Multiple Herbicide Resistance Found In Illinois Waterhemp

Common/Tall Waterhemp
Common/Tall Waterhemp

 

Herbicide-resistant waterhemp populations will challenge weed management practices and practitioners during the 2012 growing season.

University of Illinois associate professor of weed science Aaron Hager said that the increasing occurrence of waterhemp populations that possess resistance to herbicides spanning more than one site of action further complicates management because the efficacy of multiple herbicides is compromised.

Last year, University of Illinois weed science specialists published the results of a herbicide-resistance screening program for waterhemp samples submitted during the 2010 growing season. The program uses molecular biology techniques to detect herbicide-resistance traits (glyphosate, PPO inhibitors, and ALS inhibitors) in waterhemp. In 2011, a total of 408 plants from 97 different fields suspected of having glyphosate-resistant waterhemp were submitted.

Hager explained that distinguishing between multiple herbicide resistance at the field and individual plant levels is important and can impact management options.

“Field-level multiple resistance is when resistance to herbicides from more than one site of action is present within the population growing in any particular field,” he said. “When multiple-herbicide resistance occurs at the plant level, individual plants demonstrate resistance to herbicides encompassing more than one site of action.”

Thus, when three types of resistance are present at the field level and individual plants are resistant to only one herbicide, a three-way tank mixture of herbicides A, B, and C could control all the plants in the field. However, tank mixtures of herbicides A, B, and C would not control individual plants that possess resistance to these three herbicides.

Multiple resistance often occurs at both levels in a single population. A field often includes a mix of plants, some of which are resistant to just one herbicide (or herbicide family) while others are resistant to multiple herbicide families. Tankmixing two or more postemergence herbicides may not effectively control herbicide-resistant waterhemp under these conditions.

Of the 408 plants submitted and screened from 2011, only 13% were sensitive to all three herbicides; the rest of the plants in the sample were resistant to at least one herbicide. Twenty-eight percent, 19%, and 3% of the plants were resistant only to glyphosate, ALS inhibitors, or PPO inhibitors, respectively.

On a field basis, only 4% of the 97 fields from which plants were sampled had no herbicide-resistant waterhemp. Approximately 25% of the fields contained waterhemp resistant to PPO inhibitors, 84% of the fields contained waterhemp resistant to ALS inhibitors, and 66% of the fields contained glyphosate-resistant waterhemp.

“Keep in mind that these fields – and plants within fields – were not randomly selected but were sampled based on suspected resistance to glyphosate,” said Hager. He also noted that the field-level results are based on small samples (five or fewer plants per field). “It is likely that, had a larger number of samples been taken, we would have found more fields with resistance to ALS and PPO inhibitors,” he said.

Even with this sample-size limitation, over 10% of the fields were found to contain three different types of herbicide resistance, which greatly increases the difficulty of managing these populations using only postemergence herbicides labeled for use in conventional or glyphosate-resistant soybean varieties. Results from this and previous surveys suggest that glyphosate-resistant waterhemp occurs in many fields across the southern two-thirds of Illinois.

This survey was only one project in the ongoing research portfolio on herbicide-resistant weeds in Illinois. Weed scientists at several Illinois universities are studying this phenomenon and working to develop viable solutions for Illinois growers. Much of this research is made possible by multiple public and private funding sources, including the Illinois Soybean Association.

Topics:

