Herbicide resistance in Palmer amaranth is a continuing concern for soybean producers in North Carolina. We have been among the first to deal with ALS-resistance, glyphosate-resistance, and PPO-resistance. We want to continue to rapidly identify populations of concern and maintain a baseline of efficacy across the state. Surveys have been conducted across the state in 2010 and 2015, and we would like to continue them in 2022. We had plans to collect seed in 2020 and 2021, however limitations kept that from happening. By collecting seed in 2022 and evaluating the current herbicide options in 2023, we can identify areas of concern, and more importantly, confirm areas we can continue to utilize effective POST herbicide options.

Palmer amaranth continues to be an issue for our growers, therefore we propose to:
1) Conduct a statewide survey (collection) of Palmer amaranth surviving just prior to crop harvest (~September).
2) Determine the response of each population to POST herbicides currently used to control glyphosate and ALS-resistant biotype, which includes dicamba, 2,4-D, Liberty, and PPO-inhibitors (Flexstar)
3) Screen the Palmer amaranth populations response to group 15 herbicide (i.e. Dual)
4) Present data to growers in winter extension meetings and develop fact sheets.

Detailed material on resistant Palmer amaranth populations should be developed and made available through Extension presentations, Extension fact sheets, popular press articles, Extension videos, and other appropriate venues so growers have a greater understanding of what issues are currently here so effective control decisions can be made. In addition, this will be a graduate student project and an end product will be a well trained student with a strong understanding of herbicide-resistance issues in North Carolina.