• The Plant Pathology Journal
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• v.20 no.2
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• pp.110-114
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• 2004

Through in vitro screening for biocontrol agents (BCAs) against Streptomyces scabiei causing potato (Solanum tuberosum) common scab, 19 streptomycete and 17 fungal isolates with antagonistic activity were selected as BCA candidates. For the selection of BCA candidates which are highly resistant to 10 kinds of antibiotics or pesticides, chemical susceptibility testing was initially performed in vitro. A remarkable degree of variation in susceptibility to antibiotics or pesticides was observed among the isolates tested. Streptomycete A020645 isolate was highly resistant to all the tested chemicals except neomycin up to 5,000 ppm. On the other hand, out of 36 antagonistic microbes subjected to in vivo pot tests using cultivar Daejima, four streptomycete isolates namely, A020645, A010321, A010564, and A020973, showed high antagonistic activity with >60% and 55% control value, respectively, and high chemical resistance to 10 kinds of chemicals. Therefore, these isolates were selected as potential BCAs for the control of potato common scab.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.551-554
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• 1998

Bacterial specs isolated from common scab lesion on potato (Solanum tuberosum L. c.. Dejima) tuber was identified as Streptomyces turgidiscabies. This organism had flexuous spore chains and grey spore mass color, produced melanin pigment on ISP 7, but did not produce on ISP 6. S. turgidiscabies grew on agar media at pH 4.5, used L-arabinose, D-fructose, D-glucose, D-mannitol, raffinose, rhamnose, sucrose, D-xylose and meso-inositol as carbon sources, and was susceptible to 7% NaCl, thallium acetate (10 $\mu\textrm{g}$/ml, 100$\mu\textrm{g}$/ml), crystal violet (0.5 $\mu\textrm{g}$/ml), phenol (0.1%, wt/vol), oleandomycin (100 $\mu\textrm{g}$/ml), and streptomycin (20 $\mu\textrm{g}$/ml).

• Research in Plant Disease
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• v.10 no.2
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• pp.138-141
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• 2004

It was conducted to find out the effect of chemical treatment on seed tubers and soil to control potato common scab in Jeju Island in 2001. Although the treatment of soil disinfection with Dazomet Gr. (30kg/10a) was more effective comparing to the treatment of seed disinfection and the untreated, the control value was merely 40.5%. However, the combined treatment of soil and seed disinfection was considerably more effective to reduce the percentage of infection and infection area, and increase the production of marketable tubers and also increase the control value. Therefore, the combined treatments are demanded to reduce the scab incidence in Jeju field conditions.

• Research in Plant Disease
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• v.10 no.2
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• pp.135-137
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• 2004

It was conducted to select the resistant potato cultivars to common scab, to replace the existing susceptible cv Dejima in Jeju island conditions both 1997 and 2001. Among cultivars, cvs Jemchip, Alpa, Atlantic and Jopung were more resistant than others in the field with both low and high incidence of the disease. Also among the existing cultivars grown in Korea, cvs Superior, Jopung and Chubaek were resistant, expecially in terms of production of marketable potatoes.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.689-692
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• 1998

Bacterial species isolated from common scab lesion on potato (Solanum tuberosum L. cv. Dejima) was identified as Streptomyces acidiscabies. This organism had flexuous spore chains and white spore mass color, produced melanin pigment on tyrosine agar medium but did not produce on peptone agar medium. S. acidiscabies grew on agar medium at pH 4.0, used L-arabinose, D-fructose, D-glucose, D-mannitol, rhamnose, sucrose, D-xylose and meso-inositol except reffinose as carbon sources. It was also susceptible to thallium acetate (10 $\mu\textrm{g}$/ml, 100$\mu\textrm{g}$/ml), phenol (0.1%, wt/vol), streptomycin (20 $\mu\textrm{g}$/ml), and was resistant to 7% NaCl, crystal violet (0.5 $\mu\textrm{g}$/ml), penicillin (10 IU/ml) and oleandomycin (25 $\mu\textrm{g}$/ml, 100 $\mu\textrm{g}$/ml).

