• 한국식물병리학회지
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• 제11권3호
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• pp.282-284
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• 1995

Grey leaf spot on tomato plants was first observed in Sedo-myeon, Puyo-kun, Chungnam province of Korea in 1994. This disease which had not been reported before in Korea exhibited different symptoms from those of other leaf spot diseases on tomato plants. The symptoms were characterized by small irregular-shaped spots on leaves at the initial stage of the infection, subsequent spread and coalescence of the spots throughout the leaves with ultimate necrosis, and abscission from the plants. When healthy tomato plants were inoculated with a conidial suspension of the fungus isolated from the lesion of a diseased plant in a field, the same characteristic symptoms as those in the field were produced. Furthermore, the same pathogen could be reisolated from the lesions formed buy the inoculation. Conidial characteristics of the pathogen were as follows; oblong shape with constricted 3 transverse septa, round-shaped base, round- or point-shaped apex, size of 45~75$\times$12.5~17.5 ${\mu}{\textrm}{m}$, and 3.5 : 1 ratio of length to width. The pathogen was identified as Stemphylium lycopersici and thus this is the first report on the occurrence of grey leaf spot disease on tomato plants caused by s. lycopersici in Korea.

• The Plant Pathology Journal
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• 제37권4호
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• pp.347-355
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• 2021

Ripe rot caused by Botryosphaeria dothidea is one of the serious diseases of postharvest kiwifruit. In order to control ripe rot on Actinidia chinensis cultivar 'Zesy002', several commercial agrofungicides were selected by an antifungal test on an artificial medium. Furthermore, disease suppression by the selected fungicides was evaluated on the kiwifruit by inoculation with a conidial suspension of B. dothidea. On the artificial media containing boscalid + fludioxonil was shown to be the most effective antifungal activity. However, in the bio-test pyraclostrobin + boscalid and iminoctadinetris were the most effective agrochemicals on the fruit. On the other hand, the infection structures of B. dothidea on kiwifruit treated with pyraclostrobin + boscalid were observed with a fluorescent microscope. Most of the fungal conidia had not germinated on the kiwifruit treated with the agrochemicals whereas on the untreated fruit the fungal conidia had mostly germinated. Electron microscopy of the fine structures showed morphological changes to the conidia and branch of hyphae on the kiwifruit pre-treated with pyraclostrobin + boscalid, indicating its suppression effect on fungal growth. Based on this observation, it is suggested that ripe rot by B. dothidea may be suppressed through the inhibition of conidial germination on the kiwifruit treated with the agrochemicals.

• 한국응용곤충학회지
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• 제7권
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• pp.57-59
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• 1969

4종의 탄저병균, Colletrichum panacicola, C. gloeosporides, C. truncatum 및 C. nicotianae의 분생포자형성에 미치는 광선의 영향을 감자과당한천배지에서 각 분생포자현탁액을 Petri접시 전면에 접종하여 시험하였다. C. nicotianae를 제외한 세 탄저병균은 지속광선구에서 다른 두구보다 분생포자형성이 증가되었는데 그 두 구간에는 현저한 차이가 없었다. 공시 탄저병균 별로 보면 C. panacicola의 분생포자량이 가장 적었고 C. gloeosporioides는 중간, C. truncatum은 가장 많았다. 분생포자형성량의 차이는 공시 탄저병균(P=0.99), 광선처리 (P=0.95) 및 그 상호작용(P=0,99)에 따라 통계학적으로 유의성이 있었다.

• 한국식물병리학회지
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• 제11권4호
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• pp.298-303
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• 1995

The biological control effect of Trichoderma harzianum on the Fusarium wilt of strawberry and several factors affecting on its efficacy were examined through pot experiments. T. harzianum grown on wheat barn, rice straw, rice hull, sawdust or barley straw was respectively incorporated into the pathogen-infected soil, and significantly suppressed the strawberry wilt caused by Fusarium oxysporum f. sp. fragariae. The wheat bran or rice straw culture of T. harzianum suppressed the disease incidence more effectively than other substrates for culture, decreasing it to 68% of the untreated control. The conidial suspension of T. harzianum alone or the suspension mixed with crab shell also effectively reduced the disease incidence. The control effectiveness of T. harzianum was high in acid soil (pH 3.5~5.5). In sandy loam soil, the disease incidences and population densities of the pathogen were decreased by the treatment of T. harzianum, while there was no significant effect of T. harzianum on the pathogen in loam soil.

