Effect of foliar supplements of nitrogen and potassium on yield and yield components of hybrid rice (Oryza sativa cv. Daylam)

A randomized complete block design with three replications was performed in Rice Research Institute of Iran, Rasht in 2008, to find the effect of supplement foliar application of nitrogen and potassium on ’Daylam‘ hybrid rice grain yield, its components and grain protein percentage. Foliar application of 20 kg nitrogen (5 percent N) and 15 kg potassium (3 percent K2O) in different pre-anthesis stages was considered as treatments. Foliar application of distilled water was considered as control. Results showed that the grain yield and biological yield were increased in treatments which nitrogen and potassium was applied at pre-anthesis stages compared to control treatment. Foliar fertilization of nitrogen in maximum tillering stage had the highest effect on number of tiller per plant and grain number per panicle. The highest percentages of fertile tillers were related to foliar application of nitrogen at both maximum tillering and booting stages. Foliar application of nitrogen at maximum tillering and booting stage significantly increased grain protein content by 12.1 percent which it was 8.3 percent greater than control treatment. Result also showed that a significant and positive correlation exists between grain yield with biological yield and percentage of panicle fertility. Overall, it was concluded that maximum tillering stage is the best pre-anthesis phonological stage for foliar application of nitrogen and potassium on cv. Daylam hybrid rice.