Effect of different urea levels on yield and yield components of corn 704

According to urgent need of corn to nitrogen and since this element play a main role in improving of yield corn, thus, in order to investigate the effect of different levels of urea on yield and yield components of corn 704, an experiment was conducted randomized block with three replications in cropping year of 2012. Experimental treatments included six levels of urea (0, 30, 60, 90, 120 and 150 kg.ha-1). Test parameters include the number of grain rows, number of grains per row, the number of grains per ear, grain weight, grain yield, biological yield and harvest index. Results showed that the effect of urea on the number of grain rows, number of grains per row, the number of grains per ear, grain weight, grain yield, biological yield and harvest index were significant. The highest amount of yield and yield components of corn was in the treatment of 150 kg.ha-1 of urea and lower in the control plots, respectively. To achieve the highest yield and yield components of 150 kg.ha-1 in urea is recommended.