Courtesy of Purdue Extension
Before farmers go full throttle into the 2012 planting season, they would be wise to inspect what's left of their 2011 corn crop for signs of mold, says a Purdue University agricultural engineer.
Richard Stroshine said he has heard scattered reports of Indiana farmers finding higher-than-normal percentages of moldy, discolored kernels when they've removed corn from storage facilities. Elevators and other buyers of corn pay less for mold-contaminated grain, if they buy it at all.
Corn stored in bins since the fall harvest could be at a heightened threat for mold, Stroshine said. The reason? A winter that wasn't cold enough for long enough to protect the grain from fungal infection.
Moldy corn can contain toxins harmful - even fatal - to livestock. Much of the corn grown in Indiana is used as animal feed.
"Farmers should constantly be checking their grain for mold growth," Stroshine said. "If they find mold, they've got to get that corn out of the bin as soon as possible so that it doesn't spread to other grain in the bin."
A typical winter with air temperatures regularly near or below freezing allows corn to be cooled to temperatures near freezing, inhibiting mold development. That is particularly important when corn is stored at or above 15 percent moisture. This past winter saw many days above 50 degrees Fahrenheit, creating conditions more favorable for mold growth.
When mold risks are high, farmers should take steps to evenly cool the grain in the bin. A common practice, known as coring, involves taking one or more truckloads of corn from the bin and leveling the crop that remains. The process removes fine material that often accumulates in the center - or core - of the bin, filling air pockets between kernels and restricting air circulation.
To ensure even airflow distribution, farmers should maintain a level surface at the top of the bin. Without sufficient and uniform air movement in the bin, heat can build up in some areas and promote mold growth.
Farmers who cored their bins reduced the likelihood of mold problems this spring but still should keep an eye on their leftover crop, Stroshine said. Those who didn't perform coring operations will need to be even more vigilant, he said.
Bins should be visually inspected and grain temperatures monitored weekly, Stroshine said. He recommended running bin fans for 30 minutes before entering the storage facility to conduct an inspection.
"Aeration will push musty odors, which are indicative of mold growth, to the headspace of the bin," he said. "If the problems are deeper in the bin it will take longer for odors to reach the surface. So you could run the fans another 2-4 hours and check again.