Effects Of Ecological Factors On Maturity Of Flue-cured Tobacco And The Relationship Between Maturity And Quality Of Flue-cured Tobacco In Qujing Tobacco-growing Area

On the basis of2541tobacco samples (grade C3F) of2008-2009which were distributed in9tobacco-growing cities (county)89villages and towns Qujing tobacco-growing area. Generaldistribution of appearance maturity of flue-cured tobacco was analyzed, and differences offlue-cured tobacco maturity in8varieties (K326, NC102, NC297, Honghuadajinyuan, Yunyan85,Yunyan87, Yunyan97, Zhongyan100), and in9tobacco-growing cities（Qilin, Fuyuan, Huize,Luliang, Luoping, Malong, Shizong, Xuanwei, Zhanyi）, and in different villages and towns wereevaluated as well. Effects of climatic factors(sunshine duration, temperature, rainfall), edaphicfactors(organic matter, total nitrogen, available nitrogen) on flue-cured tobacco maturity werestudied. The relationship between flue-cured tobacco maturity and the rest quality indexes(appearance quality, physical properties, chemical components, sensory quality) was also studied.Main results were concluded as follows.1. Appearance maturity of Flue-cured tobacco in Qujing province comprised five gradesincluding ripe, ripe-, ripe+, premature and mature, and there was large difference among thefrequency of different maturity grades. The proportion of leaf maturity showed ripe(82.02%)>ripe-(9.96%)>ripe+(7.04%)>mature(0.59%)>premature(0.39%).2. Characteristics of variation of tobacco maturity from2008to2009in Qujing tobaccogrowing areas were analyzed. the results were indicated as follows.(1) Eight tobacco varieties hadlarge differences of the proportion of ripe grade sample for the total samples of each species, theproportion of ripe grade sample of six varieties(K326, NC102, NC297, Yunyan85, Yunyan87,Yunyan97) was much more than80%generally.(2) Nine tobacco-growing cities had significantdifferences of the proportion of each maturity grade, the proportion of ripe grade samples of fourcities(Fuyuan, Luliang, Malong, Qilin) was more than90%, the proportion of Zhanyi was82%, and which of the rest four cities were within70%-80%. Three cities (Huize, Luoping, Xuanwei)had a different proportion of ripe+leaves. For ripe-grade leaves, the proportion of Huizetobacco-growing area was21.55%, the proportion of Zhanyi was13.94%, and the rest seven citieswere less than10%. The proportions of premature and mature grade leaves were small, being inthe5%and even below1%.(3) Meanwhile the variability of the proportion of each appearancematurity grade leaves of every village (town) in each tobacco-growing city was analyzed, theoverall performance was the proportion of ripe leaves being much larger, the proportion ofpremature and mature leaves being smaller.3. The effects of climatic factors (light, temperature, water) on flue-cured tobacco appearancematurity were studied. The results were indicated as follows.(1) The maturity grade of flue-cured tobacco increased as sunshine hours increased.Sunshine condition in the range of660-680h was favorable for the growth of tobacco in Qujingarea.(2) When average temperature was within17℃-18℃at transplant time, higher than19℃onfield late period, the leaves mainly tended to be ripe. If the average temperature at the two periodswas too low, the fresh tobacco growth was not complete, and the cured leaves tended to be mature.If the average temperature at the two periods was too high, the phenomenon would appeared that“high temperature forced leaves to appear ripe”, and the cured leaves tended to be premature.(3)Tobacco seeding roots would grow well when rainfall ranged from130mm to135mm from lateApril to early June. If rainfall ranged580mm to620mm from early June to late August, it wouldbe beneficial to synthesizing and transform and accumulating of potassium content of tobaccoleaves, and promote tobacco leaves to be ripe.4. The effects of edaphic factors(organic matter, total nitrogen, available nitrogen) onflue-cured tobacco appearance maturity were studied. The results were indicated as follows.(1) Most soil was rich in organic matter in Qujing tobacco-growing area, and the averagecontent ranged from32.17g/kg to39.40g/kg. Among the range, tobacco leaf maturity tended tobe ripe with the increasing of OM content.(2) For Qujing area, if total nitrogen content ranged from1.8g/kg to1.9g/kg, tobacco wouldgrow well, and the appearance maturity of cured leaf tended to be ripe.(3) With the maturity grade tended to be “ripe”, the content of available nitrogen in soil in Qujing area showed a gradient decreasing.5. Through multiple comparison, appearance quality, physical properties, chemicalcomponents and sensory quality of tobacco leaves of different levels maturity in Qujingtobacco-growing area were analyzed, the results were indicated as follows.For six physical indexes of cured tobacco, escape equilibrium moisture ratio, the rest fiveindexes(single leaf weight, the length and broad, the rate of leaf stalk, leaf density and the fillingvalue) of different maturity level leaves had significant difference, and the differences of physicalindexes showed ripe>ripe+>ripe->mature>premature.(2) For chemical composition of curedtobacco, six indexes (total sugar, reducing sugar, potassium, water-soluble chlorine, starch,volatile acid and petroleum ether extracts) of different maturity level leaves had significantdifference. And five mineral element indexes (available calcium, available zinc, available ferrum,available manganese, available boron) of different maturity level leaves had significant difference.It indicated to compare different maturity levels from the point of the chemical composition ofcoordination, the chemical components for cured leaf of ripe level were well coordinated with asuitable content of nicotine and potassium and starch, lower content of chlorine, and highercontent of the total and reducing sugar and volatile acid and petroleum ether extracts, but thepremature leaf were bad.(3) For appearance quality of cured tobacco, the color,body, oil, colorintensity and leaf structure of flue-cured tobacco had significant difference among five ripe groups.(4) Grey relational analysis between maturity score of flue-cured tobacco and sensory qualityindexes score and the results of multiple comparison among different maturity leaves’ sensoryquality indicated that: For quality feature of cured tobacco, effect sizes of appearance maturity ondifferent quality featu re indexes had significant difference, which showed biting taste> quality ofaroma> volume of aroma> biting taste> after tests> offensive odor> ash. For style feature of curedtobacco, effect sizes of appearance maturity on different quality feature indexes had significantdifference, which showed aroma type> consistency>strength. For smoke feature of cured tobacco,effect sizes of appearance maturity on different quality feature indexes had significant difference,which showed sweetness> dry sense> downy> conglobation.