• The Plant Pathology Journal
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• v.23 no.4
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• pp.295-299
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• 2007

These experiments were carried out to examine efficacy of soil solarization for control of pink root disease by means of mulching with transparent polyethylene sheets in the hot season. The effects of soil solarization on incidence of pink-root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi were investigated. Solarization was dramatically effective in reducing pink root incidence in onion seedling and harvested onion bulb. A 30-day and 40-day solarization treatment significantly improved seedling survival and increased yield of 'Changnyeong-deago' onion while decreasing incidence of pink root. Populations of soil fungi from fields planted to onion were assayed on selective media. Solarization treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil. Increase of yield of onion bulbs was associated with control of soil-borne pathogenic fungi. Soil solarization had beneficial effects on yield, bulb diameter, or incidence of pink root.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.15-23
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• 2001

Effects of growth regulators, scion length and scion diameter on shooting and seedling characteristics were investigated to increase seedling products by root cuttings of lacquer tree. Shoots developed and emerged above-ground from the root scion at 3∼5 weeks after cut plating, most of that was a shoot but some of that were 2∼3 shoots. Otherwise, non-shooting was the reason that cortical layer was decayed. Soaking in zeatin was the most effective on shooting of root cuttings and high concentration was effective. Also soaking on high contents of BA or kinetin was effective on shooting but was lower totally than soaking on zeatin. Seedling characteristics among 3 growth regulators and 3 concentrations were not any difference in statistical significant, but were move excellent than control. As root scion was tall, shoots were developed at early. 15cm length scion was the most excellent to use seedlings but 3cm length scion was wickedness. 10cm scion, however, was highest to product of seedlings than any others. 0.3∼0.5 cm length scion was showed 76% shooting rate at 10 weeks after cut planting, but seedling characteristics were not any difference among the kind of 3 diameters.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.110-114
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• 2016

Background: This study aimed to investigate the effect of harvest time on the growth, yield characteristics and loganin content in Dipsacus asperoides Wall. Methods and Results: Dipsacus asperoides seedlings were planted within a nursery environment in early May 2015 and harvested in early, middle and late October 2015, and early November 2015. Harvest time did not result significant differences in the plant height, stem diameter, branch length, leaf width and aboveground dry weight moreover, no significant differences were observed in root length, number of roots and root diameter. However, the diameter of lateral roots was greater in the harvests from the late October and period thereafter. The highest values of root dry weight and yield were recorded in early November. Specifically, the yield significantly increased from 205 kg/10 a (index: 100) in early October to 358 kg/10 a (index: 175) in early November, in terms of root part weight. Loganin contents of D. asperoides differed significantly among harvest times raging from 0.0766% in early October to 0.1704% in late November, thereby showing an increasing trend in later harvest times. Conclusions: These results suggest that the optimum harvest time for D. asperoides is early November, when the yield is the highest. Harvest time significantly affected loganin contents, which constantly increased from early October until early November.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.62-84
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• 1991

The purpose of this study was to evaluate the cytotoxicity of four root canal sealers(Tubliseal, AH26, Apatite Root Canal Sealer I, Apatite Root Canal Sealer II) in Vitro. The root canal sealers were mixed and filled in molds which were $14{\times}1.25mm$ in diameter, in height to use for cell counting and agar overlary method, and $7{\times}1.25mm$ for millipore filter method and set for 7 days to use for experiment. Silicone and copper plate were used for negative and positive control respectively. Using the culture of L929 fibroblast, total cell number and vital cell number were counted and the ratio of vital cell number to total cell number was calculated on 2 nd, 4 th, 6 th experimental day, and the change of cell membrane permeability was tested by agar overlay method, and the succinate dehydrogenase activity was tested by millipore filter method. The obtained results were as follows. 1. In ail experimental groups, the mitotic activity of fibroblast was reduced when compared with that of negative control group, so ail experimental groups showed cytotoxicity. Apatite Root Canal Sealer I group exhibited mild cytotoxicity, and Tubliseal, AH26, Apatite Root Cenal Sealer II groups exhibited severe cytotoxicity. 2. In the test of the change of cell membrane permeability by agar overlay method, all experimental groups showed cytotoxicity. AH26 group exhibited mild cytotoxicity, and Apatite Root Canal Sealer I group exhibited moderate cytotoxicity, and Tubliseal and Apatite Root Canal Sealer II group exhibited severe cytotoxicity. 3. In the test of SDH activity by millipore filter method, there was no cytotoxicity in Apatite Root Canal Sealer I and Apatite Root Canal Sealer II group, but Tubliseal and AH26 group showed mild cytotoxicity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.4
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• pp.41-54
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• 2011

