Well-cellar style transplanting of flue-cured tobacco (Nicotiana tabacum l.) in China.
Well-Cellar Style Transplanting (WCST) spread in China is an original transplanting method of flue-cured tobacco, and has obvious comparative advantages when compared to conventional transplanting (CT). Field and pot experiments were implemented to investigate primary environmental factors that affect growth of flue-cured tobacco in WCST and CT. The results showed that variation of air temperature in WCST ranged from 14.13°C to 30.52°C which was relatively stable as compared to CT (between 11.74°C and 44.22°C) in April. Furthermore, the similar variation of soil temperature was found between the bottom of the WCST and soil surface. Variation of air relative humidity in the WCST was between 64.28% and 100%, which was narrower than the soil surface in CT (from 25.71% to 97.75%). Otherwise, soil moisture at the bottom of the WCST varied from 24.92% to 36.63%, which was much higher than soil surface in CT (between 16.92% and 35.10%). Photosynthetically active radiation (PAR) of sunlight received in the WCST was lower than in CT; however, there were significant linear relationships between WCST and CT whether on a sunny day (y = 0.95x-163.71, R2=0.88), a cloudy day (y = 0.95x-163.71, R2=0.88) or a rainy day (y = 0.36x-4.82, R2=0.97). According to fitted parameters of light response curves, light saturation point (LSP) and maximum net photosynthetic rate (Pmax) in WCST were higher than in CT; nonetheless, initial quantum efficiency (?) was higher and light compensation point (LCP) and apparent dark respiration rate (Rd) in WCST were lower than in CT. Because of better hydrothermal conditions and moderate photosynthetically active radiation, well-cellar style transplanting promotes growth and development of flue-cured tobacco.