Correlation between nitrogen application to tea flushes and quality of green and black teas

We treated the tea cultivar TTES No. 12 with different nitrogen fertilizers and prepared black and green teas from these tea flushes. Analyses of nitrogen content and levels of catechins and caffeine of shoots with two leaves and a bud were conducted to understand the influence of these factors on tea quality. Only the nitrogen content showed consistent effects on tea quality, whereas the effects of the other chemical components varied with season. A positive linear regression relationship was observed between nitrogen content of tea flushes and green tea quality, whereas a negative linear regression relationship was observed between nitrogen content and black tea quality. Thus, the quality of black and green teas could be determined based on the nitrogen content of the tea flushes.