New Herbicide-Resistant Weed Confirmed In Ohio

A weed known to many cotton and soybean growers in the South as “pigweed on steroids” has been spotted in Ohio, prompting Ohio State University Extension experts to warn Ohio growers to take measures to prevent its further spread statewide.

Palmer amaranth, which is a glyphosate-resistant weed that has had a substantially negative impact on crop yields and profitability for cotton and soybean growers in Southern states, has been spotted in a large field near Portsmouth in extreme southern Ohio, said Mark Loux, an OSU Extension weed specialist.

The concern about glyphosate-resistant Palmer amaranth, which has caused entire cotton and soybean fields to be mowed down in some Southern states, is that if the weed takes hold in Ohio crop fields, it will be even harder to control than the glyphosate-resistant weeds already present statewide, he said.

“Not only is Palmer amaranth resistant to glyphosate, this weed’s rapid growth, large size, extended duration of emergence, prolific seed production and general tolerance to many herbicides makes it a much more formidable weed to deal with than the pigweed species we already have here in Ohio,” Loux said. “Among the weeds that we already deal with, Palmer amaranth is going to require pre- and post-emergence applications, possibly multiple post-emergence applications.

“It’s already resistant to two of the main types of herbicides we use in soybeans, glyphosate and ALS inhibitors, and the weed has to be less than four inches tall when spraying in order to get control of it.”

Palmer amaranth, which can grow 3 inches a day, can release nearly a half-million seeds per plant. And because the weed is glyphosate-resistant, many growers in Southern states, in addition to spraying, have had to hire workers to go into their fields to chop down the weeds with hoes and pull them by hand.

Losses for growers dealing with this aggressive weed have been in the millions in lost agricultural crops, experts estimate.

The weed, which has typically been prevalent in Southern states, is moving north, with several other suspected cases statewide that OSU Extension experts are investigating. New infestations of Palmer amaranth have also been found farther north, in Michigan and Indiana, he said.

“We suspect Palmer amaranth was introduced in Ohio and other states through contaminated cottonseed shipped from the southern U.S. for use as animal feed here in the Midwest,” Loux said. “Palmer amaranth established from manure spread on fields that was obtained from these animal operations.”

To prevent further spread and growth of the weed in Ohio, growers and producers should avoid spreading manure on crop fields obtained from animal operations where cottonseed was used as feed, he said.

“This manure likely contains Palmer amaranth and should not be spread on crop fields,” Loux said. “To avoid that problem, growers and producers should ask if cottonseed was used as feed before using any manure obtained from an animal operation other than their own.”

The goal is to prevent the spread of Palmer amaranth, considering that Ohio already has healthy populations of glyphosate-resistant marestail (also known as horseweed), giant ragweed, common ragweed and waterhemp, he said.

“Palmer amaranth is a very competitive weed that can reduce soybean yields,” Loux said. “If you let it go, it could have a pretty explosive population increase in a very short period of time.

“It is a very expensive and difficult weed to manage.”

And the record dry, hot weather Ohioans have experienced this summer hasn’t made controlling glyphosate-resistant weeds any easier. Extended hot, dry weather and drought impact the germination, growth, hardiness and competitive ability of weeds and complicate control efforts, he said.

During extended dry conditions, weeds grow more slowly and also develop thicker cuticles on the leaf surfaces, which has the overall effect of reducing herbicide movement into and throughout the plant.

This as Ohioans have suffered through multiple days of record-setting temperatures of over 100° this summer, with scant rainfall that has resulted in most of the state except for some counties near the Kentucky, West Virginia and Pennsylvania borders experiencing moderate drought, with some counties near the Indiana and Michigan borders experiencing severe and extreme drought as of August 7, according to the most recent U.S. Drought Monitor.

And while some Ohio growers already have experienced dealing with glyphosate-resistant waterhemp, which is typically found in western Ohio and is the closest weed that Ohio has that can be compared to Palmer amaranth, the southern weed has more potential to reduce yield if it is not controlled, Loux said.

But with early diagnosis of infested fields and early intervention, the potential for damage from Palmer amaranth in Ohio can be mitigated, he said.

“This is one of those rare occasions where we have enough information to hopefully prevent additional infestations of an extremely aggressive weed, and there could be serious long-term consequences for farm profitability for failing to do so.”

Topics:

