• Research in Plant Disease
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• v.12 no.3
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• pp.284-286
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• 2006

Leaf gall was occurred on Rhododendron indicum(L.) Sweet[=Azalea indica L.] in a farmer's garden located in Geumsan-myon, and along the walk way of Gangju pond in Jeongchon-myon, Jinju, Korea. The infected leaves was deformed into very conspicuous, pale, fleshy shapeless galls. Basidia were fusiform, $3{\sim}5$ sterigma, and $8{\sim}35{\times}3{\sim}6{\mu}m$ in size. Basidiospores were musiform, straight or curved and $10{\sim}22{\times}3{\sim}5{\mu}m$ in size. The causal organism was identified as Exobasidium japonicum Shirai based on the mycological characteristics of the fungus and pathogenicity. This is the first report on the leaf gall of R. indicum caused by E. japonicum in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.2
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• pp.122-129
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• 2016

It is important to know the sensitivity of shrubs to de-icing salt in order to set guidelines for ecological tolerance of evergreen shrubs along roads. Therefore, the aim of this study was to investigate the influence of de-icing salt, calcium chloride($CaCl_2$), on the growth and physiological characteristics of three evergreen shrubs, Euonymus japonica, Rhododendron indicum, and Buxus koreana. Plants were exposed to calcium chloride at different concentrations(weight percentage, 0% as control, 1.0%, 3.0%, and 5.0%) through amended soil maintained from the start of the experiment in October of 2014 until termination in March of 2015. The survival rate, plant height, leaf length, leaf width, leaf shape index, number of leaves, fresh weight, dry weight, dry matter, root/top ratio, chlorophyll contents, fluorescence, photosynthesis, stomatal conduct, and transpiration rate were recorded. Elevated calcium chloride concentrations decreased plant height, leaf length, leaf width, leaf shape index, fresh weight, dry weight, dry matter, and R/T ratio of the three shrubs. Root growth responded more sensitively than the top growth to salinity. However Euonymus japonica was more tolerant to salt stress than Rhododendron indicum and Buxus koreana. Their growths were totally inhibited by $CaCl_2$ above 3.0% and 1.0% concentrations, respectively. Chlorophyll content, fluorescence, photosynthesis, stomatal conduct, and transpiration rate of both Rhododendron indicum and Buxus koreana were reduced sharply, while Euonymus japonica exhibited mild reductions compared to plants grown in control when increasing calcium chloride was used. Especially, the transpiration rates of Rhododendron indicum, and the photosynthesis and stomatal conduct of Buxus koreana were suppressed as the concentrations of calcium chloride increased. Therefore, Euonymus japonica should be considered as an ecologically tolerant species with proven tolerance to de-icing salt.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.75-87
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• 2018

This study was carried out to investigate the effects of planting time on the survival rate and growth. Ilex cornuta Lindl., I. aquifolium 'Silver Queen', Ardisia pusilla 'Variegata', and Rhododendron indicum(Satsuki azalea) were planted in pottery pot six times such as April 1, June 1, July 1, August 1, October 1, and December 1 in 2017. The survival rate of I. cornuta Lindl. planted in April, October, and December was 100%, whereas the survival rates were 90% in June, 50% in July, and 60% in August, respectively. The survival rates of I. aquifolium 'Silver Queen' and R. schlippenbachii were also shown about 60% in July and 70% in August, which were lower than in the other planting times at 100%. However, the survival rate of A. pusilla 'Variegata' was shown 100% in the all planting times. The growth rates of plant length, plant height or leaf length or any others of I. cornuta Lindl. were shown 20.0%, 15.5% and 16.5% planted in June, July, and August, respectively, while those planted in April, October and December were 3.2%, 12.3% and 10.7% respectively. Similarly, the growth rates of leaf numbers and plant length of I. cornuta Lindl., A. pusilla 'Variegata', and R. indicum(Satsuki azalea) planted in summer season from June to August for all plat (not only leaf numbers and plant length in was facilitated, while the growth was restrained in planting for spring or autumn. Therefore, the plantation during summer is better for increasing the survival rate and promoting the growth.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.403-408
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• 2010

