| Based on climate datas of four indexes in nine counties in Qujing tobacco-growing areas from 1971 to 2008, and characteristics of climate were analyzed among different months, years and altitudes in Qujing tobacco-growing areas. According to geographical divisions of Qujing, Qujing tobacco-growing areas were divided into five regions and the characteristics of climate and quality of flue-cured tobacco in the five regions were also analyzed.1. Wavelet analysis and linear trend analysis were used to study the annual variation of climate factors in Qujing tobacco-growing areas, and the changes of sunshine hours of root extending stage had presented a cycle of six years in the past 38 years;the changes of sunshine hours of vigorous growing stage and field period had presented two cycles, a long cycle of six years and a short cycle of three years;the changes of sunshine hours of mature stage had presented a short cycle of three years and a long cycle of twelve years; and the changes of temperature had appeared a long cycle of six years and a short cycle of three years during the root extending stage , vigorous growing stage and field period in the 38 years, but the changes of temperature did not have obvious cycle during the mature stage; The linear trend analysis showed that rainfall presented the trend of decreasing during the whole field period except vigorous growing stage, and the trend coefficient of root extending stage, mature stage and field period were -8.0 per ten years, -6.6 per ten years and -11.4 per ten years, and the trend coefficient of vigorous growing stage was 3.3 per ten years; Relative humidity also had showed the same trend of decreasing in different growing-times for Qujing flue-cured tobacco in the 38 years, and the trend coefficient of root extending stage , vigorous growing stage, mature stage and field period were -1.73 per ten years, -0.6 per ten years, -0.6 per ten years and -0.9% per ten years ,respectively.Mutation analysis was used for the climate factors during the field period in Qujing tobacco-growing areas, the results indicated that the sunshine hours became mutated from less to more at 1984 in Qujing tobacco-growing areas, the relative humidity and the rainfall mutation became mutated from less to more at 2003 as well as at 1988 and 2003 in Qujing tobacco-growing areas, respectively, but the temperature did not happen mutation during the 38 years in Qujing tobacco-growing areas.2. Quantitative characteristics of climate factors of different months were analyzed in Qujing tobacco-growing areas, the result indicated that the sunshine hours and rainfall had obvious differences in different months, but amplitude of temperature and relative humidity were smaller in different months. There were variations of all the climate factors in different months. And according to the degree of variation, the variations of sunshine hours and rainfall were moderate, the variations of temperature and relative humidity were weak.3. The altitude of Qujing tobacco-growing areas could be divided into low altitude (≤1500m), middle altitude (1500~2000m) and high altitude (≥2000m), according to the source of climate data. Quantitative characteristics of climate factors were analyzed by difference analysis among the different altitudes, and the result showed that: the low altitude, middle altitude and high altitude had significant differences at 5% level. The sunshine hours and relative humidity had significant differences among different altitudes, middle altitude and high altitude, low altitude and high altitude all had significant differences, but differences of middle altitude and high altitude did not reach significant levels. Rainfall also had remarkable differences among different altitudes, and differences between low altitude and middle altitude, middle altitude and high altitude, low altitude and high altitude all reached 5% level.4. The distribution of climate factors was analyzed in the five flue-cured tobacco regions, and the result showed sunshine hours generally appeared the trend of northwest tobacco-growing areas> middle tobacco-growing areas > southeast tobacco-growing areas > southwest tobacco-growing areas > east tobacco-growing areas; temperature and rainfall were southeast tobacco-growing areas > southwest tobacco-growing areas > east tobacco-growing areas > middle tobacco-growing areas > southeast tobacco-growing areas; and relative humidity was southeast tobacco-growing areas > southwest tobacco-growing areas > middle tobacco-growing areas > east tobacco-growing areas > northwest tobacco-growing areas. And the differences of climate factors were obvious among the five flu-cured tobacco regions.Analysis on the climate factors for the five flue-cured tobacco-growing areas indicated that altitude(2109.5m) and sunshine hours(683.3 h) of northwest tobacco-growing areas were the highest, rainfall, temperature and relative humidity were slightly lower than other tobacco-growing areas; altitude of east tobacco-growing areas was at 1800 m to 2000 m, and the sunshine hours, temperature and relative humidity were all suitable; altitude of middle tobacco-growing areas was up to 1800 m, and rainfall was aboundance; sunshine hours of the southwest tobacco-growing areas was best, rainfall was rich, and temperature as well as relative humidity were all suitable; altitude of southeast tobacco-growing areas was the lowest, but the sunshine hours, rainfall, temperature and relative humidity were the highest.Generally speaking, the climate factors of Qujing were suitable for the growth of flue-cured tobacco.5. The characteristics of tobacco chemical components for Qujing were analyzed, which showed that the chemical components of tobacco for Qujing was preferable, the contents of total sugar and reducing sugar were slightly high; the contents of total nitrogen and nicotine were located in the proper range, 1.93% and 2.31%, respectively. Potassium was up to 1.5%, the content of petroleum ether extract at the middle level, the ratio of total nitrogen to nicotine, the ratio of total sugar to nicotine and K2O/Cl were suitable. In the five flue-cured tobacco regions, the contents of total sugar of the northwest flu-cured tobacco were the highest, and flue-cured of the east's was the lowest; the contents of reducing sugar of southeast flue-cured tobacco were largest, and the east flue-cured tobacco's was the lowest; the content of potassium of southeast flue-cured tobacco was the largest, with the average of 1.95%,the chlorine content of southwest flue-cured tobacco was the highest , and contents of petroleum ether extract did not have obvious difference, the variation of the tobacco chemical components was widely for Qujing,while intensity of the variation was middle.The sensory quality of Qujing tobacco was analyzed, which indicated that the aroma quality was middle, and the aroma quantity was sufficient, the after-taste was good with a few irritant, and the quality feature of tobacco for the Qujing was better, with the score of 74.1; the score of style feature was 9.9, and tobacco of Qujing was typical clear flavor; clustering of Qujing tobacco was moderate, sweetness was preferable, and the score of smoke feature was 10.9. In the five flu-cured tobacco regions, the score of feature quality of southeast tobacco leaves was the higest (77.0±2.2), tobacco leaves of the southwest was the lowest (71.9±3.4). The score of style feature was highest in east tobacco-growing areas, and the lowest was southeast tobacco leaves; the score of smoke feature of southeast tobacco leaves was higest(11.8±1.1), and the southeast tobacco leaves (9.9±1.4) was lowest. There were widely variation for the sensory quality of the Qujing tobacco, all the variations of feature quality were gentle, except for ash color. And all the variations of smoke feature were at the moderate level. |
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