The Kochia Battle is On
NDSU has been busy in the labs this winter studying samples of suspected resistant weeds, submitted last fall. They have confirmed nine counties in North Dakota and one county in Minnesota with Kochia that is resistant to glyphosate. A couple years ago it seemed Waterhemp would be the main problem weed, and it still is confirmed in over ten counties. However, Kochia — with its wide geography of growth, the way it spreads, and its fast resistant mechanism — has taken over as our region’s major weed threat.
Dr. Jeff Stachler from NDSU has been collecting samples and testing weed seeds for many years. His newest resistance map shows that between 5 – 60% of fields in the eastern two-thirds of ND are suspected to contain resistant kochia. And the really scary part is this kochia is also believed to have dual resistance to Dicamba. These findings point out that the use of PRE herbicides is more important than ever.
It is truly astonishing to realize the speed at which these weeds are appearing. Compare the NDSU map from 2006 with the latest map. They clearly signal a wake-up call to growers that resistance management must be a part of your skill set. It is essential for all of us to consider new weed management tools.
