Evaluation on the Efficacy of Herbicide Penoxsulam 240 SC in Rice Fields.

This research was conducted in glasshouse and field conditions, respectively in Tehran and Khoozestan, hn 2007 to evaluate the efficacy of Penoxsulan SC 240 as a new herbicide. So, penoxsulam at 24, 30, 36 and 42 g ha-1 was compared with tank mix application of butachlor plus cinosulfuron at 900+20 g ha-1, butachlor plus bensulfuron at 100+45 g ha-1 and mixture of anylofus and ethoxysulfuron (Sunrise) at 945 g ha-1 for controlling barnyard grass (Echinochloa crus-galli), sedge (Cyperus difformis in glasshouse experiment and C. rotundus in field experiment) and rice broadleaf weeds. In glasshouse experiment, the efficacy of penoxsulam at 36 and 42 g ha-1 in control of E. crus-galli was the same as that of the other herbicides and better than its application at 24 or 30 g ha-1. For E. crus-galli control, in field experiment, penoxsulam at 42 g ha-1 showed the highest efficient, however, this treatment had no significant difference with butachlor plus cinosulfuron or bensulfuron. In glasshouse experiment, penoxsulam at 36 or 42 g ha-1 and sunrise were more efficient in control of C. difformis than the other treatments. In field experiment, the effect of penoxsulam at 42 g ha-1 on C. rotundus was same as twice hand weeding and better than the other herbicides. 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. In the field experiment, for controlling broadleaf weeds including Cleome viscose, Portulaca oleracea, Physalis sp., penoxsulam at 36 and 42 g ha-1 was similar or better than the other herbicides. In both experiment, all herbicides greatly reduced the dry weight of all the target weeds. In these experiments, no any evidence of herbicide phytotoxicity on rice was achieved. They had no effect on rice plant height and dry weight. In field experiment, all treatment, compared with weedy check, significantly increased the rice grain yield.