Along With Weeds, Herbicide Resistance Testing Evolves

Crops should be managed in a way to prevent weed infestations, overuse of herbicides and herbicide resistance. But in the real world, growers will use the most convenient and economical practices until a crisis forces a change. Routine monitoring of weed populations for their resistance to herbicides can avert such a crisis. Making resistance testing protocols widely available can help to attain this goal.

The journal Weed Science reports on methods of testing for herbicide resistance. The authors of a review article discuss testing techniques, including field surveys, plant sampling and dose-response levels. Rapid resistance confirmations are contrasted with more thorough DNA-based tests.

The first report of herbicide resistance came in 1957, but resistance has significantly expanded in the past decade. Today more than 200 plant species worldwide are resistant to herbicides. Modern agriculture depends on resistance testing to determine the best resistance management and mitigation. There are basic steps in testing, but details may vary depending on the herbicide mechanism of action, weed species and timing of application.

The classical approach to resistance confirmation is to collect seeds from surviving plants in suspected fields, plant them in pots and apply appropriate herbicide(s). Multiple doses, rather than a single dose, should be used. This will allow the production of a dose-response curve that will show the magnitude of resistance. The test should include three to four replications to confirm results. It can take up to 2 months to obtain results using this form of testing.

Early and rapid detection of resistance is crucial to averting economic losses. Growers seek resistance tests that allow them to make real-time decisions regarding current weed management. Quick analyses may use whole plants, seedlings, or leaf discs rather than growing new plants from seed. A leaf disc analysis, for example, may yield an initial determination of resistance on the spot or within 24 to 48 hours.

However, unlike the classical approach, these new methods are not applicable in all situations. Different tests may be needed for different weed species or herbicide mechanisms of action. Some of these rapid testing techniques are being developed for commercial use. But most growers currently rely on free testing services provided by academic, extension service, or public research institutions.

Full text of the article, “Review: Confirmation of Resistance to Herbicides and Evaluation of Resistance Levels,” Weed Science, Vol. 61, No. 1, January-March 2013, is available here.

Topics:

Leave a Reply

Herbicides Stories

HerbicidesScouting Key To Next Season’s Soybean Herbicide Program
August 12, 2014
When growing soybeans, growers need to think ahead to stay one step ahead of weeds. That means examining weed threats and evaluating which herbicides work best. Read More
HerbicidesArysta Touts Burndown Herbicide For Brome Management In Wheat
June 4, 2014
Arysta LifeScience North America recommends PRE-PARE Burndown Herbicide for effective brome management in winter wheat. Read More
HerbicidesFall Herbicide Applications More Effectively Manage Resistant Italian Ryegrass
May 14, 2014
Field studies show that a fall application of certain herbicides before weed emergence, leads to more successful crop planting and weed control in spring. Read More
Waterhemp in soybean stubble
HerbicidesThe Weed Resistance Problem: A Matter Of Billions
April 1, 2014
Not only is the amount of money being spent to control these yield robbers high, but the toll it has taken on the human population is growing lager by the day. Read More

Top 100 Articles

CropLife 100CHS: Driving Momentum To Help Farmer-Owners Grow
December 11, 2014
CHS Inc., the nation’s leading farmer-owned cooperative and a global energy, grains and foods company, must capture new opportunities to Read More
CropLife 100BRANDT, Verdesian Ink Distribution Agreement
December 9, 2014
The agreement grants BRANDT the exclusive right to sell and market Verdesian’s patented Steric chemistry in the Turf and Ornamental and eastern U.S. ag markets under the BRANDT Reaction product line name. Read More
CropLife 100CropLife 100: The Colors Of Custom Application
December 5, 2014
Although many color spray rigs are in the yards of the nation’s top ag retailers, the majority of them still come in only a few shades. Read More
CropLife 100Pinnacle Invests In Meridian Agriculture Distribution
December 4, 2014
Meridian will provide retailers with supplier-branded products and numerous opportunities to differentiate themselves from their competitors. Read More
CropLife 100CropLife 100: Entering A New Seed Era
December 4, 2014
The seed category has been re-vitalized during the past few years, and more good news (and varieties) are headed the industry’s way in 2015. Read More
CropLife 100CropLife 100: The Depressed State Of Fertilizer
December 3, 2014
Following downright giddy growth earlier this decade, fertilizer sales have fallen back down to earth the past two years. Read More

