As growers plant Bt (Bacillus thuringiensis) corn hybrids, they should implement Insect Resistance Management (IRM) and non-Bt refuges, according to the Agriculture Biotechnology Stewardship Technical Committee (ABSTC) and the National Corn Growers Association (NCGA).

"It is critical that every Bt grower implement an IRM plan and plant an appropriate non-Bt refuge," says Eric Sachs, spokesman for ABSTC, a consortium of biotechnology companies working with grower associations and land grant universities to promote stewardship of biotech products. "Growers need to understand the stewardship guidelines because their implementation plays a very important role in maintaining the efficacy and durability of Bt technology."

All Bt corn products available for the 2001 season carry the same insect resistance management requirements. Growers in Corn Belt states and the northern portion of the corn/cotton region should plant a non-Bt corn refuge representing at least 20% of their Bt corn acres within 1/2 mile of each Bt cornfield. In the southern portion of the corn/cotton region, a minimum of 50% refuge of non-Bt corn should be planted. The refuge can be treated with a non-Bt insecticide if pest pressure is heavy. If a grower knows he will need to treat the refuge, however, he should plant it within 1/4 mile of the Bt field. The refuge can be planted as a border, strips or as a separate field - whichever works best for the individual operation.

Complete details on the IRM requirements for Bt corn technologies can be accessed via NCGA’s Web site at www.ncga.com/11biotechnology/main/index.html.