Performance of Sugarcane Genotypes Under Different Nitrogen Levels in Sub-Tropical Region of Nepal

A field experiment was conducted during consecutive years of 2014-16 to study the effect of different nutrient levels on performance of sugarcane genotypes on sandy loam soils at National Sugarcane Research Program, Jitpur, Bara, Nepal. The experiment was laid out in split plot design of four nitrogen levels 75%, 100%, 125%, 150% of recommended dose (RD) i.e 112.5, 150, 187.5, 225 kg N/ha for plant crop and 150, 200, 250, 300 kg N/ha for ratoon respectively and four varieties viz. CoLk 94184, BO 147, Co 0233 and BO 141 replicated thrice. The experimental results revealed that significantly increased in number of millable cane and cane yield with increasing nitrogen levels. Application of 150% nitrogen RD (225 and 300 kg N/ha) significantly counted higher number millable canes (115548.43/ha and 100700/ha) in both plant and ratoon crop respectively. High nitrogen levels i.e. 187.5 and 225 kg N/ha showed significant higher cane yield over 150 kg N/ha by 7.22 and 9.36% in plant crop respectively. Reducing nitrogen levels by 25% of RD resulted significantly low yield of 59.78 mt/ha, shortest stalk length (1.87 m) and low single cane weight of 0.65 kg in ratoon crop but not significantly difference in stalk length, cane diameter and single cane weight in plant crop. The data indicated that significantly higher number of millable cane was counted in genotypes CoLk 94184 of 124831.06/ha and 107400/ha in both plant and ratoon crop respectively followed by BO 141 and Co 0233. Higher cane yield was produced by genotypes BO 141 (94.01 and 75.89 mt/ha) and Co 0233 (93.18 and 81.72 mt/ha) in plant crop as well as in ratoon crop respectively. The ratoon performance index (RPI) of genotypes Co 0233 (89.21), CoLk 94181 (84.01) and BO 141 (81.59) were identified as better as compared to BO 147.