Abstract:

The research aimed to explore the effects of different types of plant growth regulators and their concentration differences on the growth of spring tea shoots and tea quality, in order to provide theoretical support for high-quality and efficient spring tea production in Taishan tea area. With ‘Yujinxiang’ tea as test material, the changes and differences of chlorophyll content, leaf area, shoot length, 100-bud weight, bud density, unit yield and quality indexes of tea leaves were investigated and analyzed by different concentrations of gibberellin and Bihu growth regulator in the early stage of spring tea germination. The results showed that the effects of different plant growth regulators on the growth and quality of spring tea shoots were different. (1) Under the treatment of high concentration (75 mg/L) of gibberellin, the chlorophyll content was the highest, and the shoot length, leaf area, 100-bud weight and bud density were the most significant, but the contents of caffeine, total ash and tea polyphenols were also relatively high. (2) The effects of medium and low concentration (50, 25 mg/L) of gibberellin on the growth and quality indexes of tea shoots were lower than those of high concentration gibberellin treatment. (3) Under the treatment of plant growth regulator Bihu, which is frequently used in current production, it had a significant promoting effect on shoot length and leaf area, but it had a certain reducing effect on 100-bud weight and bud density. At the same time, it could promote the content of free amino acids and tea polyphenols, and reduce the content of caffeine and total ash, and the quality index was better. In the process of tea production, although the selection of gibberellin can increase the yield, it is not conducive to maintaining the quality of tea, while Bihu is conducive to the formation of tea quality, but it has little effect on increasing the yield. Therefore, in order to obtain high-quality and high-yield tea products, spraying plant growth regulators cannot be used as a single adjustment method.

Key words: plant growth regulator, spring tea, new shoot, yield, Taishan tea area, gibberellin, Bihu, tea quality