Madison, WI—Unusual growing and harvest conditions in 2009 have increased the risk of stored grain going out of condition this winter and spring. University of Wisconsin-Extension specialists Brian Holmes and Cheryl Skjolaas explain how this crop is different from past crops, what you can do to reduce further quality loss in storage and how you can stay safe when inspecting the grain. “Molds and fines are at the core of the situation,” said Holmes. "The cool growing conditions delayed the corn harvest which resulted in grain being harvested wetter than usual. "Combining wet grain increased kernel damage resulting in kernels susceptible to infestation by molds. "The fines resulting from the damage should have been removed before storage."If all or some of these fines remained in the storage, they are susceptible to mold infestation and interfere with aeration of the stored grain.” Wet cool conditions during the growing season, resulted in mold infestation of the crop before it was mature. These molds remain viable awaiting to explode when, and if, the right conditions develop in storage.Corn that was frosted before maturity is more susceptible to infestation by molds than is mature grain. Holmes noted that the delayed harvest caused some producers to operate their dryers at high temperature to increase the drying rate. Hot grain cooled quickly in the dryer is susceptible to stress cracking. Stress cracking increases the likelihood of kernel breakage during handling resulting in increased fines accumulation in storage. In a normal year, corn should be dried to 15 percent moisture if stored for 6 months and 14percent if stored up to 12 months.When kernels are more susceptible to mold infestation, corn should have been dried an additional percentage point lower than these recommendations. Some producers may not have made this adjustment in final moisture content.In some cases producers trying to get the drying process to move as quickly as possible may not have dried grain to the normally recommended values. “Bottom line is the current crop in storage needs extra management to reduce further quality loss. "Inspection is the key to helping preserve the quality of your stored crop,” Holmes said. Like the complexities of growing and harvesting the crop, inspecting the stored crop has varying factors. When inspecting the crop, you’re looking for accumulations of fines and signs of molds including “hot spots.”To properly check the bin entry is required. Skjolaas said, “The person entering the bin should consider their safety prior to entering. "Two recent rescues from grain bins remind us all of how quickly a person can become engulfed in grain and the unknown dangers of crusted grain.”
Before entering a bin, Skjolaas noted a person should:

• Lock out and tag out the removal auger system so it will not be turned on while you go into the bin to inspect the grain.

• Turn on the aeration fan to clear accumulated gases from the head space above the grain.

If molds are present, carbon dioxide levels may be elevated creating an oxygen deficient atmosphere.

• Use an approved respirator to filter out molds and spores that may enter your respiratory tract.

• Use precaution.

Safe entry requires using a harness with two ropes and two assistants outside the bin. This may seem like an excessive precaution but the forces of grain are significant if you become engulfed. Prior to entering the bin, check the level of the grain by looking through the hatch. If you know that grain hasn’t been removed, then it is time for entry. If grain has been previously removed, look to see if a cone on the grain surface has formed. If a cone is not present, there is a high likelihood of a cavity below the grain surface crust. Use a long pole to probe through crusted grain on the surface for a cavity below the crust before walking on it. If there is a cavity, use the pole to break up the crust.It may take some extra work to break the crust up from the outside with a pole but if you fell through the crust, rescue would take much longer. After entering the bin, move around the grain surface and smell for zones of mold odors. Make a note of where you find them. Using a temperature probe, look for zones of elevated grain temperature at various depths and locations, in particular where you noted zones of mold smell. Exit the bin and turn off the aeration fan. If the center core of grain has not yet been removed from the bin do this now.This core is a common location for fines to accumulate and increases the chances of molds in this area. Inspect the removed grain for molds and crusted grain. If a problem is observed and the grain appears to be going out of condition, turn on the aeration fan to cool down any “hot spots” that may have developed. If no problems were observed during the inspection, plan to repeat the inspection process at two week intervals throughout the rest of the winter and plan to increase the rate to weekly once daily average temperatures increase. Use the inspection procedures to determine if the aeration process is controlling the grain temperature.If not, the grain will have to be removed from the bin to market or to another bin to break up the “hot spots.” If grain is to be placed in another bin, screen the grain to remove fines before loading the bin.