Utah State University Extension
Corn smut is caused by the fungus Ustilago maydis. Smut rarely occurs in Utah and is not considered economically important for grain production. For home gardeners and small farms, serious smut infections on sweet corn can cause ears to be inedible. U. maydis spreads from plant to plant by wind-borne or water-splashed spores onto silks or through existing wounds. Therefore, keeping corn plants insect- and disease-free reduces the number of entry points for infections. This fact sheet reviews the disease cycle, identification, and management.
Taylor, Kalen; Volesky, Nick; Nischwitz, Claudia; and Murray, Marion, "Corn Smut (Ustilago maydis)" (2021). All Current Publications. Paper 2223.