Water depth effect on Echinochioa sp control efficacy in flooded rice

Alberto Pedreros L.1 y Roberto Alvarado A.1

Two trials were carried out at the Quilamapu Experimental Station (INIA) during 1989/90 and 1990/1991 to evaluate the effect of rice (Oryza saliva L.) water depth on the efficacy control of Echinochioa and the use of herbicides applications. The results obtained indicate that both the herbicides and the water depth affected Barnyardgrass population, but only in 1989/90 the phytomass of this weed was significantly affected. An interaction between herbicide and water depth was observed with Bensulfuron since control efficacy depended ofthewaterdepth utilized. Grass weed control by Molinate and the mixture of Molinateand Bensulfuron was not affected by the water level.

Keywords: rice, Echinochloa spp, water management, herbicides.
1 Estación Experimental Ouilamapu (INIA), Casilla 426, Chillán, Chile.