Influence of Seed Vigor, Herbicide Rates, and Incorporation Depths on Emergence and Seedling Development of Soybean (Glycine max)

Abstract

Imazaquin at 140, 280, and 420 g ai ha-1did not negatively affect seedling emergence from high vigor (98% germination) soybean seed but, coupled with a 5.0-cm herbicide incorporation depth, reduced seedling emergence from low vigor (67% germination) seed at all rates. Imazaquin at 420 g ha-1incorporated 5.0 cm deep reduced low and high vigor seedling height 36 and 28%, respectively. Imazaquin at all rates reduced root length from high vigor seed, whereas only the high rate reduced root length of seedlings from low vigor seed. Although 420 g ha-1metribuzin did not affect seedling emergence or root length, emerged seedlings were severely damaged when herbicide was incorporated to 5.0 cm. Trifluralin at 840 and 1680 g ai ha-1reduced emergence of low vigor seed when incorporated 5.0 cm deep. Trifluralin at 840 g ha-1did not affect seedling height or root length, but 1680 g ha-1reduced height of seedling from low and high vigor seed by 86 and 66% when incorporated 5.0 cm deep. Trifluralin at 1680 g ha-1reduced shoot dry weight of both types of seedlings only at the 5.0-cm incorporation depth.