为寻求最佳烤烟留叶方式,田间设计4种不同的打顶留叶方式进行小区试验,并测定农艺性状、产量和产值.结果 表明:采取“去下留上”方式,即去掉下桔一及上桔二以下烟叶、留叶数14片的处理表现最优,产量达150.04公斤/亩,产值4 232.628元/酉.

The effects of full biodegradable mulching film on degradation,tobacco yield and tobacco quality were studied by a field test to provide a reference for popularization and application of full biodegradable mulching film in flue-cured tobacco production.Results:The yield and output value of Yunyan 87 under the cultivation pattern of white full biodegradable mulching film with 1 m× 0.010 mm can reach 2 162.7 kg/hm2 and 5 0426.70 Yuan/hm2.The yield,output value and first and medium-class tobacco rate of Yunyan 87 under the cultivation pattern of white full biodegradable mulching film are 64.50 kg/hm2(3.07％),1 774.80 Yuan/hm2 (3.65％) and 3.58％ higher than under the cultivation pattern of PE film respectively.The cost of full biodegradable mulching film is 199.20 Yuan/hm2 lower than PE film.The tobacco leaves of Yunyan 87 under the cultivation pattern of white full biodegradable mulching film have the moderate physical structure and harmony chemical components.The degradation rate of full biodegradable mulching film 135 d after mulching is up to 63％,59.5％ higher than PE film(3.5％).Application of full biodegradable mulching film can solve the environmental white pollution effectively.

[Objective]This study compared the effects of decapitation and bagging on maturity process and smoking quality of tobacco upper leaf,and discussed the feasibility of replacing traditional decapitation with bagging,in order to provide theoretical and practical basis for developing a topping-inhibiting measure.[Method]The experiment was con-ducted in field. Tobacco plants were decapitated or wrapped by plastic bag at initial flowering stage,the changes of axil-lary bud occurrence,angle of stem to upper leaf,and contents of auxin(IAA),abscisic acid(ABA),starch and soluble sugar in upper leaf under different treatments were analyzed. The chemical constituents and smoking quality of flue-cured tobacco upper leaves were evaluated.[Result]Compared to those under decapitation treatment,the tobaccos under bag-ging treatment presented weaker axillary bud growth vigor,larger angle of stem to upper leaf. In the leaves,soluble sugar content increased,starch content decreased,IAA and ABA contents increased,and maturity process of upper leaf accelera-ted. In addition,the contents of nicotine and chlorine decreased significantly(P<0.05,the same below)while the content of total sugar,reducing sugar,total nitrogen and potassium increased in upper leaf under bagging treatment. Its aroma fla-vor and taste greatly improved. The total score of sensory evaluation(39.8)was significantly higher than that of decapita-tion group(36.5).[Conclusion]Based on comprehensive consideration of the usability and quality of tobacco upper leaf, bagging is better than decapitation. It is feasible to replace decapitation with bagging in tobacco planting.

The effect of nitrogen rates and the number of leaves remained on carbon metabolism ,yield and quality of flue‐Cured tobacco K326 were studied by field experiments .There are three levels of nitrogen fertilizer (4 kg/667 m2 ,8 kg/667 m2 and 12 kg/667 m2 ) and three levels leaf population (14 ,18 ,22) , two factors using the split‐plot design and a total of nine treats .The results showed that the effect of nitro‐gen fertilizer on carbon metabolism amylase and sucrose phosphate synthase activity were significant .The effect of leaf population on sucrose phosphate synthase activity was extremely significant .The interactions between of nitrogen fertilizer and leaf population reached an extremely significant level on sucrose phos‐phate synthase activity .On the aspect of chemical composition ,there was a significant level in nitrogen fertilizer 4 kg/667 m2 -8 kg/667 m2 and leaves remained 14-18 pieces per plant ,however ,when high ni‐trogen levels and high leaf population did not change significantly .On the whole ,the treat of nitrogen fer‐tilizer 8 kg/667 m2 and leaf population 18 -22 pieces is the best on growing field ,economy benefits and rate of first class tobacco .

以K326为材料,设置了2种施氮量和3种留叶数,研究了施氮量和留叶数对K326株型、光舍及产质量的影响.结果表明:在同一施氮量下,留叶15片为低台到高台,留叶19和23片为低台到长筒.留叶19和23片的烟株在生物学性状、光合指标上综合比较优于15片留叶烟株,烤后烟叶总氮、烟碱、钾质量分数随留叶数的增加而递减,而随总糖质量分数和产值量的增加,则先增后降;在同一留叶数下,烟株生物学性状和光合指标以及钾、氯、总氮、烟碱质量分数、产值量都随着施氮量的增加而升高,而总糖质量分数随之下降.综合分析认为,19片留叶和120 kg/hm2施氮处理在农艺性状、光合特性以及产质量上表现最好.

