به كارگيري مقادير كاهش يافته تريفلورالين و ستوكسيديم براي كنترل دم روباهي زرد و فياق در سويا

Application of reduced rates of trifluralin and sethoxydim on yellow foxtail and johnsongrass control in soybean

In order to have healthy environment, reduced costs and high production, it is essential to use herbicides lower than recommended rates. A field study was conducted in a randomized complete block design with 11 treatments and 4 replications at experimental station of Agricultural college of Sari, Iran, to investigate the effects of reduced rates of herbicides on weed control and soybean [Glycine max (L.) Men.] yield during the growing season of 2000. Two herbicides were used trifluralin (pre-plant incorporation), and sethoxydim (post emergence). Eleven treatments were trifluralin+sethoxydim at recommended rate, 75, and 50% of the recommended rate, sethoxydim at recommended rate, 75, and 50% of the recommended rate, and trifluralin at recommended rate, 75, and 50% of the recommended rate, and two control treatments of weed-free and weedy-check. Results showed that yellow foxtail (Setaria glauca) and johnsongrass (Sorghum halepense) were controlled more than 92 percent with 50% of the recommended rates of trifluralin+sethoxydim and sethoxydim alone. Fifty percent of the recommended rates of trifluralin alone could control 76 % of yellow foxtail and johnsongrass. With reduced herbicide rates, both weed control percentage and soybean yield did not show any significant difference in comparison with the recommended rate. Considering soybean yield, reduction of herbicide application rate is possible up to 50% of the recommended rate.