Non-Peer ReviewedIn 2002, 150 fields were randomly selected throughout the ecoregions of Manitoba and surveyed for grass and broadleaf weeds resistant to Group 1 (ACCase inhibitor) or Group 2 (ALS inhibitor) herbicides. One-third of surveyed fields had a herbicide-resistant weed biotype. Two biotypes new to western Canada are Group 2-resistant green foxtail and redroot pigweed. Of producers with resistant biotypes, 10% or fewer were aware of their occurrence
