• Title/Summary/Keyword: Brown spot

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First Feline Case of Otodectosis in the Republic of Korea and Successful Treatment with Imidacloprid/Moxidectin Topical Solution

  • Ahn, Ah-Jin;Oh, Dae-Sung;Ahn, Kyu-Sung;Shin, Sung-Shik
    • Parasites, Hosts and Diseases
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    • v.51 no.1
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    • pp.125-128
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    • 2013
  • In April 2010, pruritic symptoms were recognized in 3 privately-owned Siamese cats raised in Gwangju, Korea. Examination of ear canals revealed dark brown, ceruminous otic exudates that contain numerous live mites at various developmental stages. Based on morphological characteristics of adult mites in which caruncles were present on legs 1 and 2 in adult females and on legs 1, 2, 3, and 4 in adult males while the tarsus of leg 3 in both sexes was equipped with 2 long setae, the mite was identified as Otodectes cynotis. Ten ear mite-free domestic shorthaired cats were experimentally infected with O. cynotis to evaluate the efficacy of 10% imidacloprid/1% moxidectin spot-on. Live mites were recovered from 1 of 10 treated cats on day 9 post-treatment (PT) while no live mites were observed from the ear canals of treated cats on days 16 and 30 PT. The efficacy of 10% imidacloprid/1% moxidectin spot-on on O. cynotis in cats was, therefore, 90% on day 9 and 100% on days 16 and 30 PT. This is the first report of otodectosis in 3 cats naturally infested with O. cynotis in Gwang-ju, Korea. Both natural and experimental infestations were successfully treated with 10% imidacloprid/1% moxidectin spot-on.

Rust of Belamcanda chinensis Caused by Puccinia belamcandae (Puccinia belamcandae에 의한 범부체 녹병)

  • Kwon, Jin-Hyeuk;Park, Chang-Seuk
    • The Korean Journal of Mycology
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    • v.32 no.1
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    • pp.54-56
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    • 2004
  • Rust disease was occurred on blackberry lily (Belamcanda chinensis) in several farmer's fields located in Heohwa-myon, Goseong-gun, Gyeongnam province in Korea. The typical symptoms of the disease appeared as small, yellowish spot on leaves at first. The spots then turned brown, their edges rised slightly, and powdery mass of yellow or yellowish green spores appeared on the lesions. Severely infected leaves were blighted and eventually died. Urediniospores were yellow or yellowish brown in color, globoid to ovoid in shape and $21{\sim}46{\times}18{\sim}38\;{\mu}m$ in size. Teliospores were brown in color, oblong or clavate in shape and $32{\sim}64{\times}12{\sim}26\;{\mu}m$ in size. The causal fungus was identified as Puccinia belamcandae based on morphological characteristics and host specificity. This is the first report on the rust of B. chinensis caused by P. belamcandae in Korea.

Bacillus vallismortis EXTN-1-Mediated Growth Promotion and Disease Suppression in Rice

  • Park Kyung-Seok;Paul Diby;Yeh Wan-Hae
    • The Plant Pathology Journal
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    • v.22 no.3
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    • pp.278-282
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    • 2006
  • Bacillus vallismortis EXTN-1, a biocontrol agent in cucumber, tomato and potato was tested in rice pathosystem against rice fungal pathogens viz. Magnaporthe grisea, Rhizoctonia solani and Cochliobolus miyabeanus. Apart from increasing the yield in the bacterized plants (11.6-12.6% over control), the study showed that EXTN1 is effective in bringing about disease suppression against all the tested fungal pathogens. EXTN-l treatment resulted in 52.11% reduction in rice blast, 83.02% reduction in sheath blight and 11.54% decrease in brown spot symptoms. As the strain is proven as an inducer for systemic resistance based on PR gene expression in Arabidopsis and tobacco models, it is supposed that a similar mechanism works in rice, bringing about disease suppression. The strain could be used as a potent biocontrol and growth-promoting agent in rice cropping system.

Identification, Growth and Pathogenicity of Colletotrichum boninense Causing Leaf Anthracnose on Japanese Spindle Tree

  • Lee, Hyang-Burm;Park, Jae-Young;Jung, Hack-Sung
    • The Plant Pathology Journal
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    • v.21 no.1
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    • pp.27-32
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    • 2005
  • Leaf anthracnose was observed on leaves of Japanese spindle tree in Seoul, Korea from autumn 2003 to spring 2004. The causal fungus was purely isolated from he leaf spot lesions and cultured on PDA. The colony on PDA was cream to orange but blackish in the center n old cultures. Conidia were formed in blackish orange asses and were cylindrical in shape, measured 13-17${\times}$5-7 ${\mu}$m in size. Blackish brown setae were often observed on PDA and ranged up to 100 ${\mu}$m in length. Based on morphological and ITS region sequence analyses, the fungal strain was identified as Colletotrichum boninense. Koch’s postulates were fulfilled by inoculating tree leaves with 1 ${\times}$ $106^6$ conidia per ml in a moist chamber. This is the first study on the pathogenicity, growth and phylogenetic characteristics of C. boninense causing leaf anthracnose on Japanese spindle tree in Korea.

The ablation of ITO thin films by KrF Eximer laser and its characteristics (KrF 엑시머 레이저에 의한 ITO 박막의 어블레이션과 표면특성관찰)

  • Lee, Kyoung-Cheol;Lee, Cheon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.511-514
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    • 2000
  • This work aimed to develop ITO (Indium Tin Oxide) thin films ablation with a KrF Eximer laser required for the application in flat panel display, especially patterning into small geometry on a large substrate area. The threshold fluence for ablating ITO on glass substrate is about 0.1 J/cm$^2$. And its value is much smaller than using third harmonic Nd:YAG laser. Through the optical microscope measurement the surface color of the damaged ITO is changed into dark brown and irradiated spot is completely isolated form the undamaged surroundings by laser light. The XPS analysis showed that the relative surface concentration of Sn and In were essentially unchanged (In :Sn=5:1) after irradiating Eximer laser. Using aluminium mask made by second harmonic Nd:YAG laser the ITO patterning is carried out.

