Corn that has been frosted can be very susceptible to Gibberella ear rot if it remains in the field for a long time. This is particularly true if a frost comes before maturity. Fortunately, most of our corn this year reached maturity before the frost. Ear rot diseases can reduce yield and quality of the corn harvest and some of these fungi can produce mycotoxins that are harmful to livestock, so it can pay to be aware of their occurrence in your fields or grain. To check for ear rots, strip back the husks on at least 100 plants scattered throughout the field.
Scout fields separately according to hybrid, tillage and rotation history, and planting date.
It is important to be able to recognize the ear rot diseases because their potential impact is very dependent on the particular fungus involved. Once the corn is harvested, it can be more difficult to recognize the symptoms, but if there is a major problem, it will be evident in the grain. When evaluating an ear rot problem, remember that certain ear rots are a warning sign to suspect toxins, but ear rots do not always lead to toxin problems. Even those fungi that can produce toxins do not always do so. Proper handling reduces the risk of toxin development in infected kernels.