The Distribution Of Organic Potassium Index And The Relationship Between Organic Potassium Index And Quality Of Flue-Cured Tobacco In Qujing

Located in the northeast of Yunnan Province,Qujing is one of the largest tobacco-growing areas with its vast territory and diverse ecological types.This research is based on Qujing tobacco-growing areas and 2539 tobacco samples of the 9 counties.The article analyzed the quantitative characteristics and the distribution characteristics of the organic potassium index,the relations between the organic potassium index and the inherent quality,the physical characteristics,the appearance quality and the sensory quality.In addition,the article discussed the effective technological measures of improving the organic potassium index through the experiment of the interactions between irrigation times in fast growing stage and sulphur levels.Main results were as follows:1.The basic features of the content of potassium,chlorine,sulfur and the organic potassium index were analyzed.Results showed that:(1)The average content of potassium was 1.67%,the coefficient of variation was 24.10%.The potassium content of Luoping county and Fuyuan county were significantly higher than other 7 counties.The potassium content of Luoping county was the highest.The average content of chlorine was 0.31%,the coefficient of variation was 48.10%.The chlorine content of Huize county was significantly lower than other 8 counties.The average content of sulphur was 0.28%,the coefficient of variation was 44.35%.The sulphur content of Shizong county was significantly lower than other 8 counties,while Qilin county was significantly higher than other 8 counties.(2)The organic potassium index ranged from-0.37 to 3.73,the coefficient of variation was 38.34%.The organic potassium index of Luoping county was the highest,Fuyuan county came second.The organic potassium index of Luoping county and Fuyuan county were significantly higher than other 7 counties,while Qilin county and Zhanyi county were significantly lower than others.The organic potassium index was different with the changes of varieties.The organic potassium index of NC297 was the highest,K326 came second,YUN85 came the last.The organic potassium index of NC297,K326,Hong Da and Zhongyan 100 were significantly higher than others.2.The relationship between the organic potassium index and intrinsic qualities were analyzed.Results showed that: The content of total sugar,reducing sugar,phosphorus,copper,boron and molybdenum were relatively high,while TN,nicotine,calcium,magnesium,iron and zinc were moderate.The content of starch was relatively low.The organic potassium index was highly significantly positively correlated with the content of total sugar and reducing sugar.There was a linear regression relationship between the organic potassium index and the content of total sugar.The relationship between the organic potassium index and the content of reducing sugar was quadratic.The organic potassium index was highly significantly cubic negatively correlated with the content of TN,nicotine and starch.As to the medium trace element,the organic potassium index was highly significantly positively correlated with the content of manganese,while significantly negatively correlated with the content of iron and molybdenum.The organic potassium index was highly significantly positively correlated with the content of scopoletin,while significantly positively correlated with the content of rutin.There was no significant relationship between the organic potassium index and chlorogenic acid.3.The relationship between the organic potassium index and physical characteristics were analyzed.Results showed that: The filling value and the moisture content were suitable.The stem ratio was slightly higher and the leaf density was slightly lower.The organic potassium index was highly significantly positively correlated with the filling value,while highly significantly negatively correlated with the single leaf weight,leaf density and equilibrium moisture content.The relationship between the organic potassium index and the stem ratio was significantly negatively.The relationships between the organic potassium index and the single leaf weight,leaf density,filling value and equilibrium moisture content were cubic,while stem ratio was quadratic.4.The relationship between the organic potassium index and appearance qualities were analyzed.Results showed that: The organic potassium index was highly significantly cubic positively correlated with the tobacco maturity,identity and structure.Although there were certain negative correlations between the organic potassium index and the leaf color,oil and chroma,the relationships were not significant.As the organic potassium increased,the leaf maturity becames better,and the leaf identity tended to moderate.But the excessive organic potassium index had some negative impacts on the appearance qualities of tobacco,especially for the leaf identity.5.The relationship between the organic potassium index and sensory qualities were analyzed.Results showed that: The organic potassium index was highly significantly positively correlated with the smoking aroma quality,aroma quantity,irritation,aftertaste,combustibility,gray,total quality characteristics and sweetness,while significantly positively correlated with the mixed gas and concentration.There were no significant relations with the other indexes.There was a linear regression relationship between the organic potassium index and the sweetness.The relationships between the organic potassium index and the aroma quality,mixed gas,gray and concentration were cubic.And the organic potassium index was power relations with the other indexes.The equations of combustibility and total quality characteristics were better.The data of concentration,sweetness and other indacators was more dispersed.The trend was not that obvious,and the equation was less aligned.6.Effects of interactions between irrigation times in fast growing stage and sulphur levels on tobacco quality,especially the organic potassium index were studied.Results showed that: The intrinsic quality of T5(2 irrigation times in fast growing stage and 2.0g sulphur supply per plant)was the best treatment.Because of the less irrigation and the sulphur deficiency,the organic potassium index of T7 was the best.The organic potassium index of T7 and T5 were significantly higher than other treatments,while T3 significantly lower than others.It was probably because sulphur surplus and irrigation deficiency.Comprehensive analysis indicated that: Appropriate sulphur supply coordinated with reasonable irrigation times could significantly increased the organic potassium index and the overall quality of tabacco leaves.