Less severely infected plants may elongate and produce distorted heads with no grain. The pathogen attacks wheat, oats, barley, rice, corn, sorghum and about 140 species of wild grasses. All adapted wheats are believed to be susceptible. The fungus produces thick-walled survival spores within infected tissue. These penetrate leaf sheaths, and then the fungus becomes systemic within the plant.
Seedlings are more susceptible than adult plants.
Avoiding areas prone to flooding and providing for adequate drainage of surface water are the best means of controlling downy mildew. Apron fungicide seed treatment, which is registered for control of Pythium root rot, may provide protection against downy mildew for a few weeks after planting. However, under Arkansas conditions flooding may occur over a period of several months after planting. The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, marital or veteran status or any other legally protected status, and is an Equal Opportunity Employer. The mention of any commercial product in this web site does not imply its endorsement by the University of Arkansas Cooperative Extension Service over other products not named nor does the omission imply that they are not satisfactory.