Weed Control with Non-Selective Herbicides in Soybean (Glycine max) Stale Seedbed Culture

Barnyardgrass and morningglory control POST with glufosinate at 840 g a.i./ha 28 d after treatment was 79 to 85% and 83 to 90%, respectively, when no more than 35 d elapsed between initial spring soil tillage and herbicide application. For the same rate of glufosinate, prickly sida and hemp sesbania were controlled 68 and 92%, respectively. Comparable barnyardgrass control was obtained with glufosinate at 560 and 840 g/ha, which was greater than at 420 g/ha. Hemp sesbania control was similar for all rates of glufosinate. In comparison, paraquat at 1050 g a.i./ha controlled 40 to 65% barnyardgrass, 44 to 75% morningglory, 41% prickly sida, and 92% hemp sesbania. With 840 g a.i./ha glyphosate and SC-0224, barnyardgrass, morningglory, prickly sida, and hemp sesbania were controlled 55 to 89%, 55 to 81%, 45 to 61%, and 56 to 68%, respectively. Soybean yield was 5.8, 7.6, 6.0, and 5.9 times greater than the nontreated check for 1050 g/ha paraquat and 840 g/ha glufosinate, glyphosate, and SC-0224, respectively.