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

Giant Ragweed
HerbicidesStudy: Focusing On Weed Seedbank Can Help Manage Herbicide-Resistant Giant Ragweed
January 18, 2017
Researchers writing in the latest issue of the journal Weed Science provide important insights on the control of herbicide-resistant giant Read More
HerbicidesEPA Expands Enlist Duo Herbicide Registration To 34 States
January 13, 2017
The U.S. EPA has expanded the geography for application of Enlist Duo herbicide from 15 to 34 states. This means Read More
HerbicidesHow Does Herbicide Resistance Evolve?
January 6, 2017
Herbicide-resistant weeds have evolved in response to repeated use of herbicides with the same site of action (SOA), according to Read More
Kochia
Herbicides9 Recommendations For Reducing The Risks Of Herbicide Resistance
January 5, 2017
To address the increasing urgent problem of herbicide resistance, the Weed Science Society of America makes the following recommendations: Reduce the Read More
Trending Articles
AgriSync
Matt Hopkins17 Agriculture Apps That Will Help You Farm Smarter In 2017
December 9, 2016
Ag professionals are working smarter, not harder, than ever before. Smart farming technologies have enabled them to reduce costs, maximize Read More
R4023 Sprayer, John Deere
CropLife 100Ag Retail Equipment Report: The Green Party Continues
December 7, 2016
In the annual race for sales in the ag retail equipment marketplace, the color schemes for participants are a little Read More
Mike Stern
Precision AgClimate Corp. CEO Talks Retailer Support For Digital Ag
December 1, 2016
CropLife Magazine’s sister publication, AgriBusiness Global, recently sat down with Mike Stern, CEO of The Climate Corp., following the Monsanto subsidiary’s Read More
Precision AgTrimble Debuts End-to-End FMIS Platform
November 28, 2016
October’s inaugural PrecisionAg Vision Conference left this author with many thoughts and things to ponder in the coming months. Probably Read More
CHS Primeland
CropLife 100The 2016 CropLife 100 Report: Reviewing The Many Bulls And Bears Impacting This Year’s Marketplace
November 28, 2016
For virtually all of 2016, the nation was wholly focused on the big Presidential election. Some folks aligned themselves with Read More
Monsanto sign
Crop InputsMissouri Governor Meets With Bayer CEO To Discuss Monsanto Merger
November 21, 2016
Missouri Gov. Jay Nixon visited Bayer AG global headquarters in Leverkusen, Germany, on November 18 to discuss the proposed Bayer-Monsanto Read More
Latest News
Soybean field
Crop InputsNufarm Teams Up With John Deere Financial
January 19, 2017
Nufarm and John Deere Financial have teamed up to help farmers grow a better tomorrow. This program helps make purchases Read More
Sonny Perdue
LegislationTrump Formally Picks Perdue As Agriculture Secretary
January 19, 2017
U.S. President-elect Donald Trump officially announced Sonny Perdue as his choice for secretary of agriculture on Thursday, selecting a former Read More
ManagementPresident Trump, Wisconsin Review, and a Dow-DuPont Upd…
January 18, 2017
Editors Paul Schrimpf and Eric Sfiligoj reflect on a new administration, a recent winter show, and crop protection company mergers. Read More
Industry NewsBayer, MS Technologies Get China Approval For Balance G…
January 18, 2017
MS Technologies and Bayer have received import approval from China for Balance GT soybeans. The new Balance GT Soybean Performance Read More
Werner Baumann, Bayer AG, and Hugh Grant, Monsanto
Industry NewsReport: Monsanto, Bayer CEOs Among Latest to Make Trump…
January 18, 2017
The chief executive officers of German chemical giant Bayer AG and U.S. seed behemoth Monsanto, Werner Baumann and Hugh Grant, Read More
Giant Ragweed
HerbicidesStudy: Focusing On Weed Seedbank Can Help Manage Herbic…
January 18, 2017
Researchers writing in the latest issue of the journal Weed Science provide important insights on the control of herbicide-resistant giant Read More
Management3 Financial Trends To Watch In Agriculture
January 17, 2017
I recently had the opportunity to attend a meeting of credit managers for Midwest ag supply and input companies, in part Read More
Andersons Retail Store
CropLife 100The Andersons To Close All Retail Stores; Shutdown Does…
January 16, 2017
In a stunning announcement to the Toledo area, The Andersons Inc. said on Sunday that it would close its two Read More
Trimble TMX-2050 In-Cab Display
Eric SfiligojPrecision To Lead Agriculture In 2017?
January 16, 2017
Another new year is upon us! And I’m certain I speak for many in the agricultural world when I say Read More
Corn
Eric SfiligojThe Mood From Madison? In A Holding Pattern
January 16, 2017
Last week, I had the chance to attend the annual Wisconsin AgriBusiness Classic show in Madison, WI. It’s been a Read More
Syngenta Sign
Crop InputsAccenture Helps Syngenta Transform Its Global Logistics
January 13, 2017
Syngenta, a leading agriculture company, has collaborated with Accenture to design and implement a new digital logistics operating model across Read More
Fall Creek Seth Harden The Nature Conservancy
StewardshipLocal Farmers’ Watershed Initiative: Continuous Improve…
January 13, 2017
The goal in the Big Pine Watershed Project is to more intentionally do what local farmers and responsible ag retailers Read More
HerbicidesEPA Expands Enlist Duo Herbicide Registration To 34 Sta…
January 13, 2017
The U.S. EPA has expanded the geography for application of Enlist Duo herbicide from 15 to 34 states. This means Read More
Olson Ag Enterprise
CropLife 100Wilbur-Ellis Acquires Nebraska Seed Retailer
January 13, 2017
Wilbur-Ellis’ Agribusiness, a recognized leader in precision agriculture technology and the distribution and marketing of plant protection, seed and nutritional Read More
ManagementDeere-Precision Planting Update and the Ag Secretary Wa…
January 12, 2017
Editors Paul Schrimpf and Eric Sfiligoj provide the latest on the court date for John Deere/Precision Planting and the quest Read More
Monsanto sign
Seed/BiotechMonsanto, NRGene Form Agreement For Big Data Genomic An…
January 12, 2017
Monsanto Co. and NRGene have announced that the companies have reached a non-exclusive, multi-year global licensing agreement on NRGene’s genome-analysis Read More
AGCO Custom applicator
SprayersAGCO, Asmark Institute To Offer Training For Beginning …
January 11, 2017
AGCO Corp. and the Asmark Institute are collaborating to offer a new training program dedicated to educating and developing custom Read More
ManagementAg Land Values In Limbo In 2017
January 10, 2017
Several factors will come into play in 2017 that will determine the direction of land values. Randy Dickhut, senior vice Read More