This may be the worst outbreak of ear molds in Indiana since 1974, a very wet year that featured a very early killing frost in Indiana. At least that's how Richard Stroshine describes the situation farmers are facing with corn to be shelled and stored this fall. He's a grain quality specialist in the Ag and Biological Engineering Department at Purdue University.
Assume you've determined you have fields infested with molds. If you have appropriate crop insurance that might provide payment, you've contacted your crop insurance agent. Once it's time to shell and handle the grain, what's next?
If you take the grain straight to the elevator, there are several ways that you might be docked due to mold damage, notes Barry Soliday of icorn.com. "Kernels that show cob rot, mold infection and surface mold damage are screened and graded to determine total damaged kernels," he explains. Cobs and kernels ground up during the shelling process because ears have lost their integrity due to the infection appear in a different column- broken corn and foreign material.
The big problem comes if you're dealing with Gibberella-infested ears that produce toxins, note Charles Woloshuk and Kiersten Wise, Purdue University Extension plant pathologists. "The Gibb pathogen can produce two mycotoxins in infected kernels," Woloshuk says. "One is deoxynivalenol, known as DON and/or vomitoxin, which causes swine and other animals to both refuse feed and regurgitate it.
"The other is zearalenone, and it has estrogenic properties that lead to infertility, abortion and other breeding problems. As little as 1 to 5 parts per million of it in a feed ration may produce an estrogenic effect in swine."
Tables have been prepared with limits of how much of these toxins can be allowed, based on the age and classification of the animal. Consult county Extension educators if you need help interpreting where you might feed it, if you can feed it at all.
If you decide to store moldy corn on the farm, there's also concern for a high level of fines, the same thing that nets you BCFM dock at the elevator. "These fine particles decrease airflow during aeration, which increases the potential for storage problems," Soliday says. This certainly might be the year to add a grain cleaner to your incoming grain handling system, if you don't already have one in place.
Drying grain to 15 to 18% moisture stoops further growth of this fungus. However, Soliday notes that other fungi can still grow at 14 to 15% moisture. And you're dealing with 'damaged goods,' kernels already impacted by disease organisms.
"Drying below 14% and cooling the grain to 40 to 59 degrees is the safest if you're going to store it on farm," Soliday concludes.