The Resistant Weeds Epidemic

As resistant weeds become more common in crop fields across the country, the entire agricultural community is scrambling to keep pace.

As a long-time independent ag retailer in St. Marys, KS, Doyle Pearl of J.B. Pearl Sales & Service Inc. has grown used to some interesting sights in his grower-customer fields. However, on a recent visit to one customer’s farm, Pearl at first thought he had somehow ended up on a holiday-oriented operation instead of one devoted crops.

“When I looked into the field, I at first thought this grower was harvesting Christmas trees,” says Pearl. “But when I looked closer, I saw these large, bushy plants weren’t pine trees, but weeds. It was then I realized that herbicide-resistant Palmer amaranth had arrived in our area.”

Unfortunately, Pearl is not alone in witnessing this kind of sight. Since the first herbicide-resistant marestail was discovered in Delaware in 2000, the number of similar hard-to-control weeds has rapidly spread across the U.S. At last count, say experts, there were some 14 species of weeds showing single or multiple forms of herbicide resistance in more than 30 states affecting thousands of acres of cropland.

“Palmer amaranth is a huge problem for growers because we’ve seen some plants that have had three applications of Roundup Ready WeatherMax and survived,” says Dwight Lingenfelter, a weed scientist in the department of plant science at Penn State University.

“Waterhemp is another weed that has shown resistance to multiple forms of herbicides and modes of action. There’s even one population of waterhemp that was recently discovered in Iowa that is showing some resistance to 2,4-D.”

Even worse, say industry observers, the cost of dealing with these herbicide-resistant weeds is quickly becoming an issue. For example, according to Dr. Larry Steckel, a weed scientist with the University of Tennessee, resistant Palmer amaranth cost Tennessee soybean growers more than $200 million in the past two years in increased herbicide costs, application ex­penses and yield loss.

Seeds Of Discontent

And if the plants themselves aren’t bad enough, ag retailers and their grower-customers need to be equally concerned with the seeds these herbicide-resistant weeds produce. According to Willowood USA’s Dr. Jeff Stachler, one waterhemp plant discovered in Moorhead, MN, produced 644,000 seeds. In another example, running water following a rain event in a field with Palmer amaranth present was found to contain 1 million seeds only 20 minutes after the storm.

Weed Resistance Issues Chart Weed Resistance Issues Chart

“If one plant produces 100,000 seeds with only 25% emergence and 10% of those plants survive, these resistant plants can produce up to 6.25 million plants two years later,” says Stachler.

For the most part, ag retailers understand that herbicide-resistant weeds are a major problem for their grower-customers. According to a survey recently conducted by CropLife® magazine, 79% of dealerships and cooperatives say weed resistance is a serious or very serious problem in their areas. Similarly, 51% of the grower-customers themselves view resistant weeds as a serious to very serious problem (see graphs).

The Quest For Control

When it comes to figuring out how to combat these resistant weeds, opinions from experts are varied. Some have advocated hand weeding mixed with alternatives to traditional herbicide programs as an option. “In 2010, it took 110 hours to completely hand-weed a 50-acre field, costing $33 per acre charge based upon a $15 per acre rate,” says Stachler. “In 2011, with the same herbicide program, it took only five hours to completely hand-weed this field — a cost of only $1.50 per acre.”

In other countries such as Australia, growers combating herbicide-resistant weeds have adopted an all-out war on the seeds. To achieve control here, growers have taken to baling their field trash into bundles used for livestock feed or burning this residual with flame-producing equipment that is pulled along behind the harvester.

Thankfully, here in the U.S., the situation isn’t quite as extreme just yet and 81% of ag retailers polled by CropLife® say they presently have the tools and knowledge needed to help growers manage their resistance issues.

However, as Penn State’s Lingenfelter says, ag retailers shouldn’t count on a completely new herbicide to come along and solve the problem of resistant weeds. “There have been plenty of new products introduced into the market to combat resistant weeds over the past few years,” he says. “But none of these offer a new mode of action option. The fact of the matter is there has been no new mode of action introduced into the herbicide market for the past 20 years. And even if a new molecule was discovered tomorrow that might offer a new mode of action for weed control, it wouldn’t be available for use on the market for another 10 years or better.”

