Published online by Cambridge University Press: 12 June 2017
Two experiments were conducted to determine the most effective herbicide treatments for fringed sagebrush (Artemisia frigida Willd.) control in rangelands. In the first study the potassium salt of picloram (4-amino-3,5,6-trichloropicolinic acid) at 0.1, 0.6, and 0.8 kg/ha; picloram + the propylene glycol butyl ether ester of 2,4-D [(2,4-dichlorophenoxy)acetic acid] at 0.1 + 1.1 kg/ha; the monoethanolamine salt of 3,6-dichloropicolinic acid at 1.1 kg/ha; 3,6-dichloropicolinic acid + 2,4-D at 0.6 + 1.1 kg/ha; and the dimethylamine salt of dicamba (3,6-dichloro-o-anisic acid) + 2,4-D at 0.6 + 1.1 kg/ha applied in late summer at flowering, showed the greatest potential for fringed sagebrush control. In the second experiment, the potassium salt of picloram at 0.3 kg/ha applied either in the spring or late summer gave 94 to 100% fringed sagebrush control, respectively, 1 yr after application. Control of fringed sagebrush had declined to 50% 3 yr after application. Production of perennial grasses from plots receiving picloram at 0.3 kg/ha in 1976 was increased by 410 kg/ha in 1977, 450 kg/ha in 1978, and 430 kg/ha in 1979 over that of the untreated plots.