Efficacy of trifluralin and halosulfuron for weed management in white bean

Abstract

A total of six field experiments were conducted in southwestern Ontario over a 3-yr period (2016, 2017, 2018) to evaluate the efficacy of trifluralin and halosulfuron applied preplant incorporated (PPI) for weed management in white bean. Trifluralin, halosulfuron, and trifluralin + halosulfuron applied PPI caused as much as 2%, 6%, and 8% white bean injury, respectively. Weed interference delayed maturity and reduced white bean yield 56% compared with the weed-free control. Weed interference with trifluralin and halosulfuron applied alone reduced white bean seed yield as much as 35% and 29%, respectively; however, white bean seed yield with the trifluralin + halosulfuron tankmixes was similar to the weed-free control. Trifluralin, halosulfuron, and trifluralin + halosulfuron applied PPI provided 6%–12%, 75%–92%, and 71%–95% control of velvetleaf; 89%–95%, 93%–98%, and 96%–99% control of pigweed species; 5%–18%, 82%–96%, and 90%–97% control of common ragweed; 90%–97%, 81%–97%, and 95%–99% control of common lambsquarters; 23%–43%, 55%–88%, and 83%–96% control of flower-of-an-hour; 4%–25%, 94%–100%, and 95%–100% control of wild mustard; 96%–100%, 18%–45%, and 97%–100% control of barnyardgrass; and 92%–98%, 21%–40%, and 93%–98% control of green foxtail, respectively. Results indicated that low rates of trifluralin tank-mixed with halosulfuron has the potential to control problematic weeds and improve white bean yields in Ontario.