• The Plant Pathology Journal
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• v.19 no.4
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• pp.200-202
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• 2003

Leaf spots were first observed on watermelon (Citrullus vulgaris Schrad) under polyethylene film-covered green-house in November 2002. Symptoms appeared as dark-brown circles or large irregular spots on the leaves of watermelon. Occasionally, zonal growth of the lesions was observed. Under humid conditions, small black sclerotium-like bodies (sporodochia) were produced on the surface of the lesions. The sporodochia on leaf lesions were sessile, polymorphic, variable in size, 35-850 $\mu\textrm{m}$ in diameter, and 30-470 $\mu\textrm{m}$ in depth. Conidia in sporodochium were black in mass, one-celled, rod-shaped, with rounded ends, hyaline, guttulate, and measured 6-8$\times$1.6-2.2 $\mu\textrm{m}$ in size. The pathogen was identified as Myrothecium roridum Tode ex Fr. This is the first report of Myrothecium leaf spot on watermelon naturally occurring in commercial greenhouses.

• Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.68-73
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• 2007

Based on four juvenile specimens of Lutjanus collected from the southern coast of Jeju Island, three species, L. argentimaculatus, L. fulviflamma, and L. quinquelineatus, are described as the first record from Korea. The first species is easily differentiated from other lutjanid juveniles by distinct coloring of the dorsal, pelvic, and anal fins as well as two blue lines below the eye; the second species is characterized by having six yellowish brown stripes below the lateral line and a black spot on the side; the third species is identified by five longitudinal blue stripes and a black spot on the side when fresh. The new Korean names "Bul-geun-tung-dom," "Yuk-seon-jeomtung-dom," and "O-seon-tung-dom" are proposed for L. argentimaculatus, L. fulviflamma, and L. quinquelineatus, respectively.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.210-216
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• 1995

Alternaria spp.were predominantly isolated from the abnormal leaf spot lesions of pear cultivars Niitaka and Nijiiseiki. Alternaria isolates from the cultivar Niitaka were not pathogenic to both cultivars, but the isolates from the cultivar Nijiiseiki developed typical lesions of black leaf spots and were identified as A. kikuchiana. However, no typical abnormal leaf spot lesions were produced by the Alternaria isolates. Foliar spray of twelve different agrochemicals including lime sulfur, either alone or in combinations, with 7 times applications from April to July failed to reduced the disease development. Application of 17 different pesticides including fungicides, insecticides and herbicides currently used in pear orchards did not cause leaf injury similar to the abnormal leaf spot. Simulated acid rain of as low as pH 3.0 did not incite any leaf lesions alike the abnormal spot lesions. Mineral contents in the leaves of both cultivars did not differ significantly between the healthy leaves and those with abnormal leaf spots. When cuttings of pear tree were obtained in February from newly emerged twigs of the healthy or the diseased trees of Niitaka and planted in sand in the greenhouse, only those from the diseased trees developed typical leaf lesions of the abnormal spot. These results indicate that abnormal leaf spots are caused by unknown systemic agents in pear trees, rather than by Alternaria spp., chemical injury or acid rain.

• Proceedings of the KOR-KST Conference
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• 2007.02a
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• pp.334-340
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• 2007

• Proceedings of the KOR-KST Conference
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• 2007.05a
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• pp.275-282
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• 2007

• Transportation Technology and Policy
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• v.9 no.4
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• pp.41-46
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• 2012

• The Plant Pathology Journal
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• v.27 no.1
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• pp.100-100
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• 2011

• Research in Plant Disease
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• v.18 no.4
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• pp.349-353
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• 2012

Xanthomonas arboricola pv. pruni causes black spot symptom on fruit of plum, resulting in yield loss by reduction of marketable fruit production. To develop an effective control program, some chemicals were sprayed in various scheme during dormant season and growing season after blooming period. Copper-based chemicals were sprayed during dormant season and antibiotic-based chemicals were sprayed during fruit growing season. Sprays of antibiotic-based chemicals in growing season was more effective than copper-based chemicals sprays in dormant season. Three applications of antibiotic-based chemicals in 10 days interval starting 10 days after full blooming controlled disease incidence as much as 93%, whereas applications of copper-based chemicals in dormant season controlled 26-42%. Antibiotic-based chemicals application starting 10 days after full blooming was more effective than starting 20 or 30 days after full blooming.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.43-47
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• 2001

This study was conducted to investigate the integrated control strategy against pear black leaf spot disease. Using indicator plant PS-95 we selected six virus-free trees (cv. Niitaka) from commercial orchards in the major pear production area. Disease symptom by pear black leaf spot in the shoot of pear (Niitaka) has been successfully inhibited by heat treatments for 3 weeks at temperature of $40^{\circ}C$ (day) and $32^{\circ}C$ (night) or 4 weeks at $37^{\circ}C$ and $30^{\circ}C$, respectively. However, survival rate of the shoot tips on stocks was low. Seven cultivars Niitaka, Imamura- aki, Waseaka, Nijisseiki, Wasenijisseiki, Shinsetsu and Whangkeumbae produced visible symptoms in the first year after inoculation with the virus. Other 11 selections remained symptomless. Two resistant cultivars Suwhangbae and Gamcheonbae were selected, which showed high fruit quality. It is recommended that these cultivars could be top-grafted onto the infected Niitaka trees to overcome the damage caused by the disease in the orchard.

• Research in Plant Disease
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• v.23 no.4
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• pp.314-321
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• 2017

Acidovorax valerianellae had been reported a causal agent of bacterial black spot disease on corn salad in France, 2003 and on watermelon in Korea 2011. In this study, difference in host specificity between 2 groups, corn salad strains and watermelon strains, of Acidovorax valerianellae was recognized and compared. In the pathogenicity test, all 5 watermelon strains showed pathogenicity on the 6 Cucurbitaceae plants but not on corn salad, whereas 4 corn salad strains showed pathogenicity only on the corn salad. Utilization of Biolog substrates was different between watermelon strains and corn salad strains on 4 substrates, Malonic Acid, ${\alpha}-Hydroxybutyric$ Acid, ${\alpha}-Keto$ Butyric Acid, and Glycyl-L Glutamic Acid. The phylogenetic tree built with the 16S rDNA sequences showed that all of A. valerianellae stains was grouped into 1 clade separating from the other species of Acidovorax genus. Within A. valerianellae clade, watermelon strains and corn salad strains were separated into 2 sub-groups. REP-PCR analysis also separated the two groups. Host specificity, substrate utilization, and some genetic characteristics suggested that there are two pathogenic groups, watermelon group and corn salad group in A. valerianellae.