| Qujing is the largest high-quality flue-cured tobacco producing area, Flue-cured tobacco producing in Qujing is main crude materials of several key cigarette brands. Soil and ecological conditions vary widely in Qujing tobacco-planting area, resulting in differences in quality characteristics of tobacco leaf of different regions. We studied the quality characteristics of flue-cured tobacco by methods of geo-statistics in Qujing tobacco-planting area, based on tobacco-soil positioning trial, unified culture method, and two-factor randomized trials, effect of climatic factors, soil factors on the flue-cured tobacco quality were studied, and further compare the effect size of climate and soil on the quality of flue-cured tobacco. The main results are as follows:1. Comprehensive assessment of flue-cured tobacco quality and its regional characteristics of flue-cured tobacco in QujingQujing flue-cured tobacco's appearance quality, physical indicators, chemical composition and sensory quality indicators and the evaluation results have shown significant regional differences, complex spatial distribution, but spatial trend effect is not obvious. Mean score of appearance quality of flue-cured tobacco was 89.02, most of the regional tobacco appearance quality score was well; Mean score of the physical quality of flue-cured was 77.65, most of the regional tobacco physical quality score was good and general; Mean score of tobacco chemical quality was 79.92, most of the of the regional tobacco chemical quality score was well and general; Mean score of tobacco sensory quality was 74.28, most of the regional tobacco sensory quality score was general; Mean score of Qujing Tobacco was 80.82, most of the regional tobacco Quality Score was good and general.2. The relationship between flue-cured tobacco quality and main climatic factorsEffect of temperature on the chemical composition of flue-cured tobacco is embodied in every tobacco growing periods. There were parabola (opening down) relationships or linear relationships between average temperature and chemical composition. Tobacco sensory quality indices were positively significant correlated with average temperature in different stages.Effect of rainfall on the chemical composition of flue-cured tobacco is embodied in root extending stage, vigorous growth stage and maturing stage. There were linear relationship between tobacco chemical composition and rainfall during the three stages. Tobacco sensory quality indices were positively significant correlated with rainfall in different stages.Effect of sunshine hours on the chemical composition of flue-cured tobacco is embodied in maturing and field period.There were linear relationships (positive effect) between chemical composition and two periods. Tobacco sensory quality indices positively significant correlated with sunshine hours in two periods.3. Soil types, the main nutrients and their influence on Tobacco QualityQujing tobacco soil types are red soil, yellow soil, purple soil, new alluvial soils, paddy soil and lime soil; There were significant differences in Main chemical components and sensory indices of flue-cured tobacco between soil types. CHS and SQS of tobacco on yellow soil were the highest.Soil pH and soil water-soluble chloride is of suitable level, soil organic matter, total nitrogen, available potassium, available Mo, available Ca, available Mg, available Cu, available Zn, available Fe, available S and available Mn are very rich, soil total P and available P are of medium level, soil total K, available B and available Mo is low; Spatial distribution map of soil nutrients showed that, there is a big area' soil is luck of total K available B and available Mo in Qujing tobacco-planting area.There were parabolas or linear relationships between chemical components and Soil pH, organic matter and macronutrients. Tobacco ensory quality indices show different correlation with soil pH, organic matter and macronutrients.Tobacco sensory quality indices, chemical components showed different correlation with 4 secondary and micronutrients nutrients in soil.4. Effect of climate and soil and their interaction on the quality of flue-cured tobaccoThe greatest influence on the chemical composition of flue-cured tobacco is the climate, followed by the soil, the smallest is the interaction of climate and soil, climate, soil and their interactions on chemical composition of flue-cured tobacco's contribution to the total variance are 43.36%,32.02%and 24.63%, respectively.The greatest influence on sensory quality is the climate, followed by the soil, the smallest is the interaction of climate and soil, climate, and contribution of soil and their interactions on sensory quality of flue-cured of total variance were 50.77%, 41.19%and 8.05%, respectively. |
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