Corn plants infected by this fungus develop white, spongy galls that gradually turn gray-brown and then become filled with powdery black spores. Any aboveground parts of the plant may be affected, but corn smut most commonly occurs on the tassels and ears of the plant.
The disease has several common names, including corn truffle and corn mushroom. In Mexico the infected plant parts are called huitlacoche and are considered a delicacy. Corn smut spores are spread by wind and splashing water. Disease spores overwinter in the soil. The disease is most prevalent in hot, dry weather, especially when those conditions occur early in the growing season. Corn smut is seldom a problem during cool, wet summers.Prevention and Control
- Grow smut-resistant varieties such as Silver King and Argent. Avoid planting highly susceptible varieties such as Silver Queen and Country Gentlemen.
- Cut off any galls as soon as they begin to develop and destroy them before spores can be released.