Submitted by Wayne Flanary

Growers, industry and MU Extension are trying to identify if soybean red crown rot is present in any fields in Northwest Missouri. The symptoms are yellow leaves with brown spots between leaf veins. The symptoms are like sudden death syndrome.

The disease is caused by a soilborne fungus, Calonectria ilicicola, and generally shows symptoms after R-3. Patches of plants often are found in low-lying or poorly drained areas of the field. This disease may cause extreme yield losses.

This disease was found in the southern United States in the 1960s and was also found in Illinois in 2018. Since 2024, this disease has been found in nine Missouri counties.

The United Soybean Board and Missouri Soybean Merchandising Council along with the University of Missouri Extension are supporting a limited number of farmer-submitted samples to the MU plant diagnostic clinic for pathogen culturing and real-time PCR analysis, according to Dr. Mandy Bish, MU Extension state plant pathologist.

For questions and submitting a physical sample, contact the MU plant diagnostic clinic website or contact the clinic at 573-882-3019. It is important to take the soybean root system carefully so the diagnosis can be made.

For more information contact Wayne Flanary, Field Specialist in Agronomy, University of Missouri Extension, at 816-279-1691.