Instead, says Willowood’s Stachler, retailers and growers should get used to viewing weeds in the field in a whole new light. “It is best to assume that any plant of single species present in a field is resistant at some level,” 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

Trending Articles

Crop InputsPlatform Specialty Products To Acquire Arysta LifeScience
October 20, 2014
Once the acquisition is complete, Platform Specialty Products will combine Arysta LifeScience with previously acquired companies Agriphar and Chemtura Crop Solutions. Read More
Seed/BiotechMonsanto Offers New Support For Ferguson, Area Communities
October 8, 2014
Monsanto Co. has committed $1 million in new support for several collaborative efforts in Ferguson, MO, and surrounding communities in North St. Louis County. Read More
Seed/BiotechUnapproved Genetically Modified Wheat Found In Montana
October 3, 2014
USDA reports that one year after discovery of Monsanto's unapproved wheat in a single Oregon field disrupted U.S. wheat export sales, the GMO wheat has again been found in Montana. Read More
Equipment2014 Product Of The Year Voting
September 19, 2014
The deadline to vote for the 2014 CropLife IRON Product of the Year is October 31. Please cast your vote today to help us determine the winner. Read More
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
CropLife 100CHS To Build $3 Billion Fertilizer Plant In North Dakota
September 5, 2014
The fertilizer plant in Spiritwood will be the single largest investment in CHS history, as well as the single largest private investment project ever undertaken in North Dakota. Read More

Latest News

InsecticidesValent U.S.A., MGK Form Marketing Agreement
October 24, 2014
Valent has formed an agreement with Minneapolis-based MGK to manage the marketing and sales of MGK’s crop protection line of insect control products within the U.S. beginning April 1, 2015. Read More
StewardshipFlorida’s 4R Advocate Keeps Improving
October 24, 2014
Florida farmer Alan Jones uses the 4R principles of nutrient stewardship as the core of his fertility program, which allows him to maximize production and keep costs in check. Read More
Seed/BiotechMonsanto Named One Of The World’s Best Multinational …
October 23, 2014
Monsanto ranked No. 8 in the world’s largest annual study of workplace excellence that identifies the top 25 best multinational companies in terms of workplace culture. Read More
Crop InputsArysta Hires Former Agri-Chem, CPS Employee For Delta S…
October 23, 2014
New Territory Sales Manager Mark Peel’s primary role will focus on working with growers regarding fungicides in Louisiana, Mississippi, Arkansas and Tennessee. Read More
CropLife 100GROWMARK Announces Appointments In Plant Food Division
October 22, 2014
GROWMARK, Inc. has announced the three key staff changes in its Plant Food Division. Read More
CropLife 100GROWMARK Appoints New VP Of Finance And Risk Management
October 22, 2014
Wade Mittelstadt has been named GROWMARK Vice President, Financial and Risk Mangement, effective December 1, 2014. Read More
FungicidesEPA Approves BASF In-Furrow Corn Fungicide
October 22, 2014
Field trials show Xanthion In-furrow fungicide provides more rapid emergence, extended residual control and improved seedling health than untreated crops. Read More
EquipmentAgraScout App Available At No Cost To Universities
October 21, 2014
AgraScout, a fast and easy to use mobile crop scouting app, is now available at no cost to University students, Read More
LegislationNew Farm Bill Program To Provide Relief To Farmers Affe…
October 21, 2014
The USDA has implemented a new Farm Bill initiative that will provide relief to farmers affected by severe weather, including drought. Read More
ManagementGreenfield Scholars Program Aims To Sustain Agronomy Wo…
October 21, 2014
The program encourages talented students to study agronomy, crop and soil sciences while cultivating networks to develop the necessary workforce to sustain the profession. Read More
Paul SchrimpfPrecision Ag: Taking It To The Hill
October 21, 2014
A new coalition took the good news message of precision agriculture to Washington, DC, last month. Read More
ManagementUSDA Awards $18 Million In Small Business Research Gran…
October 21, 2014
The grants will provide high quality, advanced research and development that will lead to technological innovations and solutions for American agriculture. Read More
FertilizerCF Industries Terminates Merger Discussions With Yara I…
October 21, 2014
CF Industries Holdings and Yara International have terminated their discussions regarding a potential merger of equals transaction. Read More
Seed/BiotechSyngenta Ranked A Top 10 Biotech Employer For Third tim…
October 20, 2014
Syngenta ranked in the top 10 among the world’s top biotech employers, according to an annual survey conducted by Science magazine. Read More
CropLife 100Wheat Growers Break Ground For New Facility At Kennebec
October 20, 2014
Wheat Growers has broke ground for a state-of-the-art shuttle loader grain handling, fertilizer and agronomy facility in Kennebec, SD. Read More
FertilizerVerdesian Life Sciences Signs Agreement With Los Alamos…
October 20, 2014
Verdesian Life Sciences has signed a licensing agreement with Los Alamos National Laboratory to develop and market LANL’s latest nitrogen enhancement technology for plants. Read More
MicronutrientsStoller Group Announces Groundbreaking At New Office Bu…
October 20, 2014
Jerry Stoller, founder and president of Stoller Group, announced the groundbreaking at the site of the company’s future headquarters in Read More
Crop InputsBioSafe Systems Opens New Production Facility In Nevada
October 20, 2014
BioSafe Systems has completed construction of a state-of-art production facility in Sparks, NV, for its line of activated peroxygen products. Read More