Cotton Growers Continue Search for Herbicide Resistance Solutions

For nearly a decade, cotton growers have been battling to save crops from glyphosate-resistant Palmer amaranth – or pigweed. Though in many ways they are finally gaining the upper hand, an expert with the Weed Science Society of America (WSSA) says the progress has come at a great cost.

“The current model simply isn’t sustainable,” says Stanley Culpepper, Ph.D., a professor in crop and soil science at the University of Georgia and member of WSSA. “Growers have gone to war, and they are making progress from a weed management perspective, but not from an economic or environmental perspective. We need to figure out a way to get the same result far more cost effectively and in a way that better protects our natural resources.”

Palmer amaranth is no ordinary foe. This prolific weed can grow an inch or more a day and achieve heights of nearly 10 feet. It crowds out crops, draws moisture and nutrients from the soil and has a stem tough enough to damage rugged farm equipment. To add to the challenge, a single plant can produce hundreds of thousands of seeds, turning a limited incursion into an all-out infestation.

Palmer amaranth became a huge problem in cotton after growers began to rely solely on glyphosate for weed control. After repeated and exclusive exposure to the chemical, resistant weeds began to appear. It was clear that growers would need to make significant changes in their weed control practices or lose their crops.

Today, integrated weed management programs that complement glyphosate with a variety of other weed control tools and techniques have become commonplace in cotton. Growers have added herbicides to their weed control programs that use a different mode of action than glyphosate. They also are using two approaches that may seem decidedly “old school.” More than 90 percent of cotton growers in Georgia are now hand-weeding a significant portion of their cotton crop, Culpepper says. They also are tilling more to keep Palmer amaranth at bay.

Though the multifaceted approach is working, there are definite downsides. Additional herbicides, labor and fuel have tripled the cost of weed control in cotton, and that means profit margins are declining. In addition, increased tillage raises concerns about soil erosion from water and wind.

Scientists and growers are collaborating on new options. One of the latest involves the use of heavily-planted winter rye as a cover crop for cotton. Once the rye is established, it is rolled down to create a thick, horizontal bed of mulch that can reduce Palmer amaranth infestations by as much as 70 to 90 percent.

“We have a committed and creative group of growers, and if there are more cost effective ways to control Palmer amaranth, I’m confident we will find them,” Culpepper said.

The impact of glyphosate resistance on cotton crops represents a cautionary tale for anyone relying on a single herbicide mode of action for weed control, scientists say. If you reach the resistance “tipping point” in a crop, it can be very costly to turn back the tide.

According to WSSA member Bryan Young, Ph.D., a professor at Southern Illinois University and expert in herbicide resistance, more than 200 weed species are now resistant to one or more herbicides.

“It isn’t herbicides that create herbicide-resistant weeds,” Young says. “Instead, the culprit is how we use herbicides in an overall weed management strategy. To preserve the effectiveness of herbicides, it is imperative that we become better stewards of their use. Minor changes made today can avoid costly problems in the future.”

Best management recommendations and free educational materials about how to combat herbicide resistance are available on WSSA’s website.

Source – WSSA

 

Topics:

Leave a Reply

Cotton Production Stories
white ripe cotton field ready for harvest
Ginning

NCC Survey Projects 9.4 Million Acres of U.S. Cotton in 2015

February 7, 2015

U.S. cotton producers intend to plant 9.4 million acres of cotton in 2015 – down 14.6 percent from last year – according to the NCC’s annual Early Season Planting Intentions Survey.

Cotton Production

Tennessee Cotton Quick Facts Publication Now Online

February 17, 2015

The new 2015 Tennessee Cotton Quick Facts publication is now available online.

Cotton Production

University of Georgia Sets PGR Requirements for 2015

January 22, 2015

The University of Georgia has updated its plant growth regulator requirements for cotton varieties for 2015.

Cotton Production

Tennessee 2014 Variety Trial Results Now Available

January 5, 2015

The 2014 Tennessee Cotton Variety Trial Results publication is now available online.

Planting

2015 Tennessee Cotton Variety Guide Available Online

December 16, 2014

The 2015 Tennessee Cotton Variety Guide is now available online.

Planting

2014 Mississippi Small Plot Trial Data Now Available

December 15, 2014

Data from the 2014 Mississippi Small Plot Cotton Official Variety Trial is now available through Mississippi State University.

Cotton Production

High Quality Cotton Pays Off for the U.S.

December 10, 2014

It’s time to face facts. Quality cotton – especially U.S. high quality cotton – is now driving world demand.

Around The Gin
Product News

New Cheminova Chemistry to Help Control Herbicide Resistant Weeds

February 23, 2015

Cheminova plans to register pethoxamid, a new herbicide active ingredient, to help growers manage herbicide-resistant weeds.

