不同颜色遮阳网遮光对丘陵茶园夏秋茶和春茶产量及主要生化成分的影响

为研究不同颜色遮阳网遮光对夏秋茶与春茶产量和品质的影响，在中国科学院桃源农业生态试验站以“碧香早”茶树为试验材料，选用不遮光和中度遮光（遮光率(50?4)%）的黑色、绿色、银灰色遮阳网开展遮光试验。结果表明：不同季节使用黑色遮阳网能显著增加氨基酸和咖啡碱含量，降低茶多酚含量和酚氨比，与对照茶园比较，夏季、秋季、春季茶叶氨基酸含量分别增加了14.22%、17.07%、6.23%，茶多酚含量分别降低了4.40%、6.43%、27.66%，咖啡碱含量分别增加了9.48%、8.10%、7.28%。夏秋季银灰色遮阳网效果最差，绿色遮阳网效果介于黑色和对照之间,春季三种颜色遮阳网效果均优于对照；茶树遮光后品质明显优于对照，夏秋茶经遮光可达到制高档茶的要求，春茶遮光可达到制名优茶的要求。

Effects of colour shading on the yield and main biochemical components of summer-autumn tea and spring tea in a hilly tea field

In order to understand the influence of shading colors on the quality of summer-autumn tea and spring tea, three shading screens with different colours (black, green and silver) (BSS, GSS and SSS) at a moderate shading intensity (50±3)% and non-shading control (CK) were set up in a tea field (Camellia Sinensis, cv. Bixiangzao) at the Taoyuan Station of Agro-ecology, Chinese Academy of Sciences. The results indicated that 100-bud weight and bud density increased in all treatments of shade colours during different seasons. In comparison with the CK treatment, 100-bud weights in summer-autumn were significantly improved in BSS and GSS by 10.2%, 6.1%, respectively, while 100-bud weights in spring increased significantly by 4.3%, 11.1% and 5.3% under BSS, GSS and SSS, respectively. For the bud density, it was significantly higher than that of CK by 7.4% under BSS in summer-autumn and by 32.5%, 31.5% and 22.3% under BSS, GSS, and SSS in spring, respectively. With shading, the shoot water content of tea plants was increased in different seasons, but such shoot water increase was not significant over CK. Compared with CK, the tea water extractants under the shading screens were decreased, but there was no significant difference between the treatments. The use of the BSS and the GSS in summer-autumn and all shadings in spring increased the contents of amino acids (AA) and caffeine in tea leaves, while it reduced the polyphenol (TP) content and the TP/AA ratio. The treatment of BSS significantly increased the AA content by 14.2%, 17.1% and 6.2% in summer, autumn and spring, respectively. The effect of shading on the TP content was not significant in summer and autumn, but the treatments of BSS and GSS decreased the TP content by 27.7% and 19.2% in spring, respectively. BSS significantly decreased the TP/AA ratio by 16.4% over CK in summer, while BSS and GSS reduced the TP/AA ratio significantly by 20.1% and 11.8% in autumn, and 31.8% and 20.6% in spring, respectively. In comparison with the CK treatment, the theine content significantly increased under BSS by 9.5%, 8.1% and 7.3% in summer, autumn and spring, respectively. In conclusion, the use of BSS and GSS in summer and autumn and all three shading colours in spring was able to improve the tea quality in hilly tea gardens, with the colour shading effect on the tea quality in the following order: black > green > non-shading > silver for the summer-autumn tea, whilst in spring with the order: black > green > silver > non-shading. Since the BSS could significantly increase the yield and the biochemical components of the tea in different seasons, tea growers are recommended to apply this shading screen for better tea production and quality in the hilly tea gardens.