• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.25-27
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• 2003

Since 1993, a total of 50 problematic plant diseases unrecorded in Korea were surveyed in Gyeongnam province. Totally 34 new host plants to corresponding pathogens investigated in this study were 5 fruit trees, 9 vegetables, 12 ornamental plants, 3 industrial crops, and 5 medicinal plants. Among the newly recorded fruit tree diseases, fruit rot of pomegranate caused by Coniella granati and Rhizopus soft rot of peach caused by Rhizopus nigricans damaged severely showing 65.5% and 82.4% infection rate. Among the vegetable diseases, corynespora leaf spot of pepper caused by Corynespora cassiicola and the crown gall of pepper caused by Agrobacterium tumefaciens, powdery mildew of tomato caused by Oidiopsis taurica were the most severe revealing 47.6%, 84.7%, and 54.5% infection rate in heavily infected fields, respectively. In ornamental plants, collar rot of lily caused by Sclerotium rolfsii, gray mold of primula caused by Botrytis cinerea, soot leaf blight of dendrobium caused by Pseudocercospora dendrobium, sclerotinia rot of obedient plant caused by Sclerotinia sclerotiorum showed 32.7 to 64.8% disease incidence. On three industrial plants such as sword bean, broad bean, and cowpea, eight diseases were firstly found in this study. Among the diseases occurring on broad bean, rust caused by Uromyces viciae-fabae and red spot caused by Botrytis fabae were the major limiting factor for the cultivation of the plant showing over 64% infection rate in fields. In medicinal plants, anthracnose of safflower caused by Collectotrichum acutatum was considered the most severe disease on the plant and followed by collar rot caused by Sclerotium rolfsii.(중략)

• The Plant Pathology Journal
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• v.15 no.6
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• pp.345-347
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• 1999

A scab disease on eggplant (Solanum melongena L. cv. Chukyang) in plastic film houses around Kimhae area in Korea during the winter season of 0998-1999. The disease started on leaves with small dark brown spots which were gradually expanded to 1 to 3 mm diameter lesions. Later, the central parts of the lesions became collapsed and detached to make holes. Dark brown mold was grown out of the lesions on the lower side of leaf. Numerous conidia were produced on the lower side of leaf. Numerous conidia were produced on the diseased leaves and appeared to be readily dispersed in the air. A fungus was isolated from the diseased leaves, and tested for Koch's postulates to prove the causal agent of the desease. The isolated fungus grew on potato dextrose agar, forming greenish black to pale brown colonies. Conidia were ellipsoidal, fusiform or subspherical, mostly one-celled but occasionally septated, and formed in long branched chains on the erected conidiophores which were pale olevaceous brown and variable in length between 12.4 and $393.4\mu\textrm{g}$. The fungus was identified as Cladosporium cucumerinum Ellis Arthur based on the above morphological characteristics examined. The optimum temperature for mycelial growth and conidial formation was about 20 to $25^{\circ}$. In addition to cucumber, the fungus was also pathogenic to watermelon, pumpkin and oriental melon. This is the first report on the scab disease of eggplant in Korea.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.5
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• pp.54-61
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• 2010

Antifungal and antioxidative activities of Phellodendron amurense extracts were investigated for use as a natural preservative. After separation of P. amurense into phloem, xylem, leaf and fruit each part was subjected to methanol extraction. Each MeOH extract was further fractionated with several solvents(n-hexane, methylene chloride and ethylacetate). Among the methanol extracts, extracts of phloem and leaf inhibited effectively the growth of mold fungi and rot fungi, respectively. Especially, ethylacetate fraction from phloem showed the highest growth inhibitory effects against fungi tested, such as P. citreonigrum H3, P. toxicarium H4, P. corylophilu H5, A. clavatus, P. osteatus, S. commune, and G. lucidum. The fractions of fruit, which had lower antifungal activities mostly than those of phloem, strongly inhibited rot fungi such as G. lucidum, T. versicolor, and T. palustris. Compared to ferulic acid which is well known antioxidant, ethylacetate fraction of fruit showed high antioxidative activities on concentration of 1 to $100{\mu}g/m{\ell}$ in DPPH radical scavenging activity. As a result, antifungal and antioxidative activities of P. amurense suggest that its extract and fraction have a possibility as conservative of cultural heritage because it might get conservation effects against deteriorating microorganisms of cultural heritage.

• Research in Plant Disease
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• v.15 no.3
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• pp.222-229
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• 2009

A Pseudomonas strain SG3 producing biosurfactant and showing antifungal and insecticidal activities was isolated from agricultural soil severely contaminated with machine oils. The antagonistic bacterium inhibited mycelial growth of all of the tested fungal pathogens. The fermentation broth of SG3 also effectively suppressed the development of various plant diseases including rice blast, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose. An antifungal substance was isolated from the fermentation broth of SG3 by ethyl acetate partitioning, silica gel column chromatography and preparative HPLC under the guide of bioassay. The chemical structure of the antifungal substance was determined to be rhamnolipid B by mass and NMR spectral analyses. The antifungal biosurfactant showed a potent in vivo antifungal activity against gray mold and late blight on tomato plants. In addition, rhamnolipid B inhibited mycelial growth of B. cinerea causing tomato gray mold and zoospore germination and mycelial growth of P. infestans causing tomato late blight. Pseudomonas sp. SG3 producing rhamnolipid B could be used as a new biocontrol agent for the control of plant diseases occurring on tomato plants.

