Combating A New Generation Of Weeds

Traditional weed management practices are under attack as glyphosate-resistant Palmer amaranth takes a firm and frightening grip on fields throughout the Mid-south. Yet Southern growers aren’t the only ones concerned, as the now all too common sight of fields overrun with pigweed could spread throughout the Midwest, with the nuisance having already reared its head in parts of downstate Illinois and Indiana and southern Ohio.

While these yield-robbing weeds have traditionally been defeated with basic herbicides, now many growers are finding themselves “out of bullets” as the overuse of glyphosate and other technologies has further elevated the crisis of weed resistance in the U.S.

And, as former University of Arkansas weed science professor Dr. Ford D. Baldwin tells it, ag retailers are in a unique position to alleviate some of these pressures.

“I think this is really a huge opportunity for retailers, and I know retailers get pulled a lot of different ways with incentives from different companies,” he said. “One of the keys in surviving this thing is the companies with the new technologies being able to work together, but I don’t think that’s going to happen anytime soon.

“If retailers keep the growers best interest at heart,” he adds, “then I believe they can in a way force the integration of all of these new technologies without the individual companies ripping each other apart.”

Bayer CropScience, one of those companies Baldwin is referring to, is among those taking the initiative to educate growers and retailers alike on this evolving threat, and CropLife® magazine recently joined the company’s Respect The Rotation tour in Collinsville, IL, to glean valuable new information in this ongoing saga.

Revisiting Residuals

Until recently, Palmer amaranth was in many ways no different from any other run-of-the-mill weed. It is the widespread development of glyphosate-resistance in the species that has catapulted pigweed into a dubious category Baldwin refers to as “Driver Weeds,” or as he explains it “weeds that if you don’t control them, nothing else matters.”

So, in the era of glyphosate-resistance, how does one control pigweed? In the past, a correct answer to that question would be the addition of residual herbicides to the cropping plan. Not now, however.

“My message to growers is simple: don’t just use residuals, you’ve got to use multiple residuals,” said Baldwin. “You’ve got to get some diversity into your post-emergence applications, so we can save Roundup.”

The reasoning behind advocating increased residual applications is simple: herbicides in the soil can more efficiently kill the weed before germination.

“Why are residual herbicides the number one option for resistance management today?” asks Jason Norsworthy, associate professor of weed science, University of Arkansas. “It’s because they help us with our application timing, and the more you control the weeds never coming up, never germinating and never emerging, the less chance you have for resistance.”

“Also, the residuals reduce the amount of plants that you’re spraying post-herbicides on where you know you have significant, multiple resistance issues,” Norsworthy adds. “On top of that, it expands your application window so you’re spraying smaller weeds, which helps get better spray coverage too, so it is key.”

Another solid management practice that has yet to catch on, but likely will according to Norsworthy, is the overlapping of residual herbicides. “It’s not common yet but it’s starting to increase in terms of our education as well as some companies promoting it a little bit more. It always helps when a company has a particular product to offer in that overlapping of residuals, so it’s becoming a little more common and it’s definitely a direction that I think we need to go.”

With zero new herbicide technologies on the horizon, the industry must respond rapidly before resistance becomes unmanageable.

“The last new herbicide mode of action, or how the herbicide kills the plant, was discovered 30 years ago, so there’s no magic bullet coming down the pipeline,” Baldwin adds. “This is not just a farmer problem anymore. It’s an industry problem.”

A Numbers Game

With Roundup no longer effective on resistant pigweed, the days of cheap and easy weed control are long gone. As many Southern growers have no doubt learned the hard way, after infection the problem becomes so expensive and taxing that experts advise even if current pigweed populations are extremely sparse or non-existent in your area, it takes little effort for it to set up shop permanently. Being proactive, or tackling the problem before it actually becomes a problem, is a must.

“Palmer amaranth is a desert plant that just overpowers you with numbers, and it doesn’t need much water” says Norsworthy. “If you’ve got that ‘just one more year’ mentality, you’ve already lost the war. As a grower, you have to be proactive.”

Norsworthy witnessed first-hand pigweed’s prolific ability to spread. When he began his field work at the University of Arkansas back in 2007, the soybean test plot he was working on had zero pigweed plants. In 2008, same thing. Not a single plant. Then in 2009, a graduate student happened upon three pigweed plants, but Norsworthy thought little of it.

Come the very next year, and the field was, in his own words, “inundated with pigweed.” In 2011, that same field was deemed “unmanageable” by the university. All it took was five years for Palmer amaranth to completely annihilate a soybean field.

