Insects and mold can cause significant financial losses in stored grain, due to destroyed product and dockage.  Prevention always beats cure with stored grain insects, and you really only have one chance to prepare the bin properly for success.  Investing a little time before harvest to clean, repair, sanitize, and protect the bin will prevent a host of problems later that can be much more difficult to fix.

The following is a simple checklist to minimize the risk from insect infestation and assure maximum quality of stored grain:

1. Do NOT mix new grain with old. The old grain may serve as a source of insect infestation for the new grain.
2. Thoroughly clean all old grain, webbing, and debris from the bin prior to harvest.  Clean under the aeration floor if possible.
3. Repair or seal all seams, holes, or cracks using an approved patch material or sealant.
4. Check the mechanical integrity and performance of fans, ducts, augers, and the aeration or drying floor.
5. Apply insecticides to interior bin surfaces using an approved empty-bin insecticide.  Allow all interior bin surfaces to dry completely before loading grain in the bin.  Bins with inaccessible interior components may need to be fumigated, which requires additional pesticide certifications, special equipment, and extreme safety precautions.
6. Remove insect habitat and food sources right outside the bin.  Mow grass and weeds around bins, clean and remove dead vegetation, and consider the use of a labeled residual herbicide to create a vegetation free strip around each bin.  Clean up all spilled grain and keep bin sites clean.
7. Prepare and calibrate application equipment used to treat the grain with protectant products.
8. Handle grain with care during harvest and subsequent movement.  Adjust and operate combines to minimize grain damage.  Grain kept in good physical condition is less likely to become infested.
9. Store grain at proper moisture.  Moisture levels from 18-20% accelerate spoilage and are more likely to be damaged by insects.  Ideally, grain should be stored at 15% moisture or less.
10. Store grain at proper temperature.  Infestation takes place at air temperatures above 60 F, and insect activity can be sustained above 50 F.  Cooling the grain after harvest effectively reduces the risk of insect damage.  The greatest risk of infestation occurs when temperatures are warm (April – September).
11. Apply a grain protectant as a mass treatment.  Treat the grain mass while it enters the bin with insecticides labeled for the grain being stored and applied at appropriate rates.  The upper and lower layers may be treated while the bin is being filled.  If grain will be stored for several months or more, the entire grain mass may be treated.
12. Apply a grain protectant as a top dress treatment.    

Your FS Crop Specialist can access more detailed information on grain bin products and practices via the Technical section of the 2017 Crop Protection Handbook (internal use only).

Note:  Insecticides can be hazardous, if handled or applied improperly.  Always read and follow label directions and take appropriate safety precautions.