Issue No. 8, Article 3/May 25, 2012
Seedling Blight in Corn and Soybean
Although much of the state has been relatively dry this spring, seedling blight has been observed in some areas that have received more frequent rain. These problematic fields generally were planted early, followed by cool and wet conditions.
Seedling blight of corn and soybean can be caused by multiple pathogens, including Fusarium species, Rhizoctonia solani, Pythium species, Phytophthora sojae (soybean only), and others. The major symptoms being observed are poor stands, stunted plants, damping-off, discolored roots (and mesocotyls), and poorly developed root systems. These symptoms may be caused by factors other than diseases, so accurate diagnosis is important. For the best accuracy, pathogen isolations may need to be done by a plant diagnostic lab such as the University of Illinois Plant Clinic.
Corn plants affected by seedling blight.
Soybean plants that have damped-off due to seedling blight.
Corn seedlings affected by seedling blight.
Management of seedling blight can be difficult, but an accurate diagnosis may allow better management the following year through selection of specific fungicide seed treatments that may be more effective against certain pathogens.--Carl A. Bradley
Carl A. Bradley