Corn smut, caused by the fungus Ustilago maydis, is a disease that attacks susceptible sweet corn varieties. Temperatures between 80 and 95 degrees F favor the development and spread of corn smut, which produces large fleshy galls on the leaves, stems, ears, and tassels. The immature galls are white and spongy, and as they mature they turn grayish white and contain black, powdery spores. Your best bet is to cultivate sweet corn varieties that are resistant to corn smut.
Contact your local Extension office for a list of resistant sweet corn varieties for your area.
