Correlation Analysis between Well-cellar Early Transplanting of Robust Seedlings and Diseases in Shiyan Tobacco-growing Area

[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship between disease occurrence and meteorological factors during the field growth period was examined by analyzing the prevalence of flue-cured tobacco virus diseases,brown spot,and total disease in the Shiyan tobacco-growing area before(2013-2017)and after(2018-2022)the well-cellar early transplanting of robust tobacco seedlings.[Results]The implementation of a well-cellar early transplanting technique of robust seedlings resulted in a reduction in the average incidence of tobacco virus disease,brown spot,and total disease by 0.83%,8.85%,and 7.91%,respectively,in comparison to the incidence observed prior to early transplanting.These findings suggest that early transplanting can significantly reduce the incidence of flue-cured tobacco diseases.Prior to the well-cellar early transplanting of robust tobacco seedlings,there was a significant(including highly significant)positive correlation between the incidence of brown spot and total disease and precipitation in August and September.The incidence of brown spot and total disease in tobacco plants was found to be significantly positively correlated with May precipitation and significantly negatively correlated with May sunshine hours following the well-cellar early transplanting of robust seedlings.The advancement of the transplanting period by 20 d resulted in a reduction in the growing period of tobacco plants in the field under autumn rains(late August to November)in western China.This effectively circumvented the suitable conditions for disease occurrence and can reduce the incidence of disease.[Conclusions]This study offers a framework for enhancing the quality and efficiency of flue-cured tobacco production in the northwest tobacco-growing area of Hubei.

Loss Rate Estimation of Yield and Output Value of Tobacco Leaf Infected by Tobacco Blown Spot (Alternaria alternata)

[Objective] The paper was to study the effect of tobacco blown spot on the yield and output value of tobacco leaf.[Method]The upper,middle and lower leaves in tobacco plant were selected during the harvest period of tobacco to carry out loss rate estimation of yield and output value of tobacco leaf caused by different disease levels of brown spot.Regression correlation analysis was also conducted.[Result]The disease levels of brown spot had extremely significant strong negative correlation with single leaf weight of tobacco leaf,and it had extremely significant strong positive correlation with the loss rate of single leaf weight.The increase speed of loss rate of single leaf weight of middle and upper leaves was obviously faster than that of lower leaves.The loss rates of single leaf weight of upper,middle and lower leaves were 3.18%-28.95%,3.43%-28.88% and 10.07%-26.90%,respectively.The higher the disease level of blown spot was,the lower the yield and output value of tobacco leaf was,and the corresponding loss rate was also higher.Correlation analysis showed that the disease level of blown spot had extremely significant strong negative correlation with the yield and output value of tobacco leaf,and it had extremely significant strong positive correlation with the loss rate of yield and output value.The negative impact of blown spot on the output value of tobacco leaf was far greater than that on the yield.The highest loss rate of the yield of tobacco leaf was 28.56%,while the highest loss rate of output value reached 89.67%.[Conclusion] The study provided theoretical basis for accurately holding the critical period for the control of blown spot,thus reducing the damage on tobacco leaf and improving the output value of tobacco leaf.

Development of a stable attenuated double-mutant of tobacco mosaic virus for cross-protection

Tobacco(Nicotiana tabacum)and tomato(Solanum lycopersicum)are two major economic crops in China.Tobacco mosaic virus(TMV;genus Tobamovirus)is the most prevalent virus infecting both crops.Currently,some widely cultivated tobacco and tomato cultivars are susceptible to TMV and there is no effective strategy to control this virus.Cross-protection can be a safe and environmentally friendly strategy to prevent viral diseases.However,stable attenuated TMV mutants are scarce.In this study,we found that the substitutions in the replicase p126,arginine at position 196(R^(196))with aspartic acid(D),glutamic acid at position 614(E^(614))with glycine(G),serine at position 643(S^(643))with phenylalanine(F),or D at position 730(D^(730))with S,significantly reduced the virulence and replication of TMV.However,only the mutation of S^(643) to F reduced the RNA silencing suppression activity of TMV p126.A double-mutant TMV-E614G-S643F induced no visible symptom and was genetically stable through six successive passages in tobacco plants.Furthermore,our results showed that TMV-E614G-S643F double-mutant could provide effective protection against the wild-type TMV infection in tobacco and tomato plants.This study reports a promising mild mutant for cross-protection to control TMV in tobacco and tomato plants.

