Currently, kochia is the only weed in western Canada to evolve resistance to glyphosate. Based on post-harvest random field surveys in Alberta in 2012 and Saskatchewan and Manitoba in 2013, about 5% of fields in Alberta and Saskatchewan had GR kochia (strongly associated with chem-fallow, but also found in canola, wheat, and lentil) and only two fields in Manitoba had GR kochia (corn and soybean) (Hall et al. 2014; Beckie et al. 2015).
GR Russian thistle has not been documented in western Canada, but is confirmed in chem-fallow fields in Montana and Oregon (Heap 2017). By determining the rate and extent of evolution or spread of GR or auxinic-resistant kochia since the initial baseline surveys were conducted, we can better advise producers of the risk, potential agronomic and economic impact, and best management practices to mitigate or manage GR or auxinic-resistant kochia (and other species if found).
Monitoring or surveillance enhances producer awareness; awareness of the current extent of the problem is required to facilitate producer adoption of mitigation or management measures and their rapid deployment for economically and agronomically sustainable annual crop production.