• The Journal of Natural Sciences
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• v.11 no.1
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• pp.131-135
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• 1999

The objective of this research was to improve moisture retention capacity of pine bark. To achieve this, barks were ground with Wiley mill of hammer mill and were blended with recycled rockwool. Then, changes of soil physical properties were determined. The percentage of particles larger than 5.6 mm was 86.5% in raw materials. The percentage of particles larger than 1 mm decreased and those of particles smaller than 1 mm increased by grinding with Wiley mill or hammer mill. Grinding with Wiley mill showed better effect than those of hammer mill in decreasing particle size distribution. Grinding resulted in decreased total porosity (TP) and air space (AS) and increased container capacity (CC) and residual water content (RW), indication improved moisture retention capacity. The material ground with Wiley mill, than blended with 50% recycled rockwool had 81.1%, 67.7%, 13.5% and 235 ml in TP, CC, AS and RW, respectively. These results indicated that moisture retention capacity was improved by blending with recycled rockwood, but aeration of root media was much better than those of peat+vermiculite(1:1, v/v), which is commonly used in commercial production.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.415-423
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• 2018

Aphid is a typical vector that transfers various kinds of viruses to potatoes. Therefore, it is very important to control aphids moving into potato fields. We investigated the seasonal movement pattern of aphids and its virus transmission rates mainly in the three seed potato production regions at highland in Gangwon-do, Korea. In addition, we identified the aphid species with over-wintering eggs collected from barks or twigs of total 57 tree species around potato fields in winter season. The peak time of summer and winter migration of aphid was at the mid-June and the early October, respectively. A 2.8% of total aphid trapped in yellow water-pan trap was turned out PLRV-borne, and the virus transmission rate was 15.4% by Myzus persicae and 9.1% by Macrosiphum euphorbiae. PLRV-borne aphids started to flow in from the late May, and virus transmission rate of aphid trapped in mid-June was the highest with 10.4%. Totally 14 species of aphid eggs wintered in the 17 species of trees including Acer pictum subsp. mono and Acer pseudosieboldianum at the 11 sites. In particular, because it is not certain that Betula platyphylla var. japonica and Yamatocallis hirayamae do transmit potato virus, but they over-wintered in host plants distributed over a wide area, further research on transmission ability is necessary.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.202-209
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• 1991

This study was carried out to examine seed germination, seedling growth, and biomass production of Eucommia ulmoides. The results were summarized as follows ; 1. Cold moist stratification at a refrigerator showed 60.3% of seed germination, which is the most effective among pretreatment methods. 2. In case of 1-0 seedlings, sixty seedlings per $1m^2$ was the most appropriate density, and the growth quality of seedlings differed significantly among densities. 3. Height growth showed continuous growth pattern and the maximum growth was shown during the period 21 June to 20 July, which corresponds 32.7% of total annual growth. 4. As tree age and DBH increased, the production of bark and leaf increased, however, its increment rate remarkably dropped down after ten years. 5. When tree age was ten years, the rate of bark volume showed the maximum value, 12.42%. 6. Dry weight of barks and leaves and bark volume were positively related to the growth of DBH and height. 7. As tree age increased, leaf area decreased, but the number of leaves increased.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.1-20
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• 1974

