• 제목/요약/키워드: Jeju Station

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Fusarium Fruit Rot of Citrus in Jeju Island

  • Hyun, Jae-Wook;Lee, Seong-Chan;Kim, Dong-Hwan;Ko, Sang-Wook;Kim, Kwang-Sik
    • Mycobiology
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    • 제28권3호
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    • pp.158-162
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    • 2000

  • Twenty-three isolates of Fusarium spp. were obtained from decayed citrus fruits in the fields and storages in 1998-1999. Of them, six and five isolates belonged to F. proliferatum and F. moniliforme, respectively, which were the most common. F. solani and F. sambucinum had each two isolates, F. equiseti had one isolate and seven isolates were unidentified. They produced symptoms of two types in pathogenicity test: those with leathery, beige to light or dark brown, and sunken lesions without surface mycelium (type-1) and those with lesions covered with white, beige or pink surface mycelium (type-2). Four of six isolates identified to F. proliferatum and two unidentified isolates produced type-1 lesions, and all isolates identified to F. moniliforme, F. solani, F. sambucinum, F. equiseti and five unidentified isolates produced type-2 lesions.

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Studies on Physiology, Ecology and Protection of Citrus Canker Caused by Xanthomonas axonopodis pv, citri

  • Lee, Seong-Chan;Hyun, Jae-Wook;Kim, Dong-Hwan;Kim, Kwang-Sik;Lim, Han-Chul
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.124-124
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    • 2003

  • Citrus canker is very important disease in international trade of citrus. The disease was usually take place from late of June, and severe middle of July to middle of August, though disease occurrence was affected by environmental conditions. In pathogenicity test, three varieties, orange, lemon and kiyomi among 7 varieties, were succeptible, two varieties, satsuma mandarin and iwasachi, intermediate resistant. On the other hand, shiranuhi and yuzu were resistant relatively. The pathogen, Xanthomonas axonopodis pv. citri, grew well in PD broth adjusted to pH 7.0 at 26$^{\circ}C$. It's growth was best in medium containing group of monosaccharide as a carbon source and group of ammonium as a nitrogen source. Tow isolates were resistant to streptomycin among 11 isolates isolated from diseased leaves in field in Jeju-Do. The streptomycin sensitives isolate was controlled by in greenhouse test. On the other hand, the resistant and sensitive isolates were controlled by treatment with copper sulfate, the control value is 88.7％ and 90.6％, respectively.

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Phytophthora-Induced Diseases on Citrus in Jeju Island

  • Hyun, Jae-Wook;Lee, Seong-Chan;Kim, Kwang-Sik;Jee, Hyeong-Jin
    • The Plant Pathology Journal
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    • 제17권3호
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    • pp.184-188
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    • 2001

  • Phytophthora-induced diseases on citrus in Jeju island have been considered of minor importance because of the use as root stock of trifoliate orange, which is immune to Phytophthora. However, brown rot on fruit, which severely occurred in 1998 and 1999, has become a great threat to citrus production in the island. About one-half of the surveyed orchards were infected in 1998 and 4 out of 19 infected fields showed over 20% fruit infection rate. The disease was less severe in 1999, with an estimated infected area and total fruit reduction of 3,155 ha and 15,300 tons, respectively. Typical gummosis was also occasionally observed on cv. Shiranugi, which is mostly cultivated under plastic film houses. Two types of Phytophthora were consistently isolated from various plant parts, identified as P. citrophthora and P. nicotianae. The former was isolated from the aerial parts of the fruit, young leaf, and shoot in the fields. Meanwhile, the latter was only isolated from the basal stem showing gummosis in plastic film houses.

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