By No-Till Farmer Editors

Feb. 22, 2016 — The EPA has unveiled new requirements for seed-corn manufacturers as the agency addresses growing concern over rootworm resistance to single-trait Bt corn products.

Integrated pest management — including crop rotation, proactive early warning efforts and effective communication across the affected agriculture community — is a key facet of the new framework announced last week. The requirements may be in place as soon as 2017.

The EPA’s new rules are a departure from its proposals a year ago, which discussed implementing enforceable planting requirements for farmers.

“These actions will ensure farmers will have safe, effective tools for years to come to control one of the most troublesome pests confronting the nation’s corn growers,” the EPA says. “Use of Plant Incorporated Protectants (PIPs), including Bt corn, is one of the safest methods of insect control. If used properly, PIP crops greatly reduce the need for conventional pesticides and the risks those pesticides may pose to human health and the environment. For these methods to continue to be available, it is essential that they remain effective.”

The Agricultural Biotechnology Stewardship Technical Committee, a consortium of companies involved with PIP products, says it worked closely with the EPA on the new rules.

Jeff Bookout, a senior executive at Monsanto and chairman of the ANSTC, told Dow Jones Newswires that the group believes “in the farmer’s ability to freely choose the appropriate management practices that fit their fields and individual situations.”

However, some experts don’t feel the EPA’s measures are tough enough. Bruce Tabashnik, an entomology professor at the University of Arizona, told Dow Jones the EPA’s plan was “a step in the right direction,” but didn’t go far enough to address the problem. “It’s a difficult area to regulate, but without more teeth, it’s not clear if this will lead to more rotation, which would be a good thing,” he says.

The EPA says it still recommends growers develop a multi-year management plan in consultation with Bt corn companies and/or Extension entomologists or crop consultants, to use all IPM tools in rotation to reduce the frequency of unexpected damage and resistance occurrences in Bt corn.

New Requirements

The EPA’s says its framework to delay corn rootworm resistance outlines specific actions to address issues related to potential corn rootworm resistance to Bt corn, before more serious problems take root, and includes corrective measures if resistance to Bt corn is confirmed.

Here are the specific measures:

• Companies supplying Bt corn will be required to implement an Integrated Pest Management (IPM) program for corn rootworm management and work with growers to help them use these practices. IPM practices that are required by EPA to be part of that program are rotation to an alternate non-corn rootworm host crop, planting of pyramided Bt corn; Rotating to an alternate PIP, if available; and planting of non-Bt corn rootworm protected corn with a soil-applied insecticide at planting (especially practical when following a year of crop rotation).

• Bt corn companies are required to investigate reports of unexpected rootworm damage to Bt cornfields, and to work with growers to implement IPM-based corn rootworm management options. This approach replaces the previous annual monitoring strategy in which a few populations were sampled from random locations in the Corn Belt.

• Unexpected damage investigations require the use of uniform damage-level triggers across the biotech industry to identify unexpected damage to fields in single and pyramided Bt corn.

• Use of on-plant assays to confirm resistance in corn rootworm populations sampled from fields with unexpected damage.

• If resistance is confirmed, the mitigation action area is defined as ½ a mile around the resistant site. Mitigation actions occur on the affected farmland only, and other affected growers in the area will be notified by the Bt corn company if they planted the same trait.

For more information on the new rules, click here.