| A field trial was conducted to determine the appropriate topdressing amount of KNO3 for flued-cured tobacco.The results showed that the yield and quality of flue-cured tobacco were improved while the topdressing amount of KNO3 was increased from 0 kg/hm2 to 225 kg/hm2.When the topdressing amount got to 300 kg/hm2,the yield,the rate of middle and first class leaf,the average price,the production value and the chemical quality of flue-cured tobacco decreased.The appropriate top-dressing KNO3 amount is very useful to enhance K content and to reduce sugar and total sugar.Under the condition of this experiment,the appropriate top-dressing amount of KNO3 was 225 kg/hm2. |