Occurrence and Management of PSII-Inhibitor-Resistant Chenopodium album L. in Atlantic Canadian Potato Production

Andrew McKenzie-Gopsill,Cameron Wagg,Sheldon Hann,Sebastian Ibarra,Martin Laforest,Gavin Graham

doi:10.3390/agronomy10091369

Andrew McKenzie-Gopsill, Cameron Wagg + Show 4 more

Open Access

https://doi.org/10.3390/agronomy10091369

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Abstract

Potato producers in the Atlantic Canadian provinces of New Brunswick (NB) and Prince Edward Island (PE) rely on the photosystem II-inhibiting herbicide metribuzin for weed management. Recently, potato producers in the region have reported unacceptable common lambsquarters control following an application of metribuzin. Tissue and seed samples were collected from escaped common lambsquarters populations from across the potato producing regions of NB and PE and screened for the Ser264Gly mutation in psbA. Overall, 46% of sampled populations possessed the Ser264Gly mutation across the region. Cross-resistance testing to atrazine, metribuzin and linuron confirmed populations with the Ser264Gly were resistant to triazines and triazinones but remained susceptible to linuron. Dose response analysis determined a moderate level of resistance to metribuzin in common lambsquarters which would not be controlled in producers fields. A field experiment was conducted in Fredericton, NB and Harrington, PE, to determine if currently registered and unregistered products and tank-mixes would control PSII-inhibitor-resistant common lambsquarters in potato. All evaluated products, with the exception of S-metolachlor, provided control equivalent to the weed-free check without compromising potato yield or quality. This study demonstrates that PSII-inhibitor-resistant common lambsquarters are found in Atlantic Canadian potato production systems, but can be controlled with currently registered herbicides and rates with alternative modes of action.

Highlights

The Atlantic Canadian provinces of New Brunswick (NB), and Prince Edward Island (PE), are the largest potato (Solanum tuberosum L.) producing regions in Canada with over 40% of total Canadian potato acreage seeded in these two provinces [1]
Common lambsquarters populations possessing the Ser264Gly mutation were found across all sampled potato-producing regions of NB and PE demonstrating widespread incidence of photosystem II (PSII)-inhibitor-resistance (Figure 1)
46% of sampled populations possessed the Ser264Gly mutation with a higher prevalence in sampled populations found in PE (53%) than NB (42%) (Table 2)

Summary

Introduction

The Atlantic Canadian provinces of New Brunswick (NB), and Prince Edward Island (PE), are the largest potato (Solanum tuberosum L.) producing regions in Canada with over 40% of total Canadian potato acreage seeded in these two provinces [1]. Shifts in management from two-pass to one-pass systems in the region have reduced reliance on hilling and cultivation for weed management. Potato producers have limited broadleaf herbicide options post-potato emergence and rely on preemergence photosystem II (PSII)-inhibitor herbicides for season-long weed control. PSII-inhibitor—is the most widely used herbicide in potato production [2] and estimated to be applied to over 75% of potato acreage in the Atlantic region (L MacKinnon, personal communication). Linuron—a urea-substituted PSII-inhibitor—is widely used in the region and applied to 27% of potato acreage in nearby Maine, USA [2]. In Atlantic Canada, rates of metribuzin typically range from 0.42 to 0.51 kg ha−1 and 0.56 to 0.62 kg ha−1 for one- and two-pass systems, respectively; whereas linuron rates typically range from 0.86 kg ha−1 to 1.1 kg ha−1 in both systems

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