Leave a Reply

Herbicides Stories

Crop Protection Products in storage
Crop InputsNewsweek: World Is ‘Awash In Glyphosate’
February 11, 2016
The world is awash in glyphosate, the active ingredient in the herbicide Roundup, produced by Monsanto. It has now become Read More
Crop InputsSyngenta’s Acuron Flexi Receives EPA Approval
February 11, 2016
Growers looking to control their toughest weeds with flexibility will have access to Acuron Flexi corn herbicide from Syngenta, now Read More
Crop InputsWeed Expert: Adding A Second Herbicide Not Always Easy
February 9, 2016
In my last post, I reviewed some recent research that suggests one of the best ways to delay the evolution Read More
Crop InputsGenetic Literacy Project: Farmers Need More Herbicide Choices
February 9, 2016
There are two things that I think just about every weed scientist can agree on, writes Andrew Kniss for The Read More
Top 100 Articles
Elburn Cooperative
CropLife 100Elburn Cooperative Members Vote To Join CHS
December 28, 2015
With 81% of eligible producers voting, 94% cast an affirmative ballot for Elburn Cooperative, a diversified agricultural retailer based out Read More
West Central Cooperative, Jefferson, IA
CropLife 100Farmers Cooperative-West Central Merger Approved
December 21, 2015
The members of Farmers Cooperative Co. (FC), Ames, IA, and West Central Cooperative, Ralston, IA, have both approved the merger Read More
Wheat Growers Innovation Center, Bath, SD
CropLife 100Wheat Growers Opens Innovation Center
December 21, 2015
Wheat Growers’ commitment in providing its farmer-owners with the latest in technological advancements now has a one-of-a-kind focal point, as Read More
CropLife 100ARA Selects The Andersons As 2015 Retailer Of The Year
December 9, 2015
The Agricultural Retailers Association today named Maumee, OH-based The Andersons as its Retailer of the Year for 2015. The award Read More
CPS Washington Court House John Deere Sprayer
CropLife 100Application Equipment Report: It Is Easy Being Green For Top 100 Ag Retailers
December 5, 2015
On The Muppets television show, Kermit the Frog is famous for singing a song about the troubles he encounters in Read More
Fertilizer Bin
CropLife 100Fertilizer Sales: Another Down Year For Top 100 Ag Retailers
December 4, 2015
In pure number terms, the fertilizer category still dominates all crop inputs/services among CropLife 100 ag retailers. In 2015, for Read More
Latest News
Crop Protection Products in storage
Crop InputsNewsweek: World Is ‘Awash In Glyphosate’
February 11, 2016
The world is awash in glyphosate, the active ingredient in the herbicide Roundup, produced by Monsanto. It has now become Read More
Crop InputsEPA: Let’s Talk Imidacloprid, Bees On February 18
February 11, 2016
EPA will hold an online technical briefing on its preliminary pollinator risk assessment for imidacloprid, a neonicotinoid insecticide, on Feb. Read More
ManagementThe latest on Syngenta-ChemChina Deal
February 11, 2016
Executive Editor Paul Schrimpf invites Jackie Pucci and Dave Frabotta from sister publication AgriBusiness Global to discuss the latest developments Read More
AdjuvantsUniversity of Illinois Confirms Adjuvant’s Perfor…
February 11, 2016
An independent University of Illinois study has shown that WETCIT adjuvant, now with TransPhloem technology, provides greater herbicide uptake and Read More
Crop InputsSyngenta’s Acuron Flexi Receives EPA Approval
February 11, 2016
Growers looking to control their toughest weeds with flexibility will have access to Acuron Flexi corn herbicide from Syngenta, now Read More
EquipmentAGCO Showcases White Planters 9800VE Series Planters AT…
February 11, 2016
AGCO unveiled the new White Planters 9800VE Series planter during the 2016 National Farm Machinery Show in Louisville, KY. The Read More
EquipmentCase Unveils 2000 Series Early Riser Planter At NFMS
February 10, 2016
Case IH revealed the all-new 2000 Series Early Riser planter to media and attendees at the opening of the National Read More
Syngenta Sign
Crop InputsSyngenta: Keep Ag In Mind During Election Season
February 10, 2016
As presidential candidates stake out their 2016 election platforms and key priorities, growers and their business partners should seek opportunities Read More
Crop InputsMarrone Bio Innovations Submits New Bio-Fungicide For E…
February 9, 2016
Marrone Bio Innovations, Inc. (MBI) today announced that it has submitted a new biological fungicide (MBI-110) to EPA. The broad spectrum Read More
Crop InputsWeed Expert: Adding A Second Herbicide Not Always Easy
February 9, 2016
In my last post, I reviewed some recent research that suggests one of the best ways to delay the evolution Read More
Crop InputsGenetic Literacy Project: Farmers Need More Herbicide C…
February 9, 2016
There are two things that I think just about every weed scientist can agree on, writes Andrew Kniss for The Read More
HerbicidesWeed Expert Warns North Dakota Growers Of Coming Herbic…
February 9, 2016
Ford Baldwin painted a bleak picture of weed control at a recent workshop here exploring the future of ag production, Read More
HerbicidesWSSA Announces New, Updated Free Web Resources
February 9, 2016
Today the Weed Science Society of American (WSSA) announced that new and updated educational materials for both weed scientists and Read More
Soybean field
FungicidesFour Arysta Fungicide Formulations Given FIFRA Approval…
February 8, 2016
Arysta LifeScience North America recently announced the issuance of Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 2(ee) Recommendations for Read More
FungicidesAgri-Fos Systemic Fungicide Plus Receives EPA Registrat…
February 8, 2016
Vivid Life Sciences has announced the EPA registration of Agri-Fos Systemic Fungicide Plus, a highly concentrated active ingredient phosphite fungicide, Read More
Crop InputsBayer Contests EPA’s Decision On Valuable Insecticide F…
February 5, 2016
Crop Science, a division of Bayer, has announced it has refused a request by the Environmental Protection Agency (EPA) to Read More
Wheat Field North Dakota
Seed/BiotechSyngenta Wins Seed Fraud Suit Against South Dakota Grow…
February 5, 2016
Syngenta has obtained a $25,000 settlement from Paul and John Mayclin, Mayclin Farms, Plankinton, SD, in response to their Plant Read More
ManagementOABA Annual Conference Wraps Up In Columbus
February 5, 2016
More than 300 Ohio AgriBusiness Association (OABA) members and industry professionals were on hand to engage in collaborative learning and Read More