Weed Management Programs in Grain Sorghum (Sorghum bicolor)

A field study was conducted in Arkansas over three years to evaluate various herbicide treatments, including sequential and tank-mix applications for weed control in grain sorghum (Sorghum bicolor). The herbicide treatments used were quinclorac, atrazine + dimethenamid-p, S-metolachlor followed by (fb) atrazine + dicamba, dimethenamid-p fb atrazine, S-metolachlor + atrazine fb atrazine, S-metolachlor + mesotrione, and S-metolachlor fb prosulfuron. All herbicide treatments provided excellent (90% to 100%) control of Ipomoea lacunosa, Ipomoea hederacea var. integriuscula, and Sida spinosa by 12 weeks after emergence. Quinclorac and S-metolachlor fb prosulfuron provided the lowest control of Ipomoea lacunosa, Urochloa platyphylla, Amaranthus palmeri, and Ipomoea hederacea var. integriuscula. Weed interference in the non-treated control reduced grain sorghum yield by 50% as compared to the weed-free control. S-metolachlor + mesotrione and S-metolachlor fb prosulfuron reduced sorghum yields by 1009 to 1121 kg ha(-1) compared to other herbicide treatments. The five best herbicide treatments in terms of weed control and grain sorghum yield were quinclorac, atrazine + dimethenamid-p, S-metolachlor fb atrazine + dicamba, dimethenamid-p fb atrazine, and the standard treatment of S-metolachlor + atrazine fb atrazine.