Characteristics of the Light Spectrum Environment of Honzu (orthodox shading) Covering Culture and Influence of UV Irradiation or Shielding on the Quality of Tea New Shoots

Abstract

The light spectrum environment of covering cluture was investigated.
The spectrum of light transmitted by black synthetic fiber was found to be similar to light from the sun. However, it was observed that UV rays hardly penetrated honzu (orthodox shading), which is thatched with low UV-permeable materials;yoshizu (screens made of reeds); and rice straw.
The influence of UV irradiation and shielding on the quality of new tea shoots was then investigated.
It was found that UV shielding caused new tea leaves to be thinner, while the content of free amino acids, methyl methionine sulfonium chloride(MMSC), and caffeine all increased.
Therefore, the quality of “covering culture” tea depends on the amount of UV irradiation, such that low UV-permeable covering like traditional honzu it contributes to higher quality tea.