Prescribing A Regimen

Although the prognosis going forward seems dim, there are still many tools available. According to Bayer, the top choice currently among many Southern growers is the Bayer LibertyLink system for corn, cotton and soybeans. Dr. Baldwin informally estimates that over 50% of the cotton and 30% of the soybeans planted south of the Mason-Dixon line are utilizing the technology.

“LibertyLink works great, and that’s all well and good, but some of these growers you ask what their plan is for next season and they say LibertyLink, LibertyLink and LibertyLink, followed by more LibertyLink,” laments Baldwin. “But that’s not going to work, and if we do that we’re going to break Liberty quicker than we broke Roundup.”

Instead, Bayer is advocating its Respect The Rotation approach: Rotation of multiple modes of action, yearly rotation of crops and rotation of herbicide-tolerant traits. Residual applications, both pre-and post-planting, the overlapping and overlaying of multiple residuals throughout the offseason and a minimum of three modes of action combined with LibertyLink are also crucial pieces to the puzzle.

Aside from Liberty, some other management options include the family of HPPD traits and the Dow AgroSciences’ Enlist trait in corn and soybeans, and the coming dicamba and 2,4-D formulations that await EPA registration for 2013. Looking even further up the road, BioDirect, a new technology discovered by Monsanto that “uses molecules found in nature that are, like RNA, applied to diminish the production of specific proteins in the target organism,” is showing promise but is reportedly a ways down the pipeline and tentatively set for a 2014 market release.

With once-effective herbicide technologies being lost one-by-one at such a rapid rate (ALS, glyphosate, atrazine, etc.) and the number of herbicide-resistant weeds exploding from zero back in 1950 to 388 species today, agriculture’s ability to outsmart herbicide-resistance is going to make or break our global food production system going forward.

Topics: , ,

Leave a Reply

One comment on “Combating A New Generation Of Weeds

  1. OPINION: So sad that educated persons continue to endorse an agricultural practice (drenching fields in herbicide before planting) that threatens the health of consumers, decreasess the nutritive value of the food and poisons the planet.(not to mention the monopoly created over food held by glyphosate producers) To fatten their bottom line, American farmers continue to embrace the deceptive practice of “no til” (herbicide) farming. Their produce may as well be cardboard…looks great but herbicide is poison! The USDA is at fault for endorsing this practice and rumor has it they get some sort of royalty or kickback for continuing to support this and other questionable “experiments” forced on the unwitting comsumer. Wake up Dr. Ford Baldwin! you are endorsing practices that endanger the health of the planet (I bet he eats organic) Farmers PLEASE consider more sustainable, health enhancing, methods of production.

