• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.159-167
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• 1992

It would be clear that the constituents of the leaf surface lipid is ye비 important as an evaluation index of tobacco leaf quality since the quality of tobacco specific aroma with leaf species depends on the contents of the lipid and the strength of the aroma is determined by the amounts of the lipid secreted. For the reason, a rapid and peproducible method to quantify DVT, which is a kind of lipid, has been studied. The biosynthesis procedure of DVT in leaf growing processes, and the volatile or decompositional characters of DVT in leaf drying processes were also discussed. In consequence, it might be possible to get the data available to the cultivation of better tobacco leaf and the manufacture of cigarettes with better aroma and taste. The results obtained from this study are as follows. 1. Chloroform/dichloromethane solvent was better than chloroform alone for DVT extraction. The extraction yields of the leaf surface lipid were about 5% 2. The extractives with dichloromethane were treated by silylation with BSTPa and the quantitative analysis of DVT was carried out using SE -54 fused silica capillary column. It was found that rapid and reproducible data could be obtained from these methods. 3. In flue - cured tobacco species, DVT contents were $30.3\mu\textrm{g}/cm^2$ in the beginning stage of leaf drying processes and $12.1\mu\textrm{g}/cm^2$ corresponded to 30% levels of the beginning stage, in the end stage. 4. DVT contents in Burley mere 2 times as large as those in fluecured tobacco. DVT in the upper stalk position of leaf was 3 times larger than that in the lower stalk position. 5. DVT of tobacco leaves was decomposed by $SO_2$ gas or the sun light. The decomposition rate was largest in the sample used methanol as a extraction solvent.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.1
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• pp.75-89
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• 1993

Effect of the amount of fertilizer, plant density, and harvesting time on the production of tobacco leaf protein and fresh biomass was investigated. Flue-cured tobacco(M tabacum, L., cv. NC 82) seedlings were transplanted in the field dressed 200kg N per ha at 1$\times$105, 3$\times$105, 5$\times$105, 7$\times$105 plants per ha, and were harvested at the time when 6 and 10 weeks after transplanting, respectively. Harvest at 10 weeks after transplanting increased greatly number of leaves per plant and fresh weight of a plant, Precentage of senescent leaf weight, but significantly decreased fresh weight of a leaf and total protein contents g-1 fresh weight of leaf and stalk over the amount obtained from the harvest at 6 weeks after transplanting. Also, fresh leaf numbers of a plant, fresh weight of a leaf and of a plant, and total protein contents g-1 fresh weight of biomass were more decreased, but percentage of senescent leaf weight were remarkably increased under higher plant density. Therefore, it was seemed that harvesting at 6 weeks after transplanting under 1$\times$105 plant density per ha is more effective for producing higher yield of biomass and protein per plant than 10 weeks harvesting with 7$\times$105 population per ha. A trend was observed that biomass and protein yields per ha are positively correlated with plant population. Biomass yield per ha was the greatest at 7$\times$105 density(80.5t), but the peak of protein yield was at the near of 5$\times$105 population(2454kg as total protein) per ha on the regression curve. It was assumed that if tobacco plants are transplanted under 5$\times$105 plant density at the mid of May, and thereafter harvest at 6 weeks repeatedly during the growing season, it is possible to harvest 2~3 times per year, and to yield more 6.024kg of protein and over 140me1ric tons of fresh biomass ha 1 year 1 statistically in the korea tobacco growing regions.

• Journal of Plant Biology
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• v.17 no.1
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.163-169
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• 1989

Seasonal climatic factors associated with tobacco quality grade and production rate were analyzed. The degree of influence on yield distribution rate in high guality tobacco leaues was highly positive with the average temperature in early May, but negatively related to those in late May and early June. Positive correlations were noticed between the degree of influence and sunshine hours in Middle June, late June and late May in decrease order, while negative degree of influence was higher in early May than in late May, The order influenced by recipitation in a positive direction was early May, late May and middle May. Negative influence was noticed in middle and early June with a great degree.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.84-93
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• 1984

Six kinds of sugars (Maltose, Sucrose, Glucose, Fructose, Mannose and Lactose) and four kinds of organic acids (Malic, Tartaric, Lactic and Citric) were added by 2-10% for the former and 0.2-1.8% for the later in quantitatively to the inferior quality of Flue-cured leaf tobaccos, and treated at 135$^{\circ}C$ for 10 minutes to examine the effect on deliveries of tar and nicotine in smoke, variation of smoke pH and smoking taste. The results obtained are as follows. Tar and nicotine deliveries in smoke of tobacco show a great reduction with 5-6% addition of sugars. Reduction of nicotine delivery was to be 19% with addition of Glucose. Tar in smoke was, however, increased by 5-8% with 4% addition of Sucrose or Lactose. On the other hand, 4% addition of Glucose and Fructose gave 1 % reduction of tar delivery, but the reduction rate became to be small with increase of adding quantity. The smoking taste by the addition of Glucose and Fructose tobacco was found to be milder than by the other sugars. Tar and nicotine deliveries show a decreasing trend with the addition of organic acid, and Tartaric acid, among the organic acids described above, had greater effect than the other acids. 1% addition of Tartaric acid gaves 10-11% reduction in tar and nicotine delivery, and a fall of smoke pH, from 6.40 to 6.05, was found. Smoking taste by the addition of Lactic and Tartaric acid had milder than the others. And heat treatment for 10 minutes at $135^{\circ}C$ gave also better on smoking taste. The addition of mixture of sugars and organic acids, (Glucose 4%+Lactic acid 0.8% + Tartaric acid 0.2%) and then the successive heat treatment for 10 minutes at $135^{\circ}C$ improved greatly the quality of Fluecured leaf tobacco, and nicotine were reduced to 16-29%, and pH was changed from 6.46 to 6.14.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.155-162
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• 1982

