• Title, Summary, Keyword: chestnut tree

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Characteristics of Hypovirulent Strains of Chestnut Blight Fungus, Cryphonectria parasitica, Isolated in Korea

  • Lee, Sang-Hyun;Moon, Byung-Ju;Lee, Jong-Kyu
    • Mycobiology
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    • v.34 no.2
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    • pp.61-66
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    • 2006
  • Chestnut blight disease caused by Cryphonectria parasitica is widely distributed throughout chestnut tree plantations in Korea. We surveyed 65 sites located at 9 provinces in South Korea, and isolated 248 virulent and 3 hypovirulent strains of chestnut blight fungus. Hypovirulent strains had dsRNA virus in the cytoplasm, which is one of the typical characteristics of hypovirulent strains. In addition, they showed more characteristics of hypovirulent strains, i.e., suppressed conidiation, reduced pigmentation in colony color, and reduced phenol oxidase activity as well as reduced pathogenicity. Hypovirulent strains, KCPH-22, KCPH-135 and KCPH-136, had a genomic dsRNA band with the molecular weight of 12.7 kb, which is the L-dsRNA of CHV1. They also had a 2.7 kb defective dsRNA band. Single conidia isolated from hypovirulent strains were cultured and various phenotypes and absence of dsRNA bands were obtained from single conidial cultures, which means that hypovirulence transmission is unstable in asexual reproduction and variations in viral heredity by asexual reproduction. Biocontrol trial using hypovirulent strains was also carried out in the chestnut tree plantations, and canker expansion in the treated trees was stopped and healed by callus formation at the margin of the canker. These results show the potentials in successful biocontrol of chestnut blight if the vegetatively compatible hypovirulent strains could be directly used around the canker formed by compatible virulent strains.

Study on Effective Use of Aged Chestnut Woods as Furniture Materials (가구재로써 노령 밤나무재의 효율적 이용에 관한 연구)

  • Moon Sun-Ok;Kim Chul-Hwan;Kim Jong-Gab
    • Journal of the Korea Furniture Society
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    • v.15 no.2
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    • pp.53-62
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    • 2004
  • This study explored the development of wood furniture made of aged Castanea crenata Sieb. et Zucc, which has been largely planted in the southern area since 1960s and has hardly been used as furniture materials. First, the physical properties of the chestnut wood including specific gravity, stiffness, and shrinkage were compared with Zelkova serrata, Acer palmatum Thunb., Fagus crenata var. multinevis, Quercus, Tagayasan, Prunus serrulata var. spontanea, Juglans sinenis, Pteronrpus santalinus, Diospyros ebenum, and Fraxinus rhynchophylla, which have largely been used in manufacturing furniture. The chestnut wood had appropliate physical properties for wood furniture like other furniture woods. A piece of small table 50 cm in width, 50 cm in length and 60 cm in height by the chestnut tree was created for a current interior space. Since the diameter of the chestnut tree planted since 1960s is below around 30 cm, the top plate of the table had to be put together by an end-joint technique using a small strip. Finally, it is expected that this study will create a greate motivation for furniture designers, furniture studios and furniture companies in Korea to use the woods from the aged chestnut tree in developing furniture in the future.

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Disease Symptom and Effect of Water Potential on Mycelial Growth of Botryosphaeria dothidea Associated with Chestnut Tree (Botryosphaeria dothidea에 의한 밤나무의 병징과 병원균의 균사생장에 미치는 Water Potential의 효과)

  • Sung Jae Mo;Han Sang Sup
    • Korean Journal Plant Pathology
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    • v.3 no.1
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    • pp.13-16
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    • 1987
  • Infection rate of chestnut tree by Botryosphaeria(Dothiorella) dathidea was about $10\%$ at Gapyung area. disease symptom of chestnut did not appear in October but appeared in November, showing $50\%$ in May in ext year. B. dothidea was more pathogenic to chestnut than did Catinula sp. and Fusicoccum sp. B. dothidea uses soft rot, but Catinula sp. and Fusicoccum sp. causes dry rot. Mycelial growth of B. dothidea was optimal at $28^{\circ}C$. Mycelial growth was stimulated when water potential decreased from -2 bars to -12 bars and declined from -12 bars to -60 bars.

