Effect of split application of nitrogen fertilizer on morpho-physiological parameters of rice genotypes

An experiment was carried out to assess the effect of four nitrogen levels viz. T1 (full doze of urea i.e. 215 kg urea ha-1 at 15 DAT), T2 (full doze of urea at two equal splits, ½ at 15 DAT ½ at 30 DAT), T3 (full doze of urea at two equal splits, ½ at 15 DAT ½ at 55 DAT) and T4 (full doze of urea at three equal splits, 1/3 at 15 DAT 1/3 at 30 DAT 1/3 at 55 DAT) on morpho-physiological attributes of Boro rice genotypes viz. V1 (BINAdhan 5), V2 (Tainan 3) and V3 (BINAdhan 6). Plant height, number of tillers hill-1, number of leaves hill-1, leaf area hill-1 (cm2), DM (dry matter) of root, stem and leaves hill-1, TDM (total dry matter) hill-1 and chlorophyll content in leaves (at 74 DAT), were increased with the split application of N. Among the treatments, T4 showed the best performance and grain yield (45.25 g hill-1) compared to control (30.61 g hill-1). Among the genotypes, BINAdhan 5 and BINAdhan 6 showed similar performance in respect of most of the parameters but BINA dhan 6 produced the highest grain yield (40.26 g hill-1) compared to BINA dhan 5 (35.54 g hill-1) and Tainan 3 (33.90 g hill-1). Full dose of urea (215 kg urea ha-1) applied at three equal split at 15, 30 and 55 DAT was found to be the most beneficial one for the all the rice genotypes. Leaf chlorophyll content had a strong contribution to grain yield of rice.