Effects Of Foliar Potassium Fertilizer On Physical And Chemical Properties Of Upper Leaves Of Flue-cured Tobacco

In view of the problem that the upper leaves of flue-cured tobacco are small and thick,the structure is compact,the potassium content is low,and the industrial availability is low,this experiment applies foliar potassium fertilizer to the upper leaves of flue-cured tobacco at the maturity stage,and measures the basic agronomic traits,leaf tissue structure of the upper leaves of flue-cured tobacco.Physiological and biochemical indicators,determination of dry matter accumulation,chemical composition,statistical economic traits,sensory evaluation,aim to provide a theoretical basis and technical support for the opening of the upper leaves of flue-cured tobacco,improve the K content and industrial availability of the upper tobacco leaves,the results are as follows:?1?The effect of different types of foliar potassium fertilizer on the physical and chemical properties of the upper leaves of flue-cured tobacco,leaf area:the best effect of spraying KNO3 on the leaf surface potassium fertilizer,the upper leaf area increased significantly,the aspect ratio was significantly reduced,and the open film stretched.Tissue structure:Spraying KNO3 foliar potassium fertilizer treatment,leaf thickness and sponge tissue were significantly improved,but the ratio of the barrier sponge was significantly reduced.The leaf tissue was looser than the CK treatment.The KH₂PO₄ leaf potassium fertilizer and the K₂SO₄ leaf potassium fertilizer were applied.Thick,spongy tissue,and barrier sponge ratios were significantly reduced.Physiological and biochemical characteristics:spraying KNO₃ and KH2PO4 foliar potassium fertilizer treatment,photosynthesis,chlorophyll content,carotenoid content,nitrate reductase activity and invertase activity of upper leaves of flue-cured tobacco were significantly higher than that of K₂SO₄ leaf potassium fertilizer and CK treatment.Tobacco leaf yield:the highest treatment with KNO3 foliar potassium fertilizer,and the highest score for KH₂PO₄ foliar potassium fertilizer in the sensory evaluation of tobacco leaves.?2?The effect of different foliar application times on the physical and chemical properties of the upper leaves of flue-cured tobacco.With the increase of spraying times,the area of upper leaves of flue-cured tobacco increased significantly,the photosynthesis increased significantly,the K content of leaves increased significantly,and the nicotine content decreased significantly.The chemical composition tends to be coordinated.In terms of sensory evaluation,the comprehensive score increases significantly with the increase of the number of foliar application of potassium fertilizer.?3?The effects of different foliar potassium fertilizer types and spraying times on the physical and chemical properties of upper leaves of flue-cured tobacco are as follows:comprehensive consideration of upper leaf area,leaf thickness and leaf looseness,accumulation of intrinsic matter,internal chemical composition coordination,economy For factors such as traits and sensory evaluation,it is recommended that in the field cultivation management measures,spraying KNO₃ foliar potash treatment is recommended to be sprayed twice in the field,spraying on the day of topping and 15 days after topping,spraying K2SO4,KH₂PO₄ leaves.The surface potassium fertilizer treatment is recommended to be sprayed 3times in the field,respectively,on the day of topping,15 days after topping,and spraying 30days after topping.