• Weed & Turfgrass Science
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• v.5 no.4
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• pp.256-259
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• 2016

An obligate plant pathogenic fungus Puccinia zoysiae Dietel, the causal agent of rust disease, which is implicated in the damage of zoysiagrass (Zoysia spp.) in Korea. The fungus is one of the important pathogens, which attacks and colonizes susceptible zoysiagrass. Zoysia rust disease was observed in Jangseong, Hoengseong and Hapcheon in 2014 and 2015, Korea. The typical symptoms of the disease appeared first as small white spots on the leaf and stem of zoysiagrass plants, and turn brownish, dark brown spores revealed on the lesions. Uredospores were light brown in color, ellipsoid or spherical in shape and $22.0{\sim}25.0{\times}15.0{\sim}17.5{\mu}m$ in size. On the basis of the morphological characteristics, the fungus was identified as P. zoysiae. Pathogenicity of the fungus was proved by artificial inoculation on Z. japonica. The rust disease firstly appeared approx. early or middle June and then increased middle of October in Korea. In field, Z. matrella ecotypes were more resistant than Z. japonica ecotypes against the pathogen. Disease response against the pathogen was different among ecotypes of each species, respectively.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.108-111
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• 2003

A infectious fungus (J131) recently isolated from artificial cultivation farms of Paecilomyces tenuipes is known to cause a great yield loss and deterioration of products. In this study, its occurrence and characterization were made. The isolate (J131) was identified as Paecilomyces farinosus (Holm ex S. F. Gray) Brown ＆ Smith. Colonies of the isolate on PDA grew moderately fast, attaining a diameter of 19mm within 14 days at 24${\pm}$1$^{\circ}C$. Vegetative hyphae are smooth-walled and hyaline. Conidiophores mainly arose from the submerged mycelium, usually measuring 1.3-1.5$\mu\textrm{m}$ wide and consisted of verticillate branches with whorls of 2 to 4 phialides. Phialides of 3.8-5.8${\times}$1.5-1.8 $\mu\textrm{m}$, with a swollen basal portion tapered into a distinct neck of about 0.6-0.8 $\mu\textrm{m}$ wide. Conidia arisen from the phialides, were ellipsoidal to fusiform, smooth-walled, hyaline, 1.8-2.4${\times}$1.1-1.4$\mu\textrm{m}$. .When silkworm larvae were injected with concentration of 1${\times}$10$\^$8/ conidia/$m\ell$ of infectious fungus J131, infection rate was 41.3％ and synnemata formation rate was 23.6％. Black spots were appeared on the surface of silkworm larvae in 5-9 days after injection. The surface of larvae was covered with hyphae which were gradually turned into yellow from white color during the incubation period of 3-4 days. 1 to several 4-6mm long synnemata of yellow or orange color were formed on the surface. The matured synnemata were ramified from its end and produced much conidia of white color.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.67-73
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• 2013

With an increasing concern on laying hen welfare, barn system has appeared as one of the alternatives to replace the conventional cage. This study was conducted to compare the early laying performance and egg quality at the barn system with those at the conventional cage. A total of 288 shaver-579 brown layers were used for 9 weeks ($21^{st}$ to $30^{th}$ weeks of age) feeding study. Feed consumption and egg weight were significantly (P<0.01) higher at barn than at cage. However, there were no significant differences between two housing systems on hen day egg production (HDEP), egg mass, body weight, feed efficiency and livability. In case of egg quality parameters, shell thickness, albumen height and Haugh unit were significantly (P<0.05) different between two systems. Haugh unit and albumen height were significantly higher in eggs produced at cage (88.97 and 8.16 mm) compared than those produced at barn (83.11 and 6.87 mm), whereas shell thickness was thicker in eggs produced at barn than those produced at cage. Shape index, breaking strength, blood spots and yolk index data were not influenced significantly by the types of housing system. To implement welfare bestowing production, this study showed that the barn system can replace the conventional cage without serious sacrifices on starting phase egg production. In addition, this study suggested that the barn system need to be optimized in view of daily feed consumption.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.191-193
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• 1997

A new disease of arrowhead (Sagittaria trifolia L.)caused by Plectosporium tabacinum was observed at Yusung area in Korea. Infection occurred on the petioles, leaves, and seeds of young and old arrowhead plants. Small and brown spots developed on the infected areas initially, which later coalesced to form large dead areas resulting in the complete blight of the host plant. Inoculation of arrowhead seedlings by conidial suspension induced typical disease symptoms found in naturally infected plants. The new name for the disease 'arrowhead blight' is suggested. The pathogenic fungus was identified as Plectosporium tabacinum and its morphological and cultural characteristics are described.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.179-182
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• 1983

A survey on the physiological disorder of green pepper plant in the on-farm vinyl house where the by-product lime of $CaC_2$ applied and a pot experiment were carried out simultaneous to find out the causes. The results are as follows: 1. The pepper plants grown under the application of by-product lime were characterized with the dark brown spots on the leaves and the hindered rooting. Finally the leaves wilted and fell down. 2. Respiration of pepper plant grown in field where tile by-product lime of calcium car-bide applied decreased. 3. Acethylene gas was considerably detected from by-product lime and from the soil where the by-product was used. The severity of physiological disorder increased as the amount of the gas detected.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.7-10
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• 2006

