In 2009 cotton Weed resistance: train wreck in waiting

There's a good chance that glyphosate-resistant weeds could hit Mid-South cotton fields in epidemic proportions in 2009. But are cotton producers too involved in other pressing issues to implement preventative measures prior to the growing season?

That's the big concern among weed scientists these days, and a subject to be discussed at length during the National Cotton Council-coordinated 2009 Beltwide Cotton Conferences, Jan. 5-8, in San Antonio, Texas.

According to Bill Robertson, NCC manager, Soils, Agronomy and Physiology, and coordinator, Beltwide Cotton Production Conference programming, weed resistance “has spread a lot faster this year than people thought it would. We're working on an educational effort here at the National Cotton Council, to help promote awareness of some of the things we can do like rotating chemistries, cultural practices, etc.”

Robertson said that judging by what went on in the Mid-South and Arkansas this season with widespread eruptions of glyphosate-resistant Palmer amaranth, or Palmer pigweed, “a lot of growers are going to have some first-hand experiences to share about weed resistance.”

Robertson said that Palmer pigweed problems that cropped up this season reminded him of when resistant horseweed appeared in the Mid-South a few years ago. “By the time they realized they had a problem, it was too late to do anything about it.”

While the NCC is working with the Extension Service, university researchers and others to help promote awareness of resistance management issues, they realize that the effort has become more difficult because cotton producers are facing a myriad of other problems — from rising input costs to lower cotton prices.

“We're in a tough situation,” Robertson said. “There are not only monetary costs associated with managing weed resistance, but there are time issues as well. With time and labor being stretched, a weed resistance management program is going to cost more money, and it's going to take more time to do.

“It takes a full commitment to implement a lot of these resistance management practices. But it's like your doctor asking you to change your diet. You're a lot more committed to it after you've had a heart attack. We have to move this issue higher up on their priority list for them to justify a higher expense on the front end when they might not be sure they have a problem.”

For the second year in a row, the NCC will host a consultants conference at the Beltwide. Robertson says about half of the two hours allotted to the consultants conference will be dedicated to weed resistance management. The conference, which begins at 1 p.m. on Monday, Jan. 5, is open to ag consultants, county agents, distributors, dealers, company representatives and producers who want more technical information.

In the session, University of Georgia Extension weed scientist Stanley Culpepper will discuss Palmer amaranth and University of Arkansas Extension weed scientist Ken Smith will discuss other resistance issues. There will also be roundtable workshop discussions on weed resistance management.

Smith said that test plots on glyphosate-resistant pigweed in a field in Lee County, Ark., in 2008, showed several promising treatments. “We had some real success stories, which we'll talk through” at the consultant's conference.

Smith says that despite the fact that there are several practices growers can employ on their individual farms to manage resistance to Palmer pigweed, “I don't think there will be enough farmers adopting those practices to avoid having a train wreck on resistance next year.”

On Tuesday, Jan. 6, there will be a 20-minute session with entomologists and weed scientists discussing resistance management. Later in the afternoon, there will be more breakout sessions on resistance management.

There will also be a resistance symposium which will cover both weed and insect resistance in cotton, led by John Adamczyk, a USDA scientist in Stoneville, also on Tuesday.

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