Investigating in-season management strategies for triazine resistant common lambsquarters (Chenopodium album L.) In Atlantic Canadian potato production

Abstract

Potato (Solanum tuberosum L.) producers in Canada’s Atlantic provinces of Prince Edward Island (PE) and New Brunswick (NB) rely on photosystem II (PSII)-inhibiting herbicides to provide season-long weed control. Despite this, a high proportion of common lambsquarters (Chenopodium album L.) populations have been identified as resistant to this class of herbicides. With the absence of new herbicide chemistries, weed science research has regained focus on preventative integrated weed management (IWM) strategies. As such, this project aims to investigate common lambsquarters biology and seedbank dynamics to optimize control tactics that increase mortality, deplete the weed seedbank, and decrease germination and viable seed shed. Crop-topping common lambsquarters post-flowering by mowing or wick-applied glyphosate reduced common lambsquarters harvest index and viable seed production. Soil-incorporation of fast-establishing cover crops reduced the common lambsquarters seedbank as well as populations in subsequent potato crop. Combined, this study demonstrates how alternative integrated weed management strategies can be utilized for seedbank management of herbicide-resistant common lambsquarters in potato production systems.