Effects of Vermicompost on Agronomic Characters and Yield and Quality of Flue-cured Tobacco

The effects of vermicompost on the agronomic characters and yield and quality of flue-cured tobacco were investigated. The results showed that, the field growth periods of various treatments were 117-118 d, 1-2 days longer than that of the CK. The numbers of effective leaves of the treatments applied with vermicompost were 0.1-0.3 leaf more than the CK. The highest yield and the highest proportion of high-grade tobacco occurred in treatment 3 as 2 095.5 kg/m^2 and 49%, respectively, which were higher than those in the CK by 6.58 kg and 5.3%. In conclusion, the treatment with the application of vermicompost at 7 500-10 500 kg/hm^2 was the best.

Effects of Different Transplanting and Harvest Dates on Yield and Quality of Flue-cured Tobacco Leaves

In this study,the effects of nine different combinations of transplanting and harvest dates on yield and quality of flue-cured tobacco leaves were investigated.The results showed that different combinations of transplanting and harvest dates had few effects on growth period and agronomic characters of tobacco plants but exerted remarkable effects on economic characters and chemical composition of flue-cured tobacco leaves.With the postponing of transplanting stage,output value of flue-cured tobacco leaves increased.Output value of flue-cured tobacco leaves in C1treatment（normal harvest） was higher than that in C2（harvest 7 d later） and C3（harvest 14 d later） treatments.Different combinations of transplanting and harvest dates had significant effects on chemical composition of flue-cured tobacco leaves,which exhibited no obvious law.Overall,flue-cured tobacco leaves in T3C1treatment（transplanting 14 d earlier,normal harvest） displayed excellent performance compared with other treatments.

Effects of Tobacco-dedicated Plant Nutrition Regulators on Yield and Quality of Flue-cured Tobacco Leaves

During 2012-2014,field trials were carried out in Huili County,Dechang County and Mianning County of Liangshan Yi Autonomous Prefecture to investigate effects of tobacco-dedicated plant nutrition regulators on yield and quality of fluecured tobacco leaves,aiming at providing reference for tobacco production.According to the results,in tobacco fields applied with tobacco-dedicated plant nutrition regulators,growth period of tobacco was shortened compared with control group;botanical characters（plant height,stem girth,the maximum leaf length,the maximum leaf width,internode length and leaf number） were superior to control group;after application of tobacco-dedicated plant nutrition regulators,yield,output value and the proportion of high-grade and middle-grade leaves were significantly improved compared with control group;moreover,flue-cured tobacco leaves exhibited more coordinated chemical composition.

Research Progress of Factors Influencing the Yield and Quality of Flue-cured Tobacco

The key factors infIuencing the yield and quality of fIue-cured tobacco were summarized： the cIimate factors （incIuding temperature, iI umination and mois-ture） and cuItivation factors （incIuding transpIant, fertiIization, maturity and harvest）. The key factors infIuencing fIue-cured tobacco yield and quality in cuItivation process were eIaborated, so as to provide reference for research advance of fIue-cured to-bacco production technoIogy.

Effects of Amount of Green Manure Returned to Field on Yield and Quality of Flue-cured Tobacco

The effects of amount of green manure returned to field on yield and quality of flue-cured tobacco were studied by field experiment. The results showed that significant positive correlation existed between tobacco leaf yield and small or moderate amount of green manure returned to field. Path analysis showed that moderate amount of green manure returned to field affected yield and quality of tobacco leaves, small green manure returned to field mainly affected leaf yield, while large amount of green manure returned to field mainly affected leaf quality. Therefore, the effect of moderate amount of green manure returned to field on yield and quality of tobacco leaves was best, and moderate amount of green manure returned to field was recommended in production of flue-cured tobacco.

Regression Analysis of Nutrient Elements between Soil and Tobacco Leaves and Their Influences on Aroma Quality of Flue-cured Tobacco

This study aimed to analyze the relationship between nutrient elements K, Ca, Mg, Cu, Mn, Zn and Fe in tobacco-planting soils and tobacco leaves from six main tobacco-producing areas, and to investigate the influences of these elements on chemical composition and aroma components in tobacco leaves. Results showed that there were certain relationship between contents of nutrient elements in tobacco-planting soils and contents of corresponding elements in tobacco leaves; various elements exhibited different influences on the aroma quality of flue-cured tobacco. Based on the actual situation of nutrient contents in soils from different tobaccoproducing areas, contents of various elements in tobacco leaves should be regulated by soil fertilization and foliar spraying, thereby improving the aroma quality of flue-cured tobacco.

