The mixture of herbicides is routinely used as part of modern weed management practices in intensive agriculture due to the reduction in herbicide application and the risk of side effects. Therefore, to detect the joint action of binary mixtures of the photosystem II, lipid biosynthesis and auxin inhibitor herbicides, additive dose model (ADM) was used as a reference model. Four species of Portulaca oleracea L., Solanum nigrum L., Amaranthus retroflexus L. and Chenopodium album L. were affected by desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid either single or in binary mixtures. Three binary mixtures of the three herbicides with seven doses of the herbicides were studied in four separate experiments. The values of ED50, ED80 and ED90 were calculated from the three- parameter log-logistic models dose–response curves for each herbicide applied alone or in mixtures of fixed ratios. Results showed that the mixtures efficacy of chloridazon and clopyralid were reduced more than predicted by ADM in all species. In contrast, at 80% and 90% response level, the mixtures of desmedipham + phenmedipham + ethofumesate and clopyralid were mainly synergistic on all species except P. oleracea. In addition, desmedipham + phenmedipham + ethofumesate and chloridazon binary mixtures followed ADM on S. nigrum and A. retroflexus and tended to be antagonistic on C. album and P. oleracea. Hence, there is a large potential for enhancing the specificity of herbicides by using mixtures of desmedipham + phenmedipham + ethofumesate and clopyralid (different site targets), delaying the development of herbicides resistance and diminishing the dose for weed control.