Glyphosate-Resistant ‘Superweeds’ May Be Less Susceptible To Disease

Scientists searching for clues to understand how superweeds obtain resistance to the popular herbicide glyphosate may have been missing a critical piece of information, a Purdue University study shows.

Glyphosate, the active ingredient in the weed killer sold under the name RoundUp, is the most widely used herbicide in the United States, but some plants have grown resistant to it. This has caused growers to turn to additional herbicides. While the mechanisms that have led to resistance are not fully known, Bill Johnson, a professor of weed science; Steve Hallett, an associate professor of weed science; and Jessica Schafer, a graduate student in botany and plant pathology, believe that soil microbes may play a role.

Most laboratory tests done to understand glyphosate resistance are done in sterile soil, void of those microbes. Schafer said Purdue’s findings, published online early in the journal Weed Science, show that those microbes may play a significant role in how glyphosate affects plants.

“The soil you’re growing the plants in is important to the results,” Schafer said. “If we’re growing in a sterile media, we could get some false positive results because the plants are more tolerant to glyphosate in those conditions.”

Hallett and Schafer grew giant ragweed, horseweed and common lambsquarter in both sterile soil and field soil and subjected them to glyphosate. In each soil, strains of weeds both susceptible and resistant to glyphosate were tested.

Both versions of giant ragweed were damaged more from the glyphosate in field soil. The susceptible version of common lambsquarter was also more heavily damaged in field soil. Horseweed fared the same no matter which soil or strain – susceptible or resistant.

The results show that microbes can play an important role in the activity of glyphosate, presumably by invading the glyphosate-weakened plants. The results also suggest that glyphosate-resistant weeds may be more resistant to disease pressure as well.

“Soil microbes can be minor to major contributors to how glyphosate is able to affect plants,” Hallett said. “We may be selecting not only for glyphosate resistance, but inadvertently selecting for weeds that have disease resistance as well.”

A weed’s ability to withstand glyphosate was based on dry shoot and root weight after testing. The sterile soil used in the study came from field soil exposed to gamma radiation to kill microbes and bacteria. The irradiated soil was tested to ensure that its nutrients were not diminished.

Hallett, Johnson and Schafer said further studies would look at how fungi in the soil affect root development, both with and without glyphosate.

“Dirt is a living organism,” Johnson said. “It’s important to know how all the pieces interact.”

The research was conducted with internal funding from Purdue’s Department of Botany and Plant Pathology.

Topics:

