Prior to Harvest
[ ] Clean all equipment thoroughly to remove old grain, trash, and debris that might contaminate the new crop –
- combines, carts, trucks, receiving pits/hoppers, conveyers: use pressurized air/water or an industrial wet/dry vacuum
- storage bins: use a broom and shovel or industrial wet/dry vacuum
[ ] Check for leaks in the bin around ladders, roof vents, temperature cables and other openings.
[ ] Treat bin walls and flooring with an approved residual insecticide (currently approved compounds are Tempo, Centynal, Pyronyl and Insecto).
[ ] Treat the outside base of all bins with an approved residual insecticide (Tempo).
[ ] Mow, spray, or remove weeds/grass/vegetation around storage bins.
[ ] Seal floor and fans, unloading augers or other openings with heavy plastic to prepare bin for fumigation.
[ ] Treat area under perforated floors with approved products and application methods (diatomaceous earth (DE) and Phosphine)
CAUTION: Fumigants are restricted-use, potentially lethal pesticides and require formal training for safe application.
[ ] Post written notice that bin has been fumigated.
[ ] Wait the required time before entering the bin–depends on product used and air temperature (Note: Safe re-entry times range from 2 to 3 days at 70°F and 4 to 5 days at 56°F).
During Harvest
[ ] If drying with heated air, limit drying temperature to 110°F or 140°F to preserve seed or milling quality, respectively.
[ ] Dry wheat to 12.5 % moisture if it will be held through August. (Note: This keeps the air space between wheat kernels dry enough [less than 65% humidity) to control mold growth and insect activity. Moisture “shrink” costs 1.14 cents/bu-pt for each $1.00/bu value (12.5 cents/bu-pt @ $11/bu)]
[ ] Apply approved insecticide on unheated wheat as it’s transferred into storage (It is best to use a DIFFERENT product than in Step 4, thus Centynal or Sensat is suggested).
[ ] Apply a “cap-out” treatment to the wheat surface after the bin is full.
[ ] Remove spilled grain around pits/hoppers and storage bins daily to prevent contamination.
After Harvest
[ ] Insert pit traps into stored grain and check them weekly during the summer to track insect activity.
[ ] Check wheat temperature and moisture weekly after binning for stability.
[ ] Core the bin within a month after binning to provide more uniform airflow.
[ ] Move the grain to another bin before corn harvest to disrupt insect activity and potential hot spots.
[ ] Cool wheat below 65⁰F as soon as possible when the weather permits in September.
[ ] Continue cooling about 10 degrees each month to 35⁰F to 40⁰F by December and seal fans.
[ ] Fumigate wheat prior to sale if insect populations reach economic thresholds.
CAUTION: Fumigants are restricted-use pesticides and require formal training for safe control.
UPDATE: Chlorpyrifos was phaseout on Feb 28, 2022, so Reldan (chlorpyrifos) or Storcide (deltamethrin + chlorpyrifos) can no longer be used. For more details, see the February 22, 2022 issue of Kentucky Pest News (EPA Mandates the Phase-out of Chlorpyrifos after February 28, 2022).
Additional Information
See the following UK publication for more information:
- Controlling Insects in Stored Grain (ENTFact-145)
- Insecticide Recommendations for Small Grains‐2018 (ENT‐47)
- Harvesting, Drying, and Storing Wheat (ID-125)
By Sam McNeill, Agricultural Engineer Extension Specialist, and Raul Villanueva, Entomology Extension Specialist
Kentucky Pest News 