Tree roots can enhance soil shear strength and slope stability. However, there has been a limited study about root reinforcement of major tree species in Korea because of some experimental difficulties. Thus, this study was conducted to analyze the performance of Japanese larch (Larix kaempferi) and Korean pine (Pinus koraiensis) which are two common plantation species in Korea. Profile wall method was used to measure the spatial distribution of root system and its diameter within 15 soil walls of Japanese larch stand and 13 soil walls of Korean pine stand in Taehwa University Forest, Seoul National University, Korea. Root tensile properties of each species were assessed in the laboratory, and root reinforcements were estimated by Wu model. The study observed that the number and cross-sectional area (CSA) of root in both species could tend to decrease with soil depth. Especially, CSA were well-fitted to exponential functions of soil depth. Mean root area ratios (RAR) were 0.03% and 0.10% for Japanese larch and Korean pine, respectively. Estimated root reinforcement from Wu model were, on the average, 4.04 kPa for Japanese larch and 12.26 kPa for Korean pine. Overall, it was concluded that root reinforcement increased the factor of safety (Fs) of slope for small-scale landslide as the result of two-dimensional (2-D) infinite slope stability analysis considering vegetation effects.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.50-56
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• 1998

Thirty-six $F_3$ hybrid poplar (Populus trichocarpa${\times}$P. deltoides) clones were fumigated with ozone to select for ozone sensitive and resistant clones. Fumigation was applied for 6 to 8 hours each day for approximately 3 months at ozone concentrations of 90 to 115 ppb using by open-top chambers. Height, diameter, number of leaves, total biomass, biomass components, root/shoot ratios, leaf drop and stomatal response were investigated. In summary, ozone generally reduced height, diameter, number of leaves, total biomass, and root/shoot ratios. Ozone stress induced leaf drop and foliar senescence in trees. This study showed very low relationship between total biomass and stomatal conductance. Increased plant resistant to ozone is not always correlated with stomatal behaviour. Probably, characterization of biochemical and other physiological responses to ozone exposure can provide a better understanding of tree response to ozone environment.

• Imaging Science in Dentistry
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• v.42 no.1
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• pp.19-24
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• 2012

Purpose : Field of view and voxel resolution of cone beam computed tomography (CBCT) might affect the diagnostic capability. This study was performed to compare between the standard and HiRes zoom modes in the diagnosis of external root resorption (ERR) using CBCT. Materials and Methods : Sixty three small cavities (0.25 mm depth and 0.5 mm diameter) were simulated on the buccal, lingual, and proximal surfaces at three different levels of 16 roots of teeth. After covering the root with nail varnish, the roots were inserted in the sockets and the model was placed in a water-containing lacuna. CBCT scans were taken in both standard and HiRes zoom modes using NewTom VG (QR srl Company, Verona, Italy). Then, an observer assessed the images to determine the presence or absence of the cavities. This process was repeated by increasing the size and depth of cavities to 0.5 mm depth and 1 mm diameter. Data were analyzed by McNemar test. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio in evaluation of the simulated cavities were calculated. Results : There was a significant difference between the two imaging modes in diagnosing the shallow cavities (p=0.02).The sensitivity of the standard zoom in detecting the shallow cavities was lower than that of the HiRes zoom. The likelihood ratio of the HiRes zoom was higher in the diagnosis of both cavity types. Conclusion : This study suggested that a smaller voxel size in the HiRes zoom mode of CBCT is preferred for diagnosis of ERR.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.48-52
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• 2001

