This study was conducted to evaluate the effect of different application times and doses of bentazon on weeds growth in different red bean (Phaseolus calcaratus) cultivars. Three factors were studied in split factorial in the form of a randomized complete block design with three replications. The main factor was red bean cultivar (Naz and Derakhshan), the sub factor was time of herbicide application (one sprayed at the third trifoliate stage and another sprayed 15 days after the first spray), and the sub-sub factor was herbicide application dose (1.5, 2.5, 3 and 3.5 li/ha). Results indicated that the treatments significantly affected most of the measured traits. The best weed control was obtained in Naz cultivar. Spraying 3.5 li/ha bentazon at the third trifoliate stage was the most effective herbicide treatment which reduced weeds infestation and increased red bean yield and yield components.
