Effcts of different application measures of potassium fertilizer by topping on potassium contents in flue-cured tobacco plants in Yunnan Province

Field experiments were conducted to study the effects of different application measures of potassium fertilizer by topping on K contents and K absorption in flue-cured tobacco in Yunnan Province．The results indicate that the effect of applying K₂SO₄，KN0₃ or slow-released KCI is better than that of foliar-spraying KH₂PO₄，K₂SO₄ or KN0₃ on the improvement K content in leaves，especially in upper leaves．K content in upper leaves increases from 2．6％ (CK)to 3．2％(K₂SO₄ or KNO₃).