• Research in Plant Disease
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• v.15 no.3
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• pp.193-197
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• 2009

Pseudocercospora leaf spot was major disease of grape cultivar 'Campbell Early' in Korea. Leaf spot first appeared in early June and rapidly dispersed to other leaves through rainy season. Disease progress of leaf spot by Pseudocercospora vitis in plastic green house, in the two provinces (Gimje and Gimcheon), were investigated in 2007. Differences of Infected leaves (%) between cultivation systems were observed in field and plastic green house, but there was no difference between provinces. Micro environmental factors, such as temperature and relative humidity, were correlated with infected leaves by PROC REG procedure of SAS (Statistical Analysis System). As a result, regression model best described ($R^2=0.95^{**}$) the infected leaves as a function of the interaction of cumulated temperatures; Y (Infected leaves)=-7.0101+0.0496$\times$20Hcum (Cumulated hour above 20 degree)+0.0208$\times$20cum (Cumulated temperature above 20 degree)-0.2781$\times$25Hcum (Cumulated hour above 25 degree). A statistics model was shown that cumulated hour and temperature above specific degree were critical factor for Pseudocercospora leaf spot on the grapevine leaves in plastic green house.

• Research in Plant Disease
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• v.12 no.1
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• pp.10-14
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• 2006

This study was carried out to know damages of the grapevine trees by the disease to the leaf spot from 2000 to 2003. The isolates collected from different varieties and locations were identified as Pseudocercospora vitis ($(L\acute{e}v)$.) Speg. based on the morphological and cultural characteristics. According to the in vitro test, the range of temperatures for the mycerial growth and the conidical germination of the fungus were from $10^{\circ}C\;to\;35^{\circ}C$ and optimum temperature was $25^{\circ}C$. There were remarkably different features between a low infection trees group and high infection trees group in terms of number of leaves per fruit branch, length and diameter of internode and leaf area.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.10a
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• pp.49-50
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• 2005

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.102.3-103
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• 2002

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.327-341
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• 1998

The mycoflora of Korea, especially the cercosporoid taxa, have been poorly studied in the past. For this reason, a systematic revision of these taxa has been initiated, with the eventual aim of producing a monograph of the Korean cercosporoid taxa. The present study circumscribes ten species; viz., Cercospora althaeina, C. arachidicola, C. armoraciae, C. carotae, C. ipomoeae, Mycovellosiella ferruginea, Passalora miurae, Pseudocercospora araliae, P. cannabina and P. vitis. Distinguishing morphological characteristics are described and illustrated for each species.

• Research in Plant Disease
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• v.10 no.4
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• pp.341-344
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• 2004

Grapevine leaf spot caused by Pseudocercospora vitis also called leaf Isariopsis spot which is one of the most important disease in Korea. Spots on the leaves are irregular to angular. They are brown, measure 2${\sim}$20 mm in diameter. Campbell Early, the major grape cultivar in Korea, is very susceptible to this disease. Leaf spot of grape is outbreak about 95% in ratio of diseased leaves according to the areas and management state of orchards in Korea. The diseased grapevines have some difficulty in raise of the trees by early defoliation and decrease the quality of fruits by disadvantage of assimilation products accumulation. Severe outbreak of the grapevine leaf spot is one of the factors that decrease of sugar content of the fruits about 20%. The strong negative correlation was observed between disease increase of grapevine and decrease of sugar content of the fruits. The correlation equation between relative sugar content of fruits and accumulated percentage of diseased leaves was Y = 0.0009$X^2$ - 0.3717X + 116.45($r^2$= 0.98).