These studies are conducted to find out inducing factors for the non-sprouting bud which appears in the utility reclaimed hill mulberry held and to establish control method for it since 1971. The results are as follows： 1. In spring, winter bud does not germinate at all on the top of branches or does wither suddenly after or during its germination. Necrosis and browning are appeared in cortex and phloem of non-sprouting bud branch. In autumn, the deterioration of leaves, the abnormal leaves on the top of branch, and browning of veins or petioles are also observed. 2. The soil of non-sprouting bud mulberry Held were found to be sand loom derived from granite rocks. The sub soil of it was very poor in development of root system because it had hard soil and lower pore space ratio. Especially, the sub soil to bring about severe non-sprouting bud had been easily appeared with deficiency of moisture content because of high density solid. 3. Content of soil moisture was significantly lower in the severe non-sprouting bud soil than in the healthy field. The sub soil o( the healthy field contained proper moisture content. On the other hand, the sub soil of the severe non-sprouting bud held contained almost critical moisture content for wilting. 4. The depth of available soil was shallow in the non-sprouting bud than in the healthy fold. The more rate of the non-sprouting bud was severe, the more available soil depth was sallow. 5. Available boron content in soil was affected by moisture content in soil. There was. lower moisture content in the non-sprouting bud field than that in healthy fold during 5, June to 5, September. 6. There was no significant correlation between soil pH and available boron content. On the other hand, the correlation of the content of organic matter and available boron content appeared to be highly positive significance. 7. The quantity of boron was significantly contained more in healthy mulberry field (0.34∼0.43ppm) than in non-sprouting bud field (0.10∼0.28ppm). 8. Boron content in leaves and barks was significantly lower in the non-sprouting bud trees than in healthy trees. 9. The symptom of non-sprouting bud induced from boron free sand culture was similar with that arised in the non-sprouting bud field. 10. The rate of non-sprouting bud was high by the increased application of lime. Considering the facts mentioned the above, author may conclude that the non-sprouting bud of mulberry tree is caused by boron deficiency, but also it is affected by the parent rocks, organic matter, soil moisture content and lime application. 11. The non$.$sprouting bud may be completely controlled by the application of 6∼9kg borax per 10a mulberry field twice a year in spring and summer.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.98-107
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• 2013

Big and old trees in the scenic spots with the attributes of remote villas are vulnerable to man-made damages and very sensitive to the external environment such as soil conditions, so the corresponding management plans are required. Thus this study has been conducted to survey the big and old trees in the scenic remote villas and suggest the ideal management plans. The results can be summarized as follows. First, regarding the tree heath above the ground, transformation of tree, death of branches, and death of barks are closely related to tree vigor. Particularly, the areas receiving many visitors require prompt countermeasures against the dried and dead tress above the ground and the areas in which dried and dead tress occurred and also the safety measures for the visitors and facilities. Second, regarding the soil environment, visitor traffic is closely related to the tree vigor. In 15 remote villa gardens, 64% of trees are exposed to heavy traffic and the tree vigor has declined due to an increase of visitor. Thus, there is a need to give positive consideration the installation of the complementary facilities and the plantation of herbal plants in the congested areas to form the ground surface that can tolerate the heavy visitor traffic. Third, remote gardens are in general located adjacent to ponds and mountain streams and thus the trees in the waterfront areas require the prompt countermeasures against the decline of growth due to the excess-moisture in the soil. Further the blockage of the sewage system due to the heavy rains dampens the surrounding soil, which results in lethal damages to the trees. Thus, there is a need of the maintenance of the waterfront areas and sewage system before and after the rainy season. In addition, there is a need to establish medium-long term management polices through the recognition of the importance of the main trees of remote villa gardens in scenic spots and prepare the tree management manual depending on the attributes of the corresponding areas. I strongly suggest making manuals for the systematic management as well as the extensive PR activities and education for the preservation of tress on a long-term basis; and furthermore securing the budget and manpower for the research and development of a systematic management system.

• Journal of Nutrition and Health
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• v.49 no.1
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• pp.18-27
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• 2016

Purpose: Our previous study demonstrated the hypoglycemic effects of mulberry (Morus alba L.) leaf and the underlying mechanisms. Here we explored the potency of mulberry twigs (TW) and root barks (RB) in postprandial hypoglycemic effects in vitro and in vivo. Methods: The major components of TW and RB were determined by high performance liquid chromatography (HPLC). Alpha-glucosidase inhibition and glucose/fructose uptake inhibition in Caco-2 cells were determined for TW, RB, and their major components, followed by an oral sugar tolerance test (OSTT) in streptozotocin-induced diabetic rats. Male Wistar rats were fed a high-fat diet for 2 weeks and then a single dose of streptozotocin (35 mg/kg B.W) was administered by intraperitoneal injection. Rats with fasting blood glucose levels above 126 mg/dL were randomly divided into 5 groups (n = 8/group) for the following treatments by gavage for 4 weeks: vehicle (normal control and diabetic control), 200 mg/kg B.W of TW or RB or 100 mg/kg B.W of oxyresveratrol (OXY). Results: OXY and mulberroside A were identified as the major components of TW and OXY, mongolicin, and kuwanon H for RB. A significant inhibitory activity on ${\alpha}-glucosidase$ was found for TW, RB, and OXY (p = 0.0099). There was a dose-dependent inhibition of TW and RB on the intestinal sugar uptakes in Caco-2 cells, showing a greater impact on fructose compared to glucose. The OSTT showed that TW and RB significantly delayed time to maximal concentration (p = 0.0088) and decreased maximal concentration (p = 0.0043) compared to the control group. Conclusion: These results suggest that TW and RB may have a postprandial hypoglycemic effect, particularly in the case of high fructose or sucrose intake. OXY was suggested as a contributor to the hypoglycemic effect of TW and RB. Further studies are needed for the systemic effect of TW and RB in circulation.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.63-69
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• 1978

