Abstract:The effects of physiological regulations, such as the use of different growth regulators, and methods of top cutting management on potassium uptake and redistribution in sink and source in tobacco were studied under field conditions. The results indicated that no top cutting (endogenous auxin) or adding auxin at the top cutting stage (exogenous auxin) was conducive to mature leaf K content increase. Exogenous and endogenous auxines caused K redistribution from other parts of the plant to leaves. Exogenous auxin was more effective than endogenous for increasing mature leaf K content. Adding exogenous auxin to the tobacco plant twice is better than once during the growing period.