• Korean journal of applied entomology
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• v.10 no.2
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• pp.109-116
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• 1971

The study involved determination of resistance levels of spider mites to Metasystox, Folidol and C-8514 using slide dip technique: a feid trial of alternative acaricides using an O/P resistant strain. 1. Resistant strains of two-spotted spider mite( Tetranychus urticae Koch) were collected from Taegu, Kyungsan, Chunchun, Yesan, Suwon, Osan and Chungju, and kept in the glasshouse through the experiments. Resistant strains of European red mite (Panonychus ulmi Koch) were collected from Chungju, Taegu, Yesan, Chunchun, Suwon and Whasung, and Wonju susceptible was collected. Immediately after collection, tests were applied. All strains except susceptible populations had regularly been sprayed with Organo-phosphates including Parathion (or Folidol), Metasystox, Phenkapton and Trithion for more than the ten Bast years; and Organo-chlorines such as Kelthane and C-8514 more than five years. Comparisons of the resistant strains and susceptible strains at the $LC_50$ values are as follows: a. With Metasystox, resistance levels of the Chungju, Taegu, Yesan, Chunchun and Suwon resistant strains of P. ulmi were respectively, 96,52,4,3 and 2, times as resistant as the Wonju susceptible strain. b. With Folidol, resistance levels of the Chungju, Chunchun, Yesan, Whasung and Suwon strains of P. ulmi showed respectively, 126, 48, 33, 30 and 6-fold resistance levels over the susceptible strain. c. With C-8514, resistance levels of the Taegu, Suwon, Whasung and Chungju strains of P. ulmi were 42, 31, 30 and 20 times greater than the susceptible strain, respectively. d. With Metasystox, resistance levels of the Taegu, Chunchun, Yesan and Suwon, strains of T urticae were respectively, 32,29,25 and 17 times as resistant as the susceptible strain. e. With C-8514, resistance levels of the Taegu, Chungju and Kyungsan strains of T. urticae showed respectively, 59, 29 and 19-fold resistance levels over the Osan strain. 2. Field trials were carried out to assess the toxicities of eleven alternative materials which would be used for control of O/P resistant strain of Panonychus ulmi. The acaricide groups represented were 2 Organo-chlorines (Kelthane MF and Prethylen), 1 carbamate (Furadan), 1 nitrophenyl (Morocide), 1 carbonate (Morestan), 1 tin(Plictran), 1 fluorine (Nissol), 2 mixtures (Fundal and Banmite) and Organo-phosphate (Phenkapton). Of all acaricides tested Kelthane, Plictran, Fundal and Morestan were the most effective; fol]owed by Banmite, Furadan, Prethylen and Nissol. Sumite and Morocide were intermediate, but Phenkapton(Organo-phosphate) was very poor. In other words, a first application of the above outstanding materials gave very high degrees of control of O/P resistant population of European red mite for about 7 to 12 days. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage to apple trees by any of the acaricides tested of the concentrations used.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.271-282
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• 1993

This study was conducted to investigate the absorbing and/or filtering capacity of woody landscape plants growing in urban and industrial regions of Seoul and Taejon. Korea. Total sulfur content and heavy metal content were analyzed in tree foliage of Pinus densiflora, Pinus koraiensis, Ginkgo biloba. Liriodendron tulipifera, Platanus occidentalis. The total sulfur content in the leaves of woody landscape plants in Seoul and Taejon were remarkably higher than those of the tree leaves in Kwangreung. The total sulfur content of deciduous trees had 2.6 times more than that of coniferous trees. the former had better absorbing capacity of $SO_2$ gas. Especially Ginkgo biloba and Platanus occidentalis were recommanded as absorption trees of $SO_2$ because sulfur content levels of them were the highest among all species and increased until tall coloration. While coniferous trees showed no changes in total sulfur content between four seasons. deciduous trees increased in sulfur during the growing season. Pb content of all species in polluted area were higher than those in unpolluted area. In polluted area, while coniferous trees had higher absorption and accumulation of Pb, deciduous trees had higher absorption of Zn. The content of Pb, Zn and Cu in needle of Pinus koraiensis were more than those of Pinus densiflora, In Pinus koraiensis and Pinus densiflora, heavy metal content in the 2nd year needle were higher than thous in the current year needle. In Pinus densiflora, Pinus koraiensis Liriodendron tulipifera and Platanus occidentalis there was a positive correlation between total sulfur and heavy metals [(Pb+Zn+Cu)/3] content.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.872-878
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• 2014

