Herbicide Resistance Across the Prairies

Herbicide-resistant weeds are becoming a common problem for Prairie farmers, limiting their options for chemical weed management and increasing the importance of non-chemical management strategies.

Charles Geddes, a research scientist of weed ecology and cropping systems for Agriculture and Agri-Food Canada, says that herbicide resistance has been on the rise globally.

“It’s a growing problem across the country, and it’s not just happening in Canada,” says Geddes.

“It’s a global issue and one that I think farmers will have to deal with every year. It has been increasing in the Prairies and in Eastern Canada. Just to put the problem into perspective, in Canada, we’re sitting in third place for having the greatest number of herbicide-resistant weed species globally.”

Geddes notes that approximately 70 per cent of fields surveyed in the Prairies have at least one type of herbicide-resistant weed, and that this trend has largely arisen in the past two decades.

Rob Gulden, a professor in the Department of Plant Science at the University of Manitoba, says that surveys, which are conducted across the Prairies on approximately five-year cycles, have been finding new types of resistance in different weeds.