The Relationship of SPAD Value, Maturity of Fresh Tobacco Leaves and Quality of Flue-cured Tobacco Leaves

The experiments were conducted to develop a fast, non-destructive method to judge the maturity of fresh tobacco leaves using a chlorophyll meter. The tobacco cultivar Qinyan 96 was used in this experiment. The SPAD values of fresh tobacco leaves with different maturity and the economic characters, appearance quality, chemical composition and sensory evaluation of flue-cured tobacco leaves were evaluated and compared to study the relationship of SPAD values and the quality of flue-cured tobacco leaves. The results showed that, SPAD values could effectively distinguish the difference between yellow green area of 10%-20% of fresh tobacco leaves, and was negatively correlated with tobacco maturity. Corresponding to the most appropriate maturity of flue-cured tobacco leaves of three parts from bottom to top, the SPAD values were 8.6-11.4, 17.9-18.6 and 13.2-20.3 respectively. The results provide a method for rapid and nondestructive judgment of picking maturity of tobacco leaves.