The study was conducted in 2009 in the Agricultural Experimental Station in Kępa near Puławy. Obtained results are presented in tables 1 and 3. Significant differences in efficiency of Proponit 720 EC against individual weed species were observed for different doses of the preparation. Proponit 720 EC applied alone at the dose 6 l/ha after sowing exerted the best efficiency. The herbicide applied at the dose 6.0 l/ha did not cause phytotoxic effects on maize crop.