This study was carried out to investigate the physiological responses of $Rhododendron$ $mucronulatum$ Turcz. and $R.$ $indicum$ (L.) Sweet seedlings with 0%, 35%, 55% and 75% shading of full sunlight in polyethylene film house. The shading treatments were performed during the late growth season for each species (from Sept. 9 to Nov. 5, 2008). The shading treatment was effective in reducing the daily temperature by 0.9 to $1.7^{\circ}C$ during September and by 0.8 to $1.7^{\circ}C$ during October. Before the shading treatments, the water content of $R.$ $mucronulatum$ and $R.$ $indicum$ amounted to 68.5% and 66.3%, respectively. The water contents of two species after 75% shading treatment period decreased to 66.2% (3.4% reduction) and 65.9% (0.6% reduction), respectively. Notably, both species had a similar tendency indicating less reduction rate of water content with 75% shading. $R.$ $indicum$ showed higher photosynthetic capacity with higher level of shading, and its photosynthetic capacity reached the highest level ($9.63{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). On the other hand, shading-treated $R.$ $indicum$ showed higher intercellular $CO_2$ concentration, stomatal conductance and transpiration rate (55% shading > 35% shading > 75% shading) than non-treated ones. In addition, non-treated seedlings showed higher water use efficiency than treated ones. In particular, it was found that the leaf color of $R.$ $mucronulatum$ turned equivalent to purple under full sunlight, while its leaf color kept equivalent more to green with higher level of shading, as evidenced even in naked eyes. According to comprehensive analysis using Munsell Color Chart on potential leaf color variations of $R.$ $mucronulatum$ depending on the level of shading, it was found that relatively many leaf colors under full sunlight were equivalent to R (red) and Y (yellow) chart, while relatively many leaf colors with higher level of shading were equivalent to G (green) and Y chart, where the latter still showed green color.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.6
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• pp.41-55
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• 2011

This study was carried out to survey and analyze the transition of landscape plants on an apartment complexes in the 1990's and 2000's. The results are summarized as follows; The ratio of landscape area was increased from 30.0% to 34.7%. The number of trees per 100 square meter decreased from 22.5 to 15.7. The number of shrub per 10 square meter increased from 19.3 to 38.7. Species of Evergreen tree were increased 21 to 39. The species that a lot of use continuously were Pinus densiflora, Pinus strobus and Taxus cuspidata. The species that increase use were Abies holophylla and Pinus densiflora for. multicaulis. The species that decrease use exceedingly, were Pinus parviflora, Juniperus chinensis, Pinus koraiensis and Thuja orientalis. The species that do not use were Cedrus deodara. Species of deciduous tree were increased 42 to 68. The species that a lot of use continuously were Zelkova serrata, Acer palmatum, Diospyros kaki, Prunus armeniaca and Prunus yedoensis. The species that increase use were Lagerstroemia indica, Chionanthus retusa, Cornus officinalis, Styrax japonica, Sorbus alnifolia, Prunus mume, Cercidiphyllum japonicum, Acer triflorum, Prunus sargentii, Chaenomeles sinensis and Cornus kousa. The species that decrease use exceedingly, were Acer buergerianum, Sophora japonica, Malus spp., Ginkgo biloba, Zizyphus jujuba var. inermis, Platanus orientalis and Albizzia julibrissin. The species that do not use were Liriodendron tulipifera, Acer saccharinum, Ailanthus altissima and Paulownia coreana. Species of shrub were incresed 39 to 65. The species that a lot of use continuously were Buxus koreana, Rhododendron schlippenbachii for. albiflorum, Rhododendron schlippenbachii, Syringa dilatata and Euonymus japonica. The species that increase use were Rhododendron indicum, Ilex serrata, Spiraea prunifolia var. simpliciflora, Taxus cuspidata var. nana, Kerria japonica, Rhododendron yedoense var. poukhanense, Euonymus alatus, Sorbaria sorbifolia var. stellipila, Nandina domestica, Cornus alba, Hydrangea serrata for. acuminata, Prunus tomentosa, Deutzia parviflora and Pyracantha angustifolia. The species that decrease use exceedingly, were Hibiscus syriacus, Rosa multiflora var. platyphylla, Chaenomeles lagenaria and Rosa spp. The species that do not use were Juniperus chinensis var. sargentii, Jasminum nudiflorum and Sasa borealis.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.1057-1065
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• 2010

Recent urban concerns over environmental problems have furthered interest in green roof system. Plant growth and load bearing capacity of an underlying roof are key factors to determine an optimal system. This study was carried out to develop an optimal extensive green roof system for shrubs assessing the effects of substrate type and soil depth on the growth of $Rhododendron$ $indicum$ Sweet. in the experimental systems with different soil types and depths from 2001 to 2008. Substrate types of perlite alone and blended with sandy loam (v/v, 1:1) were used on the experimental systems with depths of 30 cm, 45 cm, and 60 cm. The survival rate of the plants on the perlite alone + 45 cm soil depth system (RS-A-45) was 100% during the experimental period, while those on the perlite alone + 30 cm soil depth system (RS-A-30) and perlite blended + 60 cm soil depth system (RS-B-60) showed 33% and 67%, respectively, in 2008. The overall plant growth and soil properties of RS-A-45 were superior to the others. At 8 years after installation, the total weight of RS-A-45 including plant fresh weight was about $376.6kg{\cdot}m^{-2}$ in field capacity indicating RS-A-45 can be optimal extensive and light weight green roof system.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.179-184
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• 2008

