facebook_pixel

Pigposium III: Getting Off the “Resistance Treadmill”

By Mary Hightower, University of Arkansas System Division of Agriculture

Finding ways to halt the “resistance treadmill” was a key message from weed scientists on February 28 at Pigposium III, a daylong event hosted by the University of Arkansas System Division of Agriculture focused on herbicide resistant Palmer amaranth.

About 300 attendees from the agriculture industry – including farmers, extension agents and consultants – heard weed scientists from four states describe research and strategies for managing weeds that have developed resistance to the most-used herbicides.

Jason Norsworthy, weed scientist with the University of Arkansas System Division of Agriculture, noted that it’s been 12 years since the existence of glyphosate-resistant Palmer amaranth, better known as pigweed, was first confirmed in Georgia.

A year later, in 2006, glyphosate-resistant pigweed was confirmed in Arkansas and Tennessee.

In just over a decade, “31 states now have glyphosate-resistant Palmer amaranth,” he said. “The world’s greatest herbicide is no longer effective against pigweed.”

In defining what he called the resistance treadmill, Bob Scott, weed scientist for the University of Arkansas System Division of Agriculture, said, “We’re taking one herbicide and replacing it with another, and taking another herbicide and replacing it with another, and taking another herbicide and replacing it with another. Today, the goal is to stop doing this.

“If we follow our resistance pattern, we’re just going to add dicamba to the growing list of resistance that we have,” he said. “We’ve proved this in a laboratory study.”

Scott said ALS resistance perpetuated glyphosate resistance, and glyphosate resistance perpetuated PPO resistance. He asked, “What will PPO resistance perpetuate?”

This pattern, this treadmill, will eventually lead the industry to “multiple stacked resistance,” Scott said. “I’m a weed scientist and that scares me. Stacked resistance is a game changer.”

Scott’s comments were echoed by fellow Division of Agriculture Weed Scientist Tom Barber, “If you continue to rely just on PPOs, you’ll shift the population in that field to PPO resistance.”

Norsworthy, in talking about the future of herbicide use said, it’s “just a matter of time before we have a six-way stack” in herbicide resistance.

He quoted Eric Maupin, a Tennessee farmer who is a board member of the American Soybean Association, saying “going into 2016, I have one post-emergence option for pigweed, and if I were to lose that option, I wouldn’t be farming soybean.”

“That,” Norsworthy said, “is a very sobering statement.”

Norsworthy spoke about several options being tested, including narrow windrow burning and seed destructors.

“Narrow windrow burning was quite effective, with complete control of all weed seed,” he said. “We killed every weed seed in that row.

Another option were seed destructors that used mills to crush seed. “This gets me excited,” added Norsworthy. “It lessens the seed going back into the soil.”

Larry Steckel, a Tennessee Extension weed scientist, talked about the use of cover crops.

He said he is often asked if cover crops are effective in managing resistant weeds. “Yes,” he said, with a pause. “How much time to I have left?”

Steckel said cover crops are highly effective, but not a silver bullet. But using them would likely reduce by one, the number of herbicide applications needed by growers.

Michael Popp, an agricultural economist with the University of Arkansas System Division of Agriculture, walked the audience through Palmer amaranth manager, or PAM, a PC-based program that enables growers to develop their own strategy in managing pigweed.

Kevin Bradley, a Missouri Extension weed scientist, discussed the issues with dicamba in his state. He said that farmers with crops injured by dicamba didn’t want to turn other farmers in, so the reported damage might not have been the whole story.

Bradley said the state’s legislature was pondering a bill to fine growers $1,000 an acre for illegal applications.

Pecan, peach, white and red oaks proved to be very sensitive to dicamba, and Bradley said he expected that “homeowners, with half their trees defoliated, will figure this out.”

Ples Spradley, Extension pesticide assessment coordinator for the University of Arkansas System Division of Agriculture announced where growers can find an online course that’s required for use of Enlist Duo and Engenia herbicides in Arkansas.

Jason Davis, application technologist, emphasized that droplet and nozzle size matter when applying herbicides. Producers need to find the right balance between trying to ensure the herbicide goes just where the applicator needs it, and a droplet size that will ensure the herbicide’s efficacy.

Pigposium wound up with three producers sharing their experience with various weed management methods. Harry Stephens of Helena talked about his successful use of narrow windrow burning and how a relatively small investment paid large dividends.

Dane Coomer of Piggott, told the audience about his experience with Zero Tolerance in cotton.

“It’s a mindset and it’s a goal,” he said. “If you see one on your farm, you pull it.”

Coomer said he uses chopping crews to eliminate remaining weeds by hand. “You may only see a half dozen, but there will be ones you don’t see. That crew will get the ones you don’t see too.”

Adam Chappell, a producer at Cotton Plant, talked about successful use of cover crops, telling the audience he’d been using the same beds since 2010. He pointed to a list of weed management tactics in his presentation, saying “prayer is the only thing up there that’s free.”

Using cover crops, “I’m doing the same thing with half the money,” Chappell said.

Norsworthy left his audience with this message. “Do something different next year,” he urged. “Glyphosate was the world’s greatest herbicide. And I said ‘was.’ If we had only done something different in the late 90s and early 2000s, we’d still have the greatest herbicide today.”

Topics: , , , ,

Leave a Reply

Soybeans Stories
Soybeans

Better for Soybeans: Fall or Spring Applications?

November 17, 2017

Does it really matter to soybeans if phosphorus and potassium are applied in the fall or in the spring?

Soybeans

When and Why to Double Inoculate Your Soybeans

November 17, 2017

Double inoculation can help soybean plants form nodules at an optimal rate and time, helping improve their performance potential.

