Several ag trade groups and growers' associations have asked the government to extend the public comment window for a commonly used herbicide.

The U.S. Environmental Protection Agency (EPA) reopened public comment on the Atrazine docket in late June, with web comments becoming available later. The agency is re-evaluating the levels allowed into local waterways, saying a level initially set by the EPA during the Interim Registration post was inadequately supported by science.

Farmers that apply atrazine in an area where the expected concentration in local streams is expected to be less than 3.4 μg per liter will face no changes. Farmers in areas where expected concentration in local streams is greater than 3.4 μg per liter will face required options to mitigate the chemical's impact. The options are in the form of a "picklist" or list of possible measures the farmer can choose from, including no-tillage, vegetative buffer strips, and other measures.

The more atrazine applied on a farm, the more mitigation measures required, according to the proposed regulations.

Several Missouri-based farm groups combined to make a single request for a 60-day extension to the public comment period, which is currently set to expire on Sept. 6. They include the Missouri Corn Growers Association, the Missouri Soybean Association, the Missouri Farm Bureau, Missouri Agribusiness Association, Missouri Farmers Care, and MFA Incorporated.

"The proposed changes to the interim registration review decision are lengthy, complex, and highly technical that require the consideration and review of experts familiar with the subject matter," the letter reads. "Given the number of stakeholders potentially impacted and the far-reaching implications that may result from the proposed changes on atrazine use, it is incumbent upon the EPA to ensure that all parties are afforded adequate time to learn about the proposed changes, understand how that translates to their operation and business, and formulate meaningful feedback."

That assertion was echoed by the Crop Life America (CLA) and Responsible Industry for a Sound Environment.

“The current comment period does not provide CLA sufficient opportunity to review the proposed revisions, solicit input from its members, and develop constructive comments,” the letter reads.

The proposed changes have drawn at least one request not to alter the levels, by the University of Arkansas Cooperative Extension. The letter was authored by Professor Tom Barber.

Weeds have grown resistant to common herbicides in many parts of Arkansas, Barber points out. In many places where weeds have developed resistances to glyphosate or glufosinate, atrazine is essential for weed control, Barber writes.

"Arkansas producers need every available herbicide mode of action possible to battle resistant pigweed and reduce the probability of further increasing resistance through use of single herbicide modes of action," he writes. "Removing atrazine or reducing the maximum use rate would take a viable tool from corn and grain sorghum producers as well as increase the potential for herbicide resistance in Midsouth pigweed populations."

The EPA is accepting public comments on the atrazine changes are accepted online, in addition to via mail, email, and other forms.

More information is available at the EPA Docket website.

Click here for more No-Till News.