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One Million Acres of Glyphosate Resistant Weeds in Canada:  Stratus Survey

Farmers across Canada are taking notice, as resistant weeds follow U.S. trends. May 29, 2013, GUELPH, ONTARIO – Canadian farmers are reporting that 1.1 million acres of cropland are infested with species of glyphosate resistant weeds, according to a survey by Stratus Ag Research.

The million acres makes up 1.3% of total crop acres in Canada, but 6.7% of farmers said they have the problem on at least part of their land.  The survey found that 10.9% of farms in eastern Canada are infested, compared to 5.4% in western Canada.  Provincially, Saskatchewan has the most acres of glyphosate resistant weeds at 620,000; while Ontario had the highest intensity of resistance with 4.1% of acres and 12.5% of farms affected.

The Stratus Glyphosate Resistance Tracking Study collected data from 2,028 farmers across Canada.  It is the first time an extensive survey of Canadian farmers to measure glyphosate weed resistance has been conducted.  Stratus has done similar research in the USA for three years.

“We asked farmers to tell us about the glyphosate resistant weeds they are seeing on their farms and their answers suggest that the problem is more extensive than field tests have reported so far,” said Kent Fraser of Stratus Ag Research. 

“By surveying a large representative sample of farmers about what they are seeing on their land, we can estimate the total acres affected in Canada.”

Kochia Worst in West, Fleabane in East

Farmers participating in the study report resistant Kochia representing 651,000 acres.  That makes it a problem on 1.0% of western Canada crop acres; but one in 20 surveyed farmers say they have at least some acres infested.  Few western farmers report volunteer glyphosate resistant canola as a problem.

Canada Fleabane is the dominant problem in the east:  over 180,000 acres are glyphosate resistant, affecting over 6% of eastern farmers and 2% of their crop acres.  Glyphosate resistant giant ragweed is estimated on over 90,000 acres.

Many other weed species are mentioned as difficult to control with glyphosate, but scientists have yet to confirm any true glyphosate resistance to those weeds in Canada.

Does the Northern U.S. show us what’s coming? 
Kochia is the worst glyphosate-resistance problem in North Dakota, where Stratus has been tracking resistance over three years:  7% of farms are infested, with 1.7% of total crop acres in the state affected.  Those levels are slightly higher than in western Canada, suggesting the problem there will gradually worsen.

“Existing practices have not prevented glyphosate resistance from occurring in western Canada,” said Fraser, “but rotations frequently including crops that are not glyphosate resistant has likely slowed the problem.”

The U.S. experience is more foreboding for eastern Canada.  Michigan farmers reported glyphosate resistant fleabane on over 10% of their crop acres in 2012.  That is ten times what they had in 2010.  The glyphosate resistant fleabane problem will be severe if it spreads as quickly as it has south of the border.

Farmers are concerned 
Canadian farmers are paying attention!  When asked their degree of concern about glyphosate resistant weeds, 42% of Canadian farmers were “very concerned” and another 35% were “concerned”.  Only 7% listed themselves as “not concerned”.

Farmer concern is high in all provinces, but highest in Quebec where almost half of all farmers are very concerned.

While the problem is not as bad in Canada, it is interesting that the level of concern is already as high, or higher than it is in the USA. 

“It’s unfortunate that farmers have to deal with another big worry like this,” said Fraser, “but the high level of concern is a good sign that we are ready to take it on and find solutions, as Canadian farmers always do”.

Study Method:  Stratus Ag Research surveyed 2,028 farmers from across Canada. 

Online interviews were conducted with growers from Alberta and the BC Peace Region, Saskatchewan, Manitoba, Ontario, Quebec and the Atlantic Provinces.
The growers surveyed grow a total of 4.4 million acres of field crops.  This base was utilized to represent the 77.3 million acres of field crops in Canada.
The list of crops grown by survey respondents included wheat, lentils, oats, mustard, barley, canaryseed, fall rye, chickpeas,  mixed grain, dry white beans, flax,   dry coloured beans, canola, fodder corn, corn for grain, triticale, soybeans, sugar beets, dry peas, sunflowers and potatoes.

Stratus Ag Research
Every year thousands of farmers and retailers use Stratus surveys to tell the agricultural industry what they think and need. Stratus prepares reports that directly reflect the input provided, then tells the rest of agriculture what’s working, what’s not and how needs can be better met.
A commitment to agriculture and respect for farmers is fundamental to Stratus:  Farmers should only be asked to do studies that are relevant to them; those studies must be well designed based on a solid understanding of agriculture; as far as possible results should be shared with participants; and farmers should be financially compensated for their time and knowledge.

Our thanks go to those growers who participate in Stratus surveys.  Their input helps to shape agribusiness.  If you are a grower and you would like to contribute your opinions, you can sign up for on-line surveys at

Click here for more on Stratus research

By Vice-President

Clients recognize Kent for his experience and skills in brand positioning - helping clients to refine how they tell their stories.  Kent uses his extensive marketing knowledge and practical experience on the inside of North American agribusiness to translate market research into ideas that clients can use to make decisions.

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