Soybeans

Tips to Prevent Dicamba Drift

June 15, 2017

In a video presentation, Tennessee Weed Specialist Larry Steckel discusses three actions to help reduce dicamba drift and volatilization.

Soybeans

Dicamba Damage Reports Increasing in Arkansas

June 12, 2017

Forty complaints from off-target movement of dicamba have already been reported to the Arkansas State Plant Board, as of June 12.

Soybeans

Cooperation, Preparation Are Keys to Ag Sustainability

May 5, 2017

Georgia’s Stanley Culpepper outlines the training efforts for auxin herbicides in the state and praises the people who make it all work.

Soybeans

Research: Some Applicator Hoses Can Retain Auxin Residues

April 19, 2017

According to research in the journal Weed Science, residues of the auxin herbicides dicamba and 2,4-D can be retained by certain types of applicator hoses and injure sensitive crops.

Soybeans

Managing Target Spot in Soybeans

April 12, 2017

Following a troublesome infestation of target spot in soybeans in 2016, there are several things that growers need to keep in mind for managing the disease in 2017.

Around The Gin
Product News

Indigo Offers Premium for Indigo Cotton Production

January 9, 2018

Indigo Ag has announced a new program that offers significant price premiums for U.S. cotton growers who contract to grow Indigo Cotton.

Product News

New Bayer Varieties Focus on High Yield, Adaptability

January 5, 2018

Bayer releases five new FiberMax and Stoneville varieties for introduction in 2018.

Product News

New PhytoGen TRiO Guards Cottonseed Investment

January 3, 2018

New PhytoGen TRiO seed treatment helps provide early season protection for young cottonseed from diseases, insects and nematodes.

Product News

Americot Adds Seven to Sales, Research Teams

December 20, 2017

Americot has added seven new sales and research associates to the company’s staff across the Cotton Belt.

Product News

Seven New Varieties in Deltapine Class of 18

December 11, 2017

Seven new varieties – including five Bollgard 3 XtendFlex offerings – join the Deltapine product lineup as the Class of 18.

Product News

Special Roundup Ready PLUS Incentives for Arkansas

December 7, 2017

Monsanto is offering a special Roundup Ready PLUS Crop Management Solutions platform in Arkansas for 2018 for growers planting XtendFlex cotton and Roundup Ready 2 Xtend soybean varieties.

Product News

Monsanto Sets 2018 Crop Protection Incentives

December 5, 2017

Monsanto will provide multiple tools, resources and products to help cotton and soybean growers maximize weed control in 2018.

Product News

Praxidyn’s Mixmate Named a 2018 AE50 Award Winner

November 27, 2017

The American Society of Agricultural and Biological Engineers has recognized Praxidyn's Mixmate portable ag chemical blending and recordkeeping system with a 2018 AE50 award.

Latest News
Soybeans

When and Why to Double Inoculate Your Soybeans

November 17, 2017

Double inoculation can help soybean plants form nodules at an optimal rate and time, helping improve their performance potential.

Soybeans

Better for Soybeans: Fall or Spring Applications?

November 17, 2017

Does it really matter to soybeans if phosphorus and potassium are applied in the fall or in the spring?

Soybeans

Arkansas Researchers Share Dicamba Volatility Studies

August 11, 2017

Work done by University of Arkansas weed scientists has found that every dicamba formulation tested this spring and summer demonstrated a level of volatility.

Opinion

No One Reason for “Frustrating” Dicamba Issue

July 18, 2017

Tennessee Weed Specialist Larry Steckel has walked hundreds of drift-damaged soybean fields in the past few weeks. He shares some opinions about possible reasons for the problem.

Soybeans

Tips to Prevent Dicamba Drift

June 15, 2017

In a video presentation, Tennessee Weed Specialist Larry Steckel discusses three actions to help reduce dicamba drift and volatilization.

Soybeans

Dicamba Damage Reports Increasing in Arkansas

June 12, 2017

Forty complaints from off-target movement of dicamba have already been reported to the Arkansas State Plant Board, as of June 12.

Soybeans

Cooperation, Preparation Are Keys to Ag Sustainability

May 5, 2017

Georgia’s Stanley Culpepper outlines the training efforts for auxin herbicides in the state and praises the people who make it all work.

Soybeans

Research: Some Applicator Hoses Can Retain Auxin Residues

April 19, 2017

According to research in the journal Weed Science, residues of the auxin herbicides dicamba and 2,4-D can be retained by certain types of applicator hoses and injure sensitive crops.

Soybeans

Managing Target Spot in Soybeans

April 12, 2017

Following a troublesome infestation of target spot in soybeans in 2016, there are several things that growers need to keep in mind for managing the disease in 2017.

Soybeans

Soybean Oil Used to Develop High Tech Graphene

March 20, 2017

A team of Australian scientists has used soybean oil to make graphene – the strongest and thinnest type of carbon with good electrical conductivity.

Soybeans

Pigposium III: Getting Off the “Resistance Treadmill”

March 7, 2017

Nearly 300 attendees at the University of Arkansas’ Pigposium III heard options to help them beat the “resistance treadmill” when it comes to pigweed control.

Soybeans

Crowding Out Weeds

February 24, 2017

Arkansas soybean specialist says narrowing your rows can have a big impact on weed control.

Soybeans

Control Italian Ryegrass Early

January 25, 2017

An early winter burndown for glyphosate-resistant Italian ryegrass can provide growers time and flexibility in deciding how to control escapes prior to planting.

Soybeans

Bayer, MS Technologies Get China Approval for Balance GT Soybeans

January 25, 2017

Bayer and MS Technologies have received import approval from China for Balance GT soybeans.

Soybeans

Cotton/Soybean Rotation Reminders

January 9, 2017

When rotating soybeans onto cotton acres, growers should keep the need for seed inoculation, as well as a close eye on weed control options, in mind.