Latest News

FertilizerGlobal Fertilizer Market: Cloudy With A Chance Of Sprin…
December 22, 2014
While spring demand in the Northern Hemisphere will prevent prices from slipping significantly, Rabobank believes that lower farmer margins will incent farmers to be more prudent in fertilizer application. Read More
Management2014: Looking Back, Looking Forward
December 22, 2014
Paul Schrimpf and Eric Sfiligoj discuss key emerging issues from the year past that retailers will be watching closely in Read More
FungicidesAlfalfa Expert: Root Rot More Widespread Than Previousl…
December 22, 2014
Once thought of as a wet-soil disease, aphanomyces root rot is more widespread than many realize. Read More
Seed/BiotechKaren Arthur Joins AgriThority As Seed Treatment Produc…
December 19, 2014
Prior to joining AgriThority, Arthur directed research and development programs, overseeing laboratory and field research, to build the Valent U.S.A. seed treatment portfolio. Read More
EquipmentJohn Deere To Sell Crop Insurance Business
December 19, 2014
Deere & Co. has reached a definitive agreement to sell its crop insurance business, subject to regulatory approval, to Farmers Mutual Hail Insurance Co. of Iowa. Read More
Crop InputsNufarm Fills Regulatory VP Position
December 18, 2014
Nufarm announced today that Rob Schwehr has been promoted to the position of Vice President of Innovation & Regulatory Affairs for Nufarm Americas. Read More
Seed/BiotechReport: China Approves Viptera Corn, U.S. Officials Awa…
December 17, 2014
Chinese authorities have informed some agriculture industry officials the government has approved U.S. imports of a type of genetically modified corn developed by Syngenta. Read More
FertilizerMonty’s Plant Food Brings In New Sales Rep
December 16, 2014
Monty's Plant Food Company has hired Warren Kearns as its newest Sales Representative for the South Carolina area. Read More
EquipmentHagie Wins 2014 CropLife IRON Product Of The Year Award
December 15, 2014
The self-propelled sprayer maker has a hit on its hands with the new STS Series model. Read More
Syngenta
Seed/BiotechSyngenta Sees China Approving Contentious GMO Corn Soon
December 15, 2014
Syngenta will make an announcement when it receives official documentation from China that Agrisure Viptera corn, known as MIR 162, has been cleared for import. Read More
Crop InputsVerdesian Life Sciences Names Vice President Of Communi…
December 15, 2014
Amy Bugg will oversee the execution of all promotional strategies for the corporate brand and the complete product portfolio. Read More
StewardshipFarmers, Retailers Attend 4R Certification 4U Workshop
December 15, 2014
More than 160 farmers and ag retailer attended the “4R Certification 4U” workshop December 12 to learn more about the 4Rs of nutrient stewardship, water quality research in the area and cost-sharing opportunities. Read More
Matt Hopkins10 Best New Agriculture Apps For 2015
December 15, 2014
These new agriculture apps are certain to help ag professionals do their jobs more efficiently in 2015 and beyond. Read More
ManagementARA Learnings, Retail Buying Intentions: Welcome To Cro…
December 12, 2014
This informal video program puts news and events effecting retailers into context, and features Editors Paul Schrimpf and Eric Sfiligoj. Read More
Seed/BiotechMonsanto Herbicide-Tolerant Technology Closer To Commer…
December 12, 2014
The final EIS moves Monsanto one step closer to the introduction of Bollgard II XtendFlex cotton and Roundup Ready 2 Xtend soybeans, paving the way to provide access to dicamba-tolerant soybeans and cotton. Read More
Seed/BiotechUSDA Issues Final Environmental Impact Statement On Her…
December 12, 2014
The USDA Animal and Plant Health Inspection Service (APHIS) is issuing a final environmental impact statement on varieties of cotton and soybeans that have been genetically engineered for resistance to several herbicides, including the one known as dicamba. Read More
CropLife 100CHS: Driving Momentum To Help Farmer-Owners Grow
December 11, 2014
CHS Inc., the nation’s leading farmer-owned cooperative and a global energy, grains and foods company, must capture new opportunities to Read More
LegislationARA Applauds CFATS Passage Prior To Holiday Adjournment
December 11, 2014
The streamlined bill provides a four-year authorization of the CFATS program and guidance to DHS on key issues of chemical facility security Read More