GMOs and Corn Mycotoxins

Corn grain can be naturally contaminated by mycotoxins, natural toxins produced by fungi.  Though most Kentucky corn crops are free of mycotoxins, fumonisins are the most common threat.  These toxins affect a number of animal species, but horses and pigs are among the most sensitive. Aflatoxins are generally very uncommon in Kentucky, but when they occur, they can cause serious disruption to grain marketing.  Both mycotoxin families pose health risks to humans.  

Figure 1. Fusarium ear rot of corn, usually associated with fumonisin contamination.

Fusarium Ear Rot and Fumonisons

Paul Vincelli, Extension Plant Pathologist, University of Kentucky

Figure 1. Typical symptoms of Fusarium ear and kernel rot.
Note whitish fungal growth.
 Usually damage from Fusarium ear rot affects
scattered kernels or groups of kernels, as shown here.

The content of this article previously occurred in the Kentucky Pest News, number 1315.

Pre-harvest contamination of corn with fumonisins is a possibility in some lots of this year’s Kentucky corn crop. Fumonisins are a family of mycotoxins produced by the fungus that causes Fusarium ear rot. These natural toxins have the potential to cause lethal diseases of horses and swine (the diseases are equine luekoencephalomalacia and porcine pulmonary edema, respectively). Pre-harvest contamination of corn by fumonisins is most often associated with drought stress at the silking stage, a stress that occurred widely in Kentucky and beyond.