June 15, 2006

Prepare bins, equipment for wheat harvest

Precautions taken before grain is put into the bin can pay dividends later by helping to assure quality is maintained. Don't wait until the middle of harvest to discover a bin foundation is severely cracked, or insects from grain left in the bin, truck or combine have become a problem in a bin of new grain. The following discussion can serve as a check list as you “tune up” your equipment and facilities prior to harvest.

Harvesting equipment

Remove all traces of old grain from combines, truck beds, grain carts, augers, and any other equipment used for harvesting, transporting, and handling grain. Even small amounts of moldy or insect infested grain left in equipment can contaminate a bin of new grain.

Site

Check the bin site. Spilled grain harbors insects and draws mice and rats. Clean up and dispose of any spilled grain at lease four weeks prior to harvest. If rats have tunneled under foundations, use fumigants, baits or traps to reduce or eliminate them. Tall weeds can harbor insects and provide cover for rodents. Mow the site to remove tall grass and weeds to reduce the potential for insect or rodent infestation. If necessary, re-grade the site so water readily drains away from bin foundations. One cannot always wait for the soil to dry before loading or unloading grain from bin sites. Make certain travel lanes have adequate rock or gravel to bear the weight of heavy trucks and grain carts.

Electrical

Wheat harvest necessarily occurs during hot weather. One can extend the “shelf life” and reduce mold and insect activity in the bin if the wheat can be cooled with aeration. To ensure your ability to aerate when needed, check the electrical system before harvest.

Wiring for fans and other electrical components should be inspected for corrosion and cracked, frayed, or broken insulation. Exposed wiring should be run through waterproof, dust tight conduit. Avoid kinking the conduit, and make sure all connections are secure.

Mice will nest in control boxes where they are protected from predators. They often strip insulation from wires for nest material and their urine causes corrosion on relays and other components. If you find rodent damage, clean and repair or replace damaged wiring, relays, and other components. Then seal over knock-outs and other openings that allowed rodent entry.

Aeration systems

Check fans, heaters, transitions, and ducts for corrosion and damage. Remove any accumulated dust and dirt that will reduce the operating efficiency and be sure all connections between the bin and duct are tight to prevent air leaks.

Bins

Inspect bins and foundations for structural problems. Repair as needed. Check the bin roof, including roof vents and access hatch, inside and out, for leaks, loose or sheared bolts, corrosion, etc. Be sure the access ladder is complete and securely fastened to the bin. Repair or replace any deteriorated components.

Ensure bins are clean. Remove any old grain with brooms and shop vacuums. Never put new grain on top of old unless the carry-over grain has been fumigated. Don't forget to clean bins not being used for storage this year as these can be a source of insects that will migrate to other bins.

Treating empty bins. If wheat will be stored for more than a few weeks, consider treating the cleaned, empty bin with insecticides at least two weeks before adding any grain. Apply the spray to the point of runoff to as many interior surfaces as possible, especially joints, seams, cracks, ledges, and corners. Also spray outside the bin at the foundation and near doors, vents, ducts, and fans.

Residual empty-bin treatments for wheat and feed grains include: Malathion, cyfluthrin (Tempo), chlorpyrifos-methyl, pyrethrins (many brand names and in combination with other products), silicon dioxide (diatomaceous earth sold under many brand names).

Fumigating empty bins. If a bin was infested with insects during the past year and if it has a perforated drying floor, consider fumigating the empty bin. It is generally impossible to thoroughly clean under perforated drying floors; however, much of the debris can be removed if the drying fan is removed and an extension pipe and grain vacuum are used. After removing as much grain and grain dust as possible, the bin can then be fumigated. Presently in Nebraska, magnesium phosphide, methyl bromide and chloropicrin are registered for empty bin fumigation.

Note: Not all products can be used with all types of grain. Always check product labels for specific sites and for special handling restrictions. Caution! Fumigants are dangerous restricted-use pesticides and may require gas monitoring devices and respirator protection for the applicator. It is highly recommended fumigation be done by a commercial pesticide applicator certified in safe fumigant handling and application techniques.

Disclaimer: Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by University of Nebraska–Lincoln Extension is implied.

Before applying any pesticide, read and follow product label instructions for handling, dilution, mixing, and application directions. Note: many active ingredients mentioned above are sold by several companies under many brand names. Not all products with the same active ingredient(s) are labeled for all sites. Be certain the intended site is listed on the label of the product you are considering before you buy and use it.