Triple Resistant Canola Weed Found
In Alberta, Canada

Superweeds resistant to three herbicides used in genetically engineered crop production have been discovered in northern Alberta, Canada. The triple resistant canola weeds have arisen from the crossing of three different canola varieties genetically engineered to be herbicide-tolerant.

The superweeds are resistant to the herbicides RoundupTM (glyphosate), LibertyTM (glufosinate-ammonium) and PursuitTM (imazethapyr), according to Western Producer (Feb. 10, 2000).

This is the first case of natural gene stacking in canola since genetically modified canola was adopted by farmers five years ago, according to Denise Maurice, agronomy manager with Westco Fertilizers, a fertilizer sales company.

The weeds were found in Tony Huether’s field, a farmer who has decided to stop growing genetically engineered (GE) canola.

In 1997, Huether seeded two fields with canola — one with a canola resistant to RoundupTM and the other with two canola varieties — one resistant to LibertyTM and one resistant to PursuitTM. The two fields were only 30 meters apart.

The year after he planted the fields, he discovered volunteer canola weeds resistant to Roundup where none had been planted. Double resistance was confirmed the first year, and the following year, triple resistance was confirmed.

The mixing of all three herbicide-tolerant types has been blamed on bee and wind pollination between the two close fields.

Researchers recommend at least 200 meters between fields of GE canola varieties and any other canola field to prevent genetic pollution. According to Huether, Alberta Agriculture has been testing his crops for herbicide resistance without making the results public knowledge.

“Many plants were taken and a lot of seeds taken and grown out in the lab and sprayed with the herbicide, and DNA tests done on it, and the results are not being made public. I feel that should be made public,” he said.

Canola scientist Keith Downey, who created modern canola, stated, “We haven’t created a superweed or anything like that.” He said that adding 2, 4-D or a similar herbicide to a chemical mix will kill any wayward weeds, noting,

“I don’t think it means anything to consumers,” according to Western Producer.

For more information on canola herbicide resistance, contact Beyond Pesticides/NCAMP.