First case of red crown rot confirmed in Missouri
University of Missouri Extension state plant pathologist Mandy Bish reports confirmation of red crown rot, yield-robbing soybean disease, in Marion County in northeastern Missouri.
This is the first confirmed incidence of the disease in the state. Bish said MU Extension specialists have been scouting for the pathogen since its confirmation in Illinois in 2018.
Yield losses from red crown rot can be significant, with estimates ranging from 15% to 70% in affected areas of a field. The fungus survives the winter in plant residue, prefers warm and wet conditions for growth and can infect soybean roots shortly after planting.
Symptoms begin to appear later in the season, usually when soybean plants enter the reproductive stage, Bish said. Leaves of infected plants can have symptoms that resemble sudden death syndrome.
Growers should pull up plants and look at the roots to distinguish red crown rot from sudden death syndrome. Containing the disease requires minimizing disease spread and reducing the amount of pathogen in the soil. Crop rotation to a nonhost crop like corn for two years and reducing the spread of the disease by machinery can help. Fungicide seed treatments that are labeled for red crown rot may help protect against early-season infections.
