Spatial And Temporal Distribution Characteristics Of Chemical Constituents In Flue-cured Tobacco In Sichuan Province

Tobacco raw materials are the basis of supporting the development of tobacco,especially the development of Chinese cigarettes.Sichuan Province is the third largest tobacco area in China and an important force to support the raw materials of cigarettes in China.However,the flue-cured tobacco planting in Sichuan Province is distributed in the five prefectures of North,South and West Sichuan.The sunshine duration,climate conditions and planting level are different in the planting areas,and the development level of flue-cured tobacco planting in different places is different.The chemical composition of flue-cured tobacco is an important index to evaluate the quality of flue-cured tobacco.The content of main chemical composition in flue-cured tobacco determines the quality of flue-cured tobacco,and the balance and coordination degree of each chemical index determines the industrial use value of flue-cured tobacco.Therefore,in order to accurately understand the temporal and spatial distribution characteristics of the content of conventional chemical components of flue-cured tobacco in Sichuan Province and provide decision-making reference for the improvement of the supporting planting technology of flue-cured tobacco in Sichuan Province,the temporal and spatial distribution of the content of conventional chemical components of flue-cured tobacco in the last five years in Sichuan Province was analyzed.The main research results are as follows:(1)The total nicotine content,total nitrogen content,ratio of nitrogen to alkali,starch content in the middle of Sichuan high-quality flue-cured tobacco were in the optimum or more suitable range,the total sugar content,reducing sugar content,ratio of potassium to chlorine were higher than that of high-quality flue-cured tobacco,and the chlorine content and potassium content were lower than that of high-quality flue-cured tobacco.The total nicotine content,sugar alkali ratio,potassium chloride ratio,total nitrogen content,starch content and nitrogen alkali ratio of the upper leaves are in the optimum or more suitable range,the total sugar content and reducing sugar content are higher than the range of high-quality flue-cured tobacco,and the chlorine content and potassium content are lower than the range of high-quality flue-cured tobacco.Among the chemical indexes of flue-cured tobacco in Sichuan Province,the coefficient of variation of the ratio of chlorine,potassium and chlorine is large,and the two indexes are not stable.In time series,the chemical components of flue-cured tobacco in Central Sichuan can be divided into three categories.2017 and 2018 are the first category,2013 is the second category,2014 and2015 are the third category.The chemical components of upper flue-cured tobacco can be divided into three categories.2018 is the first category.2014 is the second category.2013,2015 and 2017 are the third category.(2)he total nicotine content,total nitrogen content,ratio of nitrogen to alkali,starch content in the middle of Sichuan high-quality flue-cured tobacco were in the optimum or more suitable range,the total sugar content,reducing sugar content,ratio of potassium to chlorine were higher than that of high-quality flue-cured tobacco,and the chlorine content and potassium content were lower than that of high-quality flue-cured tobacco.The total nicotine content,sugar alkali ratio,potassium chloride ratio,total nitrogen content,starch content and nitrogen alkali ratio of the upper leaves are in the optimum or more suitable range,the total sugar content and reducing sugar content are higher than the range of high-quality flue-cured tobacco,and the chlorine content and potassium content are lower than the range of high-quality flue-cured tobacco.Among the chemical indexes of flue-cured tobacco in Sichuan Province,the coefficient of variation of the ratio of chlorine,potassium and chlorine is large,and the two indexes are not stable.(3)The total nicotine content,total nitrogen content,ratio of nitrogen to alkali,starch content in the middle of Sichuan high-quality flue-cured tobacco were in the optimum or more suitable range,the total sugar content,reducing sugar content,ratio of potassium to chlorine were higher than that of high-quality flue-cured tobacco,and the chlorine content and potassium content were lower than that of high-quality flue-cured tobacco.The total nicotine content,sugar alkali ratio,potassium chloride ratio,total nitrogen content,starch content and nitrogen alkali ratio of the upper leaves are in the optimum or more suitable range,the total sugar content and reducing sugar content are higher than the range of high-quality flue-cured tobacco,and the chlorine content and potassium content are lower than the range of high-quality flue-cured tobacco.Among the chemical indexes of flue-cured tobacco in Sichuan Province,the coefficient of variation of the ratio of chlorine,potassium and chlorine is large,and the two indexes are not stable.(4)Potassium and chlorine are two key chemical indexes that restrict Sichuan flue-cured tobacco production,By using potassium chloride instead of potassium sulfate,adding boron,magnesium,iron and other microelements,transplanting tobacco seedlings with roots and six upper leaves with stems at one time,the content of potassium and chlorine can be effectively increased,and the chemical composition of flue-cured tobacco can be further coordinated.