• Title/Summary/Keyword: zonate leaf spot

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Zonate Leaf Spot of Sorghum Caused by Gloeocercospora sorghi in Korea

  • Chul Heo;Kim, Jung-Nyo;Hyun, Ik-Hwa;Heo, Noh-Youl
    • The Plant Pathology Journal
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    • v.15 no.4
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    • pp.242-246
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    • 1999
  • Gloeocercospora sorghi caused the zonate leaf spot on sorghum (Sorghum bicolor Moench) in fields in Korea. The zonate spots were conspicuous on sorghum leaves as circular, reddish purple bands alternating with tan or straw-colored areas, which formed a coarsely zonate pattern. The lesions often occurred in semicircular patterns along the margin of leaves. The fungus produced sporodochia on the surface of infected leaves in a moist chamber. The conidia, born in a pinkish to salmon-colored slimy matrix, were hyaline, elongate to filiform, straight or slightly curved, 3- to 17-septate, and of variable lenght (28-197 x 1.6-$3.4\mu\textrm{m}$). G. sorghi isolated from diseased leaves of sorghum caused characteristic reddish-brown water-soaked leaf spots when inoculated to seedlings.

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Zonate Leaf Spot of Acer negundo Caused by Cristulariella moricola in Korea (Cristulariella moricola에 의한 네군도단풍 둥근무늬낙엽병)

  • Cho, Sung-Eun;Park, Ji-Hyun;Lee, Sang-Hyun;Lee, Hyang-Burm;Shin, Hyeon-Dong
    • Research in Plant Disease
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    • v.18 no.1
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    • pp.45-48
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    • 2012
  • In early August of 2011, following a prolonged period of cool and moist weather, several trees of boxelder maple (Acer negundo) planted in Mt. Soyo located in Dongducheon, Korea, were found to be heavily damaged by premature defoliation with zonate leaf spot symptoms. Numerous number of cone-shaped, white sporophores (conidia) were observed on lesions of the abaxial leaf surface. The morphological characteristics of conidia are of typical Cristulariella moricola, which was supported by analyzing sequences of internal transcribed spacer region of ribosomal DNA. Pathogenicity of the fungus was proved by artificial inoculation in the condition of relative humidity 100% and $18{\pm}2^{\circ}C$. This is the first report of the occurrence of zonate leaf spot caused by infection of C. moricola on A. negundo in Korea.

Incidences of Leaf Spots and Blights on Kiwifruit in Korea

  • Jeong, In-Ho;Lim, Myoung-Taek;Kim, Gyung-Hee;Han, Tae-Woong;Kim, Hong-Chul;Kim, Min-Ji;Park, Hyun-Su;Shin, Soon-Ho;Hur, Jae-Seoun;Shin, Jong-Sup;Koh, Young-Jin
    • The Plant Pathology Journal
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    • v.24 no.2
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    • pp.125-130
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    • 2008
  • Various kinds of leaf spots and blights were found in kiwifruit (Actinidia deliciosa) orchards on 2006 in Korea. Disease incidences were quite variable between open-field and rain-proof shelter. Rate of diseased leaves was recorded as about 70% at open-field orchards in late season but use of rain-proof vinyl shelters alleviated the disease incidences by 20%. Angular leaf spots appeared at early infection stage on June and several other symptoms were also recognized as the disease developed afterward. On September, brown leaf blights were the most frequent, followed by grayish brown ring spots, silvering gray leaf blights, zonate leaf blights, dark brown ring spots and angular leaf spots at open-field orchards. Four fungal species were frequently isolated from the disease symptoms. Phomopsis sp. was the most predominant fungus associated with the leaf spot and blight symptoms on kiwifruit, followed by Glomerella cingulata, Alternaria alternata and Pestalo-tiopsis sp. Phomopsis sp. was commonly isolated from angular leaf spots, silvering gray leaf blights, and zonate brown leaf blights. G. cingulata, A. alternata and Pestalotiopsis sp. were isolated from grayish brown ring spots (anthracnose), brown ring spots and zonate dark brown leaf blights. Typical symptoms appeared on the wounded and unwounded leaves, which were inoculated by each of Phomopsis sp., G. cingulata, and Pestalotiopsis sp., but A. alternata caused symptoms only on the wounded leaves.

Occurrence of Target Leaf Spot of Red and White Clovers Caused by Stemphylium sarciniforme in Korea

  • Cho, Hye-Sun;Yu, Seung-Hun
    • The Plant Pathology Journal
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    • v.16 no.6
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    • pp.328-330
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    • 2000
  • A terget leaf spot of red and white clovers was observed during 1998-2000 growing seasons in several fields of Chungnam and Chungbuk provinces in Korea. Lesions were circular to oval in outline, brown to dark brown, ranging from a pinpoint to 3-4 mm in diameter, often concentrically zonate and presenting a target effect. A fungus associated with the disease was identified as Stemphylium sarciniforme based on the morphological characteristics of the conidiophores and conidia. The fungus was pathogenic on red and white clovers in the inoculation test. This is the first record of a terget leaf spot of red and white clovers in Korea.

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