[Objective]To compare differences of tobacco oil distinctive chemical substances and routine chemical components of different genotype flue-cured tobacco variety. [Method]With Bina No. 1,Yunyan 87,K326 and Nanjiang No. 3 as study object,the differences of different genotype tobacco distinctive substances and routine chemical components were analyzed. [Result]The results showed that,Yunyan 87 and Nanjiang No. 3 tobacco oil distinctive substances are higher than that of K326 and Bina No. 1 in general,potassium content in Yunyan 87,Bina No. 1,K326 and Nanjiang No. 3 are lower,nicotine content in upper leaf of Yunyan 87,Binan No. 1 and K326 is higher,reducing sugar and total sugar content in middle and upper leaf of Nanjiang No. 3 and Yunyan 87 are higher. [Conclusion]The study can provide technique support for breeding and extension of superior flue-cured tobacco in low quality and poor oil tobacco area.

A field experiment was conducted using two-factor randomized complete block design to investigate the effects of density (D), number of leaves remained (L) and their interaction on photosynthetic characters and economic traits of flue-cured tobacco (cv Yunyan 97). The results showed that D, L and their interaction had significant effects on photosynthetic characters and economic traits of flue-cured tobacco, and the responses from the D were greater than those from L and their interaction. Under same L condition, Pn, Gs, Ci, Tr and chlorophyll content increased first and then declined as D increased. As for the low and medium D conditions, with L increasing, Pn, Gs, Ci, Tr and chlorophyll content increased gradually, but they increased first, and decreased later under high D conditions. In addition, light and CO2 response curve type from all treatments were the same, but response curve parameters were different. With L increasing, maximum Pn rised gradually under low and medium D conditions, while increased first, and decreased later under high conditions. With L increasing, both yield and output value increased significantly under seam D conditions;under seam L conditions, yield rised gradually, but output value increased firstly and then declined, when D increased. On the consideration of comprehensive analysis, effect of 16500/23 treatment was best; and theoretically the appropriate D and L for Yunyan 97 were 17093-17665 plant/ha and 21.3-23.1 leaves/plant respectively.

Pot experiments have been carried out to study the effect of external straw application on soil enzyme activities and the nitrogen and potassium contents in tobacco leaves and roots for tobacco variety Qinyan 96. The purpose of this study was to efficiently take advantage of crop waste in order to establish a reasonable resource recycling system and improve the soil environment of tobacco growth. The result shows that external straw addition significantly increased the soil enzyme activity and the nitrogen and potassium contents in tobacco leaves and roots. In a certain range, as the straw usage increased, the soil enzyme activity and the nitrogen and potassium contents in tobacco roots also increased.

In order to elucidate the nutrition foundation in plant growth and development and physiological mechanism of leaf color formation by P fertilizer application,and further provide theoretical and practical basis for rational P fertilization in high quality flue-cured tobacco production,pot experiments were carried out to study the effects of different rates of phosphorus fertilizer on leaf nutrition( N,P,K) and polyphenols content as well as their relative enzymes activities of acid phosphates and polyphenol oxidase in flue-cured tobacco leaves using Qinyan 96. The results showed that,in rational range of P application rates from P2O50 to 5. 84 g / pot,N,P,K and polyphenol contents in tobacco leaves were all increased with increasing P rate resulting in significant positive correlations,but the negative effects were obtained due to excessive P rate. Acid phosphatase activity in tobacco leaves was continuously decreased with increasing P rate resulting in significant negative correlations. These results suggested that optimal P application rate could improve leaf nutrition,and increase polyphenols content and its oxidation level to be beneficial for leaf color formation of flue-cured tobacco leaves. Acid phosphates activity can be served as an efficient physiological indictor for evaluation of supply level of soil P.

烤烟土部烟叶是卷烟重要组成成分之一,然而,我国烤烟普遍存在内部化学成分不协调、工业可用性偏低等问题,严重影响上部烟叶的使用率和烟农的利益,进一步开发提高上部烟叶可用性的相关技术迫在眉睫.综述了近年来在栽培、烘烤调制以及大田生长阶段添加外源物质等方面提升上部烟叶质量的相关技术,并进行了展望.

