Effect of Improving Temperature and Fill-In Light on Tobacco Seedling Quality in Float System in Southern Hunan

The effect of light and temperature of the flue-cured tobacco seedling was investigated to avoid growth retardation of tobacco seedling in float system, which is often caused by low temperature and short photoperiod in Hunan during spring. The results showed that increasing temperature could significantly improve flue-cured tobacco seedling emergence, seedling quality, and decrease seedling time. Also, additional light obviously improved seedling quality, and reduced seedling time. However, there was no effect on emergence rate. In summary, increasing water temperature in the late spring can obviously improve seedling quality in float system.