Crops with a Bacillus thuringiensis (Bt) trait have been modified to produce a protein that is toxic to various forms of insect larvae. Bt corn hybrids have been commercially available to farmers for more than 20 years and have contributed to a reduction in pesticide use to fight the most damaging corn insect pests.


The Environmental Protection Agency (EPA) requires all farmers using Bt crops to plant a refuge, or a percentage of the field that does not contain Bt traits. Farmers across much of the corn belt have many refuge-in-a-bag (RIB) options while farmers in cotton-growing areas are required to plant a separate, structured refuge. Planting a refuge decreases the risk of insects developing resistance to Bt protein, as it leaves vulnerable insects nearby to mate with any rare resistant insects that may emerge from the biotech crop.  


You can use the Refuge Look-Up Tool for a quick reference guide on the type of refuge required for your fields. Always consult with your seed provider to understand the stewardship requirements specific to your hybrid. 


Even with refuge requirements, growers can and should take additional action to ensure Bt traits remain a viable option for pest control for many years to come. NCGA and the Agricultural Biotechnology Stewardship Committee supports the Take Action program to provide corn growers with information and resources on Bt stewardship and best management practices. You can also access additional information on the importance of refuge planting on the Take Action website.


As one of the most threatening pests of corn production, additional tactics are recommended for managing corn rootworm each year. Click here to view for more information on strategies to effectively manage corn rootworm.