Comparison the Efficacy of Penoxsulam 240 SC with the Rice Selective Herbicides Registered in Iran

This research was conducted in 2007 to evaluate the efficacy of penoxsulan SC 240 as a new rice selective herbicide. Penoxsulam at 24, 30, 36 and 42 g ha-1 was compared with mixture of anylofus and ethoxysulfuron (Sunrise) at 945 g ha-1, tank mix application of butachlor plus cinosulfuron at 900+20 g ha-1, and butachlor plus bensulfuron at 100+45 g ha-1 for controlling barnyard grass (Echinochloa crus-galli), Cyperus difformis and rice broadleaf weeds. Efficacy of penoxsulam at 36 and 42 g ha-1 in control of E. crus-galli was the same as that of the other herbicide treatments and better than its application at 24 or 30 g ha-1. Penoxsulam at 36 or 42 g ha-1 and Sunrise were more efficient in control of C. difformis than the other treatments. In control of Alisma plantago-aquatica, penoxsulam at 36 and 42 g ha-1 had no significant difference with the other herbicides, but was significantly more efficient than its application at 24 or 30 g ha-1. Penoxsulam at 42 g ha-1 controlled Sagitaria trifolia same as Sunrise and significantly better than the other treatments. All herbicides greatly reduced the dry weight of the target weeds. The herbicides showed no any evidence of phytotoxicity on rice and had no effect on rice plant height and dry weight, compared with weedy check.