Effects of Transplanting Time on Photosynthesis Characteristics, Yield and Quality of Flue-cured Tobacco

To identify the most suitable transplanting time of NC55 in Weifang, A field experiment was conducted with four transplanting time treatments (05/02, 05/12, 05/22, 06/01) to evaluate its effect on growth, photosynthesis characteristics, chlorophyll metabolism enzyme activity, economical character and sensory evaluation in flue-cured tobacco. The results showed that transplanting time had significant effect on growth, photosynthesis characteristics and chlorophyll metabolism enzyme activity in flue-cured tobacco. Compared to 05/02 transplanting, later transplanting shortened its root elongation, vigorous growth and picking stages, thus its growth duration decreased. As the transplanting time delayed, chlorophyll content and net photosynthetic rate significantly increased but Chlase and MDCase activity decreased in vigorous growth and topping stages. But reverse trends were observed in maturing stage. As the transplanting time delay, the rate between tobacco average price and upper-middle-tobacco leaves increased first and decreased afterwards, while sensory and taste quality of flue-cured tobacco showed the opposite trend. So transplanting time of tobacco production may be delayed up to May 12 to May 22 in Weifang.