The effect of nitrogen amount and splitting time on biomass, yield and morphophysiological traits of rice flag leaf (Shiroudi cultivar)

This experiment was conducted at Rice Research Institute of Mazandaran in 2014 & 2015 as a factorial based on randomized complete block design with three replications, the factors were nitrogen amount (40, 80, 120 and 160 kg ha-1) and splitting time application (T1: 50% basal+ 50% tillering stage); (T2: 33.33% basal + 33.33% tillering stage+ 33.33% panicle initiation stage); (T3: 25% basal+ 37.5% tillering stage+ 37.5% panicle initiation stage); (T4:25% basal + 25% in maximum tillering stage + 50% in panicle initiation). Results showed a significant effect of treatments on flag leaf all morphophysiological and evaluated traits. Also, the chlorophyll index, plant biomass, and grain yield influenced significantly by the interaction of nitrogen amount and splitting time. Most flag leaf chlorophyll index (35.9) was obtained through application of 160 kg N ha-1. Least grain yield (5490 kg ha-1) was obtained at the T1 splitting and nitrogen application of 40 kg ha-1. According to results, use of 120 kg N ha-1 with splitting time application of T3 and T4 were recommended for obtaining the best desired morphophysiological traits of flag leaf and higher yield in Shiroudi cultivar.