Wick weeding: an investigation into alternative weed control strategies in Atlantic potato production systems.
Anderson L, McKenzie-Gopsill AG, White SN (2020) Wick weeding: an investigation into alternative weed control strategies in Atlantic potato production systems. Canadian Weed Science Society 74th Annual Meeting, Nov 2020, online.
Photosystem II- (PSII) inhibitors, such as metribuzin, form the foundation of weed management in Atlantic Canadian potato production. Lamb’s quarters (Chenopodium album L.) with PSII-inhibitor resistance have recently been confirmed across the potato producing regions of Atlantic Canada. With their rapid and upright growth habit, lamb’s quarters can quickly come to over-top a potato canopy. Wick herbicide applicators offer an alternative integrated weed management (IWM) strategy whereby non-selective herbicides are selectively applied at a specified height in-season, minimizing off-target applications and damage to the crop species. Rope-wick application may provide an effective means of controlling PSII-inhibitor resistant lamb’s quarters in potato production systems. The present study evaluated the use of glyphosate applied with a rope-wick applicator for control of lamb’s quarters over-topping the canopy of Shepody, NorValley, and Yukon Gold potato cultivars with spreading, semi-erect and upright growth habits, respectively. Wicking glyphosate did not impact biomass of lamb’s quarters over-topping the potato canopy, however, early rope-wick applications decreased lamb’s quarters reproductive allocation by 74% compared to the untreated control. Early wick applications resulted in greater glyphosate injury to marketable potato tubers than late applications across all potato cultivars. Overall, marketable yield did not differ across treatments or cultivars. These results indicate that rope-wick applicators may provide a viable IWM strategy for disrupting resource allocation in lamb’s quarters over-topping the potato canopy while maintaining marketable yields across cultivars with varying growth habits.