Leave a Reply

Herbicides Stories

HerbicidesExpert: IARC Herbicide Classifications Leading To Confusion, Misinformation
July 24, 2015
Few people in the crop protection industry had heard of the International Agency for Research on Cancer (IARC) before this Read More
Palmer pigweed seedhead in cotton
HerbicidesUSDA Deregulates Dow AgroSciences’ Enlist Cotton Trait
July 23, 2015
The USDA today issued its decision deregulating Dow AgroSciences’ Enlist cotton trait in the U.S. The USDA has now completed its Read More
HerbicidesNufarm Releases New Panther SC Herbicide
July 23, 2015
Nufarm has announced the availability of new Panther SC herbicide. Panther SC is the first liquid formulation of flumioxazin available Read More
HerbicidesCould The South’s Most Troublesome Weed Represent A Threat To The Midwest Farm Belt?
July 22, 2015
Palmer amaranth is undoubtedly the most troublesome weed in the southern United States, taking a devastating toll on both cotton Read More
Top 100 Articles
CropLife 100Allied Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
CropLife 100Pinnacle Purchases California-Based Specialty Crops Retailer
July 20, 2015
Pinnacle Agriculture Holdings has successfully acquired California-based NH3 Service Co.  Operating as part of Pinnacle’s Performance Agriculture brand, the new locations Read More
Asmus Farm Supply liquid fertilizer facility features 20,000 square feet
CropLife 100Slideshow: Asmus Farm Supply Shows Off Its New Liquid Fertilizer Facility
July 15, 2015
Asmus Farm Supply, Rake, IA, recently added a new liquid fertilizer facility to its company operations. The new liquid fertilizer Read More
CropLife 100Wilbur-Ellis Feed Division Facilities Receive Safe Feed/Safe Food Certification
July 13, 2015
Wilbur-Ellis Co.’s Feed Division, a marketer and distributor of value-added feed ingredients for the aquaculture, livestock and pet food industries Read More
CropLife 100BRANDT Expands To Brazil With Acquisition
July 8, 2015
BRANDT has acquired a majority interest in Target Brasil Fertilizantes Ltda. through its Brazilian subsidiary. Target Brasil manufactures, distributes and Read More
Milan Kucerak, president/CEO, West Central
CropLife 100West Central Cooperative And Its New President Are A Match Made In Deviation
June 29, 2015
To appreciate just how unique West Central Cooperative is in the world of ag retail, an observer need only consider Read More
Latest News
CropLife 100Allied Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
FungicidesReport: Sudden Death Syndrome Symptoms Appearing In Soy…
July 30, 2015
Last week, symptoms of sudden death syndrome (SDS) began to appear in April 15-planted soybeans at the University of Illinois’s Read More
Seed/BiotechAdvanta Seeds Adds New Phoenix Corn Hybrids
July 30, 2015
Corn growers in the High Plains and Western states have new options available for the 2016 growing season from Advanta Read More
ManagementTechnology and agriculture: a Futurist’s Perspective
July 30, 2015
Futurist David Zach, speaking at this week’s InfoAg Conference in St. Louis, shared thoughts on the benefits and limitations of Read More
Biofuels Plant in Lousiana
Industry NewsIdle Biofuels Plant In Louisiana To Reopen As Ammonia F…
July 30, 2015
A Lithuania-based company plans to spend $265 million to reopen an idle biofuels refinery in Grant Parish as an ammonia Read More
FFA at Monsanto Booth at the 2015 National Farm Machinery Show
Industry NewsFive Students Receive The 2015 Monty’s Plant Food Compa…
July 29, 2015
This fall, five college-bound students will have financial support through the Monty’s Plant Food Company FFA Scholarship. All five scholarship Read More
GYPSOIL Blendable Pellets
Crop InputsBeneficial Reuse Management Launches Pelletized Gypsum …
July 29, 2015
Beneficial Reuse Management (BRM) announced this week at Ag Media Summit that its GYPSOIL Pelletized Products Division will open a Read More
StewardshipOhio Water Quality Project To Determine How Much Phosph…
July 27, 2015
Researchers with the College of Food, Agricultural, and Environmental Sciences at The Ohio State University are looking for farmers in Read More
FertilizerKoch Agronomic Services Launches N-TEGRATION Technology
July 27, 2015
Koch Agronomic Services, LLC (KAS) has launched  N-TEGRATION Technology, a process technology platform designed to enable production of enhanced efficiency fertilizers at Read More
HerbicidesExpert: IARC Herbicide Classifications Leading To Confu…
July 24, 2015
Few people in the crop protection industry had heard of the International Agency for Research on Cancer (IARC) before this Read More
ManagementFCI Trade Summit Update & Precision Tank Turns 50
July 23, 2015
Editors Dave Frabotta and Eric Sfiligoj discuss the upcoming FCI Trade Summit in Las Vegas, NV, and how Precision Tank Read More
Palmer pigweed seedhead in cotton
HerbicidesUSDA Deregulates Dow AgroSciences’ Enlist Cotton Trait
July 23, 2015
The USDA today issued its decision deregulating Dow AgroSciences’ Enlist cotton trait in the U.S. The USDA has now completed its Read More
Industry NewsVerdesian Life Sciences Showcases Versatile Product Por…
July 23, 2015
Technology has revolutionized agriculture by bringing farmers, retailers and distributors to the forefront of the digital age. To meet the Read More
FertilizerWSJ: Cf Industries Exploring Merger With Dutch Chemical…
July 23, 2015
U.S. fertilizer maker CF Industries is in advanced merger talks with Amsterdam-listed chemical company OCI NV, the Wall Street Journal Read More
HerbicidesNufarm Releases New Panther SC Herbicide
July 23, 2015
Nufarm has announced the availability of new Panther SC herbicide. Panther SC is the first liquid formulation of flumioxazin available Read More
EquipmentFarmLink Launches Farm Equipment Sharing Program
July 23, 2015
FarmLink has introduced a new online farm equipment sharing community – MachineryLink Sharing – leveraging this new economy business model Read More
HerbicidesCould The South’s Most Troublesome Weed Represent A Thr…
July 22, 2015
Palmer amaranth is undoubtedly the most troublesome weed in the southern United States, taking a devastating toll on both cotton Read More
Industry NewsH.J. Baker Hires New Director Of International Sales
July 22, 2015
Global Agriculture firm H.J. Baker announced today that Steve Langley has joined the company’s Crop Performance Division and Animal Health Read More