• Research in Plant Disease
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• v.12 no.1
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• pp.15-19
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• 2006

This study was carried out to know pathogenicity of the pathogen isolated in several location of Korea and penetration mechanism of the Pseudocercospora vitis ($(L\acute{e}v)$.) Speg. Inoculation tests at room temperature were performed on both sides of leaves with different isolates of the fungus. The typical symptoms appeared on the abaxial leaf surface, but no symptom was observed on the adaxial leaf surface with all isolates. The average incubation period was nine days, since all symptoms appeared from 8 to 10 days after inoculation. In order to know the mechanism of invasion of P. vitis to grapevine, the behavior of penetration hyphae through stomata were compared in two cultivars having different level of resistance. In order to know the mechanism of resistance of grape vine to P.vitis, two cultivars having different level of resistance were compared by counting the numbers and measuring size of the stomata per leaf. In a susceptible cultivar Campbell Early, the number of stomata was more than that of a resistance cultivar 'Kyoho'. In a susceptible cultivar 'Campbell Early', the fungus entered readily into stomata after inoculation. However, in a resistant cultivar 'Kyoho', the fungus seemed to pass over or surrounded only the guard cells. In comparison of height of guard cells of stomata between the two cultivars, significant differences were observed by scanning electron microscopy and light microscopy. The height of guard cells of 'Campbell Early' showed a little higher than those of 'Kyoho' known to be resistant to the fungus.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.473-483
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• 1998

This paper is the sixth report about the fungal diseases of economic resource plants observed newly in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogens, and some phytopathological notes for each of 10 fungal plant diseases. They are identified as circular leaf spot of Ligustrum ovalifolium by Cercospora adusta, leaf spot of Viola spp. by c. violae, leaf spot of Trifolium repens by C. zebrina, hypophyllous leaf sot of Angelica gigas by Passalora depressa, brown leaf spot of Euonymus japonicus by Pseudocercospora destructiva, brown leaf spot of Lonicera japonica by P. lonicericola, brown leaf spot of Parthenocissus tricuspidata by P. vitis, black spot of Echinops latifolius by Ramularia cynarae, leaf spot of Petasites japonicus by R. major, and leaf spot of Plantagoasiactica by R. plantaginis, respectively.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.773-786
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• 2016

Grape cultivar "Campbell Early" account for 70% of table grape in Korea and Leaf Spot Disease caused by Pseudocercospora vitis is one of a major disease in greenhouse and field grown area during late summer season in both of organic and conventional grape farm. Leaf spot disease can cause lowing of sugar content in fruit and vine growth and very difficult to control especially in organic field. Photosynthesis ability and chemical components are compared between leaf spot disease infected leaves with degree of necrotic area. With increase of disease necrotic area, $CO_2$ differential value, water use efficiency and $CO_2$ assimilation and respiration ratio are decreased proportionally and on the other hand, stomatal conductance value is not affected by disease necrotic area. Chlorophyll contents are also decreased by 50% in heavily infected leaves and imply decrease of chlorophyll contents is a major source of photosynthesis ability decline. With increase of disease necrotic area in leaves, total nitrogen and phosphate contents are decreased and on the other side, total carbon, potassium, calcium and magnesium contents are increased. From this research, we can infer that not only chemical control program is important in control of leaf spot disease but also fertilizing program is significant especially in organic agronomical control of fungal disease in grape cultivar "Campbell Early".

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.113-118
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• 2015

The objective of this experiment was to evaluate the effects of application wide plastic shelter (WPS) in the 'Campbell Early' grape. WPS was developed 30cm wider than standard plastic shelter (SPS; 210cm). Under the plastic shelter, the average daily temperature was $2{\sim}3^{\circ}C$ higher than ambient temperature, but WPS treatment was $0.5{\sim}1^{\circ}C$ higher than SPS treatment. However, relative humidity 15~20% lower than ambient and shown different result between two treatments annually. The occurrence of brown leaf spot disease caused by Pseudocecospora vitis on the vineyard decreased 55.6% (2012) and 17.2% (2013) under WPS than SPS. Grape bunches collected two harvest seasons (2012, 2013), were analyzed fruit quality (total soluble solid; TSS, titratable acidity; TA, berry weight, berry size). In 2012, grapes had no differences in the quality of two treatments, but in 2013, significantly increase $0.4^{\circ}Bx$ of TSS and decrease 0.8% of TA on the WPS than SPS. It suggests that the application WPS reduced the incidence of brown leaf spot disease annually, and then affect to the fruit quality.