Handling storage of mycotoxin infested grain

By Luke Schulte, CCA, Beck’s field agronomist

Unfortunately, many farmers observed ear molds throughout harvest, leading to some level of mycotoxins in the grain. While the abnormally dry weather this fall has helped minimize the severity of these toxins, many fields still had some level of ear mold and toxins present that now resides in farm storage bins. The management of that stored grain can potentially significantly impact the mycotoxin level and potential discount fees associated with that grain as it is hauled out.

For farmers who observed ear molds at harvest but store 100% of their crop, the presence of mycotoxins may not be known yet. I’d encourage those in this situation to take the time now to get a representative grain sample to better understand the potential for toxins and the required management that may be beneficial in the coming months.

Since most of the mycotoxins reside in the fines and bees’ wings, minimizing these components within storage is critical. Ideally, this would occur before storage. However, practices such as coring bins, the use of grain cleaners, as well as methods of loadout can also play an important role in minimizing these components within the sample.

Storage, moisture, and handling

• Core bins immediately to remove fines
• Utilize the grain cart at loadout as additional transferring allows for wind to further remove fines/bees’ wings
• Dry immediately (within 48 hours of harvest) to below 15% moisture to prevent further fungal growth
• Ideally, grain stored long-term should be dried to 13.5% moisture  
• Keep well aerated and cool and maintain a temperature of 36 to 44 degrees F

Prioritize and designate

• When hauling stored grain prioritize grain that was harvested wetter as additional fines were likely created throughout harvest and drying and prioritize grain stored above 15% moisture
• Haul early since warm, moist pockets in storage will grow
• Segregate infested grain if possible
• End-users will vary in mycotoxin allowance, feed mills and ethanol production will likely be more restrictive 
• For those growers still harvesting, there is an excellent video explaining some simple combine modifications targeted to minimize the fines and, ultimately, the volume of mycotoxins within the grain sample before delivery or storage.