• 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.24 no.4
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• pp.249-256
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• 2018

Disease occurrence in apple cultivars on 13-30 apple orchards from April to October 1992-2010 was investigated at 30 days intervals in Gyeongbuk, Gyeongnam and Jeonbuk provinces of Korea. Apple cultivar 'Fuji' was found most susceptible and is being damaged by cedar apple rust, scab, gray mold, Alternaria blotch and Marssonia blotch as major leaf diseases that were observed. The percentage of occurrence of these leaf diseases varies from every year. This variation is based on different rainfall and temperature conditions, cultivation, root stock and changed system of fungicide spray during the particular year and season.

• Research in Plant Disease
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• v.10 no.3
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• pp.159-166
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• 2004

This study were carried out to identify pathogens and determine the seasonal occurrence and chemical control of safflower (Carthamus tinctorius) diseases from 2000 to 2002 in Gyengbuk province, Korea. Major diseases of safflower were, anthracnose caused by Colletotricum acutatum in open field, and gray mold by Botrytis cinerea in rain sheltered plastic house. Other diseases occurred were powdery mildew caused by Sphaerotheca fuliginea, collar rot by Sclerotium rolfsii, leaf spot by Alternaria carthami and A. alternata, rust by Puccinia carthami, root-rot and stem-rot by Phytophthora cactorum, root-rot and wilt by Fusarium oxysporum and damping-off by Pythium ultimum. Seasonal occurrence of anthracnose on safflower has begun from late April, and increased until harvesting, especially rapid increased after rainfall during stem elongation season that is from May to June. In open fields, maximum incidence of anthracnose was 67 ％ in late July. But in rain-sheltered plastic house, it was very low, about 5％ in July. Gray mold caused by Botrytis cinerea was most important disease in rain-sheltered plastic house cultivation. Maximum incidence of gray mold on floral head was 27.4％, whereas other diseases occurred below 1 ％. In the test of the chemical control of the safflower anthracnose, metiram WP, carbendazim$.$kasugamycin WP and iminoctadintris$.$thiram WP were the highest controlling chemicals. In chemical control of gray mold, iminoctadintris$.$thiram WP, fluazinam WP and iprodion WP showed highest controlling effects.

• Research in Plant Disease
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• v.12 no.2
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• pp.115-118
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• 2006

In February of 2000-2001, the gray mold disease occurred on nephrolepis (Nephrolepis sp.) grown in a flower nursery farm in Suwen, Korea. Typical symptoms were water-soaked brown or blackish lesions on terminal leaf blades. Severely infected leaves were entirely blighted with grayish fungal mycelia formed on the surface. Conidia of the fungus in mass were hyaline or gray, 1-celled, mostly ellipsoid or ovoid and $13.5{\sim}16.9{\times}6.8{\sim}9.2{\mu}m$ in size. Conidiophores were formed on PDA with $8.7{\sim}11.1{\mu}m$ in width. The sclerotia were readily formed within 2 or 3 days on PDA. In addition, the Biolog database gave the causal fungus a high similarity to Botrytis cinerea (78%) with a match probability of 100%. Pathogenicity of the causal organism was proved according to Koch's postulate. The causal organism was identified as Eotrytis cinerea based on its mycological characteristics and utilization of carbon sources with Biolog system as supporting data. This is the first report of gray mold of nephrolepis caused by Botrytis cinerea in Korea.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.2071-2075
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• 2007

Fourteen Bacillus thuringiensis isolates having both insecticidal activity and in vitro antifungal activity were selected and tested for in vivo antifungal activity against tomato late blight, wheat leaf rust, tomato gray mold, and barley powdery mildew in growth chambers. All the isolates represented more than 70% disease control efficacy against at least one of four plant diseases. Specifically, 12 isolates exhibited strong control activity against barley powdery mildew. Under glasshouse conditions, four (50-02, 52-08, 52-16, and 52-18) of the isolates also displayed potent control efficacy against cucumber powdery mildew. To our knowledge, this is the first report of B. thuringiensis isolates that have disease control efficacy against powdery mildew of barley and cucumber as well as insecticidal activity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.49-53
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• 2006

The possibility of removal of PCBs (Polychlorinated Biphenyls) in soil was studied using biological method. The effects of soil and co-substrate on both PCBs reduction rate and chloride ion concentration in soil were investigated. It was shown that PCBs concentration of all the soils used in this study were reduced from 5ppm to below 1ppm after 60days, also chloride ion concentration in slurry increased, Results showed that leaf mold and humic acid as co-substrate do not seem to be effective for biological treatment of PCBs in soil,