Leaf sheath potassium-nitrogen ratio in sugarcane genetic stocks at grand growth period and its associations with nutrients ratios, yield components, sucrose and yield of cane and sugar.

摘要

The leaf sheath K/N ratio was determined in 30 sugarcane genetic stocks at grand growth period of 4-7 months at monthly intervals. The leaf sheath K/N ratio between clones, stages and their interactions was significant at 0.1% level. The leaf sheath K/N ratio ranged from 3.75 in Co 740 to 6.6429 in CP 44-101, with a mean of 4.75. Clones Co 7712, Co975, B 37172, NCo 310, Co 7304, CoC 671, Co 62399, Co 740, Co 62101 and POJ 2878 recorded low K/N ratio in leaf sheath, while high leaf sheath K/N ratio was observed in CP 44-101, Co 62174, Co 7201, Co 1148, Co J64, H 50-7209, Co 7508 and Co 7717. Leaf sheath K/N ratio increased with age of the crop from 3.04 at 4 months to 4.48 at 5 months; 5.43 at 6months to 6.05 at 7 months. Significant positive correlations of leaf sheath K/N ratio was observed with leaf blade K/N ratio, sheath K/P ratio, K/Mg ratio, K/S ratio, K/Na ratio and K/Si. The association of leaf sheath K/N ratio was significant and positive with sucrose at 12 months and with commercial cane sugar percentage (CCS%) at 12 months. Leaf sheath K/N ratio had significant positive associations with harvest index-cane yield at 12 months. Significant negative association was observed between sheath K/N ratio and culm basic density. However, leaf sheath K/N ratio had no associations with K/P, K/Ca, K/Mg, K/S, K/Cl, K/Na, K/Si, cations/anions, cations-anions, sheath K/Cl, cane and yield at 10 and 12 months, germination, tillers, stalk number, cane volume, density, height, thickness and weight, internode number, length, weight and volume, harvest index-sugar yield, CCS%, and sucrose percentage at 10 and 12 months.