Early adopter insights on physical impact mill technology for harvest weed seed control in Canada

The evolution and spread of herbicide resistance among the weed community has increased interest in alternative weed management strategies such as harvest weed seed control. Western Canadian producers have begun adopting physical impact mills as an additional weed management strategy. A survey of early adopters of physical impact mill technology in Canada was conducted to better understand the motivations behind producers adopting, initial experiences, and research needs. Ten producers responded to the survey, accounting for 18 out of an estimated 30 impact mills in use in Canada, believed to be located primarily in the Canadian Prairies. These producers were mainly from larger farms (>4000 ha), equipped the majority of their combines (75% average) and used the mills in essentially all crops grown. The majority of respondents were located in Saskatchewan, with two mills being used in Alberta. Wild oat (Avena fatua L.) (60%) and kochia (Bassia scoparia (L.) A.J. Scott) (50%) were the weeds most frequently mentioned as specific motivators of impact mill adoption. Average increased fuel cost from the mill was estimated at CAD$3.46 ha-1, with average annual maintenance costs of about $1500 per impact mill. Producers relied on information from mill companies and other early-adopting farmers primarily, followed by extension talks and social media. Research needs were also identified by producers that could inform the future direction of harvest weed seed control research in Canada. Future research should focus on confirming efficacy, optimizing combine settings, and looking at integrated systems with precision agriculture technologies.