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Herbicide 2,4-D was less effective for bitterweed control when applied at air temperatures below 14 degrees C compared to applications at 22 degrees C even when soil water was adequate for active plant growth. There was no difference in bitterweed control whether the ester or amine formulations of 2,4-D were used. At 22° C air temperature, 1.12 kg/ha of 2,4-D + dicamba (3:1), picloram, or 2,4,5-T + picloram (1:1) did not improve short-term control (36 to 182 days) of bitterweed compared to 2,4-D alone at the same rate. However, at 14 degrees C temperature or when bitterweed were in advanced phenological states (75% with inflorescences), these herbicides provided excellent short-term bitterweed control whereas 2,4-D was inconsistent. Mixtures of dicamba with 2,4-D slightly improved residual bitterweed control, compared to the same rate of 2,4-D alone. Picloram at 0.56 to 1.12 kg/ha controlled 60 to 100% of the bitterweed populations for a year or more following applications in winter or spring. Tebuthiuron at 0.56 to 1.12 kg/ha was not as effective as 2,4-D at 1.12 kg/ha relative to initial bitterweed control, but provided excellent residual control after 1 year following winter application. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020