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A New Soybean Cultivar "Gaechuck#2": Yellow Soybean Cultivar with Lipoxygenase2,3-free and Kunitz Trypsin Inhibitor-free

  • Chung, Jong Il
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.612-615
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    • 2009
  • Lipoxygenase and Kunitz trypsin inhibitor protein are the main antinutritional factor in mature soybean seed. A new soybean cultivar, "Gaechuck#2" with yellow seed coat, lipoxygenase2,3-free and Kunitz trypsin inhibitor protein-free was developed. It was selected from the population derived from the cross between "Jinpumkong2ho" and C242. Plants of "Gaechuck#2" have determinate growth habit with purple flowers, tawny pubescence, yellow seed coat, yellow hilum, oval leaflet shape and brown pods at maturity. Seed protein and oil content on a dry weight basis were 40.7% and 18.7%, respectively. It has shown a resistant reaction to soybean necrosis, soybean mosaic virus, Cercospora leaf spot and blight, black root rot, pod and stem blight, and soybean pod borer. Gaechuck#2 matured in 4 October with plant height of 54cm and a 100-seed weight of 24.4g. Average Yield of Gaechuck#2 was 230 - 250 kg/10a in 2005 - 2007.

Identification and Characterization of Pseudocercospora cornicola Causing Leaf Spots on Cornus officinalis

  • In-Young Choi;Ho-Jong Ju;Lamiya Abasova;Joon-Ho Choi;Hyeon-Dong Shin
    • The Korean Journal of Mycology
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    • v.50 no.2
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    • pp.131-136
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    • 2022
  • Cornus officinalis plants that grow in several locations in Korea have been found to be infected with leaf spot disease. Symptoms include necrotic lesions, which are angular, irregularly shaped, vein-limited, and dark brown, on both sides of the leaves. The causal agent of the disease was identified to be Pseudocercospora cornicola based on the morphological characteristics of the fungus and molecular phylogenetic analysis of the obtained multi-locus DNA sequence data. This is the first report investigating P. cornicola found on C. officinalis in Korea.

Characteristics of the Newly Developed Rain Shelter for Grapevine and Growth of 'Campbell Early' (신개발 포도 비가림 시설의 특성과 '캠벌얼리'의 생육)

  • Lee, Yun Sang;Kim, Seung Deok;Lee, Seok Ho;Hong, Seong Taek;Lee, Jae Wung;Hong, Eui Yon;Kim, Dae Il
    • Journal of Bio-Environment Control
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    • v.24 no.3
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    • pp.252-257
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    • 2015
  • Fruit cracking and vine leaf spot of grapes tend to occur when the plants were directly exposed to rain under outdoor culture. Rain shelter facility can be an alternative method to prevent the cracking and disease of grape, but it also has some limitations in practical usages. We designed rain shelter facility which can completely shut out the rain and ventilate naturally, and it was upgraded to meet the standards of disaster prevention against snow and wind load. The newly developed rain shelter has two-story roof structure, and the $2^{nd}$ floor roof was equipped over $1^{st}$ floor roof at a distance of 40cm. For natural ventilation and water proof, the upper roof protruded about 50cm from the ridge of a $1^{st}$ floor roof. The various tests were carried to examine such as grape quality, brown spot and fruit cracking of Campbell Early under the conventional and the newly developed rain shelter facility which was built about $100{\ss}{\check{S}}$. In comparison of temperature between the conventional and the newly developed rain shelter facility when outside temperature was more than $34^{\circ}C$, the inside temperature was recorded as $40.7^{\circ}C$ and $37.4^{\circ}C$, respectively. There was no significant difference between the two facilities when outside was below $32^{\circ}C$ The quality such as soluble solids and marketable fruit was increased, and fruit cracking of grapes and vine leaf spot also drastically diminished in the newly developed rain shelter.

Alternaria Leaf Spot Caused by Alternaria mali on Black Chokeberry in Korea (Alternaria mali에 의한 아로니아 점무늬낙엽병)

  • Hahm, Soo-Sang;Kwon, Mi-Kyung;Kim, Byung-Ryun;Han, Kwang-Seop;Nam, Yun-Gyu
    • Research in Plant Disease
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    • v.22 no.1
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    • pp.50-54
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    • 2016
  • In early June 2014, leaf spot symptoms were observed on black chokeberry (Aronia melanocarpa) in Yesan-gun and Geumsan-gun, Chungcheongnam-do in Korea. The initial symptoms on leave surfaces were brown small-circular spots with a yellow halo lesion, and gradually the small spots were fused, all of infected leaves dropped eventually. A fungus were isolated from the initial lesion, and cultured on potato dextrose agar. Colony color on upper surface of plate varied from olive gray to charcoal gray. Size of conidia mostly extend to $19-50{\times}5-9{\mu}m$ in nature and $20-59{\times}8-13{\mu}m$ in culture, with 3-8 transverse septa and usually no longitudinal septum or only 1 longitudinal septum in 1-3 of the transverse compartments, and also have a short or long beak. Pathogenicity was investigated using wounded or unwounded black chokeberry and apple leaves. After 7 days of inoculation, leaf spots were similar to the symptoms naturally occurred in the field. On the basis of mycological characteristics, pathogenicity, and ITS rDNA sequence analysis, this fungus was identified as Alternaria mali. This is the first report of Alternaria leaf spot on black chokeberry caused by A. mali in Korea.