Anthracnose severely occurred on begonia (Begonia semperflorens Link.) nurseries in Gyeongju, Gyeongbuk in July, 2004. More than $80\%$ of begonia seedlings were diseased in the greenhouse surveyed and diseased leaves per plant were $12.1\%$ in average. Yellowish spots occurred on the leaves of begonia as initial symptoms, and they coalesced irregularly to form large brown pleomorphic lesions. Severely infected leaves were defoliated, resulting in abnormal growth of the entire plant. Colletotrichum sp. was repeatedly isolated from the diseased plants and was identified as Colletotrichum acutatum on the basis of the mycological characteristics on potato dextrose agar and RAPD analysis. Pathogenicity of the fungus was also confirmed by artificial inoculation on healthy plants. The optimum temperature for mycelial growth of C. acutatum was around $25^{\circ}C$. The fungus was sensitive to azoxystrobin, bitertanol, diethofencarb-carbendazim, difenoconazole and tebuconazole. This is the first report on the anthracnose of begonia caused by C. acutatum in Korea.

• Research in Plant Disease
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• v.22 no.2
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• pp.127-131
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• 2016

During the year 2014, black locust (Robinia pseudoacacia L.) had been observed with dark brown spots on the leaves at Andong, Cheongsong, Mungyeong in Korea. Symptoms initially appeared as small, black lesions on the leaves, and sometimes, the leaves become yellow and ultimately leads to fall off the leaves. The pathogenic fungus grown in potato dextrose agar was white or sometime gray with mycelia in tufts and from which numerous conidia were produced. The conidia were straight and fusiform in shape and measured $8.3-17.2{\times}2.5-4.1{\mu}m$. Internal transcribed spacer (ITS) rRNA sequence analysis for sequence similarity of the ITS region revealed 100% identity with nucleotide sequences for Colletotrichum acutatum. The morphological characteristics, pathogenicity and molecular data have been confirmed that the symptomatic pathogen was C. acutatum. This is the first report of anthracnose caused by C. acutatum on black locust in Korea.

• Research in Plant Disease
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• v.26 no.3
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• pp.190-193
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• 2020

In 2014, Anthracnose symptoms were observed on fruit of pumpkin in Gangneung, Gangwon in Korea. The typical symptoms on fruit surfaces were circular lesions, brown, shriveled with salmon-colored spore masses on the spots. A fungal isolate was obtained from symptomatic on fruit and cultured on potato dextrose agar at 25℃. The color of the upper surface of the colony varied from white to gray with occurrence of salmon-colored conidial masses and was red to violet on the underside. The causal fungus of anthracnose isolated from the diseased fruits was identified as Colletotrichum fioriniae based on mycological characteristics and sequences of the internal transcribed spacer, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase-1 gene, histone H3, actin gene, beta-tubulin gene region. Pathogenicity tests of the isolate were performed on pumpkin fruit by both wound and non-wound inoculation with conidial suspension (1×10⁶ conidia/ml) and incubated at 25℃. Lesions were observed on both wounded and non-wounded fruit of pumpkin after 7 days inoculation in only C. fioriniae. The pathogen was re-isolated from the lesions of inoculated fruits. To our knowledge, this is the first report of anthracnose on fruit of pumpkin caused by C. fioriniae in Korea.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.251-257
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• 2017

The occurrence of gray mold on Rubus crataegifolius has recently been reported in Pohang, Gyeongbuk province, Korea. The initial symptom was the appearance of small brown spots on the leaves, and these lesions became later covered with a gray fungus as the disease progressed. A fungus was isolated from symptomatic leaves and incubated. Through morphological and phylogenetic analyses, the causal agent of the disease was identified to be Botrytis cinerea. The fungal isolate was then used to inoculate on the leaves of healthy plants to determine its pathogenicity as the causal agent of gray mold as per Koch's postulates. The inoculated leaves showed the same symptoms as the originally infected plant, and the fungal pathogen re-isolated from the lesions showed the same morphological characteristics as the original pathogen. This is the first report on the occurrence of gray mold on R. crataegifolius caused by B. cinerea in Korea.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.282-288
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• 1995

To investigate the alterations in the ultrastructure of leaves by acid rain, 10mm of SAR(Simulated Acid Rain, pH 2.0, 2.7, 3.0, 6.0) was applied to three crops(red-pepper, perilla, eggplant) at a two-day interval. The symptoms of leaf damage by SAR were observed by naked eyes and SEM(Scanning Electron Microscope), and the peroxidase activity in the leaves was measured. The results are summarized as follows : The severity of SAR damages to the crops observed by naked eye were in the decreasing order of red-pepper, perilla, and eggplant. The Symptoms were characterized by brown or white spots on the leaf surface. In the SAR treatment of pH 3.0, trichomes of all crops except for eggplant were damaged. By the SAR treatment of pH 2.7, stomata were damaged in all crops. With one time treatment of SAR, the peroxidase activity of perilla was rapidly increased.