Multiple herbicide-resistant kochia and the potential impact of PPO inhibitor (Group 14) resistance
Date & Time
Tuesday, January 9, 2024, 11:15 AM - 11:45 AM
Charles Geddes

The impact of kochia on farmlands across western Canada has grown substantially in the last half-decade. While this is due, in part, to the unique biology of this weed species, it is also related to rapid evolution of and selection for herbicide resistance traits. In Canada, kochia is known to exhibit resistance to acetolactate synthase inhibitors (Group 2), auxin mimics (Group 4), and glyphosate (Group 9), while photosystem II inhibitor (Group 5) resistance also occurs in the United States. Rapid spread of glyphosate resistance among kochia populations has placed large selection pressure on proroporphyrinogen oxidase-inhibiting (Group 14) herbicides due to heavy reliance on these products to manage glyphosate-resistant kochia pre-plant in many crops grown in western Canada. This led to the first discovery of Group 14-resistant kochia in 2021. This session will highlight the history and impact of herbicide resistance in kochia and recent studies characterizing Group 14-resistant kochia on the Canadian prairies.