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Basic Study for Introduction of Chestnut Production Regulation Direct Payment (밤 생산조절직불제 도입을 위한 기초연구)

  • Park, Yong Bae;Choi, Soo Im;Kim, Se-bin;Kwak, Kyung-ho
    • Journal of Korean Society of Forest Science
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    • v.97 no.3
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    • pp.348-356
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    • 2008
  • There is the need of regulating chestnut production because of being expected with chestnut trees cultivation farmhouses to be in a difficult situation by means of FTA negotiation promotion hereafter in Korea. And this study is aim to establish compensation criteria and plan for depreciation of income of farmers who take part in chestnut production regulation. We surveyed one hundred and thirty three among chestnut trees cultivation farmhouses in chief producing districts Kyung-nam, Jeon-nam and Chung-nam in Korea. As the result of this study, this study showed compensation criteria and plans for depreciation of income for farmers's participate in chestnut production regulation and showed criteria for closing chestnut old tree orchard and working process of cutting chestnut old tree. Procedures in closing chestnut old tree orchard in a day per hecta were felling operation and crude manufacture of thirty trees per one man, five forklains in loading and unloading chestnut log from a truck and building of workroad, the two number of assistance persons in loading and unloading chestnut log from a truck, the 6.94 trucks in carrying chestnut log. After farmers close chestnut trees orchard, government cost of old trees cuts and net income decrease for 3 years in case of planting trees for landscape and environment preservation.

EVALUATION OF DISEASE RESISTANCE AND SUSCEPTIBILITY TO CHESTNUT BLIGHT FUNGUS, CRYPHONECTRIA PARASITTCA, OF CHESTNUT VARIETIES IN KOREA

  • Lee, Sang-Hyun;Hwang, Myung-Soo;Kim, Kyung-Hee;Lee, Jong-Kyu
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • pp.69.2-70
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    • 2003
  • For the selection and breeding of chestnut varieties resistant to the chestnut blight fungus Cryphonectria parasitica, disease resistance and susceptibility of 28 varieties widely planted and growing in Korea were evaluated by artificial inoculation of a pathogenic fungus. For this experiment, a typical virulent strain (KCPC-19) was selected. Artificial inoculation was conducted into all varieties by using two different materials and methods, i.e., bark and wood tissue sections in the laboratory and living trees in the field. In the bark and wood tissue section method, the size of necrotic area and canker development on chestnut varieties were examined and compared 4 days after inoculation. There were wide variations of chestnut varieties in disease resistance and susceptibility against chestnut blight fungus, but 3 varieties, Daebo!, Ishizuchi, and Sandae, were shown to be relatively resistant to the disease with the necrotic area of 0.95-1.03 cm2, while Arima was the most susceptible with the size of 2.0 cm2. In the living tree inoculation examined 5 weeks after inoculation, 3 varieties, Daebo, Ishizuchi, and Riheiguri, showed the higher resistance, but Tono 2 did the highest susceptibility among tested varieties.

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Fractal Analysis of Electrical Tree Patterns Occurred in XLPE (XLPE에서 발생하는 전기트리 패턴의 프렉탈 분석)

  • Kim, Duck-Keun;Lim, Jang-Seob;Lee, Jin;Chun, Ki-O;Kim, Tae-Sung
    • Proceedings of the KIEE Conference
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    • pp.2060-2062
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    • 1999
  • When the high voltage is applied on insulation materials that have voids and impurities inner one, then probability of electrical tree inception is increased at defects. Electrical tree gives a profit to degradation analysis, because it is possible to observe by eyes and provides electrical degradation step. And electrical tree is divided to three types in usual - tree type, bush type and chestnut type tree. But these three types are divided not by method of quantitative analysis but visual and experiential analysis. In this paper, three types of electrical tree were calculated by quantitative analysis using fractal mathematics and classified to fractal dimensions (FD). FD of tree types are 1.1$\sim$1.4, bush types are 1.4$\sim$1.6 and chestnut type trees have above 1.6 FD.

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Effects of Biological and Environmental Factors on the Occurrence of Chestnut Blight in Chestnut Tree Plantations (밤나무 재배지에서의 생물적, 환경적 요인이 밤나무 줄기마름병 발생에 미치는 영향)

  • Lee, Sang-Hyun;Kim, Kyung-Hee;Byun, Jae-Kyung;Lee, Jong Kyu;Moon, Byung-Ju
    • Journal of Korean Society of Forest Science
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    • v.95 no.1
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    • pp.139-144
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    • 2006
  • Chestnut trees have been severely damaged by the various cankers in Korea. Field surveys for elucidating the relationships between disease occurrence and environmental factors, i.e., tree age, temperature, rainfall precipitation, direction, degree of slope, chemical properties of soils, and so on, were carried out in the chestnut tree plantations located at Gyeongnam, Jeonnam, Chungnam, and Gyeonggi-Do Province. Totally, one thousand and one hundred thirty seven trees from 36 experiment plots were investigated. Trees infected by at least one of the canker fungi were estimated up to 66%. The most severely infested area was Sunchon in Jeonnam Province with the rate of 80%, while the most lightly infested area was Kongju in Chungnam Province with 39%. Disease occurrence was found to be highly correlated with tree age. The disease occurred most frequently on trees ranged from 7 to 12 years old, while it was relatively low on trees below 5 years old or above 25 years old. Canker positions on the tree formed by the pathogenic fungi were most often at 1.6-2.0m above the ground. Over five hundreds bark samples from the canker area on the tree were collected and the pathogenic fungi were isolated. The most commonly isolated fungus was identified as Cryphonectria parasitica, the chestnut blight fungus.

