Damage to soybean plants caused by exposure to dicamba. Purdue University

The EPA announced last night that it had extended for two years the registration of the dicamba for application to cotton and soybeans. This has been a subject of great controversy in Arkansas. The state Plant Board banned its use in Arkansas through Oct. 31.

“EPA understands that dicamba is a valuable pest control tool for America’s farmers,” said EPA Acting Administrator Andrew Wheeler in an EPA news release. “By extending the registration for another two years with important new label updates that place additional restrictions on the product, we are providing certainty to all stakeholders for the upcoming growing season.”

Among the new requirements on use where it is allowed:

Only certified applicators may apply dicamba over the top (those working under the supervision of a certified applicator may no longer make applications)

Prohibit over-the-top (OTT) application of dicamba on soybeans 45 days after planting and cotton 60 days after planting

For cotton, limit the number of over-the-top applications from 4 to 2 (soybeans remain at 2 OTT applications)

Applications will be allowed only from 1 hour after sunrise to 2 hours before sunset

In counties where endangered species may exist, the downwind buffer will remain at 110 feet and there will be a new 57-foot buffer around the other sides of the field (the 110-foot downwind buffer applies to all applications, not just in counties where endangered species may exist)

Many farmers in Arkansas have continued to press for rules that will allow use of dicamba to control pigweed.