The present invention is directed to compositions containing a pigment synthesis inhibitor herbicide selected from the group consisting of a pyridazinone, isoxazolidinone, triketone, and isoxazole, and pyroxasulfone in a ratio of pigment synthesis inhibitor herbicide to pyroxasulfone of from about 1:0.3 to about 1:150. The present invention is further directed to methods of increasing the activity of a pigment synthesis inhibitor herbicide with the compositions of the present invention.