Effects of Various Directly Covered Shading Levels on Chemical Components in Tea New Shoots of the First Flush.

Abstract

We evaluated the temporal effects of directly covered shading on the growth of new tea shoots and the contents of their chemical components. Tea shoots were grown under various black shading nets during the first flush season. The shade treatments showed a remarkable effect on the growth of new shoots, as well as on the contents of their chemical components. With higher shading conditions, the growth of new shoots was less than that with lower shading conditions. The epigallocatechin (EGC) content of new shoots was lower with higher shading conditions than with lower shading conditions, and the difference in contents with each shading treatment increased over time. The theogallin content was higher in new shoots with 75% and 90% shading than in those with no shade, and the theogallin content of new shoots decreased during shoot maturation under all shading conditions. The content of each amino acid changed differently under different shading conditions. With 75% and 90% shading for 20 days, the theanine (Thea) content of new shoots was found to be higher than that with no shade.