New Recommendations for Drying Aflatoxin Corn

Original estimates for dry down was at least 13%, but now a Purdue grain specialist says that may not be necessary.

Published on: Oct 12, 2012

Word in the country is that several farmers are taking Purdue University ag economists at their word and selling corn out of the field, figuring price won't go up later. Some are also worried about storage concerns for this crop.

If you are storing some corn, here are some suggestions. Richard Stroshine, Purdue grain quality specialist, says that if you don't have aflatoxin, storing this year shouldn't be much different than storing any other year.

He originally feared farmers would be binning corn while it was very warm. However the weather broke and that didn't materialize. Handling corn has been somewhat easier than anticipated so far.

Dry grain to 14.5: You will likely need three cooling cycles to drop temperature for winter storage.
Dry grain to 14.5: You will likely need three cooling cycles to drop temperature for winter storage.

Others also originally said to dry aflatoxin corn down to 12 or 13% to prevent further growth. Now Stroshine is suggesting that if you are storing corn, dry to 14.5%. That may be somewhat lower than normal, but not as low as previously suggested.

You can stop Aspergillus at 16% if it's cool too, Stroshine says. However, other molds can grow at lower moisture levels. That's why he's suggesting 14.5% if you're going to hold corn for any period of time.

Aspergillus is the fungus that can produce aflatoxin. However, other molds can produce other myciotoxins. Some of those cause as much or more trouble with certain species of livestock, such as hogs, than aflatoxin.

As always, he advises running grain through a grain cleaner before binning it. This year that should help remove the lightest, most damaged kernels. Then core and level bins. One that's done, start the aeration process to lower the temperature. If you've got a half-horsepower fan and a 40-foot diameter bin with 20 feet of depth, then figure on 150 hours to move a cooling front through the grain. Make sure each front moves completely through before shutting off fans. Stroshine estimates that it will take about three cycles to get grain down to just above freezing if you're carrying into winter.