Herbicides Stories

Crop InputsEU Glyphosate Controversy Heating Up Yet Again
August 17, 2016
The battle over glyphosate rages on in Europe, creating a lot of question marks over whether the herbicide will continue Read More
Winter Wheat
HerbicidesNew Wheat Herbicide Helps Growers Manage Resistant Weeds
August 2, 2016
Quelex herbicide from Dow AgroSciences is now registered by the U.S. EPA, providing wheat growers a new solution for advanced Read More
Palmer pigweed seedhead in cotton
HerbicidesStudy: Fall Weed Controls Can Make Significant Impact On Glyphosate-Resistant Palmer Amaranth
July 28, 2016
An article published in the latest issue of the journal Weed Science shows that adopting harvest-time and post-harvest weed controls Read More
Palmer pigweed in soybean stubble
HerbicidesSpecial Issue Of Weed Science Explores Human Aspects Of Herbicide Resistance
July 27, 2016
Weeds that evolve resistance to herbicides are a serious threat to global agricultural production. In this Special Issue of Weed Science, Read More
Trending Articles
Bayer Monsanto
Crop InputsBayer-Monsanto Mega-Merger: 6 Things You Need To Know
September 14, 2016
Mega mergers have become almost routine in the agricultural industry. Right on the heels of Monday’s news that fertilizer giants Potash Read More
Potash Corp Agrium
Crop InputsAgrium, Potash Corp To Merge To Create $36 Billion Company
September 12, 2016
Canada’s Agrium Inc. and Potash Corp of Saskatchewan Inc. have agreed to combine in a deal that would create a Read More
Osage Co-op Elevator Osage, IA Finished Building
OpinionAre We Crazy?
September 8, 2016
At some point in the first few months of my employment here at CropLife® magazine, I started getting curious about Read More
ManagementMAGIE 2016 Highlights and Deere Anti-Trust
September 1, 2016
CropLife Editor Eric Sfiligoj discusses the recent Midwest AG Industries Exposition and the Department of Justice’s objection to John Deere Read More
ASMARK 2016 Retailers Live! Tour - CPS
CropLife 100CPS Acquires Texas Retail Operation
August 23, 2016
Crop Production Services (CPS) has acquired the assets of Larry’s Chemical and Spray, Inc., for an undisclosed amount in an Read More
Key Cooperative Marcus Construction Steel Building
Retail FacilitiesMarcus Construction Builds High-Speed Agronomy Center For Key Cooperative
July 7, 2016
Key Cooperative in Grinnell, IA, wanted a state-of-the-art Agronomy Center to better serve its customers. Marcus Construction delivered exactly that. Read More
Latest News
Syngenta Seedcare Institute
Seed/BiotechSyngenta Opens New North America Seedcare Institute In …
September 23, 2016
Syngenta unveiled its new Seedcare Institute in Stanton, MN, during a recent grand opening celebration. More than 150 industry leaders, Read More
StewardshipMonsanto Invests $1.6 Million In System To Quantify Gre…
September 23, 2016
The USDA – Natural Resources Conservation Service (USDA-NRCS) recently awarded the National Corn Growers Association (NCGA) and its Soil Health Read More
Pipe rack
LegislationCourt Sides With Ag Retailers On PSM
September 23, 2016
The D.C. Court of Appeals has ruled the Occupational Safety and Health Administration violated the Occupational Safety and Health Act when Read More
ManagementPacific Coast Fertilizer Announces Interest In Longview…
September 22, 2016
Pacific Coast Fertilizer LP (PCF) announced at the Cowlitz Economic Development Council board of directors meeting its interest in developing Read More
Young corn plants in soil
UncategorizedCool Planet Raises Additional $9 Million To Commerciali…
September 22, 2016
Cool Planet has announced the first close of a new financing round to commercialize the company’s Cool Terra Engineered Biocarbon Read More
Crop InputsJim Loar Promoted To President And CEO Of Cool Planet
September 22, 2016
In a move that reflects and reinforces the company’s commitment to the agricultural market, the Cool Planet board of directors Read More
BlendersNorth Dakota Coop Debuts Dry Fertilizer Plant
September 22, 2016
North Central Grain Cooperative has begun operations at a new dry fertilizer plant at its Rolla, ND, site. It is Read More
Crop InputsMonsanto, Bayer Officials Defend Proposed $66 Billion M…
September 21, 2016
Top officials for Monsanto and Bayer defended their proposed $66 billion merger before skeptical senators on Tuesday, insisting that the Read More
ManagementUpcoming Shows & Recent Events
September 19, 2016
Editors Paul Schrimpf and Eric Sfiligoj talk about upcoming trade shows and events and review the Mid America CropLife Association Read More
Industry NewsVerdesian Life Sciences Appoints New CEO
September 19, 2016
Verdesian Life Sciences, a plant health and nutrition company, today announced that its board of directors has named Kenneth M. Avery Read More
Corn
Crop InputsEPA Settles With Syngenta For Alleged Multi-Regional Pe…
September 19, 2016
The U.S. EPA has announced a multi-region settlement with Syngenta Crop Protection, LLC (Syngenta) in Greensboro, NC, for alleged violations of Read More
ManagementMerger Mania
September 16, 2016
Editors Paul Schrimpf and Eric Sfiligoj discuss this week’s mega-ag mergers of Bayer and Monsanto and Potash and Agrium. Read More
Monsanto sign
Crop InputsMonsanto Ends Up Being A Bargain For Bayer
September 16, 2016
History will say Bayer got a bargain in its $66 billion purchase of Monsanto, writes David Nicklaus, St. Louis Post-Dispatch. The Read More
Greg Musson, Gar Tootelian
CropLife 100California Ag Retailer Steps Up To Feed Families Affect…
September 16, 2016
GAR Tootelian, Inc. (GAR) in Reedley, CA, is challenging the Central Valley to help raise enough money and provide 525,000 meals Read More
Crop InputsBayer, Monsanto CEOs Discuss Merger
September 15, 2016
Werner Baumann, Bayer CEO, and Hugh Grant, Monsanto CEO, discuss why they decided to merge their companies. Read More
Corn close up
Crop InputsNY Times: Bayer-Monsanto a Bad Deal for Farmers
September 15, 2016
Via NY Times: Don Halcomb, a 63-year-old farmer in Adairville, KY, is expecting his profit to vanish this year, largely Read More
Werner Baumann, Bayer AG, and Hugh Grant, Monsanto
Crop InputsBayer-Monsanto Merger Creates New Global Ag Giant
September 14, 2016
During the whole of 2016, many of the companies that do business in the agricultural industry have concluded the best Read More
Bayer Monsanto
Crop InputsBayer-Monsanto Mega-Merger: 6 Things You Need To Know
September 14, 2016
Mega mergers have become almost routine in the agricultural industry. Right on the heels of Monday’s news that fertilizer giants Potash Read More