Variations of phyllosphere microorganisms in asymptomatic and tobacco brown spot leaves before and after spraying 12% difenoconazole + fluxapyroxad SC

12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight,cucumber powdery mildew,etc.This study evaluated the bioactivity of Jiangong against Alternaria alternata and explored variations of phyllosphere microorganisms in both asymptomatic and tobacco brown spot leaves at different persistence periods(0,5,10,and 15 days post-fungicide application)using high-throughput sequencing technology.The results indicated that Jiangong effectively inhibited mycelial growth(average EC_(50) value of 0.51μg/mL),conidia germination(average EC_(50) value of 3.47μg/mL),and the carbon metabolism of A.alternata.Both asymptomatic and symptomatic leaves presented complex microbial communities.Higher fungal diversity was noted in asymptomatic leaves,while higher bacterial diversity was found in symptomatic leaves.After application,the diversity and abundance of microbial community structures in both types of leaves changed over time.Fungal microbiome communities showed greater sensitivity than bacterial groups,with the microbiome communities of asymptomatic leaves being more affected than those of symptomatic leaves.Fungal community diversity decreased for both symptomatic and asymptomatic leaves after 5 days of application,while the diversity of fungal community in symptomatic leaves showed an upward trend after 10 days of application.Meanwhile,bacterial community diversity increased in both symptomatic and asymptomatic leaves after 5 days of application but then declined in asymptomatic leaves after 15 days.The abundance of the dominant function group of phyllosphere bacteria(metabolism,genetic information processing,environmental information processing)was not affected by the application of Jiangong.However,the abundance of the dominant function group of phyllosphere fungi(animal pathogen-endophyte-wood saprotroph,endophyte-plant pathogen,plant pathogen-undefined saprotroph)was significantly affected by the application of Jiangong,and high variation was found in symptomatic leaves than that of asymptomatic leaves.The application of Jiangong-induced alterations in the community structure of the tobacco phyllosphere microbiome provides a basis for future tobacco brown spot control strategies based on phyllospheric microecology.

Plant Chemical Defenses against Insect Herbivores—Using theWild Tobacco as a Model

The Nicotiana genus, commonly known as tobacco, holds significant importance as a crucial economic crop. Confrontedwith an abundance of herbivorous insects that pose a substantial threat to yield, tobacco has developed adiverse and sophisticated array of mechanisms, establishing itself as a model of plant ecological defense. Thisreview provides a concise overview of the current understanding of tobacco’s defense strategies against herbivores.Direct defenses, exemplified by its well-known tactic of secreting the alkaloid nicotine, serve as a potent toxinagainst a broad spectrum of herbivorous pests. Moreover, in response to herbivore attacks, tobacco enhancesthe discharge of volatile compounds, harnessing an indirect strategy that attracts the predators of the herbivores.The delicate balance between defense and growth leads to the initiation of most defense strategies only after aherbivore attack. Among plant hormones, notably jasmonic acid (JA), play central roles in coordinating thesedefense processes. JA signaling interacts with other plant hormone signaling pathways to facilitate the extensivetranscriptional and metabolic adjustments in plants following herbivore assault. By shedding light on these ecologicaldefense strategies, this review emphasizes not only tobacco’s remarkable adaptability in its natural habitatbut also offers insights beneficial for enhancing the resilience of current crops.

Comparison of Combustion Characteristics of Tars Produced with Tobacco Stem Biomass Gasification

In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.

Slag Characteristics of Biomass Pellet Fuels with Different Additives to Tobacco-Stalk for Tobacco Curing Heating

Since pure tobacco stalk(TS)biomass pellet fuels tend to slag,five anti-slagging agents were added to the crushed TS to obtain a pellet fuel that could be used in biomass burners to provide heat for tobacco curing.The obtained results revealed that the main component of TS pellet fuel was K_(2)Si_(2)O_(5).During fuel combustion process,additives generated higher melting point silicate compounds by Al–K,Ca–K,and Ca–K elemental structures to replace single K elemental structure of TS,enhancing the anti-slagging efficiency of the pellet fuel from 21.63%to 78.29%and promoting the precipitation of K,Mg,and Na elements in the slag block.By investigating the anti-slagging mechanism pathways of the additives in TS biomass pellet fuels,altering of the structure of silicate ion group pathway was found to improve anti-slagging effects that met the requirements of production formula.