Quality of Flue-cured Tobacco in Different Flavors

[Objective] The aim was to explore the differences of quality of flue-cured tobaccos in different flavors. [Method] With Yunnan, Guizhou and Hunan provinces as representative areas, comparisons were performed on flue-cured tobaccos in different types of flavor in terms of note strength, sensory quality, and chemical components to analyze the correlation of chemical components and sensory quality.[Result] Large differences were found among fragrance type, middle flavor and highly flavored type tobaccos in terms of note and note components were rich of middle flavor type; conventional chemical composition differences were relative large among the three types; carbohydrate content was higher in fragrance type and middle flavor type; nitrogen compound content was relatively low in middle flavor type tobacco; the content of potassium and chlorine also showed some differences among three flavor types tobaccos. [Conclusion] The research provides data and theoretical supports for formula design of flue-cured tobacco.

Effects of Applying Trace Clements on Yield and Quality of Flue-cured Tobacco Cuibi-1

[Objectives]To optimize the fertilization technology of flue-cured tobacco Cuibi-1.[Methods]From 2015 to 2016,the experiment of spraying Saikun multi-trace element water-soluble fertilizer was carried out.[Results]7 d and 14 d after transplanting tobacco seedlings,3750 mL/ha,300 times diluted Sakun multi-trace element aqueous solution was sprayed,the growth period of Cuibi-1 in the field was extended by 3-5 d.The incidence of mosaic disease at the rosette stage and granuville wilt at the foot leaf harvesting and curing stage decreased by 4.50-20.85 kg/ha,the yield increased by 67.8-68.7 kg/ha,the proportion of high-quality tobacco increased by 1.29-3.01 percentage points,and the output value increased by 2692.5-3441 yuan/ha,the sensory smoking quality has improved.[Conclusions]Increasing the application of multiple trace elements can increase the economic benefit and industrial use value of tobacco leaf production of Cuibi-1.

Effects of Boron Application on Growth and Quality of Flue-cured Tobacco NC297 under Different Potassium Supply Levels

In order to provide reference for high quality tobacco producion,this experiment adopted a randomized block design in a field plot,and analyzed the effects of boron fertilizer on the growth,development on comprehensive quality of flue-cured tobacco by using mathematical statistics methods such as multiple comparison with NC297 as test material.The results showed that:spraying boron fertilizer on flue-cured tobacco leaves can promote the growth of flue-cured tobacco NC297 to a certain extent,effectively reduce the total particulate matter and tar content of tobacco,and play a positive role in regulating the total sugar,reducing sugar,nicotine and potassium content of flue-cured tobacco;the comprehensive quality of NC297 was the best when boron was applied at medium potassium level(K2B1).

Effect of Different Boron Fertilizer Supply Patterns and Levels on Growth,Development and Quality of Flue-Cured Tobacco

Boron,one of the essential trace elements for normal growth and development of tobacco,has a great impact on the yield and quality of flue-cured tobacco. The objective of this study is to explore the best pattern and level of boron fertilizer supply of red soil in the Honghe tobacco area. In this study,the randomized block design was used to study different boron fertilizer supply methods and levels. The results showed that during transplanting,it was good to apply 1. 50 kg/ha Fertibor boron with pure boron content≥15%; at the resettling stage,it was good to spray 225 kg solution composed of 75 m L/ha Compo liquid boron with pure boron content≥130 g/L mixed with water onto leaves when night fell in a sunny day. The two fertilization methods had better effect than the basal application of boron fertilizer,and the resistance to pests and diseases or economic character of tobacco plants was better than under spraying treatment.

Effects of N Application Rates and NO_3-N to NH_4-N Ratios on Yield and Quality of Flue-cured Tobacco Planted in Black Soil

A field experiment about effects of nitrogen application rates and different NO3-N to NH4-N ratios on agronomic, chemical and biological characteristics as well as yield and quality of flue-cured tobacco grown in a black soil was conducted from 2004 to 2005 in Heilongjiang Province. The results showed that the nitrogen application rates at 45 kg·hm^-2 with the ratio of 75% NO3-N to 25% NH4-N resulted in the highest potassium and reducing sugar contents in the flue-cured tobacco leaving with the highest quality grade and value. It is recommended that this ni- trogen application rate and NO3-N to NH4-N ratio should be widely applied on flue-cured tobacco grown in the black soil in Heilongjiang Province.

