Heating Nutrient Solution in Float System of Tobacco Seedling

In order to solve the chilly problem during late spring, seven measures were used to heat nutrient solution in float system of tobacco seedling. The results showed that, by using any of these seven measures, the solution temperature could be controlled within 25 and 28℃, the temperature of greenhouse and medium temperature could be increased by 3-4 ℃ during night. Emergence time was shortened for more than 7 days, and the seedbed period was shortened for more than 20 days, germination rate and seedling quality were improved significantly.