This study aimed to enhance storage and freshness of strawberry fruits and foliage vegetables by spray treatment with Chlorella vulgaris as a bio-fertilizer. The tested strain, C. vulgaris CHK0008, was isolated from an organically cultivated rice paddy and identified as C. vulgaris by its morphology and 18S rDNA and 23S rDNA sequence homology. We successfully cultured C. vulgaris CHK0008 in BG11 modified medium (BG11MM) and adjusted $2.15{\times}10^6cell/mL$ C. vulgaris CHK0008 to one OD value by measuring the optical density at 680 nm using a UV-vis spectrophotometer. The soluble solid content of 'Seolhyang' and 'Yukbo' strawberry fruits treated by spray application with C. vulgaris CHK0008 was enhanced by 22.2% and 11.5% respectively, compared to untreated controls. Additionally, the decay rates of treated 'Seolhyang' and 'Yukbo' strawberry fruits decreased 63.8% and 74.4% respectively, compared to untreated control. Surface color changes and chlorosis of leaves in leaf vegetables such as lettuce, kale, red ornamental kale, white ornamental kale and beet were observed in samples treated with water spray for 10 days after cold storage. However, the decay rate of leafy vegetables treated with foliar application of 25% C. vulgaris CHK0008 liquid culture was significantly decreased compared to that of the untreated control during storage at $4^{\circ}C$.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.390-399
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• 2014

The objective of this study was to establish a processing technology for preserved leaves based on the results from the examination of the optimal period and condition for dye-absorbing treatment for Eucalyptus cinerea F. Mull. ex Benth. (silver dollar eucalyptus) being used frequently as plant material for flower design. Cut foliages of E. cinerea with uniformly matured leaves were cut into 20 cm lengths and their lower stem parts were placed in dye solution in growth chambers with different temperatures (10, 20, 30, and $40^{\circ}C$), vapor pressure deficits (VPD; 0.23, 0.70, 1.17, and 1.61 kPa), and photoperiods (0, 6, 12, 24 hours) for 3, 6, 9, and 12 days, and then dried in a room of $20^{\circ}C$ for three days. Lower temperature during preserving dye treatment reduced the changes in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Especially, high temperature increased red degree (a) and decreased yellow degree (b) due to browning. Lower VPD reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Shorter photoperiod reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. The ${\Delta}E$ value increased with increasing absorbing duration under three environmental conditions. The flexibility of stem and leaves after dipped into preserving dye solution and dried for 3 days increased with decreasing temperature, VPD and dipping duration. Therefore, the optimal environment condition for dye treatment was 0.23-0.70 kPa VPD at $10-20^{\circ}C$ in the darkness, and the optimal and economical duration was 3 days. These conditions reduced the speed of water loss by decreasing transpiration, so yellowing or browning by rapid water loss deteriorated the quality of preserved leaves out of these ranges.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.35-45
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• 1997

This study has been carried out to estimate carbon fixation, and carbon NPP based on equation form of $Wt=aD^bH^c$ in natural stand of Quercus mongolica and Quercus variabilis in Chungju. The effect of improvement of environment was also evaluated by estimating sink of $CO_2$ gas in forest ecosystem of Korea in a year. The following effects have been obtained in analysing estimate of allometric equation. Equation form of $Wt=aD^bH^c$ was the most adequate, those of $Wt=a(D^2H)^b$, $Wt=aD^b$ estimate of the biomass and the carbon fixation in Quercus natural stand of Chungju. Total above ground of Quercus mongolica was 130.58 t/ha and that of Quercus variabilis was 137.38 t/ha. Annual production of two stands was 9.96 t/ha/yr, 8.64 t/ha/yr, respectively. Carbon fixation of total above ground was 60.52t C/ha in Quercus mongolica stand, and was 62.22t C/ha in Quercus variabilis stand. Annual fixation of carbon was 4.78t C/ha/yr and 4.28t C/ha/yr, seperately. Annual emission of carbon estimated 2.44t C/ha/yr in contrast of forest area in Korea. It was showed that the annual fixation of carbon was higher 1.84t C/ha/yr~2.34t C/ha/yr than annual emission of carbon. But foliage was 2.39t C/ha/yr and 1.89t C/ha/yr, which occupied 40% and 50% of annual carbon fixation of total above ground. Annual carbon fixation may fluctuate about 1.89t C/ha/yr~2.39t C/ha/yr by seasons.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.26-34
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• 2015