Product News

Brake Herbicide Receives Section 18 Approvals in Six States

February 18, 2015

Brake Herbicide has received Section 18 emergency use exemptions for control of glyphosate-resistant Palmer amaranth in six cotton producing states.

Precision Technology

TeeJet Matrix 430 Provides Simple, Easy-to-Use Guidance

February 18, 2015

TeeJet Technologies’ new Matrix 430 GNSS guidance system is ideal for a wide range of field applications.

Precision Technology

TeeJet Launches RX520 High-Precision GNSS Receiver

February 17, 2015

TeeJet Technologies has introduced the RX520 dual frequency GNSS receiver for precision farming operations.

Disease Control / Nematodes

Velum Total Approved for Cotton, Peanuts in 2015

February 12, 2015

Bayer CropScience has received registration for Velum Total, a new insecticide/nematicide for use in cotton and peanuts in 2015.

Disease Control / Nematodes

EPA Approves TOPGUARD Terra for Cotton Root Rot Control

February 6, 2015

TOPGUARD Terra fungicide from Cheminova has received EPA registration for control of cotton root rot.

Product News

Deltapine to Release Five Bollgard II XtendFlex Cotton Varieties

January 27, 2015

Following USDA deregulation of the Bollgard II XtendFlex cotton technology, Deltapine has announced plans to offer five new B2XF varieties for the 2015 season.

Product News

Bollgard II XtendFlex Cotton Poised for Limited Introduction

January 21, 2015

A limited introduction of Bollgard II XtendFlex cotton varieties is planned for the 2015 planting season through Deltapine and select licensees.

Latest News
Cotton Production

Tennessee Cotton Quick Facts Publication Now Online

February 17, 2015

The new 2015 Tennessee Cotton Quick Facts publication is now available online.

Ginning

NCC Survey Projects 9.4 Million Acres of U.S. Cotton in 2015

February 7, 2015

U.S. cotton producers intend to plant 9.4 million acres of cotton in 2015 – down 14.6 percent from last year – according to the NCC’s annual Early Season Planting Intentions Survey.

Cotton Production

University of Georgia Sets PGR Requirements for 2015

January 22, 2015

The University of Georgia has updated its plant growth regulator requirements for cotton varieties for 2015.

Cotton Production

Cotton Grower Acreage Survey: Growers Dialing Back Acres in 2015

January 5, 2015

The 2015 Cotton Grower Acreage Survey suggests cotton farmers could reduce cotton plantings by more than 10 percent this year.

Cotton Production

Tennessee 2014 Variety Trial Results Now Available

January 5, 2015

The 2014 Tennessee Cotton Variety Trial Results publication is now available online.

Production Outlook / Acreage

Rabobank: Fertilizer Supply May Outweigh Demand in 2015

December 30, 2014

According to Rabobank’s recent Fertilizer Quarterly report, fertilizer supply for 2015 appears to outweigh global demand, making the pricing forecast for the first quarter of the year rather cloudy.

Planting

2015 Tennessee Cotton Variety Guide Available Online

December 16, 2014

The 2015 Tennessee Cotton Variety Guide is now available online.

Planting

2014 Mississippi Small Plot Trial Data Now Available

December 15, 2014

Data from the 2014 Mississippi Small Plot Cotton Official Variety Trial is now available through Mississippi State University.

Cotton Production

High Quality Cotton Pays Off for the U.S.

December 10, 2014

It’s time to face facts. Quality cotton – especially U.S. high quality cotton – is now driving world demand.

Planting

AgriLife Extension’s On-Farm Cotton Variety Trial Data Available

November 26, 2014

The annual Replicated Agronomic Cotton Evaluation trial results for the South, East and Central Regions of Texas are now available from the Texas A&M AgriLife Extension Service.

News

Registration Open for Cotton Incorporated Crop Management Seminar

October 21, 2014

Cotton Incorporated will conduct its 2014 Crop Management Seminar on November 12-13 at the University of Georgia Tifton Campus Conference Center. And attendees can expect an economic and environmental focus on keeping cotton sustainable.

Harvest

Storms Shred Thousands of Cotton Acres in Arkansas

October 9, 2014

To date, Mother Nature has blessed the latter part of the cotton season – including early harvest – with favorable

Cotton Production

Updated Mid-South Defoliation Guide Now Available Online

September 16, 2014

With defoliation and harvest season nearing, the 2014 Mid-South Defoliation Guide has been updated and is ready for grower use.

Cotton Production

USDA Lowers U.S. Cotton Production and Export Estimates

September 11, 2014

Based on information contained in USDA’s September World Agricultural Supply and Demand Estimates Report, U.S. cotton production and exports for 2014 will both be down over earlier projections.

Cotton Production

Terminate Cotton Irrigation at First Cracked Boll

August 26, 2014

Darrin Dodds, Mississippi State Extension cotton specialist, says that when growers see the first cracked boll in their cotton fields, it’s time to terminate their irrigation program.