The study was conducted to find effect of irrigation treatment during growth stage on growth and yield of Paeonia lactiflora Pallas L.. In case of top ground part, growth of irrigation treatment at early growing stage(from May 1 to June 12) was larger(stem length of 79.4cm) or thicker(stem diameter of 6.5mm) than stem length of 13.6∼7.4cm and stem diameter of 0.5mm of natural plot and control. The growth of under ground part, root length(34.0cm) and number of root/plant(43.6ea/plant) in irrigation treatment at early growing stage were relatively larger or more number than that of control, and root yield was gained 2,349kg/10a and increased 13% and 8% compare with natural plot and control, respectively. Commercial ratio of root was higher for irrigation treatment at early growing stage, it was increased by 20% than 1,708kg/10a of natural plot.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.73-80
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• 2003

An experiment was carried out at the Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh from March to July, 2001 to investigate the effect of biofertilizers on morpho-physiological characters of okra. The experiment was laid out in a randomized complete block design with four replications. There were nine treatments such as $\textrm{T}_0$ (control), $\textrm{T}_1$ (Azotobacter biofertilizer), $\textrm{T}_2$ (Azospirillum biofertilizer), $\textrm{T}_3$ (Azotobacter+Azospirillum biofertilizers), $\textrm{T}_4$ (Azotobacter+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_5$ (Azospirillum+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_6$(Azotobacter+Azospirillum+Cowdung 5 ton $\textrm{ha}^{-1}$), $\textrm{T}_7$ (Cowdung 5 ton $\textrm{ha}^{-1}$) and $\textrm{T}_8$ (60% Nitrogen). The experimental results revealed that significant variations exist among the treatments regarding morphological characters e.g. plant height, number of leaves/plant, stem base diameter, tap root length, and physiological characters like, root dry weight, leaf area index and crop growth rate. Number of leaves/plant, stem base diameter, root length, root dry weight, leaf area index and crop growth rate were found higher in $\textrm{T}_4$, $\textrm{T}_5$, $\textrm{T}_6$ and $\textrm{T}_8$ than the others. In all the parameters, $\textrm{T}_8$ gave the similar result with biofertilizers in combination with cowdung treatments and $\textrm{T}_7$ showed identical with $\textrm{T}_0$ (control). Biofertilizer treatments had insignificant effect on 1000-seed weight(g). Experimental results mentioned above revealed that morpho-physioligical characters of okra could be modified by the application of biofertilizer+cowdung. However, biofertilizers+Cowdung treatments were comparable to $\textrm{T}_8$(60% Nitrogen) in this study. This suggests that $\textrm{T}_4$ or $\textrm{T}_6$ or $\textrm{T}_5$ were more benificial in environmentally friendly okra cultivation and may be used as an alternative of inorganic nitrogen by saving cost of production and sustaining productivity.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.69-73
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• 2008

Fields experiments were conducted to investigate the effect of various tillage depth (TD) on productivity and quality of C. auriculatum Royle ex Wight from 2005 to 2006. The length of vine was elongated in lower TD treatments as 50 cm longer in 10 cm TD than 30 cm TD, and stem diameter and dry weight had increased in the lower TD. Length, width, and weight of leaves showed the quantitive growth in the lower TD treatments, but the chlorophyll content had increased in the deeper TD treatments. Root number and length had increased in the deeper TD treatments, but the root diameter and decomposed root was increased in the deeper TD. The total yield of root showed the increasing tendency in the deeper TD treatments as 6.2 ton/ha in 10 cm TD and increased as $7{\sim}9%$ in the 20 cm TD treatments.