What are we working on?

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Project
The Prairie Weed Monitoring Network: Building a strong biovigilance foundation.

Principal investigator
Charles Geddes, Agriculture and Agri-Food Canada – Lethbridge

Co-Principal Investigator
Julia Leeson, Agriculture and Agri-Food Canada – Saskatoon

Summary

Canada is home to the third largest number of unique herbicide-resistant weed biotypes, surpassed only by the United States and Australia. Since the 1990s, about two new herbicide-resistant weed biotypes have been discovered in Canada each year. Assessments from 2014-2017 showed that 59% of fields in the Canadian prairies were infested with at least one herbicide-resistant weed biotype, and that herbicide resistance costs prairie farmers an estimated $530 million CAD annually in reduced crop yield, quality, and increased cost of weed control. Of increasing concern in this region are populations of kochia and wild oat each with resistance to up to four herbicide modes of action; in addition to invasive Amaranthus spp. at risk of further spread from eastern Canada and the United States.

This project aims to develop the Prairie Weed Monitoring Network (PWMN) and to implement a comprehensive weed biovigilance strategy, including: weed monitoring, risk assessment, and forecasting for the prairie region of Canada. It will include detailed assessments of (i) weed abundance in 4000 fields, (ii) herbicide-resistant weeds pre-harvest in 800 fields, and (iii) herbicide-resistant kochia and Russian thistle post-harvest in 800 fields, across the prairie provinces. These data, and those of past surveys, will be leveraged along with other open data resources to conduct spatial risk analyses for the evolution of herbicide-resistant weed biotypes of greatest concern and where they are most likely to occur, in addition to the development of a tool to forecast weed community shifts in response to management factors and climate change. Overall, this coordinated suite of objectives will provide farmers, agronomists, agricultural industry, researchers, and policy makers with information required to manage weeds effectively, anticipate new weed threats to farming systems, and mitigate selection pressure for herbicide-resistant weeds.

Objectives

1. Establish the Prairie Weed Monitoring Network (PWMN), a network of federal researchers, provincial specialists, and academics guiding weed biovigilance for the prairie region.
2. Complete the seventh set of weed abundance surveys in the prairie provinces since this series of provincial surveys began in the mid-1970s.
3.  Complete the fifth set of pre-harvest herbicide-resistant weed surveys in the prairie provinces since this series of provincial resistance surveys began in the early-2000s.
4.  Complete the third set of post-harvest herbicide-resistant kochia and Russian thistle surveys in the prairie provinces since this set of provincial surveys began in the early-2010s.
5.  Complete a spatial risk assessment for the evolution of herbicide-resistant weeds in prairie cropping systems by integrating data from weed surveys, species-specific biology, cropping systems, and herbicide sales/use.
6.  Develop tools to forecast weed community behaviour and range shifts in response to management factors and climate change.