This study was carried out to evaluate the growth characteristics, carbon and nitrogen content of containerized 1-0 Chamaecyparis obtusa seedlings at various levels of fertilizer (2 g/L, 1 g/L, control) and three container volumes (500 mL, 400 mL, 320 mL). The growth of root collar diameter was highest in the 2 g/L (3.14 mm), followed by the 1 g/L (2.75 mm) and control (2.41 mm) treatments, while the height of seedling was significantly higher in the 1 g/L (21.88 cm) than other treatments (2 g/L: 20.92 cm; control: 19.06 cm). The growth of root collar diameter by container volume was better in the 500 mL than in the 320 mL. Dry weight of seedling was the highest in the 1 g/L ($4.41g\;seedling^{-1}$), followed by the control ($3.67g\;seedling^{-1}$) and the 2 g/L ($2.92g\;seedling^{-1}$) treatments. The dry weight of seedlings by container volume was significantly higher in the 500 mL than in the 320 mL. Nitrogen concentration in foliage was ranged from 1.51% in the control to 2.45-2.60% in the fertilizer treatments. However, carbon concentration of seedlings was not affected by the fertilizer or the container volume treatments. The growth of seedlings following planting in mountain area was better in the fertilized seedlings compared with in the unfertilized seedlings. The results indicate that the 1 g/L fertilization was an optimum rate for growth following planting of Chamaecyparis obtusa seedlings.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.155-162
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• 2008

The Welsh onion beet armyworm, Spodoptera exigua (Hubner), has attacked Welsh onion and is now the most important pest of Welsh onion in southwestern Korea. The beet armyworm has a wide host range, occurring as a serious pest of vegetable and fields. The relatively high abundance of beet armyworm has stimulated frequent application of insecticides to foliage. Insecticide resistance is a major problem in management of this insect. Accordingly, pesticide application for the control of beet armyworm was tried in both the open field and in laboratory, using 4 synthetic compounds such as metaflumizone and chlorfenapyr, indoxacarb, flufenoxuron, emamectin benzoate. In the laboratory, each developmental stages from eggs, larva to pupa was tested against 4 insecticides. Against the eggs of welsh onion beet armyworm, there was no significantly different with each other. These tested chemicals no killing effect to eggs. However, the population of 1st larva hatched from eggs were reduced because they eaten the egg shell with residual insecticides. The tested insecticides were taken very high mortalities to 1st to 3rd larva of Welsh onion beet armyworm. Otherwise, there were decreased the death rate from 4th to 6th larva. On the other hand, their value of control effects were relatively good against Welsh onion beet armyworms in the field between 87.2 and 90.5% on 10 days after insecticide application.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.28-39
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• 2017

The purpose of this study was to analyze the tendencies of the written test questions regarding the scientific plant names in the subject of scenic planting in the national qualification test for landscape engineers. To achieve this purpose, targeting the 20 questions in the subject of scenic planting, the study chronologically analyzed the types of the presented questions about the scientific names of the plants, the changes in their year-to-year number, and their presentation frequency over the past 11 years from 2006 to 2016. The following was found by an analysis of the tendency of the questions presented over 11 years from 2006 to 2016 regarding the scientific plant names in scenic planting in the written test of the national technical qualification examination for landscape engineers. The number of these questions was 234, and they were classified into 13 items: scientific names, families/genuses/ species, characteristics, barks, roots, foliage, flowers, fruits, properties, places of origin, stalks, leave, and uses. After analyzing the examination question trends per year, the year in which the highest number of questions was given was 2013 at 56.6%; the ratio of questions asking botanical names increased until 2013, although that ratio decreased starting in 2014 due to consistent efforts from the landscaping field. The plant species most frequently asked about were Betula platyphylla and Taxus cuspidata and others frequently asked about included Pinus densiflora, Acer palmatum, Forsythia koreana, Cercis chinensis, Robinia pseudoacacia, Cornus officinalis, Zelkova serrata, Abies holophylla, Camellia japonica, Sophora japonica, Chaenomeles sinensis, which were asked about more than 10 times. The number of plant species presented as question items or choice items was 240 and their presentation frequency was 806, Among these, 66 species were steadily presented more than five times. They were presented 486 times, accounting for 27.5% of all species. The number of the new plant species which began to be presented in 2009 were 119(49.58% including Quercus myrsinaefolia) of all 240 species, indicating that their presentation frequency was gradually increased. As a result of comparative analysis of questions on arbor and shrub, evergreen and leaf abscission that have been presented for recent 11 years, the questions on arbor were more than shrub, the questions on leaf abscission were more than evergreen.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.1-15
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• 1980

