Effects of Different Transplanting Times on the Changes of Metabolism and Development of Tobacco Planted in Yunnan Area for TypeⅢ Mild Fragrant Tobacco Producing

Purpose Our aim was to study the effects of different transplanting times on changes of development and metabolism of flue-cured tobacco in Yunnan producing area for type Ⅲ mild fragrant tobacco.Method Tobacco cultivar Yunyan 87 were cultivated under covering of plastic film in Yongbei, Yongsheng of Lijiang City with the same methods of cultivation and management, but 3 different transplanting times of 14 day earlier (T1), normal transplanting (T2) and 14 days later (T3). The tobaccos were sampled respectively for analyzing the changes of agronomic traits, yields and metabolism.Results The changes of transplanting times lead to different climatic conditions, resulted in changes of their plant morphology, metabolism and development. Compared with T1 and T3, in stages of both proliferating and mature periods, leaves of T2 tobacco are the thickest, leaf areas of T2 are the largest, the ratio of its palisade and spongy tissue is more moderate, and the height of tobacco is the highest with the best yield and economic incoming per hectare.Conclusion With Yunyan 87 as variety of Yunnan mild fragrant typeⅢ, the best time for transplanting of tobacco seedling is the earlier May.