Crazy Top Downy Mildew (fungus - Sclerophthora macrospora): This disease is a problem when fields become flooded early in the life of the plant. The fungus produces swimming spores which require water for mobility. Infected plants are sterile and have numerous shoots at the base of the stalk. Leaves are thickened, distorted, and a lighter green color than normal leaves. Tassels and ears develop green, leafy shoots. The fungus is commonly found in grasses along the edge of the field. Spores are washed into the field in flood water. Infection of the young corn plants takes place at this time. Varieties vary in their reaction to this fungus. Due to the low percentage of occurrence, little has been done to rate varieties for their reaction. Avoid fields that flood regularly and plant on a raised bed which will help reduce the exposure of young seedlings to standing or flowing water.
