Molds, mycotoxins and storage keys to this year’s corn crop

By Nathan Winter
Extension Educator – Agricultural Productions Systems
McLeod/Meeker County
The cool summer with below average heat units followed by an extremely wet fall have caused great concern for a quality corn harvest in the fall of 2009. The wet and cool conditions have made for extremely favorable conditions for mold development on corn in the field. The higher moisture corn in the fields along with the presence should be concerns for livestock and non-livestock producers, but to what extent is going to be variable.

To better understand some of the problems with grain in many area fields it is important to understand what is potentially harmful. Molds are any of various fungi that often cause breakdown of organic matter. Mycotoxins are any of the mold-produced substances that may be injurious to vertebrates upon ingestion, inhalation, or skin contact. The other term that is often talked about is aflatoxoins. Aflatoxins are naturally occurring mycotoxins that are produced by some species of the fungus Aspergillus, most notably Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are toxic and among the most carcinogenic substances known.

Molds and mycotoxins can cause problems for livestock, but seeing some mold doesn’t necessarily make it a critical issue. Low levels of molds sometimes produce high levels of mycotoxins. High levels of mold sometimes produce insignificant levels of mycotoxins. Colors of mold can partly be an issue. Some of the colors of molds that are sometimes noticed include black and gray, white, and blue-green-pink. Aflatoxin in one of many mycotoxins and perhaps the most serious when present in feed for milk cows and in grain markets. Aflatoxin is more prevalent in a hot dry growing season like 1988 and is not likely to be an issue this fall.

One of the concerns at this point is for crop producers that have crop insurance coverage for molds.