, Indiana, Kentucky Minnesota, Missouri, Ohio and Wisconsin, according to the Crop Protection Network.
The speed at which the disease can move is illustrated by its progress in Illinois. A single infected field was identified there in 2018. Since then, RCR has spread to more than one-third of the state’s 102 counties.
In Minnesota, Ohio and Wisconsin, agronomists confirmed isolated cases of the disease in farmers’ soybean fields for the first time just this year.
“When the disease was found in Minnesota (Rock County) in August 2025, the nearest known location with red crown rot was over 400 miles away in NW Illinois,” says Dean Malvick, University of Minnesota Extension plant pathologist.
Compounding concerns is that the modes by which red crown rot is spreading into the Midwest aren’t fully known, he adds.
Seed Companies Are Working On Solutions
“Most or all soybean varieties” adapted to the Midwest that have been evaluated by researchers to date appear to be susceptible to the disease, although differences in disease susceptibility have been reported, Malvick notes.
“Certainly, the seed companies are looking at resistance… and are getting some idea of what genetic backgrounds relate to resistance to red crown rot,” he said during a recent podcast.
While no soybean varieties are fully resistant, high-performing, disease-tolerant seed can help growers reduce the potential impact of RCR, according to Bill Kessinger, Stine technical agronomist.
Kessinger tells growers in affected areas he believes the No. 1 goal is to continue focusing on selecting high-yielding soybeans that will provide the best return-on-investment. Secondly, then consider how well those varieties score for resistance to RCR before making your final selections.
“We have to understand, with regard to seed, what we are going to give up compared to what we are going to get, and what risk we want to take as a grower,” Kessinger says. “It’s not an all or nothing decision … and everything still has to revert back to yield.”
BMPs And Seed Treatments Can Help
Integrated management practices are critical to addressing RCR, as the fungus overwinters and survives in the soil, reports Horacio Lopez-Nicora, Ohio State University assistant professor of soybean pathology and nematology.
“Once established, this pathogen is nearly impossible to eradicate, so integrated management is the only sustainable path forward to reduce its impact on our soybean crop,” Lopez-Nicora explains in an online article.
He says practices such as crop rotation with nonhost crops, improving drainage, using seed-applied fungicides and managing soybean cyst nematode populations — which can intensify red crown rot severity — will be important to farmers working to protect yields in RCR-affected areas next season.
Malvick adds that some seed treatment fungicides are reported to reduce the impact of red crown rot in soybeans.
“There’s more evidence building now that’s showing some of them work against both SDS and red crown rot,” Malvick says. “We don’t again have that evidence for the northern U.S. but we have enough information to say we probably have products that will be reasonably effective at least.”
Current soybean seed treatment options include Saltro and Victrato (pydiflumetofen, cyclobutrifluram; Syngenta), ILeVO (fluopyram; BASF) and Pretium SDS, a biological seed treatment (natamycin; Nufarm). Manufacturers advise checking with local retailers to see which seed treatment products are approved for use in your specific location.
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