• 한국연초학회지
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• 제8권1호
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• pp.49-56
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• 1986

To obtain the information of low chlorine leaf production, the chlorine content of the soil and cured leaf in Burley tobacco growing area was investigated. The results obtained are as follows. 1. The chlorine concentration in soil at transplanting time in Kwang-ju growing area was higher than in Jeon-ju(1983), and paddy field sell showed higher concentration of chlorine than upland field in Jeon-ju(1984). The chlorine concentration in soil was different between years, locations, and cultivated land (paddy field and upland field), but the concentration, on the whole, was under the levels that might effect the leaf quality. 2. The chlorine concentration In soil was highest around todays after transplanting, and after harvesting, the concentration decreased to half of transplanting time. 3. The distribution of chlorine through the parts of tobacco plant showed remarkable difference between years, locations, cultivated land and growing stages. 4. There was significant positive correlation between chlorine concentration in top soil and chlorine content of cured leaf. 5. Chlorine content of cured leaf in Kwang-ju area(1.79%) was higher than that of Jeon-ju area(O.79%), relatively. 6. It was considered that the accumulation of salt from the sea by sea. wind did not main factor of high leaf chlorine content in seaside district.

• 한국연초학회지
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• 제18권1호
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• pp.60-65
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• 1996

Chemicals including antibiotics and bactericides were screened for suppression of streptomycin-resistant Erwinia cmutouom subsp. cmutovom (Ecc) strains in laboratory and field conditions. Oxytetracycline, ethoquinolac and dichlorophen suppressed the growth of streptomycin-resistant Ecc strains in vitro. Fractional inhibitory concentration (FIC) indices of oxytetracycline and ethoquinolac mixed with streptomycin against the Ecc strains were equal to and less than one, respectively. Consequently the efficacy of those chemicals in mixture with sorptomycin were non-antagonistic But that of dichlorophen mixed with streptomycin was more than one, therefore the efficacy of the mixture was antagonistic. Spray of oxyteoucycline, ethoquinolac and agrimycin-100 on the topped burley tobacco plants was efficacious in reducing tobacco hollow stalk at the same level of sorptomycin treatment in three-year field trials, which suggests that those are promising chemicals to be alternative to streptomycin for control of tobacco hollow stalk.

• 한국연초학회지
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• 제16권2호
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• pp.97-101
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• 1994

Tobacco stalks were cut and removed from the field after harvest, and urea was treated by placing it on the cutting portions of the remaining tobacco stumps. Relative virus infectivity of the root residue(compared to the fresh root residue infected with TMV) was reduced to 14.6% in December, 1993(before overwintering) and to 8.5% in March, 1994 just before transplanting, indicating that the TMV infectivity decreased remarkably, but was preserved still in the root residue in the field soil. There was no significant difference in infectivity of remaining root tissue between the treated and untreated root residue. However, as roots with urea treatment had been extensively decayed, only about one - fifth of the initial root volume remained after overwintering. TMV occurred less (by one - third) in the urea treatment than in the control, suggesting that urea treatment effectively provented tobacco from TMV infection by reducing the inoculum potential.

• 한국연초학회지
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• 제25권2호
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• pp.154-159
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• 2003

Using sucker agents for tobacco can lead some advantages including saving labor, increasing yield and reducing the spread of diseases. At present, the sucker control agents used in China mainly depended on importing. The agents includes two groups, systemics (Maleic hydrazide: MH, etc) and partial systemics (Butralin, Flumetralin, Pendimethalin, etc). Now, Pendimethalin(a.i. 33%, wp) was used extensively all over the tobacco field in China. Sucker control agents will also be used for tobacco production in China. Because of the high price of the imported agents, China has studied on the domestic production of tobacco sucker control agents and has made some progresses.

• 한국연초학회지
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• 제23권2호
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• pp.115-122
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• 2001

The effect of mineral oil treatment in Burley 21 tobacco field on the control of potato virus Y(PVY-VN) mostly transmitted by green peach apid(Myzus persicae Sulzer) in nature was studied and the virus infection in some plants including potato, pepper, bramble, radish, etc near the tobacco fields as a virus infection source was tested by capillary tube precipitatioin test with PVY-antibody and bioassay in Xanthi-nc tobacco. The main source of PVY-VN infection in tobacco field in korea was potato(ca. 40% of test plants infected). Pepper and bramble were also infected by PVY-VN. The control level of PVY-VN infection by treatment of 0.75% liquid mineral oil with 3 % nonionic emulsifier to the plants was 84.8 % in case of the artificial transfection with a infected apterous aphid in laboratory. However, the reduction of PVY-VN disease severity in tobacco fields treated with mineral oil at late June was only 35.5%. These results suggest that mineral oil treatment is not so effective for the protection of aphid-born virus(PVY - VN) infection in tobacco fields.

