Effect of Planting Method, Planting Density and Nicosulforon on Weeds and Corn (Zea mays L.) Var. KSC704 Yield and Yield Components

A field study was conducted to determine the effects of planting method, density and nicosulforon on corn (KSC704) and weeds grown in corn at Agricultural and Natural Resources Research Center of Khorasan-Razavi Province, Iran in 2009-2010 growing season. The treatments were: three planting methods (one row, two row and in-row), two planting density (75000 and 90000 plants/ha) and three doses of nicosulforon (Cruz®) (1.5, 2 and 2.5 l/ha) plus weed free and weedy checks. The layout was a split plot by factorial arrangements where planting methods were positioned in main plots while planting density × doses of nicosulforon were positioned as factorial in sub plots. Plot size was 3m×8m. Results showed significant decrease in weed dry matter in nicosulforon treated plots compare to the untreated control. No significant differences were observed between nicosulforon doses (1.5, 2 and 2.5 l/ha). Different planting methods had no significant effect on corn yield. Corn yield at planting density of 90000 plants/ha was significantly more than that of 75000 plants/ha. Corn grain yield, height, stem diameter, number of leaves placed upper the main ear, the height of the main ear, total leaf number, number of grain in ear, grain number in ear row, grain row number in ear in nicosulforon treated plots were significantly more than that of untreated controls. No significant differences were observed between weed free (control) and nicosulforon treated plots. Nicosulforon at doses of 1.5 l/ha and planting density of 90000 plants/ha were the best treatments.