Leaf nitrogen — sodium ratio in sugarcane clones and its associations with other parameters at grand growth period

Abstract

Leaf N/Na ratio had a range of 3.64 in CP 44-101 to 6.09 in Co 6806 as per variety mean and their differences were significant. The wide variation of leaf N/Na ratio was between 2.54 in Co 1148 at 7 months to 7.86 in CoA 7601 at 4 months. High leaf N/Na ratio were observed in Co 6806, Co C 671, Co 7508, Co 7204, Co617, Co A 7601, Co 7201,Co 7717, Co 740, Co 853, Co 6304, while clones recorded low N/Naratio were CP 44–101, Co 62399, Co 1148, Co 975, Co 7704, H 50–7209, Co 997, Co 62101, Co 62175, Co J 64 and Co 775. Statistically significant decreas & of leaf N/Na ratio between stages were observed from 6.21 at 4 months to 3.42 at 7 months. The interactions-between clones x stages were also significant at 0.1 % level. The associations of leaf N/Na ratio were significant and positive with leaf N/P, N/K, N/Ca, N/Mg, N/S, N/C1, N/ Si ratios, sucrose % juice at 10 and 12 months, cane yield at 10 and 12 months, sugar yield at 8, 10 and 12 months, cane volume, cane height, cane thickness, cane weight, harvest index-sugar yield-8,10 and 12 months both on fresh weight and dry weight basis. There was a significant negative association between leaf N/Na ratio and leaf cations minus anions. However, leaf N/Na ratio had no effect on at any one stage with leaf cations/anions ratio, sheath N/P, N/K, N/Ca, N/Mg, N/S, N/C1, N/Na, N/Si, cations/anions ratio, cations minus anions, internodes numbers, stalk numbers, cane density, culm bulk density, harvest index-cane yield, harvest index-CCS %, harvest index-sucrose % juice-10 and 12 months both on dry weight and fresh weight basis.