茶是常绿树木,是全年可进行光合作用的作物。茶树的新芽依靠其间进行的光合作用和树体内蓄积的碳水化合物等而生育。另外,虽然老叶的光合强度在冬季降低,到春季才稍显恢复,但通过秋冬两季同化产物的蓄积,仍对来年头轮茶的收获量和树势维持有很大影响。还可从头轮茶比其他二、三轮茶品质最好这一点看出保护冬季叶(老叶)的重要性。 Tea is evergreen and is a crop that is photosynthetically active throughout the year. The shoots of tea trees depend on photosynthesis and the carbohydrates accumulated in the tree during their growth. In addition, although the photosynthetic intensity of old leaves decreased in winter and only slightly recovered in spring, the harvest of the first round of tea and the maintenance of tree vigor were still greatly affected by the accumulation of assimilate products in autumn and winter. Also from the first round of tea than the other two or three rounds of tea, the best quality point of view to protect the importance of winter leaves (old leaves).