Abstract:

To explore the effects of shading nets with different colors on tea yield, quality and the microclimate environment of the tea field in northern China during the high-temperature summer season, shading nets with six different colors (black, red, silver-gray, green, blue and yellow) and non-shading control (CK) were set up in a northern tea garden, and the variations of tea field temperature and humidity, tea photosynthesis, tea yield and quality were analyzed. The results indicated that, in comparison with the CK treatment, black nets, silver-gray nets and blue nets had the best temperature reduction and humidification effects; red nets, blue nets and yellow nets were more effective in promoting photosynthesis of tea; red nets, silver-gray nets, blue nets and yellow nets had relatively good yield increasing effect (but the duration of shading needed more attention), and the effect of red nets on the leaf area was the most obvious. In addition, black, green and blue shading nets could improve the content of amino acids, while silver-gray and blue shading nets had a significant reducing effect on the ratio of tea polyphenols to amino acids. Although the adjustment effects of shading nets with different colors on the yield, quality and the microclimate environment of tea field are quite different, in general, the blue nets, red nets and silver-gray nets are beneficial to the cooling and humidifying of tea field, promoting photosynthesis, and increasing yield and quality of summer tea.

Key words: summer tea, shading effect, microclimate environment, photosynthesis, yield, biochemical components