Effect of supplement foliar application of nitrogen and potassium on yield, grain quality and nitrogen utilization efficiency of hybrid rice c.v. Bahar-1

An experiment with randomized complete block design with 3 replications was carried out in the Rice Research Institute of Iran, Rasht, during 2008 to study the effect of supplement foliar application of nitrogen (5% N) and potassium (3% K2O) at different growth stages (maximum tillering stage, booting stage, and both of them) on grain quality and nitrogen efficiency of hybrid rice, c.v. Bahar-1. Results showed that foliar application of nitrogen and potassium significantly increased the grain yield (10256.3 Kg ha^-1), by 56% compared with control treatment. The highest amount of grain protein (11.6%) was related to foliar application of nitrogen in both maximum tillering and booting stages when compared with control. Also, the results showed that foliar fertilization at different growth stages had not significant effects on nitrogen utilization efficiency and nitrogen harvest index. Among cooking quality and milling factors, gelatinization temperature, chalky and broken rice percentage were not affected by foliar fertilization, significantly, while percentage of grain amylose, gel consistency and percent of hale rice significantly affected. Overall, it could be concluding that hybrid rice, cv. Bahar-1, has mediocre cooking quality, and foliar fertilization improved its milling performance.