In what's turning out to be perhaps the worst harvest season since 1974, finally getting corn out of the field won't be the end of the story. Best case, you'll likely have wetter than normal corn to dry and store. Worst case, you may also have to contend with molds, and perhaps the possibility of mycotoxins in the corn.
Because of the possibility of molds, Richard Stroshine, Purdue University grain quality specialist, advises bringing moisture down to 20% or below as quickly as possible. That slows down mold growth. The two most common ear rots showing up in Indiana are diplodia and gibberella. Diplodia causes kernel damage but doesn't produce mycotoxins. Gibberella, the pinkish mold, is capable of producing two toxins. Both affect hogs more quickly than other species, but at high enough levels, even ruminants can be affected.
Iowa State University researchers have studied the shelf life of corn at various moisture levels. It's highly correlated to harvest moisture percentage and grain temperature. A 10 degree drop in grain temperature form 50 to 40 degrees can almost double shelf life. Taking corn even one percentage point drier when reaching storage levels can also have a dramatic impact on overall shelf life.
What you need to know now, the Iowa State researchers say, is that the clock on declining shelf life starts ticking even in the wet holding bin. The longer corn is left there, the shorter shelf life will be, even after drying. That corn will be more susceptible to hot spots and other storage issues if it's held into the spring or summer.
Meanwhile, Stroshine advises against keeping corn with mold quality issues that long. He suggests getting it all the way to 15% or under and 50 degrees or under as soon as possible. Growth of molds that occur in storage, different than the ear rots that attacked in the field, are stymied under those conditions.
To buy extra insurance against potential mold and spoilage, dry corn to 14% this year, even if it is only going to be in the bin for a relatively short time into early winter. While it costs more money to dry that extra percent and wouldn't normally be recommended, the protection against further mold development that you achieve may be worth it this year, the grain quality specialist concludes.