Effects of Plant Population on Growth and Nicotine Content of Flue-cured Tobacco

In order to reduce the excessive nicotine content of upper leaf,field experiments on effects of different plant populations (1480, 1200 and 1025 plants per 666.7m 2) on the growth, development, yield, quality and nicotine content of major flue-cured tobacco cv.K 326, Yunyan 85 and CB-1 grown in southeast tobacco growing areas were conducted. The results showed that by properly increasing the plant population, 1)the weight per leaf was decreased,especially for the upper leaf; 2)the proportion of the upper leaf was also reduced; 3)the tobacco leaf (particularly the upper leaf) had lower nicotine content, less irritancy and higher usability.