Relationship between soil moisture and transpirational water-consumption of flue cured tobacco under different water supplying conditions

Through artificial water control experiment in the shed of rain-free condition, the physiological water requirement patterns of flue-cured tobacco and the relationships between transpiration water consumption and soil water content were studied under different water supplying conditions. The results showed that the change of evapotranspiration in the whole growing period of tobacco plant had a single-peak curve under abundant water supplying conditions. The maximum water consumption of transpiration was at vigorous growing stage, followed by maturing stage and relatively small at root extending stage, which accounted for 45.23%, 34.8% and 19.97% of total water consumption, respectively. The transpiration water consumption of flue-cured tobacco was increased with the increase of soil water supplying, and the effects of drought stress at different growing stages on tobacco evapotranspiration were significant, especially at vigorous growing stage. On the basis of this experiment, the correction coefficients of soil water stress for transpiration of flue-cured tobacco under different water supplying conditions were worked out. Furthermore, the correction functions of transpiration water consumption to soil water supplying and the time-soil moisture model of practical transpiration water consumption for flue-cured tobacco were also put forward under insufficient water supplying conditions.