Managing Common Smut in Southern U.S. Corn Fields

Common smut is a fungal disease that survives on crop debris and in soil. While common smut is a disease that can affect corn in any location, fields in southern states can be particularly vulnerable to infection. The severity of infestation depends on conditions that allow the fungus to penetrate growing plants, such as excess nitrogen, herbicide or mechanical injury, and weather.

“High nitrogen and high organic matter are more prone to common smut infections,” said Rex Brandon, Pioneer Field Agronomist. “Sand blasting from wind, insect bites or anything that breaks down the surface tension of the plant provides an opening for the fungus to enter.”

At flowering, silks may also offer an entryway for infection if exposed before pollination occurs. Common smut can grow down through the silks and into the developing kernels. This is often the case in southern states with very dry and hot conditions, when pollen delay occurs, or when the pollen is not viable enough to ensure timely pollination and prompt separation of silks.