Some farmers didn't get their grain dried this fall and winter. Now that temperatures are rising and spring is just around the corner, farmers need to be vigilant about keeping an eye on their stored grain, University of Nebraska-Lincoln (UNL) specialists say.
Tamra Jackson, UNL plant pathologist, says it is still important to watch for grain molds and ear rots in stored grain.
"Many producers harvested when moisture was high," she says. "The best way to stop those molds is to dry down grain."
However, those who had to rely on natural air drying were not able to dry down their grain last fall, says Tom Dorn, UNL Extension educator in Lancaster County.
Although cold temperatures likely stopped fungi growth this winter, Jackson says, once temperatures get above freezing fungi will continue to grow and reduce grain quality.
Jackson says observing temperature and looking at grain frequently is key as temperatures rise.
She has heard that some farmers are seeing a white, moldy crust forming over the grain. Fusarium and diplodia have been the most common culprits. Some of these fungi can produce mycotoxins, such as fumonisin. While fumonisins are especially harmful to swine, cattle are less susceptible. So selling grain to a feedlot might be one avenue in which to sell moldy grain.
Dorn hopes as temperatures rise this month producers can put some natural air through the grain.
Dorn suggests using a temperature probe to take grain temperatures near the bin wall about every 20 ft. around the outside of the bin and a couple of places near the middle of the bin.
"If there is more than a 10° difference in temperature between any two spots in the bin, run the aeration fan long enough to push a temperature front through the entire grain mass," he says.
Farmers who do not have a temperature probe can test for signs of heating by turning on the aeration fan and leaning into the access hatch or by climbing into the bin, Dorn says.
"If air hitting the face feels warmer than expected, you detect a musty odor or condensation is forming on the inside surface of the bin roof on a cold day, continue to run the fan long enough to push a temperature front through the bin," he says. "If the bin is equipped with a stirring system, run two or three rounds to break up hot spots and equalize the moisture throughout the grain mass.
"If the warming signs are present, and the bin is not equipped with a stirring system, pull a load or two out of the bin and monitor the condition of the grain coming out of the auger. If you detect heating, run the aeration fans to cool and dry the grain if air properties allow. Or, you can market the grain."
Dorn also recommends leveling the grain surface if the remaining grain will be left in place.
For corn that is above 15% moisture that will continue to be held in the grain bin on the farm, Dorn recommends to finish drying it to a safe moisture content.
"The first objective is to warm grain that was cooled in late fall to preserve it during the cold months," he says.
Grain should be warmed in stages by running a warming front through the bin when outside air temperatures are 10-12° higher than the grain temperature.
For more information on when to run an aeration fan to dry the corn, visit Crop Watch, UNL Extension's crop production newsletter, or for more information on molds watch Market Journal.