Field study was conducted in order to evaluate the efficacy of new herbicide quinclorac to control barnyardgrass and bulrush, the most important weeds of paddy rice. Treatments consisted of rice cultivars (Hashemi and Khazar) and quinclorac rates (50, 100, 200 and 400% the recommended dose), recommended dose of butachlor and quinclorac, each alone and plus bensulfuronmethyl (BSM), weedy and han...