Effects Of Harvest Maturity On The Quality Of Flue-cured Tobacco Leaves Of Yunyan 87

In order to find the most suitable harvest maturity of each part tobacco leaves, provide the technical information for specialized harvest and the scientific basic for specialization curing organization, the variety regulation of roasted tobacco leaves quality by different harvest maturity of Yunyan 87 in Yongzhou tobacco area had been studied in this paper. The results indicated that:1. Appearance Quality:In terms of unripe tobacco leaves, the appearance quality was the worst, the proportion of greenish and variegated tobacco was the highest than the others, the highest reached 91.4%, and the color was dim, the leaf structure was tight. Along with the extension maturity, the greenish tobacco was tended to decrease, the color was tended to orange, the color intensity was tended to deep, the leaf structure was tended to loose, the oil was tended to rich. But in terms of overripe tobacco leaves, the color intensity was tended to pale, the oil was tended to lean, along with the extension maturity, the body was tended to thin gradually.2. Economic Character:Along with the extension maturity, the ratio of fresh quality leaves and dry leaves was tended to decline, but the overripe tobacco tended to rise gradually. The tobacco leaves yield presented low-high-high-low variety trend with the extension of maturity, the yield of ripe lugs was the highest, meanwhile, the yield of mature cutters and leaf was the highest. The average price of unripe tobacco was the lowest, the most average price disparities with ripe tobacco reached to 7.79 yuan per kilogram. The average price of lugs and cutters was added following the extension maturity while declined with overripe, the average price of leaf was added following the extension maturity. The output value was rise along with the extension maturity, but the overripe tobacco was tended to decline, the unripe tobacco was the lowest, the disparity with ripe tobacco was reached to 64.6 percent. The output value of mature cutters was not remarkable difference with ripe cutters due to yield increase. Top and medium grade tobacco proportion was improved with the extension of maturity, it was highest when leaves was mature, while decreased when overripe. 3. Chemical Components:The sugar content of cutters and leaf was in a suitable range, but the ripe tobacco in the second kang, the unripe and mature tobacco in the third and sixth kang, the unripe tobacco in the forth and fifth kang can't reach to the lowest standard of high-quality tobacco leaves, the ratio of carbohydrates with reducing sugars was too low. The leaves of medium and lower part tobacco presented high-low-high-low variety trend in the nicotine content. The upper part leaves presented high-high-low-high variety trend in the nicotine content. Nitrogen content presented to decline trend with the extension of maturity. The main chemistry composition harmony presented mature-overripe-mature-unripe sequence decline variety trend.4. Smoking Quality:Along with the extension of maturity, smoking quality of tobacco presented up-trend and declined slightly when overripe. Smoking quality of medium and lower part, the mature tobacco leaves was best, declined slightly when overripe. Smoking quality of upper par, the overripe leaves were better than mature leaves, the mature was middle, but the unripe tobacco leaves was the worst.