Take refuge, if you plant Bt varieties


ST. LOUIS – A National Corn Growers Association found more than nine out of 10 growers are aware of and effectively complying with Insect Resistance Management (IRM) requirements as mandated by the Environmental Protection Agency.
These findings are based on 2005 on-farm assessments along with an independent survey conducted on behalf of the Agriculture Biotechnology Stewardship Technical Committee (ABSTC).
Since 1999, Bt corn registrants – Dow AgroSciences, Monsanto, Pioneer Hi-Bred International, a subsidiary of DuPont, and Syngenta Seeds – have monitored adherence to the IRM requirements to help ensure Bt corn borer technology remains effective against pests.
Positive trend. The annual Bt corn borer IRM telephone survey, managed by an independent third party, found 92 percent of U.S. Bt corn growers met or exceeded the minimum recommended refuge size. This level of adherence with the requirements is consistent with past results of 91 percent in 2004 and 86 percent in 2003.
In a separate program of on-farm visits, more than 94 percent of producers assessed were found to be meeting the refuge requirements.
Both large and small acreage growers are meeting refuge management requirements at similar levels.
EPA mandate. The EPA-required Bt corn refuge obligates farmers to plant at least 20 percent refuge – that is, corn that does not contain a Bt gene for controlling corn borers. In certain cotton areas of the South, growers are required to plant at least a 50 percent refuge.
All areas of the country require that the refuge is planted within one-half mile of the Bt corn. In 2005, 96 percent of growers adhered to this refuge distance requirement, an improvement over past years of 93 percent in 2004 and 89 percent in 2003.
Penalties. An element of the on-farm assessment program that reinforces how seriously Bt technology providers regard resistance management is the potential penalties for noncompliance. Failure to properly plant and manage refuges in two crop seasons can lead to a grower’s inability to access technology for use on their farm in the third year.
Farmers visited in 2004 and found to be out of compliance came back into compliance in 2005, and have maintained access to corn borer protected Bt corn for this growing season.
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