A bark comprises about 10 to 20 percents of a typical log by volume, and is generally considered as an unwanted residue rather than a potential1y valuable resourses, As the world has been confronted with decreasing forest resources, natural resources pressure dictate that a bark should be a raw material instead of a waste. The utilization of the largely wasted bark of genus Pinus, Quercus, and Populus grown in Korea can be enhanced by learning their chemical properties. However, the chemical study of tree bark grown in korea have never been undertaken. In the present paper, the studies on the chemical properties of bark comprise carbohydrates, lignin, and extractives, composition of reducing sugars and five essential elements. The results may be summarized as follows: 1. Bark are much richer in quantity of lignin and extractives than the corresponding wood, and are chiefly consisted of lignin, extractives and carbohydrates orderly. It is the same with ash contents. Alcohol-benzene extractives of populus bark are the highest among three genus. 2. Although glucose constitutes the major sugar in both pine and hardwoods bark, in pinus, arabinose and xylose are the next but in hard woods, the next is xylose. 3. Essential elements, Ca and Kjeldahl-N are higher in the bark than in the wood. Ca content is the highest among others, and N,K followed it. Essential elements are higher in Quercus than in Populus and pinus.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.405-410
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• 2007

This study was performed to investigate anticancer activities and immuno modulatory activities in the several parts of the A. mono and A. okamotoanum. The cytotoxicity of 1 $mg/m{\ell}$ of the water extracts on normal human lung cell(HEL299) was < 19.5%. The anticancer activity of all extracts were increased in over 55% against AGS (stomach adenocarcinoma), A549 (lung adenocarcinoma), Hep3B (liver adenocarcinoma, and MCF-7 (breast adenocarcinoma) cells. The growth of human immune B and T cells was improved of A. mono and A. okamotoanum in adding 1.0 $mg/m{\ell}$ concentration. The secretion of the IL-6 and $TNF-{\alpha}$ of human immune B and T cells was increased with all extracts of A. mono and A. okamotoanum. All extracts of. A. mono and A. okamotoanum increased NK cell growth. The results showed that the barks and woods extracts of A. mono and A. okamotoanum had useful biological activities. In addition, bark of A. okamotoanuim showed the highest anticancer and immune activities.

• 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.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.50-56
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• 2002

This experiment was carried out to obtain some information about overwintering, physiological and ecological characteristics of apple snails. Another purpose of this experiment was to characterize an appetite for rice plants by apple snails and to elucidate their choice of fresh green ones (vegetables, some other crops, weeds in rice fields). The freshwater snails were found with higher population at sites abundant organic compounds such as plant debris and at regions with high temperature. They also prefer calcium-rich water. This is a naturally occurring process. Apple snails were exceptionally veil-adapted to the south regions of Korea, especially Janghang, Jangseong and Haenam, even if the temperature of winter season is cold below 0$^{\circ}C$. Apple snails were not very selective in their food choice and eat almost everything available in their environment. A snail have something called a radula in its mouth for grinding up its food. A apple snail also chews on fruits and young succulent plant barks. In case of reproduction. apple snails deposit about 157$\sim$784 (average of 321 eggs) milky white to pale orange colored eggs above the waterline. In approximately every 22.4 seconds a new egg appears. The total time needed to deposit a egg mass varies from 58 minutes$\sim$4 hours 13 minutes. Apple snails reproduct actively from May to June and from September to October. An appetite of apple snails for rice plants was the different depending on their size and glowing stage for rice plants. Apple snails had a great appetite of rice plants as well as dropwort, tomato, cabbage, radish, aquatic plants etc. They preferred to eat young rice plants and drastically quit eating rice plants of over 40 cm in height. Thus considering the food preference of apple snail for various plants including rice, they were thought to be a potentially strong predator in fields, especially, at regions with warmer winter.