Impact of Nitrogen rates on growth and yield attributes of Sweet Corn grown under different Phosphorus levels

The effect of different nitrogen levels (0, 200 and 400 kg urea ha -1 ) and phosphorus rates of 0, 100, 200 and 300 kg ha -1 in the form of triple superphosphate on growth and yield components of sweet corn was investigated at a research field, in Takestan, Iran, during 2006 growing season. The experiment was carried out using split plots based on randomized complete block design with four replications. Results showed that nitrogen fertilizer effect was significant on number of grains per ear, number of nodes per stalk, ear height, ear diameter, husked green ear weight, 1000-grain weight, plant height and grain yield of sweet corn. Phosphorus rates significantly affected plant height, ear diameter, ear height, grain yield, husked green ear weight and 1000-grain weight. Interaction effect of nitrogen × phosphorus was only affected 1000-grain weight, grain yield and husked green ear weight. whereas the rest of studied traits were remained unaffected. The highest grain yield (7781.10 kg ha -1 ) was that of application of 200 kg urea ha -1 coupled with 200 kg ha -1 of triple superphosphate. It is concluded that optimum dose of phosphorus/nitrogen for sweet corn crop is 200 kg ha -1 . It is also suggested that further research should be done under different environmental conditions. (Journal of American Science 2011;7(10):201- 206). (ISSN: 1545-1003).