Study On Harvesting And Curingtechniques Of The Upper Flue-Cured Tobacco Leaf In Mountain Area Of Northwest Of Hunan

For improving the availability of tobacco upper leaves in the mountain area of northwest of Hunan, the experiments of study on the comprehensive effect of harvesting methods of upper leaves, study on the suitable field-maturity of upper leaves focus harvested, study on the effect of different time of change yellow period to the tobacco upper leaves, study on the effect of differ temperature and humidity to the tobacco upper leaves were carried in SangZhi county,ZhangJiajie city in the years of2010,purpose to explore a suitable technology of main varieties of flue-cured tobacco upper leaves in northwest of Hunan,the main conclusions are as follows:1. Comprehensive analysis and evaluation of appearance quality, physical properties, chemical composition through the different harvest maturity of one-time harvest of flue-cured tobacco upper leaves, the result show that; harvest maturity of upper leaves have an important effect on the quality of flue-cured tobacco. Appearance quality and coordination of the chemical composition of the tobacco samples M3(after transplanting about123days, leaves with more yellow, yellow is more and green is less, the main vein change white more than2/3and the sub-vein change white more than1/2, stem and leaf angle close to right angle, the leaves is bending liked a arch, the surface of the leaves changed shrinkage, with a lot of yellow mature spots.) is better than other three mature tobacco samples, the content of total sugar and reducing sugar is highest, the ratio of the two sugar,the ratio of reducing sugar and nicotine is closest to the ideal value, the content of nicotine is showed a slight increase in law when the harvest time is extended.2. The appearance quality, physical quality and the coordination of chemical composition of flue-cure tobacco leaves of traditional separate harvest is poor than one-time no connected to stem harvest and one-time connected to stem. physical quality and the coordination of chemical composition of flue-cure tobacco leaves of one-time no connected to stem is better than one-time connected to stem, it shown in the following aspects:the appearance quality of one-time no connected to stem of score is higher than the other two treatment; the physical quality of traditional separate harvest is poor because of the weight of a leaf and the rate of content stem is higher, more, the balance of content water of one-time no connected to stem is higher than one-time connected to stem and the other index are little difference; the content of total, reducing sugar and nicotine of tobacco is increased and the starch is decreased thanks to extending the harvest time, one the whole, the one-time no connected to stem harvest is best.3, when the difference of temperature and humidity is2.0centigrade, the oil, tinges, color uniformity and thickness of the tobacco sample is better than2.5centigrade and3.0. and the maturity, leaf development condition and smooth or slightly green aspect are little difference. The single leaf weight, leaf density and leaf area quality is increased when the difference of temperature and humidity is become increased, but the total and the reducing sugar is decreased, it is not conductive to the resolve of the starch, it is little affect to the content of nicotine. On the whole, the treatment of difference of temperature and humidity of2.0centigrade is best.4, when the time of period of yellowing is54hour, the appearance quality, physical quality and the coordination of chemical composition of flue-cure tobacco leaves is better than the treatment of48hour and60hour, it shown in the following aspects:the color uniformity, content of sugar and oil of the tobacco is increased, the starch is decreased, the question such as compact and rigid identity is improved.