NCC Comments On Rimsulfuron

The NCC submitted comments regarding EPA's review of four chemicals, including rimsulfuron, which have a significant impact on the cotton industry.

Published: December 30, 2015
Updated: December 30, 2015

December 22, 2015

OPP Docket
Environmental Protection Agency Docket Center (EPA/DC), (28221T)
1200 Pennsylvania Ave. NW
Washington, DC 20460-0001

Mr. Jose Gayoso, Pesticide Re-Evaluation Division (7508P)
Office of Pesticide Programs
Environmental Protection Agency
1200 Pennsylvania Ave. NW,
Washington, DC 20460–0001

Re: Docket ID No. EPA–HQ–OPP–2012-0178.

Dear Mr. Gayoso:

In response to the Environmental Protection Agency’s (EPA) September 25, 2015, Federal Register notice opening a public comment period on EPA’s draft human health and ecological risk assessments for the registration review of a group of 35 different pesticides referred to as sulfonylureas (SU), along with certain other identified active ingredients, the National Cotton Council (NCC) appreciates the opportunity to provide the following comments related to the importance of the SU active ingredient rimsulfuron as a weed management tool for use in cotton production.

The NCC is the central organization of the United States cotton industry.  Its members include producers, ginners, cottonseed processors and merchandizers, merchants, cooperatives, warehousers and textile manufacturers.  A majority of the industry is concentrated in 17 cotton-producing states stretching from Virginia to California. The NCC represents producers who cultivate between 10 and 14 million acres of cotton.  Annual cotton production, averaging approximately 16 to 20 million 480-lb bales, is valued at more than $5 billion at the farm gate.  The downstream manufacturers of cotton apparel and home furnishings are located in virtually every state. Farms and businesses directly involved in the production, distribution and processing of cotton employ more than 230,000 workers and produce direct business revenue of more than $27 billion.  Accounting for the ripple effect of cotton through the broader economy, direct and indirect employment surpasses 420,000 workers with economic activity well in excess of $120 billion. In addition to the cotton fiber, cottonseed products are used for livestock feed, and cottonseed oil is used as an ingredient in food products as well as being a premium cooking oil.

Weed resistance is an on-going issue for crop production across the U.S. and this includes cotton. A key to managing weed resistance is the continued availability of herbicides that are formulated with weed control chemistry having different modes of action (MOA) such as the active ingredient rimsulfuron.

Rimsulfuron is a SU that is labeled for use in cotton production up to 30 days before planting as a burndown herbicide (removing weeds prior to  planting the crop) to control winter annual broadleaf weeds such as henbit, chickweed, small wild radish, and curly dock.  Rimsulfuron is formulated in combination with another SU active ingredient thifensulfuron-methyl and marketed under the brand name as LeadOff®.  The product label allows for applications during late fall or winter in order to minimize weed populations requiring clean-up prior to spring planting.

Important for U.S. cotton production and future weed-resistance management is that both rimsulfuron and thifensulfuron-methyl are SU herbicide active ingredients whose MOA places them in Group 2 based on the Weed Science Society of American classification system. The SU herbicides are generally referred to as Acetolactate Synthase (ALS) inhibitors, and SU containing products are effective at very low use rates in helping cotton growers manage for weed-resistance.  Although some common weed species are known to be resistant to ALS chemistry, the chemistry continues to play a vital role in better management strategies that do not solely rely on a single MOA chemistry, but rotate or combine MOAs in order to effectively control the multitude of weed species present and minimize further resistance evolution of weed populations.

While use of a herbicide product containing a SU active ingredient like rimsulfuron may not appear to be significant for cotton acreage, the importance of retaining multiple MOAs and products that fit niche uses in weed management is very important for sustainable cotton production.  The NCC urges the EPA to include in its registration review of the rimsulfuron/thifensulfuron-methyl end-use product  for cotton, the weed resistance management benefit that make it a viable option as cotton producers identify herbicide products that fit the necessary weed management needs of their farm.

Respectfully submitted,
Reece Langley
VP – Washington Operations