Effect of nitrogen fertilizer application and different stages on the quality of green tea
1995
Watanabe, I. (National Research Inst. of Vegetables, Ornamental Plants and Tea, Kanaya, Shizuoka (Japan))
Studies were carried out on the effect of the time of nitrogen fertilizer application to tea plants in spring on the quality constituents of new shoots using sand culture in a green house. Fertilizer was applied in spring each week at 300 ppm N starting from 35 before the first plucking. The contents of total nitrogen, total amino acids, tannin, caffeine, and the composition of the amino acids and amides were determined. Nitrogen application, 5 to 3 weeks before the first plucking, did not affect the content of theanine (gamma-glutamyl ethylamide), one of the major constituents of tea quality, and thereafter the content decreased. These results suggested that inorganic nitrogen fertilizer should be supplied until two weeks before the first plucking
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