Effects of Different Chemical Fertilizer Reduction Techniques on Flue-cured Tobacco Production

[Objectives]This study was conducted to find out the most suitable special formula fertilizer for flue-cured tobacco production in tobacco-growing areas of Zhaotong City,so as to provide a basis for scientific fertilization and reduced application of inorganic fertilizers with improved efficiency in tobacco production in Zhaotong City.[Methods]Different formulas of special base fertilizer and special topdressing for tobacco were designed by optimizing and adjusting the application amounts and proportions of nitrogen,phosphorus,potassium and medium trace elements in fertilizer formulas,and the formulas of special base fertilizer and special topdressing for flue-cured tobacco production were selected through a field plot experiment.[Results]The combination of special base fertilizer and special topdressing was conducive to the early growth and rapid growth of tobacco plants under the condition of reduced fertilizer application,and the treatment using organic-inorganic compound fertilizer as the special base fertilizer was the most obvious,with an average growth period of two days increased.Compared with conventional fertilization,the yield,output value,average price,proportion of superior tobacco and proportion of medium and superior tobacco increased in the organic-inorganic compound fertilizer treatment,with the yield increasing by 5.96%,the output value increasing by 17.08%,the average price increasing by 10.49%,the proportion of superior tobacco increasing by 4.63%,and the proportion of medium and superior tobacco increasing by 2.44%.It was concluded from indexes including growth period,agronomic traits,disease incidence and economic traits,the fertilization mode of organic-inorganic compound fertilizer with the addition of trace elements(boron,magnesium and zinc)applied as the base fertilizer and nitrogen and potassium topdressing was most efficient and economic.[Conclusions]This study provides a basis for scientific fertilization and reduced application of inorganic fertilizers with improved efficiency in tobacco production in Zhaotong City.

Relationships between Application Amount of Quicklime and Soil Nutrients,Flue-cured Tobacco Quality in Panzhihua City

[Objective] This study aimed to investigate the improving effect of quick- lime on acid soil in tobacco-growing areas in Panzhihua City. [Method] The effects of four application amounts （450, 900, 1 350 and 1 800 kg/hm2） of quicklime on soil nutrients and flue-cured tobacco quality were observed for two consecutive years. [Result] In acid soil, the application of quicklime significantly improved soil pH. In addition, it showed significant effects on soil nutrients, flue-cured tobacco quality, tobacco output and tobacco leaf chemical components. When the application amount of quicklime was increased to 1 350 kg/hm2, the improving effect of quick- lime on soil nutrients was best, the flue-cured tobacco yield and quality all reached the highest, and the chemical components of tobacco leaves were closest to the in- herent indicators of high-quality tobacco leaves. [Conclusion] This study will provide certain reference for accurate application of quicklime in tobacco-growing area in Panzhihua City.

Effects of Different Flue-curing Barns on Aroma Quality of Upper Flue-cured Tobacco Leaves of K326

[Objective] This study was conducted to compare the aroma quality of up-per leaves of K326 flue-cured in different barns, and provide theoretical references for the development and optimization of bulk curing barn and the supporting tech-niques. [Method] The upper leaves of K326 were flue-cured in a commonness barn, a four-shelf bulk curing barn and a three-shelf bulk curing barn separately, and then the contents of aroma components and taste quality indices of the finished leaves were measured and compared. [Result] The contents of total aroma components, chromoplast pigment degradation products, phenylalanine aroma components and neophytadiene showed no significant differences in the leaves flue-cured in four-shelf bulk curing barn and commonness barn, but were significantly or very significantly higher than those in the leaves flue-cured in three-shelf bulk curing barn. The con-tents of carotenoid degradation products, Mail ard reaction products, cembranes aro-ma components and total aroma components （except neophytadiene） showed no significant difference among the three treatments. The results of sensory evaluation revealed that the sensory taste of the leaves flue-cured in four-shelf bulk curing barn was the best, as the finished leaves had rich, delicate aroma, comfortable and clean aftertaste. The leaves flue-cured in commonness barn was better than those flue-cured in three-shelf bulk curing barn in aroma quality, amount and aftertaste. [Conclusion] The four-shelf bulk curing barn had a large volume for tobacco leaf processing, but a similar baking environment to the commonness barn, which is conducive to the formation and accumulation of aroma components, so the finished leaves had similar appearance and quality with those flue-cured in commonness barn. The upper flue-cured leaves in three-shelf bulk curing bran had poorer quality than those flue-cured in the other two barns.

