influence of different herbicide application methods on weed control of marigold nursery

a field experiment was conducted at college of aburaihan, university of tehran, iran in 2007 to evaluate the herbicides efficacy in a marigold nursery to control weeds including annual flowers. experimental design was a rcbd with total 12 treatments replicated four times. treatments were trifluralin preplant incorporated at two and three li/ha, trifluralin preplant non incorporated at two and three li/ha, oxyfluorfen preplant at two and three li/ha, oxyfluorfen postemergence at two and three li/ha and cholorothol-dimethyl preplant at 10 kg/ha, two-times hand weeding, weedy and weed free treatments were also included as control. application of oxyfluorfen preplant and trifluralin preplant at both rates of two and three li/ha controlled weeds by 70 percent. this treatment had no phytotoxic effects on marigolds and did not reduce their yields either. among applied herbicides, application of non-soil incorporated trifluralin treatment compared with treatment of the same soil incorporated with herbicides, due to easier application, indicated its preference and also had no phytotoxic effects on marigold.