A field plot experiment with the soils from Weining,Kaiyang and Tianzhu in Guizhou,where are strikingly different ecological regions.The effects of soil and climate on the carotenoid and cuticular extract content of cured tobacco leaves were studied by using flue-cured variety of Yunyan 85 as the test material.Results showed ecological conditions had notable effects on the carotenoid and cuticular extract content of cured tobacco leaves.The geographic difference of the carotenoid and cuticular extract content was significant,but the tillage method of breaking down plowpan had no obvious effect.The carotenoid content showed the tendency of increase with the elevation increasing,besides,the altitude′s threshold effect existed.The cuticular extract content of the clear flavour tobacco was higher than that of the moderate aroma tobacco.The influence degree of different ecological factors on the carotenoid and cuticular extract content of cured tobacco leaves was distinctly different.Climate was the key ecological element which affecting the carotenoid and cuticular extract content.The variability of carotenoid content among climate factors was 2—3 times higher than the variability among soil factors.The contributing rate of climate to the variation of β-carotene and lutein content was 74% and 64% respectively.The contributing rate of soil to the variation of β-carotene and lutein content was respectively 9% and 12%.The amount of sunshine hours and cumulative rainfall at the earlier growing stage in field,and the daily mean relative humidity at maturing stage were the top three climate factors affecting the carotenoid content of cured tobacco leaves.The available potassium,pH and available phosphorus were the top three soil factors affecting the carotenoid content.The variability of the cuticular extract content among climate factors was 3—4 times higher than the variability among soil factors.The contributing rate of climate to the variation of trichome secretion and alkane waxiness content was 61% and 63% respectively.The contributing rate of soil to the variation of trichome secretion and alkane waxiness content was respectively 13% and 7%.The average temperature at the earlier growing stage in field,the relative humidity and≥10℃ accumulated temperature at maturing stage were the top three climate factors affecting the trichome secretion content of cured tobacco leaves.The available potassium,available cuprum and pH were the top three soil factors affecting the trichome secretion content.The cumulative rainfall and average temperature at the earlier growing stage in field,the average temperature at maturing stage were the top three climate factors affecting the alkane waxiness content of cured tobacco leaves.The available manganese,available phosphorus and cation exchange capacity were the top three soil factors affecting the alkane waxiness content.The effect of soil factors on the stalk position character of the carotenoid content was more remakable than the effect of climate factors.However,the effect of climate factors on the stalk position character of the alkane waxiness content was more obviously than the effect of soil factors.

Genetic factors,cultivation measures and ecological environment are internal factors and external conditions that affect fast growth of tobacco at early stage in field.The advances in the three influencing factors for tobacco growth at early stage in field were summarized.Moreover,the well-cellar style transplanting techniques for tobacco in Guizhou province were introduced.

The relationships between nicotine content and the contents of medium and trace elements in flue-cured tobacco leaves from different stalk positions were analyzed with descriptive statistics analysis,stepwise regression analysis and path analysis.The tobacco was cultivated with the same cultural practices at twelve counties in seven main tobacco-growing provinces.The results indicated that the contents of medium and trace element and nicotine content in flue-cured tobacco leaves from different stalk positions were of medium degree of variation.The variation of Mn content among different areas was the largest in all the tested medium and trace elements,while that of P content was the smallest.Among leaves from different stalk positions,the variation of nicotine content in lower leaves was relatively larger.The elements in the order of direct effect influencing nicotine content in lower leaves were SiCuCaZnB,in middle and upper leaves were PFeCuMoB and SiFeCaCuB,respectively.Because of the interactions among medium and trace elements,their combined influences on nicotine content in leaves from different positions presented many variations.To reduce nicotine content in tobacco leaves by regulating the contents of medium and trace element,proper measures should be taken to leaves from each position: focusing on increasing the contents of Si,Ca and Cu for upper leaves;decreasing B and Fe contents and raising Mo content for middle leaves;reducing B content and increasing Zn and Cu contents for lower leaves.

In order to find out the effects of climatic factors on leaf trichome exudates,a field experiment on flue-cured tobacco cv.Yun 85 was conducted at Longgang of Kaiyang County,Weining County and Tianzhu County in Guizhou Province.Ripe leaves harvested from lower,middle and upper stalk positions were fluecured,and the major surface substances were extracted with methylene chloride and analyzed.The results showed that the contents of major components in trichome exudate differed significantly between leaves grown under different climatic conditions.The contents of major trichome exudate in leaves from Tianzhu were considerably higher than those from Weining and Longgang;and the difference between Tianzhu and Longgang leaves reached an extremely significantly.The contents of different trichome exudates varied greatly among leaves grown under different climatic conditions,β-cembratriene-diol had the biggest variation,its average variation coefficient reached 114.28%;while retinol had the least average variation coefficient of 40.66%.For different soils,the climate affected the contents of trichome exudates in different ways,it indicated that there existed certain interactions between factors of climate and soil.

