Research on suitable soil water potential index of tobacco field.

In order to promote the efficient utilization of water resources in tobacco-planting areas,by using the new-pattern automatic soil water potential control device,through the pot experiment in-situ field,we studied the influences of different soil water potentials on the dry matter accumulation and distribution in various vegetative organs,root activity,and tissue nitrate reductase activity of flue-cured tobacco at different growth and developmental stages.By adopting the conic regression and simulation method,the optimum soil water potential indexes for flue-cured tobacco at various growth stages were initially inferred as follows:-18.5~-19.7 kPa at root stretch stage,-12.47~-13.94 kPa at prosperous growth stage,and-16.15~-16.79 kPa at mature stage.