Leave a Reply

Herbicides Stories

Corn close up
Crop InputsMonsanto’s First HPPD Herbicide Garners EPA Approval in Field & Seed Corn
May 19, 2017
Monsanto announced today that EPA has federally approved Harness MAX Herbicide, the first herbicide in the Monsanto portfolio to provide Read More
Palmer amaranth
Crop InputsDow: Modes of Action, Multi-Year Plans Limit Weed Issues
May 2, 2017
Controlling weeds is becoming increasingly difficult. Success requires a multi-pronged strategy that keeps weeds at bay during the growing season Read More
Case Patriot Sprayer closeup
Equipment2017: Drift Control’s Most Important Year, So Far
May 1, 2017
This upcoming growing season promises to be slightly different than any that have come before it. In 2017, USDA estimates Read More
Engenia soybeans
Crop InputsINNVICTIS CROP CARE Introduces VANDAL MOC Soybean Herbicide
April 25, 2017
INNVICTIS CROP CARE, LLC has announced the U.S. EPA registration for VANDAL MOC, a combination of sulfentrazone plus metolachlor. VANDAL Read More
Trending Articles
Migrant farm workers
LegislationTrump: Immigration Crackdown Won’t Impact U.S. Agriculture
May 16, 2017
President Donald Trump said he would seek to keep his tough immigration enforcement policies from harming the U.S. farm industry Read More
AGCO Ratliff featured
Eric SfiligojRemembering Robert Ratliff
May 15, 2017
With all the fast-paced happenings in agriculture this spring, with multiple mergers in the works and planting season in full Read More
Case sprayer nozzle closeup
EquipmentSpray Application: A Nozzle Renaissance
May 2, 2017
If you had asked four-decade ag veteran Mark Bartel, President of Wilger Inc., just a few years ago what lay Read More
ManagementWashington Update, Dow-DuPont Earnings, and the Passing of an AGCO Legend
April 27, 2017
Editors Paul Schrimpf and Eric Sfiligoj talk about the latest Beltway news, crop protection company 1st quarter numbers, and the Read More
Crop InputsFlying Under the Radar No More, FMC Goes Big
April 13, 2017
Describing FMC as “under the radar,” admittedly, is probably a stretch. But in a snap of the fingers, FMC upped Read More
Young Corn Plants
Crop NutritionStill Hunting Yields
April 1, 2017
There’s no denying it — the agricultural marketplace today is undergoing a fundamental shift in fortunes. Not too many years Read More
Latest News
Eric SfiligojMonsanto ‘Picks Its Battles’ by Nixing Deere Deal
May 23, 2017
Having been in the trade journalism game since the mid-1980s, I remember several watershed moments during my career. One of Read More
FungicidesSyngenta Launches New Seed Treatment Fungicide
May 22, 2017
Syngenta has announced the launch of PLENARIS seed treatment fungicide for the control of downy mildew in sunflower. PLENARIS contains Read More
Corn close up
Crop InputsMonsanto’s First HPPD Herbicide Garners EPA Appro…
May 19, 2017
Monsanto announced today that EPA has federally approved Harness MAX Herbicide, the first herbicide in the Monsanto portfolio to provide Read More
ManagementPrecision Planting Deal, China Developments, and Enviro…
May 18, 2017
Editors Eric Sfiligoj and Dan Jacobs discuss the latest news on John Deere’s now dead deal for Precision Planting, China’s Read More
Soybean aphid leaf
InsecticidesMulti-state Research Reveals IPM Best Option for Treatm…
May 17, 2017
About 89.5 million acres of soybeans will be planted across the U.S. in 2017 — a record high, according to Read More
GROWMARK-2017-Interns
CropLife 100GROWMARK Names 2017 Summer Interns
May 16, 2017
Forty-two college students are exploring agricultural career opportunities this summer as GROWMARK interns. They are working at FS member cooperatives Read More
Migrant farm workers
LegislationTrump: Immigration Crackdown Won’t Impact U.S. Ag…
May 16, 2017
President Donald Trump said he would seek to keep his tough immigration enforcement policies from harming the U.S. farm industry Read More
Flooded corn in Indiana
FertilizerBoth Wet and Dry Conditions Threaten Nitrogen Loss
May 15, 2017
The weather is notoriously unpredictable, leading to challenges for planting, harvesting and applying the nitrogen (N) your corn crop needs. Read More
farmer Kip Tom
Precision AgAg Tech: On the Cusp of Something Big?
May 15, 2017
The investment and ag-tech sectors’ continuing courtship of agriculture, smoldering for three or four years now, was well in evidence at Read More
AGCO Ratliff featured
Eric SfiligojRemembering Robert Ratliff
May 15, 2017
With all the fast-paced happenings in agriculture this spring, with multiple mergers in the works and planting season in full Read More
Greg Musson, Gar Tootelian
ManagementOpinion: Shaking Your Perspective in Ag Retail
May 12, 2017
Some of you I’m sure have encountered our recently retired salesman extraordinaire, Dan Bellanger. He worked in the industry for Read More
Exterior view of CPS Big Lake facility which includes enclosed receiving and load out area
CropLife 100New Alternative Weed Resistance Traits Could Experience…
May 12, 2017
It wasn’t too many years ago that ag retailers and their grower-customers could hardly wait for new options to fight Read More
Diane Allemang and Dan Jacobs
Crop InputsFMC Agricultural Solutions, Casa Pacifica Partner to He…
May 11, 2017
FMC Agricultural Solutions is teaming up with Casa Pacifica Centers for Children and Families, an organization that supports vulnerable children Read More
UncategorizedWhat’s Up With ARA
May 11, 2017
CropLife Editor Eric Sfiligoj talks with Brian Reuwee regarding what issues are on the docket for the Agricultural Retailers Association. Read More
BASF Maglis tablet retailer grower
Precision AgQ&A: What BASF’s Latest Foray into Precision …
May 11, 2017
In late April, BASF agreed to acquire U.S. precision ag player ZedX, a leader in the development of agronomic weather, Read More
Pam Marrone
Crop InputsMarrone Bio Innovations Enters into Distribution Agreem…
May 11, 2017
Marrone Bio Innovations, Inc., a leading global provider of bio-based pest management and plant health products for the agriculture markets, Read More
Bayer
Crop InputsBayer to Sell Liberty Business to Seal Monsanto Deal
May 8, 2017
Bayer has agreed to sell its Liberty herbicide and LibertyLink-branded seeds businesses to win antitrust approval for its acquisition of Read More
Trump, Senate, Cabinet
LegislationTrump’s EPA Appointee Dismisses Half of Major Sci…
May 8, 2017
(Via NYTimes.com) EPA has dismissed at least five members of a major scientific review board, the latest signal of what Read More