• Journal of Ginseng Research
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• v.28 no.3
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• pp.149-156
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• 2004

The objectives of this study were to investigate the morphology of mycorrhizal roots, and the effects of root age and soil texture on the mycorrhizal infection in ginseng (Panax ginseng C. A. Meyer) growing in Korea. Ginseng roots at ages of two to six years were collected from fields in late June. Their infection by arbuscular mycorrhizal fungi(AMF) was studied by clearing the roots and staining fungal hyphae with trypan blue. Root infection varied greatly depending on the developmental stages of young roots. Young tertiary roots, in diameter of smaller than 0.8 mrn, formed during the current growing season had root hairs and were frequently and in some cases heavily infected by AMF. Hyphal coils and arbuscules were abundant, while vesicles were rarely observed. Older secondary or tertiary roots in diameter of bigger than 1.0 mm with fully differentiated primary xylem formed during the previous growing season had no root hairs, and were not infected at all. The rates of mycorrhizal infection in the young tertiary roots were not affected by the age of the ginseng plants, suggesting that fungal populations might have not much changed during the aging of the cultivated fields up to six years. The differences in the infection rates among the different ages of ginseng were caused by differences in the amount of young tertiary roots in the samples. Soil texture, either sandy loam or clay loam, did not affect the rate of root infection. There were large variations in the infection rates among the different farms and locations within a farm. It strongly suggested that infection rates of the ginseng roots by AMF would be influenced by the practice of the farmers, possibly by avoiding consecutive planting, introduction of new topsoil, and the ways of handling the soil before transplanting the ginseng, such as fumigation or sterilization that might have affected indigenous inoculum sources of the AMF.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.31-36
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• 1981

These experiments were conducted to investigate some effects of the soil fumigants Dow-fume MC-2, Cylone, TeloneC-17, and D-D on the growth response of the Korea ginseng(two-year old), Panax ginseng C.A. Meyer, and the chemical composition of the plants. Fumigant treatment increased growth of roots, stems, and leaves. The increase of root growth rates ranging from 2.8 to $58.7\%$ in fresh weight and 8.1 to $63.8\%$ in dry weight were observed in the 2-year old ginseng plants grown in the old ginseng soil treated with the different soil fumigants. The chemical analysis of inorganic elements such as N, P, K, Ca, Mg, Na, Fe, Mn, and Zn was made for the roots, stems and leaves of the 2-year old plants. The increases or decreases of content of the elements were observed, and their contents of each of the elements were changed with the kind of fumigants, part of the plants, and soil depth of the fumigant treatments, but their changing tendencies were not steady.

• 보존과학연구
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• s.32
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• pp.123-136
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• 2011

There are more than 2,800 different species of termites in the world, but just there is one species (Reticulitermes speratus kyushuensis Morimoto) in Korea. Once wooden structures are damaged by termites, we are applying chemical control methods such as fumigation, treatment of insecticidal and antiseptic chemicals, soil termiticide treatment, and termite colony elimination system to pest control. But in Korea, the termite infestation is gradually increasing, so it is essential to study on the present situation of termite control in US or Japan. Accordingly, in this part we have studied focusing on the case of US. In the US, there are three groups of termites : Subterranean, Drywood, Dampwood termites, and they caused more severe infestation compared with Korea. When a structure has become infested with termites, it is important that appropriate action must be taken: the chemical pest control (soil treatment, termite baiting, termite colony elimination), the modification and maintenance of buildings and the regular inspection for follow-up. And with consideration for different characteristics of termites, the process of pest control is made according to each species of termites. Most of the subterranean termite control is done by applying either termiticide to the soil or termite monitoring and baiting system around the structure. On the other hand, drywood termite control methods can be categorized as either the treatment for the whole structure or the treatment for localized area. Applications to the whole structure are done by fumigants or heat and the localized treatments are carried out with chemicals as well as heat, freezing, microwave and electricity.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.139-145
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• 1987

This study was carried out to find out the effects of ammonia gas on the leaf destruction of vegetable crops, and nitrogen contents in their leaves. Radish, chinese cabbage, tomato and cucumber were fumigated with 0.05, 0.1, $0.2mg/{\ell}$ ammonia gas for 2 hrs under different exposure time, light and soil water condition at vegetative growth stage. The results obtained were as follows. The crop damages measured by percentage of leaf destruction were more severe at the night time fumigation than treatment during the day, at the full sun condition than the shading, and at the higher soil water contents. Cucumber plant showed higher resistance to ammonia gas than tomato plant. The chrolophyll contents in leaves of each crops were remarkably decreased by increment of ammonia concentration from $0.05mg/{\ell}$ to $0.2mg/{\ell}$, but the N content in them was increased.

