Early detection, monitoring and management of herbicide resistant weeds in field vegetables

Project Code PRR16-010

Project Lead

Marie-Josée Simard and Robert Nurse   Agriculture and Agri-Food Canada


To develop and communicate to growers tools and approaches for early identification and risk mitigation of herbicide resistance in vegetable crops

Weeds are an important challenge for viable vegetable production and contribute significantly to yield losses. Some crops such as carrots and onions are very poor competitors and cannot tolerate competition with weeds. Typical weed management in vegetable crops relies on regular application of herbicides. However, because only a few herbicides are registered and available to vegetable growers, weed resistance to certain herbicide groups used in these crops has become a major problem.

The rapid proliferation and spread of herbicide resistant weeds poses a constant threat to the sustainability of vegetable crop production in Canada. To effectively manage the risk of resistance development and diffusion it is essential that herbicide resistant weeds are detected early, monitored closely and properly controlled using integrated management approaches.

This 3-year project aims to: conduct surveys to document, map and monitor new herbicide resistant weed cases in several vegetable crops in Ontario and Quebec; develop rapid, molecular-based herbicide resistance testing methods; determine the ecology and seed bank dynamics of some key herbicide resistant weed species; and assess the feasibility of using living mulches to reduce the seed bank of herbicide resistant weed populations in vegetables. Recommendations on how to incorporate and use the developed tools as part of best management practices will be communicated to growers through presentations and field tours. Better understanding of weed resistance and seed bank dynamics, and rapid identification of resistant weeds will help growers make informed weed management decisions and achieve sustainable vegetable production.



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