Effect of Cono-Weeder and Herbicide Application on Weeds Population, Growth Indices and Yield in Rice

In order to investigating the effects of herbicides and cono-weeder application on weeds population، growth indices and rice yield، an experiment was conducted in Rice Research Station at Amol، Mazandaran province، Iran، during 2010 growing season. The experiment has been set in a split-plot which arranged in a Randomized Complete Block Design (RCBD) with three replications. Main treatments were mechanical weed control at three levels including without (control)، one and two times application of cono-weeder. The second treatments were herbicides application at seven levels including application of recommended dose of bentazon، bensulfuron-methyl، oxadiazone، butachlor، thiobencarb، hand weeding and weed infested control. Based on weeds density and dry matter، the maximum control of weeds was observed in plots which treated by hand weeding control and two times of con-weeder application. The maximum of grain yield was harvested in three treatments including hand weeding control، two times of cono-weeder application without or with herbicides application. Between three mentioned treatments had no significant different for economic yield. In general، based on the results of weed control and grain yield، two times application of con-weeder was the best treatment.