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Study: How resistant waterhemp emerged in Canada

A multi-university study has tracked the invasion of herbicide-resistant waterhemp into Canada and what it means to all farmers.

Professor Pat Tranel with the University of Illinois says there are two species of waterhemp in the Midwest, classified as one. He says both types, including the non-weedy one, have been found in Canada, “One of those appeared to be a migration event from the Midwest. Wherein the other population, the other field, it looked like the non-weedy variety was now becoming weedy.”

Tranel says that shows the different ways waterhemp evolves resistance, “They can evolve resistance from their own mutations within a field or there can be these migration events. So, it kind of raises the bar for what farmers need to be vigilant for in terms of resistance evolution.”

Tranel says it backs up what they’ve been preaching about weed management, “A simple system is easy for the weeds to evolve resistance to and so you need to do multiple strategies. Crop rotations, multiple effective modes of action herbicides, and then using strategic cultural weed management strategies like cover crops as well as tillage in the right place and at the right time.”