Corn Smut: Is It A Concern?

 

Since corn silage harvest has started to occur throughout the state we have been receiving a lot of questions regarding corn smut and whether or not it is a concern if fed to livestock. Common corn smut is considered a minor disease of economic importance in South Dakota.

 

 

Corn smut is caused by a fungal pathogen, Ustilago zeae, and can survive over the winter or for several years, depending on environmental conditions. These survival spores, called teliospores, can be transported long distances with soil particles, on unshelled seed corn, and can be transported in animal manure from animals which are fed infected corn stalks. When this manure is spread onto the field, the spores can germinate and infect plants for several years. This year we have had a lot of hail events which has caused wounds (Figure 1 and Figure 2) on the plants and provided an entry point for the corn smut fungus.

 

Is it harmful?

 

Corn smut does not produce any harmful mycotoxins or aflatoxins. There are no direct hazards from feeding the grain or corn stalks to the livestock. The livestock may find the spores irritating to their nasal passages and sinuses and may choose not to feed on smutty grain or stalks and may instead choose to feed on alternative feed stuff if available. Not only is corn smut not harmful to livestock but it is also not harmful to people. In fact, some cultures view and consume the immature corn smut galls as a delicacy.