Beyond Current Year Yield Loss: Importance of Late-Season Palmer Amaranth Seedbank Management in Cotton

Weed management efforts typically focus on controlling weeds within crop, particularly during early crop growth stages. Weeds such as Palmer amaranth exhibit prolonged emergence periodicity, leading to cohorts of late-emerging weeds avoiding control measures. It is a common sight to notice Palmer amaranth escapes prior to cotton harvest, made up of plants survived early-season control inventions as well as the ones recruited during late-season. Whereas these escapes found during late-season are less likely to affect current-season cotton yields, they contribute tremendously to seedbank addition, future weed management costs and increase the risk of herbicide resistance. Palmer amaranth seedlings that emerge after cotton harvest also contribute tremendously to seedbank replenishment. Sustainable weed management requires a strong emphasis on reducing seedbank inputs, looking beyond the current year.