Reports of corn not keeping well have been reported here as far back as six weeks ago. Recently, Richard Stroshine, Purdue University grain storage and corn quality specialist, reported that he was receiving considerably more calls than usual about storage problems with corn compared to the same time of year in other years. Matt Roberts, Syracuse, who assists in grain storage Extension work, based in northern Indiana, has also fielded similar questions.
"This past winter was milder than usual," Stroshine begins. As it turns out, according to Ken Scheeringa, assistant state climatologist, it was the fifth warmest winter on a statewide basis dating back to 1930. The average temperature was 5.4 degrees above normal on a daily basis. To a weatherman, that's a very significant deviation from normal.
"We usually have a week or more of days in which the air temperatures are cold, but this year did not have those strings of cold air days," Stroshine continues.
Having cold air for a week or so allows you to move a cooling front through the bin to bring the temperature down near freezing, he adds. Stroshine doesn't recommend freezing grain, but he does recommend lowering the temperature significantly by aerating until it reaches a point somewhere above freezing. Once grain is brought down to that level, there is usually very little fungal growth, he adds.
The situation is worse if grain is peaked in the bin and/or there is a concentration of fines in the middle of the grain mass in the bin. That's why Stroshine typically recommends coring bins and pulling down the peak once harvest is over. Some reports received here were from people who did not follow that procedure after harvest.What happens when you don't remove corn from the center and reduce the concentration of fines, or leave the grain peaked, is that air flow can be reduced. The grain may not have cooled out properly, especially this year when cooling was an issue in the entire bin. As a result, there was a prime opportunity for fungal growth inside bins that weren't cored properly.