The trichome secretion,catabolite of trichome secretion and hydrocarbon waxiness content of leaf surface of cured organic flue-cured tobacco leaves from Guiding,Daozhen,Xingyi,Weining and Tianzhu counties in Guizhou province were measured and analyzed using hierarchical clustering method to find out the quality of cured flue-cured tobacco of different ecological producing areas.The results showed that there was obvious difference in trichome secretion,catabolite of trichome secretion and hydrocarbon waxiness content of leaf surface of cured organic flue-cured tobacco leaves among 5 different ecological producing areas,the total trichome secretion and catabolite content of cured organic flue-cured tobacco leaves from Daozhen and Guiding counties was significantly higher than those from Tianzhu,Xingyi and Weining counties,and total hydrocarbon waxiness content of leaf surface of cured organic flue-cured tobacco leaves from Daozhen,Xingyi and Weining counties was significantly higher than that from Tianzhu and Guiding counties.

[Objective]The present study was carried out to elucidate the relationship of physical properties of flue-cured tobacco leaves with its nicotine content.[Method]The methods of stepwise multiple regression,path analysis and grey relation analysis were used to analyze the correlation between physical properties and nicotine content of flue-cured tobacco leaves.The experimental data included average nicotine content and physical properties of flue-cured tobacco leaves(C3F and C3L) which were planted in 12 counties of 7 major flue-cured tobacco planting provinces in China.The varieties of flue-cured tobacco and cultivation practices were the same at all locations.[Result]The most important physical property of flue-cured tobacco leaves which affected the nicotine content was the single leaf weight,followed by single leaf area and foliar density.The stem percentage and length-width ratio were found slightly correlated to nicotine content.Further,the single leaf weight and foliar density showed significantly positive effect on nicotine content,but the single leaf area was found to negatively affect the nicotine content.[Conclusion]In practice,the nicotine content of flue-cured tobacco leaves can be controlled by regulating its single leaf weight and single leaf area.Further,by controlling the development of various physical properties,quality flue-cured tobacco leaves may be obtained.

In three tobacco planting areas of Guizhou,by use of soil exchange with plough layer breaking,the effects of climatic and soil factors on characteristic materials in tobacco leaves were studied by means of two factors variance analysis and multiple linear regression analysis(stepwise method).The results showed that climatic factors had higher contribution rate to contents of secretion of glandular hairs,nicotine,total nitrogen,reducing sugar and total sugar in tobacco leaves compared with soil factors.However,the main factors affecting potassium contents in tobacco leaves were soil factors.In a certain range,rainfall was favorable to the formation of secretion of glandular hairs,the increase of average temperature was favorable to control of nicotine,rainfall was favorable to the increase of total sugar in vigorous growth stages,the increase of sunshine hours was favorable to the increase of reducing sugar in vigorous growth stages,and the increase of sunshine hours was favorable to control of total nitrogen in mature stages.When mineral composition and active potassium contents in soils were similar,there was mutual inhibition competition between total nitrogen contents in soils and potassium contents in tobacco leaves.

The relational analysis on nicotine content and smoking quality of flue-cured tobacco under the same cultivation conditions by large-scale field tests were conducted in 11 counties in 7 provinces of China main tobacco-growing areas.The results indicated that aroma quantity and irritation had the closest relation to nicotine content,followed by aroma quality,and the former was significantly positive correlation,while the latter was negative.However,there was less correlation between flavor,miscellaneous volatiles and nicotine content.The affect of nicotine on smoking quality should be comprehensively considered when the nicotine content was regulated by agronomic measures.And the scale of agricultural regulation should be grasped in order to achieve overall improvement in internal quality of tobacco leaves.

The plot experiment was conducted to study the effect of green manure dressing on physiological characteristics of flue-cured tobacco leaves.The results showed that the green manure that was applied before tobacco seedling transplanting could increase the chlorophyll content,stomatal conductance,transpiration rate and net photosynthetic rate and could different degree improve the water use efficiency and stomatal limitation in different periods after transplanting tobacco seedlings.

Flue-cured tobacco was planted in silty loam collected from Weining and loam clay collected from Kaiyang under the same cultivated pattern in Kaiyang county to study the effect of dynamic changes of main nutrients in different texture yellow soils from Guizhou on the yield and qualities of tobacco leaves in the growth and development cycle.The results showed that silty loam in the middle fertility level mineralized more,as the contents of inorganic nitrogen and available phosphorus were higher,which was beneficial to the storage of applied ammonia nitrogen;the density of nitrogen and potassium,potassium-chlorine ratio and the yield of tobacco leaves were higher compared with loam clay in the high fertility level.Loam clay had higher content of active potassium,which was beneficial to the storage of applied nitrate nitrogen,the sugar-nicotine ratio was more coordinate.