Tillage and Planting Date Influence Foxtail (Setariaspp.) Emergence in Continuous Spring Wheat (Triticum aestivum)

Abstract

Foxtail emergence patterns were evaluated in spring wheat under three tillage regimes, moldboard plow, chisel plow, and no-till, and three wheat planting dates. The first planting date was as soon as feasible in spring, and the second and third planting dates averaged 9 and 17 d later. Foxtail emergence patterns and seedbank density were evaluated each year for three consecutive years. Green foxtail was the dominant weed species. Tillage regime did not influence initial percent emergence of foxtail. Subsequent percent foxtail emergence was sometimes lower in no-till or chisel plow than in moldboard plow regimes until emergence approached 100%. By the third year, total foxtail plant emergence was greater in no-till and chisel plow than in moldboard plow and also greater in no-till than chisel plow. Earlier planting generally increased percent foxtail emergence until midseason. At 22 d after planting, average emergence of foxtail was 48, 67, and 81% for planting dates one, two, and three, respectively. Delayed planting increased rate of foxtail emergence but decreased density of emerged seedlings. Producers adopting chisel plow or no-till systems can expect to see greater foxtail infestations than in moldboard plow systems. Subsequently, more extensive weed management in reduced tillage systems will be needed to prevent heavy foxtail infestations. Delaying wheat planting may be a viable option for foxtail management through reduced plant densities and more simultaneous emergence patterns.