• 한국응용곤충학회지
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• 제18권1호
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• pp.35-41
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• 1979

인삼탄저병에 감염된 포기의 종자에는 $42\%$, 겉으로 건전한 포기의 종자에도 $4\~17\%$의 탄저병균을 보유하고 있었으며, Fusarium, Alternaria, Phoma, Trichoderma 등도 많이 분리되었다. 탄저병균은 실내에 있는 잎의 조직에서 18개월간 생존하였으며, 옥외의 노지, 지하 10, 30cm에서도 월동할 수 있었다. 인삼잎에 탄저병균의 분생자를 접종하였을 때에 $25-35^{\circ}C$ 발병하였고, $17^{\circ}C$이하에서는 전혀 병반이 형성되지 않았다. 암흑구, 400룩스구에서 탄저병반은 미소하였고, 1200룩스구에서 중정도, 직사광선에서는 극심하였다. 그리고 연령이 어린 잎일수록, 분생자수가 많을수록 병반면적율은 높았다. 병원균의 균사생장 및 분생자형성의 최적온도는 $25^{\circ}C$였고, 균사생장의 최적 pH는 2.8-4.2였으며 분생사형성은 5.2-5.8이었다. 포장에서 살균제와 인삼${\cdot}$탄저병균의 분생자를 함께 3년생식물에 처리했을 때 방제효과가 큰 것은 difolatan 그리고 maneb, zineb, captan, phaltan의 순위였으며 ferbam과 보르도액은 약간 낮았다.

• 한국식물병리학회지
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• 제11권4호
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• pp.348-352
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• 1995

Severe gray mold neck rot of onion occurred in most farmers' fields in the southern part of Korea, and 20∼50% of onions were infected by the disease at Goheung, Chonnam, in 1994. Symptoms of the disease appeared on the lower leaves near the soil surface in late February. The symptoms initially appeared as yellowish blotch with compact gray mold on the surface of the infected leaves and developed to blast of the aboveground parts of onions. As brown to dark brown symptoms progressed around the necks of onion later, the bulbs were rotting gradually. Botrytis sp. repeatedly isolated from the lesions produced the typical symptom on the neck of healthy onion 7 days after wound inoculation of conidial suspension of the fungus. The fungus reisolated from the bulbs was identified as Botrytis allii Munn based on the morphological and cultural characteristics and pathogenicity. This is first report of a gray mold neck rot of onion in Korea.

• The Plant Pathology Journal
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• 제29권4호
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• pp.451-453
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• 2013

Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C) between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder's point of view.

• 한국식물병리학회지
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• 제11권1호
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• pp.90-93
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• 1995

Leaf blotch of Welsh onion was observed at a farmer's field at Kangnung in July 1990. Further collection o the diseased materials was made in 1993 and 1994. The symptom initially appeared as discolored spot and later yellowish blotch with the long axis parallel to the leaf veins, which turned to sooty colored concentric lesion due to heavy production of conidiophores and conidia. Cladosporium allii-cepae (Ranojevic) M. B. Ellis was repeatedly isolated from the leaf lesions. Healthy Welsh onion inoculated with conidial suspension of the fungus produced the typical symptom 10 days after inoculation. Koch's postulates were fulfilled by reisolation of the fungus. This is the first report of a Cladosporium leaf blotch of Welsh onion in Korea.

• 한국식물병리학회지
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• 제14권5호
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• pp.467-472
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• 1998

Gray mold rot of perilla was epidemic at Kangdong, Pusan and Miryang, Kyungnam in 1997 and 1998. The incidence of this disease ranged form 21.3 to 68.1% at Kangdong area. Leaf necrosis initially appeared on the edge of the infected leaves, and it was developed to the center of the leaves forming typical V-shaped brown necrotic lesions. Under high moisture condition, abundant mycelia of the pathogen was formed on the surface of the lesions. Infected stems became slender and were completely blighted up to the top of the plant. Two isolates, LVF12 and SD7, were isolated from diseased lesions showing typical symptoms, and the pathogenicity was tested using mycelial disks and conidial suspension inoculation. The developed symptoms were same as the naturally produced ones. These two pathogenic fungi were identified as Botrytis cinerea based on the morphological characteristics using a microscope and a scanning electron microscope, and cultural characteristics. This is the first report of gray mold or perilla in Korea.

• 한국식물병리학회지
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• 제14권6호
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• pp.732-734
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• 1998

Leaf spot of Amelanchier asiatica was observed in Korea.. The major symptoms of the disease were small necrotic spots and severe early defoliation. On the basis of morphological characteristics of the fungus observed from naturally infected leaves, the causal organism was identified as Entomosporium mespili (DC. : Duby) Sacc. The conidial suspension prepared from sporulating lesions was sprayed on healthy leaves with or without wounding to prove pathogenicity of the fungus. Small spots were noticed tow days after inoculation, and acervuli containing numerous conidia were observed 7 and 10 days after inoculation from wounded and unwounded leaves, respectively. This is the first record of the disease on A. asiatica in Korea.