News On The Pigweed Front

There are lessons to be learned for the Midwest from the places where Palmer amaranth resistance to glyphosate first emerged.

Most growers and consultants across the Cotton Belt got to simply watch with awe as pictures of indestructible Palmer amaranth started coming out of central Georgia, growing large, gobbling up acres and cranking out seeds in the untold billions.

Glyphosate had battled mightily for years against all unwanted plants, but in 2005 it gave up the ghost on Palmer amaranth in a catastrophic collapse that rewrote the books on weed control in the Southeast, and eventually to the Delta and beyond.

Palmer pigweed in cotton
Palmer pigweed seedhead in cotton.

“We have lost the ability to control Palmer with Roundup in these fields, and we are going to continue to lose it as resistance spreads throughout our state – especially in circumstances where we are too dependent on glyphosate.” said Stanley Culpepper, Extension weed specialist at the University of Georgia in April 2007.

Flash forward to today, and while the situation is by no means perfect, growers are regaining control of their acres from the wrath of nature.

“We had a great 2012 as far as Palmer amaranth control – in fact, we had a great crop year as well,” says Culpepper, who is still at the grindstone on the resistance management fight. “During 2013, we have not been so lucky thus far. Mother Nature has greatly challenged our growers and their ability to implement their weed management programs in a timely fashion because of the excessive rainfall preventing field operations.

“Regardless of these challenges, I am amazed how well our growers are hanging in there,” he continues. What he means is that over the past five years there has been a gradual attitude change in growers toward being proactive about the problem. Culpepper pinpoints 2009 as really the turning point in grower mentality, when they “realized what this pest was doing to them and they took it seriously. They got aggressive. They have become very good managers and they are going after it.”

Long Road Back

The evidence, as demonstrated by significantly cleaner cotton fields throughout the 2012 and even in 2013 indicates that growers are making inroads. However, it is coming at a tremendous cost. The trail of expenses starts at increased herbicide cost, which averages about $68 per acre not including the actual application, and continues with hand weeding (surveys estimate 54% of the crop in Georgia was handweeded at least once) and a variety of tillage regimens.

“Some growers are doing a lot of tillage and some none, but on average growers spent $5.84 per acre more on tillage just to manage Palmer amaranth,” says Culpepper. “It could be deep turning, cultivating, preplant incorporating herbicides, anything tillage-related.

“So obviously, the total economics of the system is not sustainable,” he adds, “and it is my job to maintain the level of control achieved during 2012, but get control programs costs down to a more economical level.”

Still, despite the challenges there were definitely some program bright spots in 2012. For example, hand-weeding costs were down about half in 2012 vs. 2010. “We were spending about $25 an acre to hand weed two years ago, but now we are in the $12-$15 an acre range,” says Culpepper. “That shows we are doing better across the board, and have become very aggressive as a whole — driven by that change in grower mentality.”

Georgia growers deep-turned over a quarter million acres of land in the last three years and cultivated about 35% of the cotton crop. “If you talked to any of our growers, nobody wants to deep turn, nobody wants to cultivate; but we had to do things to preserve the family farm,” says Culpepper. “Now as we get restarted over the next couple years to a more economical production plan, we hopefully can get back to conservation tillage and actually do it better than we ever did before.”

As far as herbicides, the last few years have provided Culpepper and Georgia growers a solid education on the pros and cons of various products, and made it possible to create the best program options possible that also preserve yield.

Monsanto’s Roundup Rewards program made a huge difference in increasing adoption of residual herbicides by providing substantial rebates on selected actives. Fully implemented it could save a grower $20 to $22 per acre in herbicides. “I don’t believe (or at least hope) anyone thinks you can spray Roundup, Roundup, Roundup any more, nor do they believe you can do the same with Liberty,” says Culpepper. “They understand that a sound management program requires that we rotate chemistry and are diversified.”

There’s also a better understanding of herbicide strengths and limitations related to timing of application. “We have learned in the last two years what happens when we spray Liberty at sunrise vs. the middle of the day, or how long products can sit in the field and remain viable without rain,” says Culpepper. “Those kinds of things can greatly influence the level of control that a grower will get, and can make or break a system.”

In the short term, Warrant preemergence is going to be an additional tool to help Georgia cotton growers because it is a great tank mix partner with Reflex, which is currently used on about 90% of Georgia cotton, says Culpepper. “Those together in combination are very effective.”

Economics will be slower to come, but for now Culpepper is willing to revel a little in the heroic efforts Georgia growers have shown so far. “We are going to be implementing a diversified crop management system across the board, it’s not just spray, spray, spray anymore. That’s not sustainable. And our growers are definitely on that,” he says.

Topics:

Leave a Reply

Weed Resistance Stories

Weed ResistanceWeeds: The Fearsome Five
October 1, 2013
Although there are currently dozens of weeds that show some kind of resistance to herbicides, these five are the most troublesome. Read More
Weed ResistanceWeed Management Program Profiles
October 1, 2013
Here’s quick look at weed control strategies and their cost. Read More
Weed ResistanceRecognizing Resistance
October 1, 2013
Recognizing the presence of herbicide-resistant weeds and formulating a total management plan is becoming more important than ever. Read More
Mature Waterhemp in Corn
Weed ResistanceWhen Weed Control Goes Wrong
October 1, 2013
Beyond the possibility of resistance developing, ineffective control exacts cost to growers in lost yield. Read More

