بررسي تاثيرات كاهش مصرف علفكش ها در تلفيق با كاهش فاصله رديف / افزايش تراكم روي علف هاي هرز سويا

Survey on effect of integrated reduced rates of herbicides with narrow row/high population on soybean weeds

Field experiments were conducted to determine whether soybean grown in 36-cm rows and a 2* population could improve weed control relative to 60-cm rows and 1* population under reduced herbicide options. Experiment was conducted in split plot design with four replications at Karaj and Lorestan. Main plots were 1) 36-cm rows and 2* population and 2) 60-cm rows and 1* population. Five treatments of herbicides were as supplots included 1) a standard treatment of Basagran + Nabues (100%), 2) Basagran + Nabues (25% of the standard rates), 3) a standard treatment of Treflan + Sencor (100%), 4) Treflan + Sencor (25% of the standard rates), 5) without herbicide (control). Weed control was better with Basagran + Nabues than Treflan + Sencor. Weeds control was less in the 25%-herbicide treatments than in the standard treatments when soybean was grown in 60-cm with 1* population. The 25%-herbicide treatments when soybean was grown in 36-cm rows with a 2* population provided weed control and grain yield similar or further than 60-cm rows and 1* population with 100% herbicide. Weed control was poor and yield was reduced when no herbicides were applied regardless of row spacing or population.