Abstract: ObjectiveCooperation mechanism of mix application of gibberellin(GA)and potash foliage fertilizer on promoting the growth of tobacco upper leaves and tobacco quality was illuminated to provide reference for improving to-bacco quality and developing featured tobaccos.MethodSpraying GA,three simple substance potash foliage fertilizers (K1,K2 and K3)and mix application of GA and the three simple substance potash foliage fertilizers(GAK1,GAK2 and GAK3)were set as treatments,and spraying clear water was control.Growth of upper leaves,tobacco yield and variation of chemical components in different treatments were studied,and effects of each treatment on growth,yield and quality of tobacco upper leaves were evaluated.ResultSpraying GA,potash foliage fertilizers and mix application at topping stage could improve the growth,yield,and quality of tobacco upper leaves.Especially in GAK3 treatment,average leaf area and dry weight of upper leaves increased by 33.47% and 22.94% respectively,superior tobacco yield,total yield and output value increased by 32.37%,10.71% and 19.80% respectively,and chemical components were the coordinating.The effects of GA,GAK1 and GAK2 were the second,while K1,K2 and K3 were the least effective at promoting tobacco upper leaves growth.ConclusionsCombined application of GA3 and inorganic potash foliage fertilizers synergeticly promotes the growth,yield,and quality of tobacco upper leaves,and potash foliage fertilizers present antagonism in promoting growth of tobacco upper leaves.