Top 100 Articles

CropLife 100CHS: Driving Momentum To Help Farmer-Owners Grow
December 11, 2014
CHS Inc., the nation’s leading farmer-owned cooperative and a global energy, grains and foods company, must capture new opportunities to Read More
CropLife 100BRANDT, Verdesian Ink Distribution Agreement
December 9, 2014
The agreement grants BRANDT the exclusive right to sell and market Verdesian’s patented Steric chemistry in the Turf and Ornamental and eastern U.S. ag markets under the BRANDT Reaction product line name. Read More
CropLife 100CropLife 100: The Colors Of Custom Application
December 5, 2014
Although many color spray rigs are in the yards of the nation’s top ag retailers, the majority of them still come in only a few shades. Read More
CropLife 100Pinnacle Invests In Meridian Agriculture Distribution
December 4, 2014
Meridian will provide retailers with supplier-branded products and numerous opportunities to differentiate themselves from their competitors. Read More
CropLife 100CropLife 100: Entering A New Seed Era
December 4, 2014
The seed category has been re-vitalized during the past few years, and more good news (and varieties) are headed the industry’s way in 2015. Read More
CropLife 100CropLife 100: The Depressed State Of Fertilizer
December 3, 2014
Following downright giddy growth earlier this decade, fertilizer sales have fallen back down to earth the past two years. Read More

Latest News

Seed/BiotechKaren Arthur Joins AgriThority As Seed Treatment Produc…
December 19, 2014
Prior to joining AgriThority, Arthur directed research and development programs, overseeing laboratory and field research, to build the Valent U.S.A. seed treatment portfolio. Read More
EquipmentJohn Deere To Sell Crop Insurance Business
December 19, 2014
Deere & Co. has reached a definitive agreement to sell its crop insurance business, subject to regulatory approval, to Farmers Mutual Hail Insurance Co. of Iowa. Read More
Crop InputsNufarm Fills Regulatory VP Position
December 18, 2014
Nufarm announced today that Rob Schwehr has been promoted to the position of Vice President of Innovation & Regulatory Affairs for Nufarm Americas. Read More
Seed/BiotechReport: China Approves Viptera Corn, U.S. Officials Awa…
December 17, 2014
Chinese authorities have informed some agriculture industry officials the government has approved U.S. imports of a type of genetically modified corn developed by Syngenta. Read More
FertilizerMonty’s Plant Food Brings In New Sales Rep
December 16, 2014
Monty's Plant Food Company has hired Warren Kearns as its newest Sales Representative for the South Carolina area. Read More
EquipmentHagie Wins 2014 CropLife IRON Product Of The Year Award
December 15, 2014
The self-propelled sprayer maker has a hit on its hands with the new STS Series model. Read More
Syngenta
Seed/BiotechSyngenta Sees China Approving Contentious GMO Corn Soon
December 15, 2014
Syngenta will make an announcement when it receives official documentation from China that Agrisure Viptera corn, known as MIR 162, has been cleared for import. Read More
Crop InputsVerdesian Life Sciences Names Vice President Of Communi…
December 15, 2014
Amy Bugg will oversee the execution of all promotional strategies for the corporate brand and the complete product portfolio. Read More
StewardshipFarmers, Retailers Attend 4R Certification 4U Workshop
December 15, 2014
More than 160 farmers and ag retailer attended the “4R Certification 4U” workshop December 12 to learn more about the 4Rs of nutrient stewardship, water quality research in the area and cost-sharing opportunities. Read More
Matt Hopkins10 Best New Agriculture Apps For 2015
December 15, 2014
These new agriculture apps are certain to help ag professionals do their jobs more efficiently in 2015 and beyond. Read More
ManagementARA Learnings, Retail Buying Intentions: Welcome To Cro…
December 12, 2014
This informal video program puts news and events effecting retailers into context, and features Editors Paul Schrimpf and Eric Sfiligoj. Read More
Seed/BiotechMonsanto Herbicide-Tolerant Technology Closer To Commer…
December 12, 2014
The final EIS moves Monsanto one step closer to the introduction of Bollgard II XtendFlex cotton and Roundup Ready 2 Xtend soybeans, paving the way to provide access to dicamba-tolerant soybeans and cotton. Read More
Seed/BiotechUSDA Issues Final Environmental Impact Statement On Her…
December 12, 2014
The USDA Animal and Plant Health Inspection Service (APHIS) is issuing a final environmental impact statement on varieties of cotton and soybeans that have been genetically engineered for resistance to several herbicides, including the one known as dicamba. Read More
CropLife 100CHS: Driving Momentum To Help Farmer-Owners Grow
December 11, 2014
CHS Inc., the nation’s leading farmer-owned cooperative and a global energy, grains and foods company, must capture new opportunities to Read More
LegislationARA Applauds CFATS Passage Prior To Holiday Adjournment
December 11, 2014
The streamlined bill provides a four-year authorization of the CFATS program and guidance to DHS on key issues of chemical facility security Read More
Seed/BiotechBayer CropScience’s ILeVO Approved By EPA
December 11, 2014
EPA has approved ILeVO, the only seed treatment that protects the root system against infections caused by the Sudden Death Syndrome fungus and has activity against dangerous nematodes. Read More
Biologicals in Emerging Markets Map.
Crop InputsBiocontrols Could Quadruple By 2025; Will Regulators Pl…
December 11, 2014
The European experience with GMOs offers caution — and a promise — for biologicals. Read More
Crop InputsBASF Donates $75,000 To Feeding America
December 10, 2014
The donation will support Feeding America’s National Produce Program, an initiative that helps with planning, transportation and logistics to ensure fresh produce deliveries to the 200 member food banks around the country. Read More