Field Prevention and Control of Tobacco Black Shank in Guizhou Province

[Objectives]The paper was to explore the prevention and therapeutic schedule of tobacco black shank.[Methods]Different concentrations of 25 g/L fludioxonil·37.5 g/L metalaxyl-M,10 billion/mL Bacillus amyloliquefaciens,110 g/L amino acids·24 g/L manganese zinc,120 g/L calcium·20 g/L magnesium,and 4%metalaxyl-M·64%mancozeb were employed to assess their efficacy in controlling tobacco black shank.The disease index was subsequently evaluated.[Results]25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)(transplanting dosage:750 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2,sealing dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2)resulted in a notable impact on the prevention of tobacco black shank.The incidence in the treated area was 10.78%,a 35.72%reduction compared to the control.The estimated yield was 99700 yuan/hm 2,a 34.91%increase compared to the control.25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb(control dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,with an interval of 7 d between applications)demonstrated a significant efficacy in controlling tobacco black shank.At 7 d following the second application,the relative preventive efficacy was observed to be 88.99%.Additionally,the estimated yield was 109900 yuan/hm 2,representing an increase of 244.51%compared to the control.[Conclusions]During the transplanting and sealing stages,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)may be employed to enhance the growth of tobacco plants and mitigate the occurrence of tobacco black shank.Additionally,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb can be utilized for the treatment of tobacco black shank during the initial incidence stage.

The impact of tobacco use and nicotine addiction on health: A literature review of nursing interventions for smoking cessation

Tobacco use remains one of the leading preventable causes of morbidity and mortality globally,with nicotine addiction significantly impacting health outcomes.This literature review explores the multifaceted nature of tobacco use and its health implications,emphasizing the role of nursing interventions in smoking cessation.The review highlights various strategies employed by nurses,including assessment,counseling,pharmacotherapy support,and behavioral interventions,which are essential for effective tobacco cessation.By analyzing current evidence-based practices,the study underscores the importance of comprehensive assessments and personalized care plans tailored to individual patient needs.It also addresses the significance of motivational interviewing and the 5 A’s framework in facilitating successful quit attempts.In addition,the review discusses the integration of cognitive-behavioral therapy and stress management techniques as vital components of behavioral interventions.Recommendations for improving tobacco cessation efforts include enhanced training for healthcare professionals,the establishment of community-based support groups,and advocacy for robust tobacco control policies.The findings underscore the critical need for ongoing research into the long-term effectiveness of cessation interventions across diverse populations.This study aims to inform nursing practice and public health policy,ultimately contributing to the reduction of tobacco-related health issues and promoting healthier communities.

Determinants of Tobacco Cultivation and the Associated Impacts of Adoption in Hurungwe District, Zimbabwe

Tobacco is an essential cash crop in Zimbabwe and a strategic livelihood option for hundreds of thousands of rural households. However, the crop is linked to negative environmental, economic, and social impacts. The existing studies on tobacco cultivation in Zimbabwe present contradictory findings on the determinants and impacts of adoption, leaving unanswered questions about the crop’s sustainability impact in the country. This article investigates the determinants of smallholder farmers’ decisions to grow tobacco and the associated impacts of adoption. Random and purposive sampling were used to select 273 household surveys, including tobacco and non-tobacco smallholder farmers, and 56 expert interviews to answer the research questions. We employed regression models alongside expert interviews and document analysis to identify the determinants influencing the decision-making process of smallholder farmers in Zimbabwe regarding tobacco cultivation. Additionally, our investigation aimed to elucidate the perceived impacts associated with the adoption of this agricultural practice. The regression analysis indicated that the farmer’s age, education level, farming experience, family size, household income, and perceived high farm profitability are significant drivers of tobacco adoption. We also discovered divergent and convergent perceptions of the critical impacts of tobacco cultivation. The study highlights the need for proactive multi-stakeholder collaboration and sustainable financial arrangements to address the negative impacts of tobacco production. As the primary stakeholder responsible for regulating and promoting agricultural activities, the Zimbabwean government should provide meaningful financial support, increase access to credit, and ensure better market facilities for alternative crops to reduce the over-dependence on tobacco.

