A simple method for the comparative testing of herbicides for emergent weeds was developed and used over a three-year period to compare the effect of recently introduced herbicides with that obtained from the use of a 2,4-D ester in a fuel oil carrier. The herbicides tested included amitrol (3-amino-l, 2, 4-triazol), dalapon (sodium salt of 2, 2 dichloropropionic acid), erbon (2- (2, 4, 5 tricholorophenoxy) ethyl 2,2 dichloropropionate), Kuron (propylene glycol butyl ether ester of 2-(2,4,5 trichlorophenoxy) propionic acid), Kuramine (amine formulation of 2-(2,4,5 trichlorophenoxy) propionic acid), CMU (3-(p-chlorophenyl) -1, 1-dimethylurea) and the propylene glycol butyl ether ester of 2,4-D. These compounds were tested singly and in various combinations of two herbicides. TCA (sodium salt of trichloroacetate) was combined with several of the forms also. Several species of marginal and emergent weeds were included in the tests such as cattail, sedge, grass, rush and other plants often occurring in shallow waters and pond margins. On the species of weeds treated, dalapon, amitrol, the propylene glycol butyl ether ester of 2,4-D and CMU were most effective when used alone. Combinations of TCA-kuron, dalapon-kuron, amitrol-kuron, amitrol-erbon, TCA-erbon, amitrol-dalapon and dalapon-2,4-D were as effective in killing the vegetation treated as was the standard 2,4-D ester in oil treatment. Generally a combination of two herbicides gave better results than either of the agents used alone. CMU was the only herbicide tested which had strong residual effects although several of the treatments exhibited residual effects extending into the season following the one in which they were applied.
