One of the situations that can arise when the corn crop is placed under drought stress is the opportunity for various fungi to produce a group of chemicals known as aflatoxins and mycotoxins. As harvest progressed, these toxins have been noted in some shipments of grain to elevators. Note that aflatoxins are poisonous to humans and livestock, and should not be consumed. Grain merchandisers are prevented from buying grain that is contaminated with 20 parts per billion or more aflatoxin. This prevents humans and livestock from aflatoxin contaminated food and feed products. Mycotoxins are of more concern when feeding contaminated grain to horses and swine.
Anytime a corn crop is stressed by drought, there should be concerns about aflatoxins and mycotoxins. But one must remember that not all fungi produce aflatoxins. The primary fungus responsible for aflatoxins is Aspergillus ear rot; and the primary source of mycotoxins is from fumonisin, caused by Fusarium ear rot.
Aspergillis ear rot is a olive-green mold on the ears, while Fusarium is salmon-pink to reddish discoloration on individual kernels or groups of kernels.
The key to confirming the presence of these toxins is laboratory testing of the grain. If you suspect you corn crop is contaminated with fungi, there are specific consequences that may result. Discounts in price may occur, or even a requirement to destroy the grain. Key here – if you have crop insurance – contact your crop insurance agent before doing anything with the standing crop.
There are several good WEB based articles on aflatoxins, mycotoxins and the impact on grain/
CLICK HERE - Aflotoxin Testing - from USDA
CLICK HERE - Mycotoxins Produced by Fusarium
CLICK HERE - Aflatoxins in Corn