Poor stand establishment can be caused by several factors, including soilborne fungi. Germinating seeds of maize and soybean may be attacked by soilborne fungi that cause seed rot and root rot. Chemical treatments of corn seeds reduce infection. Seed rot and seedling blight of corn generally are not a production problem, unless weather is very wet or other conditions are unfavorable. However, scouting for seed rot or seedling blight of corn is still recommended.

Severe infection may kill the embryo before germination or destroy the seedling before or after emergence. These diseases are prevalent in poorly drained, excessively compacted, or cold and wet soil. Stand reduction is affected by planting depth, soil type, age, variety, and quality of the seed . In addition to seed rot, Pythium also causes seedling blight of corn and infects roots of adult plants during the growing season. Root infection weakens plant vigor, which induces other disease problems.

Information on stand reduction in corn fields is useful for the management of seedling disease of corn, as well as for management of soybean seedling blight. Under corn-soybean rotation, Pythium is a major cause of soybean damping-off. It also can infect corn seeds and seedlings. Our data showed that about 60 percent of Pythium isolates from soybean also infect corn. Pathogen populations can increase on corn and threaten next years soybean. Because soybean seeds usually are not treated, they can be attacked by the disease. If you know which diseases of corn are present this season, you can estimate the risk of soybean seedling blight next season and manage seedling blight.