• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.360-368
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• 1997

Shepherd's purse (Capsella bursa-pastoris) is one of the minor but important vegetable in Korea. The present study records 4 fungal diseases of this plant occurring under natural condition for the first time in Korea. They are white rust caused by Albugo candida, downy mildew by Peronospora parasitica, leaf spot by Pseudocercosporella capsellae, and powdery mildew by Erysiphe cichoracearum of these, white rust and downy mildew were most common causing severe damages and should be managed for the development of greenhouse cultivation of this plant.

• Research in Plant Disease
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• v.17 no.3
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• pp.386-390
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• 2011

In June 2011, walnuts (Juglans regia) from orchards in Kimcheon and Muan, in southern Korea, were found to exhibit downy mildew-like symptoms of a foliar disease. Whitish polygonal efflorescence was produced on the abaxial surface of affected leaves and discolored light green blotches on the corresponding adaxial surfaces. In the later stage of disease development, diseased tissues collapsed and became necrotic. Based on morphological and cultural characteristics, the causal fungus was identified as Microstroma juglandis. The sequence of ITS rDNA of the present isolate showed 100% similarity with those of M. juglandis obtained from GenBank databases, thus confirming its identity. Pathogenicity tests were conducted on leaves of walnut seedlings, fulfilling Koch's postulates. The disease has been previously reported in North America, Europe, Oceania and some western Asia. This is the first report of downy leaf spot on walnuts in East Asia.

• Research in Plant Disease
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• v.9 no.1
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• pp.52-56
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• 2003

It was conducted to investigate the effect of rice downy mildew (RDM) infection to plant growth and yield components in water seeding stage, and to screen of varietal resistance to downy mildew. Being infected by rice downy mildew, chlorotic spot appeared in the leaf and leaf length was shortened. As the infected rice was growing, internode was not elongated properly and was deformed, and then panicle was not arised or mal-formed. Plant height of infected rice was shortened at all growth stage, and while the number of tillers of infected rice was more decreased than that of healthy plant before maximum tillering stage, and that of infected rice was more increased after heading stage. While the number of internode of infected tiller was much increased than that of healthy tiller internode length of infected tiller was shorter. As the rice infected by RDM severely, the number of panicles per square meter and ripening of rice was more decreased and yield of rice was extremely much decreased. As result of the varietal resistance screening with rice seedling, Geyh-wabyeo and Donjinbyeo were resistant varieties to downy mildew.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.668-675
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• 1998

These surveys were conducted to check the occurrence of disease in various horticultural crops in alpine areas, especially Daekwallyong areas, Pyongchang-Gun, and Hyeongseong-Gun in Kangwon province. TuMV on Chinese cabbage was one of the most serious diseases, especially in 1994 and 1997. The incidence of soft rot and clubroot has been increased gradually. Brittle root rot on Chinese cabbage was significantly decreased. Soft rot, gray mold, downy mildew, powdery mildew, bottom rot and Alternaria leaf spot were the common diseases on most vegetable crops. Gray mold (Botrytis cinerea) on celery, cercospora leaf spot (Cercospora sp.) on melon, powdery mildew (Erysiphe cichoracearum) on lettuce, and clubroot (Plasmodiophora brassicae) on parsley are newly found in Korea. The most common and predominant diseases were viruses, especially CMV, TMV, TuMV, BBMV, and gray mold, wilts, and cercospora leaf spot on many flowers in alpine areas. Fusarium oxysporum f. sp. eustomae causing wilting on lisianthus (Eustoma grandiflorum), Turnip mosaic virus causing mosaic and color breaking on stock, Cercospora spp. causing cercospora leaf spot on various wild lily, Cladosporum echinulatum causing leaf spot on carnation, and phytoplasma causing witches' broom on statice (Limonium sinuatum) and blazing star (Liatris spp.) were newly found during these surveys in Korea.

• Research in Plant Disease
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• v.10 no.1
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• pp.1-7
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• 2004

The year of 2003 was characterized as a cool humid year. Low temperature and frequent rains were continued during March to July, resulting in 1.6 times higher rainfalls and 32％ less sunshine period compared to the average yean Due to 2003's climatic condition, rice blast, and bacterial leaf blight occurred severely. Higher rainfalls caused severe epidemic of phytophthora disease and, in case of red-pepper, 55％ of cultivation acreage was devastated by the disease over the country. Besides, crop diseases which become severe under cool-humid conditions, such as gray mold, sclerotinia rot, downy mildew, increased significantly compared to the previous year. In fruit trees, brown spot of apple, and pear scab occurred severely causing much yield loss.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.135-145
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• 1981

Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.