On the Extending for the Plywood Glue by Bark Powder of Persimmon Tree and Chestnut Tree (감나무와 밤나무 수피(樹皮)를 이용(利用)한 합판(合板) 접착증량(接着增量)에 관(關)한 연구(硏究))

  • Suh, Jin-Suk;Doh, Geum-Hyun;Jo, Jae-Myeong
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.3
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    • pp.17-21
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    • 1988
  • In order to investigate the extending effects on urea-formaldehyde resin- or phenol- formal- dehyde resin- glued keruing plywood, hot pressing temperatures were controlled to 110, 140, 170 and $200^{\circ}C$. As the extender, wheat flour, persimmon bark powder, chestnut bark powder, the equivalently- extended with the above three powders, and diatomite powder were respectively mixed with 5, 10, 15 and 20% ratios to the resin liquid, and also with these the no- extended was allowed. Based on the measured bonding strength, the conclusions were drawn: 1. In the urea- formaldehyde resin, extending effects on the bonding strength were in the order of wheat flour, the equivalently- extended with the wheat flour, persimmon- and chestnut bark powder, persimmon bark powder, chestnut bark powder. In the phenol- formaldehyde resin, the effects in the order of wheat flour, persimmon bark powder, diatomite powder, chestnut bark powder were resulted in. Specifically, superior bonding strength to the no-extended were given with the wheat flour and persimmon bark powder. 2. On the whole, the bonding strength decreased gradually, as the hot pressing temperature increased except for the diatomite powder extending.

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Study on Chestnut Insect Pests by Environmentally Friendly Controls in Korea (친환경적 밤 종실해충 방제 연구)

  • Lee, Chong-Kyu
    • Korean journal of applied entomology
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    • v.48 no.1
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    • pp.95-100
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    • 2009
  • This study was conducted to develop environmentally friendly control techniques to reduce chestnut insect pests. The study sites were selected in intensive chestnut orchards of Jinju city, Gyeongnam province. In early and middle-ripening cultivars of chestnut tree, the damage of chestnut fruits by Dichocrocis punctiferalis was significantly lower in wromstop than other treatment such as wromstop+wood vinegar, Capture-machine (p<0.05), While there was no significant difference among treatments in late-ripening cultivars. The hight control effect for D. punctiferalis was showed the highest in wromstop treanment with 40.49% and 41.89% in early and late-ripening cultivars. The control effects for Curculio sikkimensis in late-ripening cultivars of chestnut tree were 34.59% in wromstop imidacloprid treatment and 28.94% in air control treatment.

Analysis of Management State of Chestnut Cultivation (밤나무 재배 경영실태 분석)

  • Park, Yong Bae
    • Journal of Korean Society of Forest Science
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    • v.97 no.4
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    • pp.398-407
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    • 2008
  • This study is to give management state information about changes of income and net profit due to the fluctuations of chestnut prices to someone who will manage a chestnut orchard or has been managing a chestnut orchard in the market opening time. This study, hence, evaluated 133 households who manage a chestnut orchard at Jin-ju, San-cheoung in Gyeong-nam, Gu-rae in Jeon-nam, Gong-ju, Bu-yeo, and Cheoung-yang in Chung-nam. This study analyzed three scenarios by chestnut prices and by tree ages to provide informations for working expenses, production cost, income and net income to cultivators. In case of chestnut of one thousand won, the income of chestnut trees generated from nine ages and the net income is obtained from ten ages and turned into deficit from twenty-eight ages. In case of chestnut of one thousand and five hundred won, the income of chestnut trees generated from seven ages and the net income is obtained from nine ages. In case of chestnut of two thousand won, the income of chestnut trees generated from six ages and the net income is obtained seven nine ages. We calculated out labor costs and material cost and figured out management cost by tree ages. Namely two man and twenty woman are employed in harvesting 3,000 kg by hectare from ten till eighteen ages maximum harvesting seasons. Material cost is fertilizer cost, agricultural chemicals cost and seeding cost.