Red Crown Rot Spread Through Midwestern Soybean Fields
The soil-borne pathogen, which causes up to 70 percent yield loss, has migrated across the U.S. since 2018.
Updated on Sept. 25, 2026 in Botany
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Red crown rot, a plant disease first documented in North Carolina in 1972, has established itself throughout the midwestern United States. The pathogen was identified in Illinois in 2018 and has since spread across several other states.
Why it matters
The disease represents a persistent agricultural threat because the pathogen can survive in soil for over seven years. Its movement through equipment and wind complicates containment for growers managing affected land.
The pathogen persists in soil for more than 7 years, causing significant crop loss. Documented yield reductions in heavily affected areas reach 60 to 70 percent.
The players
Ontario soybean growers
Agricultural producers managing crop biosecurity as they scout for potential pathogen exposure.
The details
Red crown rot spreads locally by a few inches annually, but transmission to new fields occurs primarily through the movement of inoculated soil on equipment and via wind dispersal. The pathogen remains viable in the soil for over seven years, necessitating long-term management strategies for farmers. Researchers are currently tracking its presence in states including Alabama, Louisiana, Virginia, Delaware, Missouri, Iowa, Minnesota, Indiana, and Ohio.
Timeline
1972: Red crown rot was first observed in North Carolina.
2018: The pathogen was identified in Illinois.
September 2026: No documented cases of the disease were found in Ontario.
The Tech Race
The current spread follows a pattern set by the 1972 initial discovery of red crown rot in North Carolina. Agricultural monitoring efforts now face a race to contain the pathogen as it moves from established regions into new territory.
Farmers in the Midwest and those scouting in Ontario must prioritize equipment sanitation to limit the transfer of inoculated soil. Yields in infested areas remain at risk of 60 to 70 percent losses until long-term soil management strategies are implemented.
The takeaway
Growers should maintain rigorous field scouting protocols, particularly given the seven-year survival window of the pathogen in the soil. Tracking the geographic progression across the U.S. remains the most critical metric for farmers to evaluate their specific risk levels.
Further reading
For more context on plant pathology, visit our Botany section.
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