• 보존과학연구
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• s.22
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• pp.41-52
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• 2001

The wooden building is mainly damaged by the termite which have an effect of the structure by making emptied inner part of wood. One class, Japanese termite, inhabits throughout Korea and is often detected. So the deterioration by termite attacking the wooden building needs to be controlled. Termites are over 2,800 species in the world, usually they inhabit in the tropical or subtropical region and don’t over winter in dormant condition. So their activity and distribution are chiefly restricted by temperature and humidity. The termite inhabiting in Korea is Reticulitermes speratus kyushuensis Morimoto, which known to have an optimal temperature range at $12~30^{\circ}C$ and minimum temperature at $6^{\circ}C$ for activation. These temperatures correspond to the mean temperature($5.6^{\circ}C$~$25.8^{\circ}C$) from March to November and the activity time of termitein Seoul. In addition, as a result of environmental pollution by industrial development, the climate of Korea is getting warm. The increase of mean temperature in Korea has been $1.1^{\circ}C$ for the past seventy five years, so it is expected that the damage of wooden building by termite will increase gradually. Therefore, in order to protect wooden building from damages by termite, it needs not only development of new pest control methods, but also studies on the control of environmental factors having an effect on the activity and growth of termite. For the conservation of the large cultural properties such as the wooden building in the open air, it would be effective to use the methods of fumigation, insecticidal and antiseptic chemical treatment of wood materials, soil termiticideinjection treatment, and termite colony elimination system.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.13-19
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• 1992

This study was conducted to determine the efficacy of using uniconazole,[(E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-penten-3-ol)] as a phytoprotectant against $SO_2$ injury in snap been (Phaseolus vulgaris L. 'Strike'). Thirteen days prior to $SO_2$ fumigation, plants were given a 100 ml soil drench of uniconazole solution at concentrations of 0.02, 0.10, 0.25 and 0.50 mg/pot. All four uniconazole concentrations were significantly effective in providing protection against $SO_2$ exposure(3 h at 1.5 ppm), but uniconazole treatment above 0.02 mg/pot severely reduced stem elongation, leaf enlargement, flowering date and pod number and weight. Uniconazole treatment had little or no effect on stomatal conductance but reduced transpiration rate on a whole plant basis by nearly 40%. This may reflect an alteration in canopy structure by reducing stem elongation and leaf enlargement. Although uniconazole did not increase the activities of superoxide dismutase(SOD) and peroxidase(POD) in non-$SO_2$-fumigated plants, it significantly increased those enzyme activities in $SO_2$-fumigated plants. Chlorophyll concentration on the basis of unit area was increased 50-60% by uniconazole. However, the difference was not detected on the basis of dry weight. $SO_2$ increased variable chlorophyll fluorescence (Fv) 48% after 1.5 h of exposure in non-uniconazole treated plants but decreased Fv in the plants after 3 h of exposure. By appliing uniconazole, it was possible to maintain high Fv values in the latter group of plants. These results suggest that the phytoprotective effects of uniconazole are related to its growth-retarding properties as an anti-gibberellin as well as the increase of activites of free radical scavengers such as SOD and POD.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.216-224
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• 1998

The objective of this study was to investigate the effect of sesame monoculture and sesame in rotation (SR) with maize. soybean. barley or rye on reduction of injury by continous cropping in sesame. Field studies were conducted for 3-years (1995~1997) at the experimental field of the Crop Experiment Station. Compared to CS (continuous sesame). SR treatments turned out to keep more organic matter and higher exchangeable cation concentrations in soils. BS (barley and sesame in a 1-year rotation) and RS (rye and sesame in a 1-yea r rotation) treatments had significantly greater available $P_2O_5$ contents in soils than CS, MS (maize and sesame in a 3-year rotation) and SbS (soybean a nd sesame in a 3-year rotation). The pH of the soils under different treatments were not significantly different. SR treatments exhibited significantly lower bulk density and higher pore space than CS. Soil microbial biomass C (SMBC) and N (SMBN) were determined by the chloroform fumigation-extraction method. SMBC and SMBN were significantly higher in soils under BS and RS than those under CS, but only during the 1 year of monitoring. MS and SbS treatments resulted in higher SMBC and SMBN than CS. The occurrence of injury by disease of sesame is the important primary factor of injury by continous cropping, but the disease occurrence with rotation did not decrease in th is experiment. Under CS treatment, the growth and grain of sesame was significantly lower than those under other treatments. Compared to CS, the increments of grain yield of sesame were 68, 63, 57 and 51% for MS, RS, SbS and BS, respectively in the first harvest. In the second harvest, they were 24% for MS, 28% for RS, 20% for SbS and 19% for BS. The average increase ratios during the two years were 41, 41, 34, and 33% for MS, RS, SbS and BS, respectively.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.342-356
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• 2014

