The good news so far is despite fears that drought-stressed corn might also be stricken with Aspergillus fungus, no reports of aflatoxin had been sent to Purdue Extension state specialists near the end of September. The Aspergillus fungus is capable of producing aflatoxins, although the presence of them doesn't automatically mean that the grain contains the toxins.
Charles Woloshuk and Kiersten Wise, both Plant Disease Extension specialists at Purdue University, have been on the look- out for Aspergillus ear rot, especially in southern Indiana and other locations that were especially hard hit by drought. So far, they have not found the fungus in commercial fields.
However, that doesn't mean you can forget about the possibility of it. "It may be out there and we just don't have reports of it yet," Woloshuk says. "The time to find out if a field has ear rot is before you harvest it. Once you harvest the grain, it becomes harder to know what you have. It's also easier to decide what to do with corn that might be infected before you harvest it. You still have the option of segregating it from corn that's not affected if you find it before combining."
Aspergillus generally produces a mold on the ear that is olive in color, Wise says. You may need to pull back a few shucks and inspect ears. However, just because you find mold doesn't mean that you have aflatoxins. You may not even have Aspergillus molds. It can easily be confused with other molds in the field, she notes.
In a recent video, Woloshuk demonstrated that if it is truly Aspergillus mold, it tends to be dusty and leave residue on your hand if you rub over it. What you're seeing are spores being released, specialists note. Not all olds display this characteristic.
Aspergillus is commonly confused with penicillium mold in the field. However, Wise says penicillium mold tends to have more of a bluish color. That particular mold does not produce mycotoxins. It can still cause damage to corn, but it won't be the source of aflatoxins, a form of mycotoxins.Corn that is infected, should you find mold, should be dried and cooled as quickly as possible, Wolshuk says. You should consider talking it down to 14.5 to 15% moisture to aid in stopping further growth of the mold, even once the corn is shelled.