• 한국균학회지
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• 제51권3호
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• pp.179-190
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• 2023

Grapevine downy mildew, caused by Plasmopara viticola, significantly damages vineyards and is one of the most devastating diseases affecting cultivated grapes worldwide. In this study, we characterized the phenotypic and molecular traits of 11 P. viticola isolates from four grape-growing regions in South Korea. Additionally, we investigated the diversity of pathogenicity among these isolates and conducted an assay to evaluate the response of grape cultivars to P. viticola infection. Lemon-shaped sporangia were identified in the collected isolates, which released zoospores into the suspension at room temperature. Within a few hours of inoculation, the zoospores developed germ tubes. We tested 11 P. viticola isolates for pathogenicity in 845 grape cultivars to screen for grape host resistance to downy mildew infection. Among the tested isolates, JN-9 showed the highest virulence. Grape cultivars displayed varying phenotypic reactions to P. viticola infection: approximately 7% were highly susceptible, 41% were susceptible, 20% were moderately susceptible, 8% were resistant, and 24% exhibited extreme resistance. Phylogenetic analysis based on four genomic regions (internal transcribed spacer 1 [ITS1], actin, beta-tubulin, and cytochrome c oxidase II) revealed a close evolutionary relationship among all the Korean isolates, forming a single monophyletic lineage. Notably, these isolates showed greater similarity to European isolates than to American isolates. This comprehensive study contributes to a deeper understanding of the identity and behavior of P. viticola, which is crucial for developing effective resistance strategies against this pathogen in grape cultivars cultivated in South Korea.

• 한국유기농업학회지
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• 제19권4호
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• pp.529-541
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• 2011

Bordeaux mixture made with each grade of lime and copper sulfate was tested general property and disease control value. Bordeaux mixture was made by composition of each grade of lime (95%, 80%) with each grade of copper sulfate(98.5%, 95%). Phytotoxicity was evaluated to Bordeaux mixture made with each grade of lime and copper sulfate, and then low grade copper sulfate (95%) was more severely in the grapevine leaf. Bordeaux mixture, made with each grade lime and copper sulfate, were tried to evaluate control effects of downy mildew in field. As a result, Bordeaux mixture (95% of lime and 98.5% of copper sulfate, 6-6) applied 5 times at late in June was showed more effective disease control value than any other trials of Bordeaux mixture. There was no difference in nutrient status of petiole each treatment. But fruit characteristics were shown more slightly improved quality.

• The Plant Pathology Journal
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• 제21권2호
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• pp.111-118
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• 2005

Weather data for disease forecasts are usually derived from automated weather stations (AWS) that may be dispersed across a region in an irregular pattern. We have developed an alternative method to simulate local scale, high-resolution weather and plant disease in a grid pattern. The system incorporates a simplified mesoscale boundary layer model, LAWSS, for estimating local conditions such as air temperature and relative humidity. It also integrates special models for estimating of surface wetness duration and disease forecasts, such as the grapevine downy mildew forecast model, DMCast. The system can recreate weather forecasts utilizing the NCEP/NCAR reanalysis database, which contains over 57 years of archived and corrected global upper air conditions. The highest horizontal resolution of 0.150 km was achieved by running 5-step nested child grids inside coarse mother grids. Over the Finger Lakes and Chautauqua Lake regions of New York State, the system simulated three growing seasons for estimating the risk of grape downy mildew with 1 km resolution. Outputs were represented as regional maps or as site-specific graphs. The highest resolutions were achieved over North America, but the system is functional for any global location. The system is expected to be a powerful tool for site selection and reanalysis of historical plant disease epidemics.

• 농약과학회지
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• 제4권1호
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• pp.38-43
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• 2000

포도 병해충 방제기술 확립을 위한 연구의 기초단계로서 포도 재배 농가를 대상으로 병해충 방제실태 및 피해에 대한 설문조사를 실시한 결과, 방제가 가장 어려운 해충은 포도호랑하늘소와 포도유리나방이었으나, 병은 탄저병, 노균병, 흰가루병, 새눈무늬병, 갈색무늬병 등 다양하였다. 병충해의 발생은 포도 재배방식에 따라 차이가 있었으며, 해충보다는 병에 의해서, 시설재배보다는 노지비가림재배에서 감수율이 더 컸다. 농가의 병충해 식별능력은 높다고 할 수 없었으며, 병충해가 발생하면 주로 농약상이나 이웃 농가에 문의하고, 농약상이 처방해 주는 농약을 처리하는 것으로 나타났다. 방제력을 활용하는 농가는 사용하지 않는 농가보다 적었으며, 대부분의 농가가 예방차원에서 방제를 하고 있었다. 반 이상의 농가가 적어도 한가지의 농약을 영양제와 혼합처리하고 있었으며, 살충제는 5회 이내로 처리하는 반면, 살균제는 6회 이상을 처리하고 있었다. 단위 면적 당 방제비용은 변이 폭이 매우 컸다.

• The Plant Pathology Journal
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• 제35권2호
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• pp.125-136
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• 2019

Vitis vinifera is very susceptible to downy mildew (Plasmopara viticola). A number of authors have suggested different genetic populations of this fungus exist in Europe, each showing a different degree of virulence. Work performed to date indicates this diversity to be the result of different factors. In areas where gene flow is greater and recombination more frequent, the diversity of P. viticola appears to be wider. In vineyards isolated by geographic barriers, a race may become dominant and produce clonal epidemics driven by asexual reproduction. The aim of the present work was to identify the conditions that influence the genetic diversity of P. viticola populations in the vineyards of northwestern Spain, where the climatic conditions for the growth of this fungus are very good. Vineyards situated in a closed, narrow valley of the interior, in more open valleys, and on the coast were sampled and the populations of P. viticola detected were differentiated at the molecular level through the examination of microsatellite markers. The populations of P. viticola represented in primary and secondary infections were investigated in the same way. The concentration of airborne sporangia in the vegetative cycle was also examined, as was the virulence of the different P. viticola populations detected. The epidemiological characteristics of the fungus differed depending on the degree of isolation of the vineyard, the airborne spore concentration, and on whether the attack was primary or secondary. Strong isolation was associated with the appearance of dominant fungal races and, therefore, reduced populational diversity.