Comparative Analysis on Chemical Components and Sensory Quality of Aging Flue-Cured Tobacco from Four Main Tobacco Areas of China

Complicated changes are happening during the aging process of flue-cured tobacco （FCT） and understanding of the changing components is of great significance in improving the quality,shortening aging time,and enhancing production and economic efficiency in tobacco industry.The aging samples of FCT from four main producing areas of China,i.e.,Yunnan,Sichuan,Hubei,and Dongbei,were used to study the changing rule of the components such as alkali,acid,and carbohydrate as well as the aroma and their relationship with sensory quality;and based on the correlation among the components and the sensory quality index,multivariable models were established to predict the aging quality.The results showed that the sensory quality of FCT increased steadily during the aging time,and at the same time,the acidic components （total organic acids,volatile acids） increased gradually,while the alkaline substances （nicotine,volatile alkali）,carbohydrate （total sugars,reducing sugar） and pH values showed a downward trend.Correlation analysis found that the sensory quality and pH values were negatively correlated （P0.05）,while the sensory quality with total organic acids and aroma were positively correlated.The optimal model for predicting the quality of FCT was y=56.75-0.63x12＋50.09x2-13.27x22,（y：sensory quality;x1：pH;x2：total organic acids）.The average predicating error was 1.04% with maximum predicating error of 2.89% and the accuracy rate of above 97%.

Quality Evaluation and Comprehensive Analysis of Flue-cured Tobacco Leaf in Fuzhou

The appearance quality, physical properties, chemical components and sensory quality of 69 flue-cured tobacco leaf samples from 6 counties of Fuzhou City in 2013 were analyzed and evaluated, and were compared with those in southeast area of China. The results showed that the flue-cured tobacco leaves in Fuzhou in 2013 had better hygroscopicity, toughness and filling ability, as well as suitable dragging force. However, some of the tobacco leaves were slightly thin, and had relatively high stem ratio. The tobacco leaves in Fuzhou had higher potassium content, lower starch content, and higher potassium to chlorine ratio. The middle tobacco leaves had better coordination of chemical components and general sensory quality（medium to medium-super level）. Most upper and middle flue-cured tobacco leaf samples had medium-super aroma quality, relatively sufficient aroma quantity,and relatively concentrated smoke; while the lower flue-cured tobacco leaves had little aroma quantity and insufficient smoke. The appearance quality score of lower tobacco leaf samples in Fuzhou in 2013 was slightly lower than that in southeastand whole China. The scores of maturity and leaf structure of middle tobacco leaves in Fuzhou were equivalent to those in southeast China and the national averages.The upper leaves in Fuzhou obtained an equivalent score in oil content and slightly lower scores in other indexes as compared with those in southeast China.The middle-lower tobacco leaves in Fuzhou had better hygroscopicity and toughness compared with those in southeastand whole China. The total alkaloid content per plant andreducing sugar content and potassium content in the middle and lower parts were higher than those in southeast and whole China. However, the scores of coordination of chemical components of lower and upper tobacco leaves in Fuzhou were slightly lower than those in southeast and whole China. The sensory quality of the 3 parts of tobacco leaves in Fuzhou were similar to that in southeast and whole China, but the score of consistency of upper tobacco leaves in Fuzhou was slightly higher.

Canonical Correlation between the Leaf Quality Indicators of "Moderate Aroma" Flue-cured Tobacco

In order to find out the correlation between tobacco quality evaluation indicators in China's traditional " moderate aroma" tobaccoproducing areas and simplify the tobacco quality evaluation indicators,we evaluate the appearance quality and smoking quality of 143 flue-cured tobacco leaf samples in China's " moderate aroma" tobacco-producing areas,test the physical traits and chemical component,and analyze the canonical correlation between four quality evaluation indicators. The results show that there is significant or extremely significant canonical correlation between four evaluation indicators( tobacco smoking quality,chemical component,appearance quality and physical trait quality); the cumulative variance contribution rate of evaluation indicators is in the order of chemical component( 69. 17%) > appearance quality( 68. 76%) > physical traits( 64. 13%); appearance quality is most closely related to physical traits( 93. 84%). The individual indicators for tobacco quality evaluation make different contribution to the correlation between quality evaluation indicators. The chemical component evaluation indicators mainly include total sugar and ratio of total sugar to betaine; sensory taste indicators mainly include aroma volume,smoke concentration,irritation and softness degree; physical trait evaluation indicators mainly include leaf weight,leaf length and leaf density; appearance quality indicators mainly include leaf organizational structure,color,maturity and identity. Studies have shown that in the large-scale ecoregion,using canonical correlation analysis to simplify tobacco quality evaluation indicators is feasible.