Smokeless Tobacco Use among Women in Kasama District-Zambia

Background: Smokeless tobacco is defined as a product that contains tobacco, is not smoked or burned at the time of use, and commonly consumed orally or nasally. These products can be placed in the mouth, cheek or the lip and are sucked or chewed. The Zambian government, in the 2019 country report, gave an estimated figure of 4.5% of females aged 15 years and above in 2017 used smokeless tobacco and by 31st December, 2018, there was an increase of smokeless tobacco users to 6.8% women of the same age group. This study aimed to explore the extent of smokeless tobacco use among women in Kasama district-Zambia. Methodology: An analytical cross-sectional quantitative study design was used to collect data using the modified structured interview schedule, adopted from Medicine for Global Health. Simple random sampling method using rotary technique was used to select 430 respondents after meeting the inclusion criteria. Informed consent to participate in the study was obtained. Data was analysed using version 26.0 of the Statistical Package for Social Sciences. Appropriate parametric or non-parametric statistical tests (Chi-squared or Fisher’s exact test) were adopted in testing for associations between variables. Univariable and multivariable binary logistic regression analysis were employed in identifying smokeless tobacco use among women using an investigator-led stepwise approach, guided by various fit statistics and the likelihood ratio test. All statistical analyses adopted a 5% significance level at 95% confidence interval. Results: The results showed that most of the respondents were aged between 18 and 25 years (45.6%), (53.7%) lived in urban settlements and the majority (80%) were unemployed. The majority of respondents (83.5%) had a friend/relative who used smokeless tobacco and over half (53.5%) thought smokeless tobacco was beneficial to them. The commonly mentioned benefits of smokeless tobacco included body warmth (13.6%) and vaginal tightening (7.9%). The results revealed that most of the respondents attained a secondary level of education (38.4%). According to the study, smokeless tobacco use among women of Kasama-Zambia was significantly associated with the following;age (p Conclusion: Based on these findings, the study recommends that efforts should be channeled towards the dissemination of information on the impacts of smokeless tobacco use in order to overcome cultural beliefs attached to smokeless tobacco use.

Association of cannabis use disorder with atrial fibrillation in young men without concomitant tobacco use:Insights from nationwide propensity matched analysis

BACKGROUND Recent data are inconclusive regarding the risk of arrhythmias among young cannabis users.Furthermore,many young adults use both cannabis and tobacco,which could add a residual confounding effect on outcomes.So,we studied young men who have cannabis use disorder(CUD)excluding tobacco use disorder(TUD)to understand their independent association with atrial fibrillation(AF)and related outcomes.AIM To study the association of CUD with AF and related outcomes.METHODS We used weighted discharge records from National Inpatient Sample(2019)to assess the baseline characteristics and mortality rates for AF-related hospitalizations in young(18-44 years)men in 1:1 propensity-matched CUD+vs CUD-cohorts without TUD.RESULTS Propensity matched CUD+and CUD-cohorts consisted of 108495 young men in each arm.Our analysis showed an increased incidence of AF in black population with CUD.In addition,the CUD+cohort had lower rates of hyperlipidemia(6.4%vs 6.9%),hypertension(5.3%vs 6.3%),obesity(9.1%vs 10.9%),alcohol abuse(15.5%vs 16.9%),but had higher rates of anxiety(24.3%vs 18.4%)and chronic obstructive pulmonary disease(COPD)(9.8%vs 9.4%)compared to CUD-cohort.After adjustment with covariates including other substance abuse,a non-significant association was found between CUD+cohort and AF related hospitalizations(odd ratio:1.27,95%confidence interval:0.91-1.78,P=0.15).CONCLUSION Among hospitalized young men,the CUD+cohort had a higher prevalence of anxiety and COPD,and slightly higher proportion of black patients.Although there were higher odds of AF hospitalizations in CUD+cohort without TUD,the association was statistically non-significant.The subgroup analysis showed higher rates of AF in black patients.Large-scale prospective studies are required to evaluate long-term effects of CUD on AF risk and prognosis without TUD and concomitant substance abuse.

Effects of Three Major Tobacco Curing Techniques on Raw Tobaccos

[Objective] The aim was to compare effects of three curing techniques （Chinese tobacco curing-method for improving tobacco quality and fragrance, Chi-nese （three-phase） tobacco curing technique, and Zimbabwe tobacco curing tech-nique） on quality of tobacco and to select optimal curing method. [Method] In Peng-shui county in Chongqing, tobacco variety K326 was chosen as test materials to conduct tobacco curing tests as per three techniques to analyze key components of raw tobacco, grade quality and evaluation quality. [Result] The content of starch in tobacco was reduced by Chinese tobacco curing-method for improving tobacco quality and fragrance, and the ratio of middle and high quality grade tobaccos improved by 1.8%-7.95%; average price increased by 1.64-3.21 yuan/kg; evaluation grade grew by 1.5-4.4. The technique is proved in enhancing tobacco fragrance quality and quantity as wel as improving and adjusting fragrance, taste and flavor. [Conclusion] Chinese （three-phase） tobacco curing technique improves tobacco quality and provides references for production demonstration areas of tobacco curing.

