Canada Thistle Concerns in 2018


Severe weather affects more than yield. It can make hard-to-control weeds more problematic the following year. In 2017, drought in the Northern Plains jeopardized the spring wheat crop and created ideal conditions for increased Canada thistle competition this growing season.

A perennial weed with deep roots, Canada thistle can transition into dormancy to remain viable during extremely dry conditions. A lack of significant rainfall during last year’s growing season, July’s unrelenting high temperatures and reduced soil moisture shaped the perfect environment for the troublesome weed to expand in sparse wheat stands last fall into the upcoming spring.

Northern Ag Network spoke to Jon Verhelst with Corteva during the 2018 Commodity Classic on what producers can do to get a head of Canada Thistle. 

Obtaining effective control
Because of last summer’s drought, Joe Yenish, field scientist, Dow AgroSciences, predicts Canada thistle will be a significant problem for the region’s growers this year. Roots now lurking in the soil’s subsurface have energy reserves to fuel Canada thistle’s strong emergence potential.

“Canada thistle grows from the roots as well as the seed. Choosing the right chemistry and timing for postemergence control is critical,” says Yenish. “Clopyralid, an active ingredient in PerfectMatch herbicide, is the industry standard for postemergence in-season control of this noxious weed.”

Consistent, broad-spectrum control
PerfectMatch® herbicide is a broad-spectrum herbicide that effectively controls annual grasses, such as wild oats and foxtails, along with annual broadleaves, such as kochia and wild buckwheat, as well as perennial Canada thistle.

Herbicide efficacy studies conducted across Montana, North Dakota and South Dakota showed 40 percent greater control of Canada thistle and more consistent weed control with PerfectMatch herbicide compared with Huskie Complete herbicide.1

“Typically, Huskie Complete will provide more visible control one week after treatment, because it gives you a very quick discoloration of the foliage. But you are not getting a complete kill,” Yenish says. “That changes as the length of time after application increases. By harvest time, the farmer combining will see much less Canada thistle control from treatments of Huskie or Huskie Complete than with treatments of PerfectMatch.”   

For more information on PerfectMatch herbicide, visit

12015 Dow AgroSciences efficacy trials



About DowDuPont Agriculture Division
DowDuPont Agriculture, a business division of DowDuPont (NYSE: DWDP), combines the strengths of DuPont Pioneer, DuPont Crop Protection and Dow AgroSciences. Together, the DowDuPont Agriculture Division provides growers around the world with the most complete portfolio in the industry, developed through a robust research pipeline across germplasm, biotech traits and crop protection. DowDuPont Agriculture is committed to delivering innovation, helping growers increase productivity and ensuring food security for a growing global population. DowDuPont intends to separate the DowDuPont Agriculture Division into an independent, publicly traded company. More information can be found at

Northern Ag Network and Corteva 2018

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