Effect of Root Temperature on Growth of Tea and Quality of Plucked New Shoot (Camellia sinensis (L.) O. Kuntze)

• Main Authors: Shu-Mei Lee, 李淑美
• Other Authors: Iou-Zen Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/38776748476445252555

碩士 === 國立臺灣大學 === 園藝學研究所 === 90 === This study aims to explore how temperature affects the growth of tea trees, especially the reaction on its root temperature to provide reference for planting management and adjustment, in order to effectively promote the growth of tea buds, and to increase the output and quality of tea trees. At present, as far as Taiwanese fermented tea is concerned, the most accepted local breeds, which containing the highest economic output effects, are the Chin-Shin Oolong and the newly bred TTES No. 12. This study therefore uses the above two breeds as subjects and proceed to two different temperature experiment sets: 1. Control both air and root temperature; place the subjects (bonzai) at the same temperature-controlled greenhouses with watering facilities and apply water-bath in controlling the root temperature. The air temperature (day/night) is 33/27, 28/22, 23/17, and 18/12℃. The root temperature is 15, 20, 25, 30℃. The composition of air and root temperature handling consists of 16 groups. 2. Under natural environment, the air temperature is not controlled but the root temperature is controlled. The handling of the root temperature consists of four groups, 15, 20, 25, and 30℃. The results show that both air and root temperature have made significant effects on the dormancy, germination, growth & development, the content of mineral nutrients in tea buds, and the production of tea saplings. At the same time, the results also show different growing features between different breeds, i.e. different adaptation upon temperature. The range of temperature adaptation of TTES No. 12 is relatively wide, which means it cannot only endure higher temperature but also can germinate and grow at lower temperature. The best composition of air and root temperature for TTES No. 12s leave buds to grow and develop is 33/27℃ and 25℃. For Chin-Shin Oolong, it has narrower range of temperature adaptation. The growth and development of its leave buds is significantly restrained when the air temperature is too high/low, or the root temperature is too high/low. The best condition for its leave buds to grow and develop is 28/22℃ and 20℃. The results also show that on the one hand, the circumstance of limited differences between air and root temperature benefits the growth and development of both breeds new shoots, buds, and leaves. On the other hand, both low air temperature (18/12℃) and low root temperature (15℃) delay the germination and picking of the new shoots. TTES No. 12 and Chin-Shin Oolong have more new shoots germinate and develop at 33/27℃+ 30℃ (air temperature + root temperature) and 23/17℃+ 20℃, respectively. As far as the production of tea sapling is concerned, TTES No. 12 has a higher production rate at 28/22℃+ 25℃, whereas Chin-Shin Oolong occurs at 23/17℃+ 20℃. For leaves bud character TTES No. 12, the best condition is 23/17℃+ 20℃, and the best condition for Chin-Shin Oolong is at 23/17℃+ 15℃. The nitrogen content in buds & leaves (one bud and two leaves) is lower at low air temperature (18/12℃) but high root temperature (30 and 25℃). The total free amino acid content of both breeds is higher at 33/27℃+25℃ and 28/22+, 23/17+, and 18/12℃+ 30℃, respectively. The opposite tendency shows among the total free amino acid content, the caffeine, and the total polyphenols in leaves bud. Both breeds have more (flower) buds at high air temperature (33/27 and 28/22℃) but low root temperature (15℃), or low air temperature (23/17 and 18/12℃) but high root temperature (30℃), which suggests that the circumstance of bigger differences between air and root temperature benefits the forming of buds but not the follow-up growth and development of the buds. After being formed, lower temperature is better for buds to grow, develop, and blossom. The result of root temperature experiment shows that the growth and development of tea trees is also affected by root temperature. Low temperature (15℃) delays the growth and development of new shoots. The buds and leaves contain less nitrogen, manganese and free amino acid but more phosphorous and calcium. High root temperature (30 and 25℃) not only promotes the growth of buds and leaves but also promotes the forming of buds which affects the production of tea saplings. For TTES No. 12 and Chin-Shin Oolong, both of their root temperature at 15℃ and 30℃, significantly restraint the growth and development of their buds and leaves. In general, for both breeds, the 20℃ root temperature prompts more tea sapling production. To conclude, the suitable root temperature for tea trees is also significantly affected by the air temperature. Generally speaking, when the root temperature is close to the air temperature, it is better for new shoots, buds, and leaves to grow and develop. However, at higher air temperature, with the root temperature can be slightly lowered or at lower air temperature (15℃) with the root temperature can be slightly higher, both conditions can significantly promote the growth and development of new shoots, buds, and leaves. Therefore, maintain adequately the root temperature is crucial.