• 한국연초학회지
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• 제20권2호
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• pp.172-177
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• 1998

The culture filtrate of Streptomyces sp. B25, which was identified in this experiment, was tested for the control of tobacco mosaic virus (TMV) with the susceptible tobacco cultivar, NC 82, under the field conditions following the preliminary examination of its characters for TMV control. Control efficacy of the culture filtrate against TMV infection continued over 50% up to 6 days after treatment, and its systemic effect was about 30% of the direct effect. In field conditions control efficacy of the culture filtrate against TMV infection was 95.3 % at 2 weeks after TMV inoculation, and decreased to 58.3 % at 3 weeks after inoculation. Five fold-dilution of the culture filtrate showed about half of the control efficacy by the stock culture filtrate. Analysis of the antibiotic material responsible for the inhibition of TMV infection through nuclear magnetic resonance experiments revealed that the antibiotic is antimycin $A_1$, which is firstly reported as an anti-phytoviral antibiotic in this experiment.

• 한국연초학회지
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• 제22권2호
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• pp.123-132
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• 2000

Evaluation method of soil fertility by combination of soil color characteristics and survey data from soil map as well as chemical properties was investigated on total 35 field and pot experiments. Total 35 tobacco fields including 11 fields located at Cheonweon county in Chungnam Province, 9 fields located at Goesan county in Chungbuk Province, and 15 fields located at Youngcheon county in Kyongbuk Province were selected in 1984 to cover the wide range of distribution in landscape and soil attributes. Yields of tobacco grown on the plots of both the pot and field experiment which were not applied with any fertilizer were considered as basic fertility of the soil (BFS). The BFS was estimated by 32 independent variables including 15 chemical properties, 3 color characteristics, and 14 soil survey data from soil map. Twenty-four independent variables containing 16 quantitative variables selected from 24 quantitative variables by collinearity diagnostics and 8 qualitative variables, were classified and analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Tobacco yield of field experiment showed high variations by eight times in difference between minimum and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including quantitative variables was still more confidential than that by a single index and that showed more improvement of coefficient of determination ($R^2$) in pot experiment than in field experiment. Evaluation for the BFS by MLR in field experiment was still improved by adding qualitative variables as well as quantitative variables. The variability in the BFS of field experiment was explained 43.2% by quantitative variables and 67.95% by adding both the quantitative and qualitative variables compared with 21.7% by simple regression with NO$_3$-N content in soil. The regression evaluation for the best evaluation of the BFS of field experiment by MLR included NO$_3$-N content, L value, and a value of soil color as quantitative variables and available soil depth and topography as qualitative variables. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for tobacco field.

• 한국연초학회지
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• 제18권1호
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• pp.54-59
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• 1996

Erwinia carotovora subsp. Carotovora (Ecc), a pathogen of tobacco hollow stalk disease, was isolated for testing susceptibility to streptomycin from diseased plants in burley tobacco growing area. Of 157 isolates tested, 17 isolates (108%) were resistant to the antibiotic at the antibiotic from field soils, which streptomycin had been used continuously for three years for control of the disease was three times higher than those of non-used. There was no difference in virulence and generation time between streptomycin-sensitive and resistant strains.

• 한국연초학회지
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• 제9권2호
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• pp.49-57
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• 1987

This study had been conducted to determine morphological characteristics of soil in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected soils through field experiment. Morphological characteristics of troll affecting the dry weight of tobacco leaves cultivated in the field were investigated Among soil morphological characteristics, topograpy, slope, topsoil depth, soil depth, and soil texture had influenced with high significant on the dry weight of tobacco leaves. For prediction of dry weight (productivity) of tobacco leaves without fertilizer , multiple regression analysis were introduced using soul morphological characteristics. A combination of topography, slope, topsoil depth, and soil texture was very reliable for prediction of productivity. The regression equation was y = -16.88 -14, 34$X_1$ +20.43$X_2$ +50.21$X_3$ -7.54$X_4$ +13.45$X_5$ R = $0.670^{**}$ Where $X_1$ : Topography $X_2$ : Slope $X_3$ : Topsoil Depth $X_4$ : Soil Depth $X_5$ : Soil Texture

• 한국연초학회지
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• 제16권2호
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• pp.128-133
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• 1994

This study was carried out to get agronomic information about the tobacco culture in paddy soil where incidence of grey tobacco leaves used to appearly uptake of iron, manganese and chlorine due to soil acidity and high water level. Application of lime to paddy soil(pH5.4-5.6) reduced content of iron, manganese known as proceeding materials giving rise to variegated grey tobacco after curing, compared with non-treatment. Grey leaves were found mainly at lower and middle stalk positions, and incidence of grey tobacco was lowered by application of lime in the well drained field but was not affected by level of fertilizer application. Amendment of soil acidity by lime tended to decrease chlorine and manganese content in leaves. Nicotine and mangenese content of leaves were lowered by reduction of one-quarter fertilizer level. In case of lime treatment, increase of yield reached to 4-6% comparing with those of non-treatment but price per kg was not affected. Reduction of N fertilizer level to three-quarters had the equal yield but high quality of leaf comparing with standard fertilization in paddy field.