Arkansas Cotton: Brake Herbicide Effective Against PPO-Resistant Pigweed

Cotton growers in Arkansas and elsewhere will have a new weapon at their disposal this season in the battle against PPO-resistant pigweed.

Earlier this week, the U.S. Environmental Protection Agency announced that a new formulation of the fluridone-based herbicide Brake will be labeled and available for pre-emergence application in cotton.

Tom Barber, associate professor of weed science for the University of Arkansas System Division of Agriculture, said the new formulation, Brake FX, includes the chemical fluometuron (commonly known as Cotoran), making it more suitable for a pre-emergence application in cotton.

“When Brake was first developed, it just didn’t take off in cotton because there were so many other options on the market,” Barber said. “But now, with the onset of glyphosate- and PPO-resistant pigweed, we need all the options we can get in cotton.”

Barber estimated that about 70 percent of all cotton grown in Arkansas receive applications of the PPO herbicide Reflex, which has gradually lost its effectiveness against the resistant Palmer Amaranth, commonly known as pigweed.

The EPA issued a full Section 3 label for Brake, and Barber said the Arkansas State Plant Board has indicated they will fully support its use on Arkansas cotton. The board had previously signed off on use of previous formulations under Section 18 emergency use labels.

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The labeled rate for Brake FX will be 32-42 fluid ounces per acre, depending on soil type.  The 32 ouncers-per-acre rate is equivalent to 3 pints per acre of Cotoran and 0.15 lbs. of the active ingredient per acre of Brake (fluridone), and is very effective in controlling glyphosate- and PPO-resistant pigweed, Barber said.

Barber said there should be more than adequate supplies of Brake FX available to Arkansas cotton growers, who reported harvesting record-low acreage in the crop — about 205,000 acres — according to a January U.S. Department of Agriculture report.

Barber said that as with any new application, growers should test the herbicide on a small portion of their acreage to see how it fits into their production system.