The occurrence of witches' broom of Rhus javanica was first noticed in Korea by the author in 1979. Subsequently, studies were made on the symptomatology, etiology, and transmission of the disease, as well as the effect of some antibiotics on the disease development. The results of these studies are summarized as follows: 1. Symptoms of the infected plant were characterized by dwarfing of the tree accompanied by yellowing and brooming of the foliage. 2. Electron microscopy of witches' broom diseased Rhus javanica plant revealed the occurrence of numerous mycoplasma-like organisms (MLO's) in the phloem tissue cells (sieve tube elements and phloem parenchyma cells) of the rachis and midribs of infected leaves. 3. The MLO's were bounded by a single unit membrane and contained ribosome-like granules and strands presumed to be DNA. It also appears that the MLO multiply possibly by budding as well as binary and plurinary fission. 4. In the midrib of healthy leaves, vascular bundles were collaterally discontinuous. In the diseased leaves, however, xylems were connected to each other and phloem cells showed an atrophy. Granules, which were prominent in the normal abaxial epidermis, were not observed in the peidermis of diseased leaves. 5. Electron microscopy revealed crystals or osmopholic granules in the phloem parenchyma cells, and that normal stacks of grana were not developed in the chloroplasts of infected levels. 6. The disease was experimentally transmitted by grafting. Budding was more effective than crown grafting for transmitting the disease. The disease has been transmitted by grafting even when complete union of stocks and scions has not taken place. The disease agent was not transmitted by sap inoculation. Insect transmission has not been confirmed. 7. Dipping the roots of infected plants into the 500 ppm and 1,000 solutions of either tetracycline HCI or oxytetracycline, HCI was more effective on temporary remision of the symptoms than spraying the 100 ppm and 200 ppm solutions of the same antibiotics. A greater effect was achieved through dipping into 1,000 ppm than into 500 ppm.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.103-118
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• 1989

The occurrence of witches' broom in Ligustrum ovalifolium was first noticed in Korea by author in 1984. The present study was carried out with particular emphasis on the symptomatology, etiology, transmission of the disease and antibiotic treatments. The infected tissue was observed by the fluorescence and electron microscopy and its biochemical characteristics were compared with healthy one by electrophoresis. The results are summarized as follows : 1. symptoms of the infected trees were characterized by the dwarfing of the organs, yellowing and brooming of the foliage. 2. The observation by the trans electron microscopy on the witches' broom of L. ovalifolium revealed the occurrence of numerous mycoplasma-like organisms(MLOs) in the phloem tissue cells of the midribs of infected leaves. 3. The MLOs were surrounded by a single unit membrane, and they appeared to be multiplied by binary fission. 4. The presence of crystals unidentified in the phloem parenchyma cells was noticed by electron rnicroscopy, 5. The disease was able to be transmitted by budding, crown, and greenwood graftings to L. ovalifolium, L. obtusifolium, L, japonicum and also transmitted, even when the stocks and scions were not completely grafted. 6. Insect transmission on L. ovalifolium and L, obtzrsifolium was carried by Hishimonus sellatus. 7. The infected roots dipped in the 1,000 ppm of teracyclin solution was only temporarily effective in controlling the disease. 8. Infected plant with MLOs showed specific fluorescent reactions in phloems with DAPI stain. 9. The protein and peroxidase separated by electrophoresis showed strikingly distinctive difference between the healthy and diseased leaves.