This study was conducted to investigate the effects of topping time and degree on the characteristics of three tobacco varieties, and to establish the early topping (Button stage) method at Eumseong Experiment Station, Korea Tobacco Research Institute in 1979-1980. The results are summarized as follows; yield increased in the plots of By 104, topping at button stage and under first leaf from floral axis. Quality was good in the plot topped at button stage and under first leaf from floral axis. Price per l0a was highest in the plot topped at button stage and under first leaf from floral axis.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.156-160
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• 1985

24 cultivation areas at fields of the Tobacco Experiment Station in Suweon, Eumseong, and Daegu were selected to get the fertilizer response and evaluate fertility level of upland soil. Fertilizer levels treated were 0, 70, 100, and 130kg/10a of compound fertilizer (10-10-20) for tobacco. The results are as follows; 1. Fertility level could be evaluated by dry weight of tobacco loaves harvested from non-fertilized fields. 2. There was significant in yield differences between fertilizer levels of 70 and 100kg/10a but was no difference between 100 and 130kg/10a of fertilizer level. The lower fertilizer efficiencies were showed at the fields harvested high yield of tobacco leaf without fertilizer. 3. Optimum fertilizer level for non-fertilized field with leaf yield less than 208.5kg/10a was 100kg/10a, and at low productive field with dry leaf weight less than 33.3kg/10a, higher level of fertilizer, 130kg/10a, was considered to be the optimum to get the got income with tobacco cultivation.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.5-20
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• 1991

For the quality enhancement of harvested-year leaf tobacco to the quality of 2-year naturally aged leaf tobacco, cellulose and nicotine degradative bacteria were isolated and identified. Effects of artificial fermentation treated cellulase and nicotine degradative bacteria on the quality of leaf tobacco were investigated from the chemical and sensory points of view. 1, Changes in chemical composition of leaf tobacco resulted from the addition of cellulase extracted from Cellulomonas sp. [3ml(${\mu}{\textrm}{m}$ D-glucose/ml. mil-1) of enzymes solution 11009 of leaf tobacco] and nicotine degradative bacteria, Pseudomonas sp. 2ml(IX109 cells$\div$ 100g of leaf tobacco), and subsequently fermented at 40${\mu}{\textrm}{m}$$^{\circ}C$, 65% R. H. for 40 days are as follows : 1) Content of crude fiber decreased 12% It took 9 min, 53 sec. to reach full combustion in control group but took only 7 min. 47 sec. in the treated group, taking almost equal time to 2-year naturally aged leaf tobacco(7 min. 35sec.). 2) Light intensity of control group was 60.96% with bright lemon color but that of treated leaf tobacco accounted for 47.69 with orange to dark brown color series, which was almost equal to the value, 45.69, of 2-year naturally aged leaf tobacco. 3) Linoleic acid, serving mild taste among organic acids, amounted to 1.llmg/g in control group but increased to 1.35m9/9 in the treated leaf tobacco, identical to the content(1.35mg/g) of 2-year naturally aged leaf tobacco. 4) Content of solanone, on of the typical leaf tobacco flavor compounds, accounted for 2.95% in control group but increased to 2.87% in treated group. 5) Methyl furan, useful flavor compound in smoke composition, accounted for 17.6$\mu\textrm{g}$/cig. in control group but increased to 25.9$\mu\textrm{g}$/cig. in treated group. However, acroleine decreased from 69.3$\mu\textrm{g}$/cig. in control group to 58.6$\mu\textrm{g}$/cig. in treated group 2. In sonsory test, mild taste evaluation of control group scored 5.47 and treated group 7.93 which was evaluted almost equal to the value(8.00) of 2-year naturally aged leaf tobacco. Aroma evaluation of control group scored 5.60, treated group 8.20, and 2-year naturally aged leaf tobacco 8.33. In addition, total harmony taste of control group showed 5.67, treated group 8.07 (p<0.01), and 2-year naturally aged leaf tobacco 8.00. From these results, it can be said that quality of treated leaf tobacco is not inferior to that 2-year naturally aged leaf tobacco.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.97-101
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• 1968

Effects of weather factors on leaf tobacco yield were studied from the yield data of flue-cured yellow tobacco variety Yellow pryer and weather recordes for 13 years from 1952 to 1964. The results are summarized as follows; 1. Leaf tobacco yield variation was large and larger coefficient of variance was calculated. 2. Yield of leaf tobacco was correlated largely to leaf number, with simple correlation coefficient r=0.736. Leaf number was correlated largely to sunshine hours during May with r=0.745, and multiple correlation coefficient R=0.837 between leaf number and multiple weather factors during May to June. 3. Leaf tobacco yield was largely affected by the sunshine hours (r=0.717) and temperature (r=0.329) in May and precipitation (r=0.421) in June. 4. From the study of partial regression of leaf tobacco yield on weather factors a formulation Y=441.664-31.255$X_1$+1.19$Y_2$-0.031$X_3$ was calculated for the estimation of leaf tobacco yield. Here R=0.8074 d.f.=7 was significant.