Flumioxazin plus metolachlor mixtures preemergence (PRE) were evaluated with or without postemergence (POST) herbicides for weed control and peanut (Arachis hypogaea) response in three North Carolina studies. Metolachlor PRE at 2.24 kg ai/ha controlled goosegrass (Eleusine indica) and yellow nutsedge (Cyperus esculentus) 93 and 80%, respectively, and control was not improved with flumioxazin or norflurazon. Metolachlor plus flumioxazin PRE at 0.07 or 0.11 kg ai/ha controlled common lambsquarters (Chenopodium album); entireleaf (Ipomoea hederacea var. integriuscula), ivyleaf (I. hederacea), and pitted morningglory (I. lacunosa); and prickly sida (Sida spinosa) better than metolachlor plus norflurazon PRE at 1.34 kg ai/ha. Morningglories (Ipomoea spp.) were controlled 77 and 86% with flumioxazin PRE at 0.07 and 0.11 kg/ha, respectively, and control was increased to nearly 100% with acifluorfen plus 2,4-DB or lactofen plus 2,4-DB POST. Peanut injury by flumioxazin and norflurazon was observed at one location in 1997; however, yields were not reduced. Peanut treated with metolachlor plus flumioxazin PRE at either rate yielded at least 3,750 kg/ha compared to 3,120 kg/ha with metolachlor plus norflurazon PRE or 1,320 kg/ha with metolachlor PRE.

Efficacy of primisulfuron and reduced rates of nicosulfuron on woolly cupgrass, wild-proso millet, and giant foxtail in field corn was evaluated in 1994 and 1995. Nicosulfuron was applied at 18, 27, and 36 g ai/ha alone and with 20 g ai/ha primisulfuron. Woolly cupgrass control from nicosulfuron at 18 and 27 g/ha was less than control from 36 g/ha (79% and 84% vs. 90%, respectively). Woolly cupgrass control was 5% greater when primisulfuron was combined with nicosulfuron at 27 and 36 g/ha than when nicosulfuron was applied alone. Corn grain yields were similar among all nicosulfuron plus primisulfuron treatments applied to control woolly cupgrass in 1994. In 1995, corn grain yield was increased 900 kg/ha when primisulfuron was combined with nicosulfuron at 18 g/ha compared to nicosulfuron applied at the same rate alone. Wild-proso millet control 3 WAT with nicosulfuron at 18 g/ha was less than control with nicosulfuron at 36 g/ha. Wild-proso millet control 8 WAT with nicosulfuron alone was greater than when nicosulfuron at any rate was applied with primisulfuron. No differences in corn grain yields were observed across nicosulfuron rates or combinations with primisulfuron to control wild-proso millet either year. Giant foxtail control and corn grain yield were not affected by nicosulfuron rate or combined applications of nicosulfuron and primisulfuron either year.

Cloransulam-methyl applied postemergence (POST) following various preplant-incorporated (PPI) herbicides was evaluated in four experiments for weed control in North Carolina soybean over a 2-yr period at three locations. Acifluorfen plus bentazon or chlorimuron alone applied POST injured soybean more than cloransulam-methyl when following any soil-applied herbicide. When following trifluralin PPI, cloransulam-methyl controlled common ragweed, entireleaf morningglory, and pitted morningglory comparable to acifluorfen plus bentazon or chlorimuron. Common lambsquarters and prickly sida control was higher when acifluorfen plus bentazon was applied POST following trifluralin PPI compared to trifluralin PPI followed by cloransulam-methyl or chlorimuron. Acifluorfen plus bentazon or chlorimuron POST controlled yellow nutsedge and smooth pigweed more than cloransulam-methyl POST when following trifluralin PPI. When trifluralin was applied PPI in mixtures with chlorimuron plus metribuzin, flumetsulam, or imazaquin, control of most species was similar regardless of POST treatment used. Soybean treated with cloransulam-methyl yielded 250 kg/ha more than treatments with chlorimuron when these herbicides followed trifluralin plus flumetsulam or trifluralin plus imazaquin. Net returns with different herbicide systems followed trends similar to soybean yield.