) Zea mags L.( بررسي اثرات تراكم كاشت و مقادير مختلف كودهاي نيتروژن و پتاس برعملكرد دانه و اجزاي عملكرد ذرت

Effects of plant densities, different levels of nitrogen and potash on grain yield and yield components of maize (Zea mays L.)

A field study was conducted at Aboureihan research farm of Tehran University in 2000 to find out the effects of plant densities, different levels of nitrogen and potash on grain yield and yield components of maize (Zea mays L.). A split plot design with four replications was used in which the plant densities (6.5, 7.5 & 8.5 plants/m^2) were the main plots. Each main plot was sub-divided into 9 sub-plots to accommodate the other treatments i.e N100K0, N150K0, N200K0, N100K50, N,00K100. N100K150 N150K50, N150K100, and N150K150. The results indicated that plant densities had a significant effect on grain yield, number of grain per ear and hundred seed weights. The maximum grain yield (14724 kg/ha) was obtained in 7.5 plants/m^2. Different levels of nitrogen and potash had significant effect on grain yield, hundred seed weight and number of seeds per ear. However, there was no significant effect on number of row per ear and ear length. Results also showed that by applying N150K100, maximum grain yield, number of grian per ear and weight of 100 seeds can be obtained. It was concluded that treatment of N150,K100, could increase yield and yield components of maize and also applying nitrogen without potash decreased the yield and yield components of maize.