Effect of different levels of nitrogen on the chemical composition of tea (C. Sinensis L) grown at higher altitude

The effect of different levels of nitrogen on water extracted substances (we),total polyphenols (tp),epigallocatechin (egc),epicatechin (ec),caffeine and amino acids in fresh tea leaves grown at higher altitude (1500 meter from sea level) and plucked in various months of the years,was studied. after plucking the tender leaves (bud+3) from tea bushes,the leaves were oven's dried at 60°c for 24 hours. the dried leaves were used for determination of water-extracted substances,total polyphenols and amino acid contents by using 751g uv-spectrophotometer and egc,ec and caffeine contents were determined by the high performance liquid chromatography (hplc). the nitrogen level did not affect the we significantly. the data show that tp content was increased up to certain level with the increase of nitrogen level (180 kg ha) but decreased with further increase of nitrogen. from treatment t4 (n=180,p=30,k=90 kg ha-1).tp increased significantly by the application of 180 kg n ha-1. the egc,ec contents increased up to certain level with the increase of nitrogen and then declined after the application of 180 kg ha-1. the nitrogen level did not affect the caffeine contents.