Cotton Defoliant Decision Favorable

September 11, 2000

Cotton producers say the Environmental Protection Agency's reassessment of registration for the cotton defoliant tribufos ended favorably with a final decision providing for continued use of the products DEF and Folex. Tribufos is an organophosphate and so was subjected to extensive scrutiny by EPA under standards established in the Food Quality Protection Act.

Tribufos is registered only for cotton, and EPA found no dietary or drinking water risks. However, the agency did express concerns about exposure risks to workers despite industry data to the contrary and a 40-year history of safe use. Worker safety issues are covered by legislation and require EPA to weigh benefits of a product against its risks.

For the past 18 months, National Cotton Council (NCC) producer representatives have worked closely with EPA and the major tribufos registrant, Bayer Corp., as reassessment proceeded. That effort included the NCC's hosting a tour of cotton operations in the Phoenix area for four EPA staff members last November to discuss and demonstrate the importance of tribufos and defoliation and to provide EPA staff the opportunity to observe cotton harvesting and ginning operations.

The dialogue continued after NCC scheduled a meeting with EPA attended by Allen Helms, Jr., then chairman of the American Cotton Producers (ACP), Mark Williams, a NCC producer director, and Roger Isom, who represented the California Cotton Growers Association.

"Tribufos is critical to cotton production in the U.S.," said Helms. "We told EPA about the benefits of DEF, including its ability to work when temperatures drop below 65 degrees. We also pointed out the role that proper defoliation plays in ensuring a harvest that captures the highest fiber quality possible. Providing quality cotton ensures customer satisfaction and positively affects farm income."

NCC staff also prepared and submitted an extensive benefit analysis on DEF to EPA. Keith Menchey, NCC's manager, science and environmental issues, said that late in the reassessment, EPA proposed a 150-foot aerial application buffer strip from water bodies that support aquatic life. NCC staff consulted at length with growers across the Cotton Belt but particularly those in the Southeast and the Delta. The growers expressed concerns that a buffer would prove problematic. These concerns were communicated to EPA and, upon consideration, the buffer zone proposal was retracted.

New mitigation measures to be proposed by EPA include application rates of 1½ pints/acre/year, except in California and Arizona, which maintain a rate of 2½ pints/acre/year; an increased re-entry interval of seven days, up from the current 24 hours; and closed delivery systems by 2002. Changes in application rates and re-entry intervals will not take effect this growing season.