This study aims to provide the fundamental data for restoration through the analysis of vegetation structure characteristic for managed area with deforest and fumigation among the places damaged by oak wilt disease in Bukhansan National Park. Study areas were selected in six damaged areas with 18 plots ($20m{\times}20m$) including comparing plots between year 2006 and year 2011 after preliminary study finding the exact location with easy access. Analysis items are density and coverage of under story layer, Importance Percentage of under story layer and Importance Percentage of urban adapted species and alien species. As a result, density and coverage under the canopy layer's vegetation was higher than comparing plot in Musugol valley and Soquicheon valley which 4 years and more passed. And Wondobong, Darakwon, Doseonsa and Dobong valley which had not been passed 3 years after deforestation and fumigation decreased in those of vegetation. However, the plots in Wondobong and Doseonsa was analyzed to be higher in density of shrubs than comparing plot. In terms of distirbution of species in under canopy layer which is grown as a upper vegetation, Quercus serrata and Sorbus alnifolia dominated each other in under canopy layer except for Wondobong and Darakwon. Wondobong continuously maintained Quercus mongolica and Q. mongolica and Pinus densiflora dominated in under canopy layer of Darakwon. S. alnifolia which is Urban adapted species were distributed in most study areas. In terms of alien species, Magnolia obovata and Robinia pseudoacacia were newly intruded in the opened crown, and Pueraria thunbergiana was distributed in Soquicheon valley. As the result of soil analysis, acidification(pH 4.49) and low level of organic matter(3.23%), available phosphate(1.40mg/kg) and exchangeable cation were analyzed and it was considered that those environment poorly support the vegetation growth.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.50-58
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• 1992

Studies were conducted to determine the combined effect of uniconazole [(E) -1-(4-chlorophenyl)-4, 4-demethyl 2-(1,2,4 triazol-1-yl)-1-penten-3-ol] and silver thiosulfate $[Ag {(S_2O_3)}^3\;_2-]$ (STS) on reduction of ozone injury in tomato plants(Lycopersicon esculentum Mill. 'Pink Glory'). Plants were given a 50ml soil drench of uniconazole at concentrations of 0, 0.001, 0.01 and 0.1 mg/pot at the stage of emerging 4th leaf. Two days prior to ozone fumigation, STS solution contained 0.05% Tween-20 was also sprayed at concentrations of 0, 0.3 and 0.6 mM. Uniconazole at 0.01 mg/pot and STS at 0.6 mM were effective in providing protection against ozone exposure(20h at 0.2ppm) without severe retardation of plant height and chemical phytotoxicity, respectively. Combined treatment with uniconazole, STS significantly reduced ozone injury at the lower concentration than a single treatment with uniconazole or STS. Uniconazole treatment reduced plant height, stem elongation and transpiration rate on a whole plant level and increased chlorophyll concentration. STS did not give any effect on plant growth and chlorophyll content but increased transpiration rate in non-ozone-fumigated plants. Ethylene production in the leaves of ozone-fumigated plants was decreased by uniconazole and STS pretreatment, but there was no protective effect on epinasty of leaves in uniconazole-treated plants. STS increased ethylene production in non-ozone-fumigated plants, but it significantly reduced the degree of epinasty and defoliation of cotyledons when plants were exposed to ozone. Uniconazole slightly increased superoxide dismutase and peroxidase activities. But STS showed little or no effects on such free radical scavengers. Day of flowering after seeding was shortened and percentages of fruit set were increased by uniconazole treatment. STS was highly effective on protecting reduction of fruit set resulting from ozone fumigation. These results suggest that combined use of uniconazole and STS should provide miximum protection against ozone injury without growth retardation resulting in yield loss.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.41-49
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• 1992

To determine the efficacy of uniconzaole[(E)-1-(4-chlorophenyl)-4,4-dimethy 2-(1,2,4-triazol-1-yl)-1-penten-3-ol)](XE-1019) as a phytoprotectant against $O_3$ injury in tomato plants(Lycopersicon esculentum Mill. 'Pink Glory'), plants were given a 50ml soil drench of uniconazole solution at concentrations of 0.001, 0,01, 0.1 and 0.2mg/pot thirteen days prior to $O_3$ fumigation. All four uniconazole concentrations were effective in providing protection against $O_3$ exposure(16h at 0.3 ppm). Uniconazole treatment above 0.001 mg/pot significantly reduced stem elongation, leaf enlargement, leaf area and fresh weight of plant, whereas increased chlorophyll concentration. Transpiration rate on a whole plant basis was reduced by uniconazole treatment and $O_3$ exposure. Uniconazole reduced ethylene production induced by $O_3$ injury but had little or no effect on defoliation of cotyledons and leaf epinasty. Activities of peroxidase (POD) and superoxide dismutase(SOD) were slightly increased by application of uniconazole. With increasing exposure time, $O_3$ increased POD activity but decreased SOD activity. The phytoprotective effects of uniconazole were diminished by applying gibberellin at $10{\sim}20$ ppm. These results suggest that the phytoprotective effects of uniconazole are related to its role of increasing activities of free radical scavengers such as POD and SOD, in addition to growth-retardation as an anti-gibberellin.