The following is a release from the Iowa Department of Agriculture:
DES MOINES - Farmers are reminded to properly handle treated seeds that were unable to be planted this year due to the historically wet spring weather. Seeds treated with a pesticide to protect them from pests or disease cannot enter the grain supply, so it is important that treated seed be stored for planting next year or disposed of properly.
If a farmer chooses to keep the seed, the leftover treated seed must be stored separately from grain and properly labeled to indicate the type of seed treatment. It should be stored in a dry, well-ventilated location and the percentage of germination checked before use.
Farmers may also want to talk with their seed dealer as they may be able to help arrange for the seed to be moved to another farmer so that it can still be planted yet this year.
If a farmer does choose to dispose of the seed, the best option for a small quantity of leftover seed may be to plant it in fallow or other non-cropped areas of the farm. Note that treated seed may be hazardous to wildlife and must be planted according to seed label and bag instructions.
Planting treated soybeans on acres that farmers were prevented from planting this year may also be an option. Some crop insurance companies are now allowing the use of treated soybean seed as a cover crop. It is critically important that a farmer have the approval of their insurance company before using treated soybeans as a cover crop. In addition, if an herbicide was applied to an area that was going to be planted to corn that is now going to be planted to a different crop, the herbicide label should be checked to be sure that crop can be used with that herbicide
Other disposal options for treated seeds include incineration in a boiler, such as at a power plant or cement kiln, that is permitted to burn treated seed as a fuel source.
Disposal at a state permitted solid waste disposal facility may also be possible, especially if a farmer has a large quantity of treated seed in need of disposal. Farmers should contact the Iowa DNR Solid Waste section at 515-281-6807 for more information on disposal at these facilities.
More information about disposal of treated seeds can be found on the American Seed Association's online seed treatment guide at http://seed-treatment-guide.com/guide/planting-disposal-treated-seed/.