Effect of Controlled Atmosphere Storage(CAS)Technology of Flue-cured Tobacco Laminas on the Alcoholization Quality of Tobacco

To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the process of storage, the lam- ina samples of natural alcoholization for 1 year were selected. Comparable analysis on the appearance quality, chemical components and sensory quality of flue-cured tobacco laminas in the process of alcoholization was carried out by using the meth- ods of CAS and natural alcoholization. The results showed that appearance and color through the treatment of natural alcoholization were deep, browning and ac- companied by the phenomenon of oil, while color scale of flue-cured tobacco lami- nas through the treatment of CAS was uniform, fullness was better, and these two methods were close or identical after opening for 3 months. The contents of total sugar and reducing sugar during the process of alcoholization were also gradually decreased, but the ratio of reducing sugar to total sugar of laminas via CAS was higher than that of the natural alcoholization treatment. Compared with the natural alcoholization,the descending trends of total nitrogen and nicotine contents during CAS were gentler, the ratio via CAS was closer to 1, and the coordination of chemical components was more superior. During the period of alcoholization for 6 to 12 months, sensory quality of laminas via the natural alcoholization treatment was more superior than that of CAS treatment. However, after 18 months of alcoholiza- tion, sensory quality of laminas via the CAS treatment was more superior than that of the natural alcoholization treatment, and the CAS treatment could improve opti- mum sensory quality by 0.5 to 1.5 scores. Additionally, the CAS treatment could prolong the time of optimum alcoholization quality for 6 months, compared with the treatment of natural alcoholization. The CAS method could influence the alcohoJiza- tion quality of flue-cured tobacco laminas and prolong the retention period of opti- mum quality status for flue-cured tobacco laminas by regulating the environmental aas composition, thereby realizin.q quality control of flue-cured tobacco laminas.

Changes of Granule Structure and Enzyme Hydrolysability of Starch in Upper Flue-cured Tobacco Leaves During Bulk Flue-curing

[Objective] This study aimed to investigate the changes of granule struc- ture, characteristic and related enzymatic activity of starch in upper flue-cured tobac- co leaves during bulk flue-curing process, to provide theoretical basis for reasonably regulating the starch content in upper flue-cured tobacco leaves and improving the quality of upper flue-cured tobacco leaves. [Method] Changes of amylase activity, enzyme hydrolysability and granule structure of starch in upper flue-cured tobacco leaves were studied during flue-curing process using conventional physical and chemical analysis and SEM. [Result] During the flue-curing process, the starch con- tent of tobacco leaves changed greatly at yellowing stage, and the activity of amy- lase presented the double-peak curve. The SEM observation results showed that most of the starch granules in fresh tobacco leaves were spheroidal and long cylin- drical, while some individuals were in irregular shape, with obvious groove-like in- vagination and layered structure on granule surface; during the flue-curing process, a large amount of starch granules showed layered structure on the surface at yellow- ing stage, and the long cylindrical starch granules were reduced greatly; at the end of flue-curing, there were barely any long cylindrical starch granule in flue-cured to- bacco leaves. Average long-axis-diameter of starch granules in fresh tobacco leaves was 3.21 μm, showing an overall gradually increasing trend during the flue-curing process, which was significantly enhanced at 38 and 42 ℃. The diameter of starch granules increased by more than 60% at the end of 42 ℃ and there was no re- markable difference after 47 ℃. During the flue-curing process, enzyme hydrolysabil- ity of starch in flue-cured tobacco leaves first increased, reached a peak at 38 ~C, and then decreased. [Conclusion] During the bulk flue-curing, the yellowing stage is the critical period for starch content, granule structure and characteristic changes of flue-cured tobacco leaves, it is of positive effects to improve the quality of upper flue-cured tobacco leaves by regulating the flue-curing conditions at yellowing stage.

Construction of Anti-breaking Models of the Main Veins of Flue-cured Tobacco Leaves and Principal Component Analysis

[Objective] This study aimed to explore the related mechanisms of the breaking of flue-cured tobacco leaves. [Method] Anti-breaking models of the main veins of flue-cured tobacco leaves were constructed for principal component analysis on the anti-breaking index, leaf traits and cellulose contents. [Result] The results showed that the growth traits had certain relevance with the cellulose contents while the leaf weight assumed a significant negative correlation with the anti-breaking index, indicating that the heavier the leaf weight was, the weaker the anti-breaking capacity of flue-cured tobacco would be; the cross-sectional area of main veins and the cellulose contents had shown a positive correlation with the anti-breaking index, indicating that the thicker the main vein of flue-cured tobacco was, the higher the cellulose contents would be, and the stronger the anti-breaking capacity of flue-cured tobacco leaves would be. [Conclusion] This study provided theoretical basis and reference to improve tobacco production and enhance the quality of flue-cured tobacco.