• The Plant Pathology Journal
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• v.15 no.1
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• pp.72-75
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• 1999

A scab disease occurred on watermelon seedlings by the infection of Cladosporium cucumberinum. This is the first report demonstrating the scab disease on watermelon in Korea. The casual agent attacked all plant parts of the seedlings on the ground. Infection sites were initiated with sunken and dark green spots, and then suddenly developed to large lesions softened with gummy substances. When hypocotyl and leaf stalk of seedlings were infected and softened, upper parts of seedlings were brokin down, dried and eventually died. Conidiophores of the fungus were characterized by pale olivaceous brown color, and variable length of about 3-5 mm in width. Conidia were formed I long branched chains, and conidium was ellipsoidal, fusiform or subspherical single cell mostly without septum. Morphological characteristics of the fungus were almost identical to Cladosporium cucumerinum Ellis & Authur. The fungus was also pathogenic to cucumber, squash and oriental melon, suggesting that it is a common pathogen to cucurbits. However, the fungus was not pathogenic to bottle gourd.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.109-115
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• 1996

국내 감자 연작 재배지에서 수집하여 분리동정한 더뎅이병원균인 Streptomyces scabies의 배양적, 형태적, 생리적 특성을 조사한 결과는 다음과 같다. 이병감자에서 분리된 균들은 병원성 균주와 비병원성 균주들로 구분되었고, 이들 간에는 뚜렷한 차이를 보였는데, 전형적인 병징을 나타내는 병원성균주는 비병원성균주와는 달리, 나선형의 포자사슬, 회색 포자, 멜라닌 색소를 생성하고 D-glucose, L-arabinose, D-fructose, D0mannitol, raffinose, rhamnose, sucrose, i-inositol, D-xylose 등의 탄소원을 이용하였으며, 또한 7% NaCl 및 streptomycin sulfate, crystal violet, olean domycin(10$\mu\textrm{g}$/ml, 100$\mu\textrm{g}$/ml)등의 항생물질에 감수성을 나타내었다.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.777-788
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• 2023

Potato common scab disease is caused by pathogens belonging to Streptomyces spp. and results in a serious yield loss worldwide. Despite decades of research aimed at disease management, a definitive control method remains undiscovered. This study aims to explore the correlation between the C/N ratio and urea application with potato common scab pathogen dynamics and disease severity. We applied sawdust with a high C/N ratio and urea into the soil prior to potato cropping, both in pot and field experiments. Disease severity assessments and quantification of the TxtB gene were conducted at the harvest stage. Furthermore, culture experiments were performed to assess the direct impact of urea on the pathogen. Our findings revealed that higher disease severity was correlated with a high C/N ratio application and pathogenic gene quantity. Urea exhibited a direct influence on S. scabiei activity, reducing the disease severity in pot experiments. However, the effects of urea application on disease suppression in the conductive field were inconclusive. Although the results of urea application experiments displayed inconsistencies between pot and field trials, urea worked as the control to suppress S. scabiei activity. Further investigations are needed under various field conditions to confirm these findings.

• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.115-127
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• 2014

This study was conducted to select environmental friendly organic materials for controlling the main disease of Yuzu (Citrus junos Sieb). Meloanose caused by Phomopsi scitri and Scab caused by Elsinoe fawettii are the most common disease in Yuzu. In this study, of which Meloanose disease severity was severe at late of June corresponded with high humidity due to frequent rainfall at that time. In addition, occurrence of two disease have shown in old tree than young. After processing with environmental friendly organic materials, reduction of disease severity was 51~73% and 41~75% in case of Meloanose and scab, respectively. Based on result, environmental friendly organic materials tested in this study may source for controlling both Meloanose and scab diseases on Yuzu.

• Korean Journal of Organic Agriculture
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• v.8 no.3
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• pp.99-109
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• 2000

This experiment was conducted to investigate the changes of rate of infected common scab and yield characteristics of fall potato(Solanum tuberosum L.) where green manual crops had been previously cultivated, crushed and tilled and P\ulcornerE transparent vinyl film had been mulched and tunneled to solar heating of soil from May 21. 1998 to July 28. 1998. The total yields of green manual crops which had been previousely cultivated were as followed order : pioneer 855F(64.3MT/ha), soybean(25.0MT/ha), red clover and orchardgrass. The average below-ground temperature at the depths of 5, 10 and 20cm were 54, 45 and 44$^{\circ}C$ during the mulching period, respectively The rate of infected area per potato tuber of common scab decreased by solar heating the soils with mulching after the soybean and red clover cultivation as with previous croppings. Plant height, SPAD(soil plant analysis development) reading, fresh weight of stems, and fall potato's tuber yields tended to increase by the cultivation of green manual crops and mulching of P\ulcornerE film. Fall potato's tuber yields were remarkably affected in the plot of soybean, red clover and pioneer 855F+cultivation of fall potato. T-N, K and Ca contents of fall potato(stem and tuber) also tended to increase by the cultivation of green manual crops and mulching of P\ulcornerE film. T-N, K and Ca contents of soil tended to increase after the cultivation of green manual crops and mulching of P\ulcornerE film and then reduced to contents of soil before green manual planting after potato harvesting.