Host plants of Ectinohoplia rufipes (Mitschulsky) were investigated in golf courses in Gapyeong, Gyeonggi. Ten plant species in 7 families were observed to be fed on from golf courses. Thus, total number of host plants of Ectinohoplia rufipes were 94 species in 30 families. Rhododendron indicum and Rhododendron japonicum for. flavum in Ericaceae, Euonymus alata for. ciliato-dentatus in Celastraceae, Ulmus davidiana for. suberosa in Ulmaceae, Malus pumila var. dulcissima and Malus baccata in Rosaceae, Weigela florida for. subricdor in Caprifoliaceae, Betula platyphylla var. japonica in Betulaceae, Salix purpurea var. japonica in Salicaceae, and Quercus palustris in Fagaceae were newly listed host plants of Ectinohoplia rufipes in golf courses. Betula platyphylla var. japonica, Malus pumila var. dulcissima and Quercus palustris were heavily damaged host plants of Ectinohoplia rufipes.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.243-255
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• 2017

Plants planted in the green-roofed areas in Busan and Jinju were surveyed. The woody plants investigated in this study were classified into 52 families and 156 species, and the herbaceous plants were classified into 30 families and 97 species. Woody plants mainly planted were Rhododendron yedoense var. poukhanense, R. indicum, C. kousa, P. mume, and E. alatus. However, Pinus spp. were planted in all areas. The main herbaceous species planted were Sedum kamtschaticum, S. takesimense, S. middendorffianum, T. quinquecostatus var. japonica, and A. spathulifolius Maxim. According to surveying the distribution of woody plant pests, they could be classified into six orders, 24 families, and 46 species that usually appeared from April to October but especially between June and September. We investigated 39 insect species in relation to pest damage to leaves, 21 insect species in relation to that of branches, and 39 insect species in relation to that of stems of woody plants.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.1-9
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• 1990

Landscape plants as attenuator of vehicular noise were basically experimented with 8 kinds of trees and shrubs at the university nursery, and checked the attenuating effects by the planted distances, species and sound frequencies. The experimental results are shown and sumarized as follows ; 1. Most plants showed the considerable noise attenuating function in the sound frequencies of 63Hz and 1,000Hz. Tall trees such as Juniperus chinensis var. kaizuka and Magnolia grandiflora showed better effects than shrubs or small trees such as Gardenia jasminoides, Osmanthus fragnance, Osmanthrs heterophyllus, Rhododendron indicum, Chamaecyparis obtusa 'Tetragona Aurea' and Pinus paruiflora in 63Hz frequency, but shrubs showed better effects in 1,000Hz. 2. Trees showed 6~8dB attenuation and shrubs 4~5dB regardless an increase of distance between sound source and receiver in 63Hz. 10 meter width of tree belt could reduce 10 more dB, but 5 meter of shrub belt showed the same effect in 1,000Hz. 3. Trees having more leaves and wider crown showed constantly increase of attenuation of sound by the distance in 1,000Hz, and distinct increase of attenuation were observed in 2,000 more Hz.

• KIEAE Journal
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• v.14 no.5
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• pp.49-57
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• 2014

This research is about analysis and evaluation of biodiversity of Suwon's street tree, then understanding the problem of it and finally finding a solution. Because the increasing damage of the street trees by disease and insects, insecticide is applied to prevent further damage. However, this insecticide is found to be cancer genic and causing hygienic threat to civilians. Therefore, by gathering Suwon's internal statistics about Suwon's street tree, the trees are divided into three categories, tall evergreen trees, deciduous trees, shrubs following Frank's 30-20-10 theory(1990). Also, according to species diversity index, the problem of disease and insect is researched in terms of biodiversity, and here we suggests solutions to counter such problems. According to the results, the trees planted in Suwon was found to be 31 families, 43 genus and 58 species. The most used kinds, almost 85% of the whole species, are found to be Rhododendron indicum (L.) Sweet, Buxus koreana Nakai ex Chung & al, Euonymus japonicus Thunb, Ligustrum obtusifolium Siebold & Zucc. Besides these, the rest of 15% of street trees had little variety. Therefore, it is necessary to plant tree variously and equally in terms of biodiversity. If this Frank's 10-20-30 solution is not enough to completely solve coulure problem, then further research will be done on soil properties, and local features for improvement of Suwon street tress.