Non-tobacco Related Materials Control Mode of Export-oriented Tobacco

Non-tobacco related materials （NTRM） come from field production, tobacco stringing, grading and purchasing, affecting cigarette quality and having potential safety hazard. The research reviewed control on NTRM from source, production and processing to enhance use efficiency of raw materials and guarantee raw material safety.

Effects of Different Curing Techniques on Material and Aroma of Flue-cured Tobacco

[Objective] The aim was to compare the effects of three-phase technique, quality and aromatic-flavor improvement technique and Zimbabwe technique on to-bacco quality to select a suitable technique in tobacco production. [Method] Tobacco leaves in down, middle and upper parts of a tobacco variety KRK26 were col ected to analyze raw tobacco quality characters. [Result] With quality and aromatic-flavor improvement technique, the proportions of high-quality and middle/high quality tobac-cos improved by 4.68% and 1.97% and average price enhanced by 1.15 yuan/kg, increasing by 10.33%, 9.07% and 3.12 yuan/kg, compared with three-phase tech-nique. It is proved that the technique would better improve tobacco fragrance and quality and coordinate tobacco fragrance, taste and throat-irritation. [Conclusion] Quality and aromatic-flavor improvement technique provides references for tobacco production.

Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization

Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jinsha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jinsha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth(7-16 weeks after transplanting),the soil net N mineralization at Fenggang(56 kg N ha^(-1))was almost double that at Jinsha(30 kg N ha^(-1)).While soil NH_4-N and NO_3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves>middle leaves>lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves.

Effect of Water Control before Transplanting and Rooting Powder Treatment on Tobacco Seedling Quality and Physiological Properties at Green Stage

Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that： （1） water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control ＋ rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; （2） water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control; （3） all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting ＋ rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.

Variation of Enzyme Activity in Flue-cured Tobacco-growing Soil Planted with Different Lastseason Crops

The rice soil （last crop was rice） and arid red soil （last crop was corn） were used as a test material for the pot experiment. The variation of enzyme activi-ty in flue-cured tobacco-growing soil planted with different last-season crops was in-vestigated at different growth stages in this study. The results showed the activity variation of the 3 enzymes differed in the 2 soils at different growth stages. The catalase activity in the arid red soil trended to decrease overal from the vigorous growing stage to harvesting stage; while it decreased gradual y in the rice soil until the harvesting stage. The phosphatase activity in the 2 soils al increased with the proceeding of growth period. The urease activity in the arid red soil decreased gradual y at different growth stages, but the variation of urease activity in rice soil was irregular. During the growth of flue-cured tobacco, the catalase and urease ac-tivity in the arid red soil increased first and then decreased, and the phosphatase activity increased gradual y. ln rice soil, the catalase activity increased first and then decreased; the phosphatase activity decreased first and then increased; the urease activity increased first, then decreased and increased last. The activity of al the en-zymes in the 2 soils showed significant differences compared to the control except some enzymes at the vigorous growing stage. lt was suggested the planting of flue-cured tobacco would affect greatly the soil enzyme activities.

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.

Study on Loading Leaves Density with Cage Clamp on Quality of Cured Tobaccos in Bulk-Curing Barn

In order to determine the best loading density of tobacco leaf with cage clamp in bulk-curing barns, a curing test was conducted on middle-part tobacco leaves. The results showed that for good appearance quality of cured tobacco, the loading density at 59.52 kg/m2 （4 000 kg/barn） was the best, fol owed by 66.96 kg/m2 （4 500 kg/barn） and 74.40 kg/m2 （5 000 kg/barn）. As leaf loading density increased, the contents of leaf nicotine and total nitrogen increased, sugar content had smal changes, the ratio of sugar to nicotine decreased and tended to be balanced and the content of neutral aroma substances was decreasing, but the difference among treatments was not significant. With the increase of loading density, the sensory quality of cured leaf was better. When leaf loading density was 66.96 kg/m2 （4 500 kg/barn）, apperance quality of cured leaf improved considerably, with prominent aro-ma. Therefore, the best loading density of tobacco leaf in cage clamp of bulk-curing barn would be 66.96 kg/m2 （4 500 kg/barn） .