• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.484-490
• /
• 1998

Microorganisms associated with seed-rhizome rot of gingers preserved in three underground storage caves were identified with respect to rot types. Rot patterns were grouped into 4 different types : yellow soft rot, brown rot, localized ring rot, and water-soaked rot. Water-soaked rot was highest in frequency with 40% and ring rot the least with 14%. Causal pathogens differed with rot type, yellow soft rot by Erwinia carotovora and Pseudomonas aeruginosa, brown rot by Fusarium solani and Pseudomonas aeruginosa, localized ring rot by F. solani, and water-soaked rot by Pythium spinosum and P. ultimum. Pythium myriotylum, the causal pathogen of ginger rhizome rot which occurs severely in fields was rarely detected from storage seed-rhizomes suggesting its minor involvement with storage rot. Pathogenic Pythium isolates were frequently obtained from both rhizome surface and inner tissues of rotten rhizomes. Detection frequency of Pythium isolates in inner tissues decreased as increasing distance from rhizome surface. In wound-inoculation tests, above pathogens caused a varying degree of rot on healthy rhizomes at 15$^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$ with increasing severity at higher temperatures.

• Mycobiology
• /
• 제28권1호
• /
• pp.47-50
• /
• 2000

The capability of higher ascomyceteous fungi to cause typical soft-rot decay for wood under laboratory conditions is reviewed and discussed. Fungi tested were extremely active in the decomposition of timbers. Scanning electron micrographs illustrated typical soft-rot decay pattern of higher wood decay ascomycetes, with the exception of H. trugodes that caused white-rot decay. Most of the fungi tested could be grouped as soft-rot fungi that showed typical soft-rot type II. Hypha confined primarily to the resin canals in softwoods or vessel elements in hardwoods and spread tracheid to tracheid via pits of cell wall to cell wall with mechanical force.

• 식물병연구
• /
• 제12권1호
• /
• pp.20-24
• /
• 2006

백합 구근저장고에서 채취한 부패한 구근을 부패 형태별로 구분하여 관여하는 미생물을 동정하고 상처 접종으로 병원성을 조사한 결과 부패 형태는 기저부 갈색 부패, 신초부 갈색 부패, 수침상 부패 및 푸른곰팡이 등 4가지로 구분하였다. 기저부 갈색 부패가 72.5%로 빈도가 가장 높았고, 신초부 갈색 부패가 23%로 빈도가 가장 낮았다. 부패 형태별로 우점균이 달라 기저부 갈색 부패는 Fusarium oxysporum, 푸른색 부패와 신초부 갈색 부패에서는 Penicillium brevicompactum과 P. fellutanum이 우점균 이었다. 몇 가지 살균제를 이용한 백합 구근 소독효과를 조사하였던 바 ???L탄 수화제가 방제가 95.2%로 가장 방제효과가 높았으며, 지오판 수화제, 프로라츠 유제, 지오람 수화제 및 벤레이트티 수화제는 각각 85.6%, 71.8%, 62.5% 및 62.0%였다.

• 한국식물병리학회지
• /
• 제14권2호
• /
• pp.184-185
• /
• 1998

Rhizoctonia stem rot of Saururui herba [Saururus chinensis (Lour) Baill] was observed during plantations from 1996 to 1997 in Chungbuk area. Infected plant showed damping-off and stem rot at soil line. The causal fungus of stem rot isolated from the infected plant was identified as Rhizoctonia solani according to the criteria based on the cultural and morphological characteristics. The stem rot of Saururi herba caused by Rhizoctonia solani was first described in Korea, and the name the“Rhizoctonia black stem rot”is proposed.

• Journal of the Korean Wood Science and Technology
• /
• 제36권5호
• /
• pp.1-10
• /
• 2008

Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified oriented strandboard (OSB) from southern mixed hardwood and southern yellow pine was investigated in this study. Brown rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolar were used to examine the decay resistance of the OSB. The OSB test specimens were colonized by brown and white rot fungal mycelium in both the brown and white-rot culture bottles after 8 and 12 weeks, respectively. The wood species and fungus type had the significant effects on the decay resistance. Brown rot decay was evident for all untreated southern pine and mixed hardwood controls. The white-rot decay, however, did not show significant weight loss at both species control samples. The incorporation of ZB and CB composites provides suitable protection against brown-and white-rot fungi. No significant weight loss was observed from the borate treated OSB.

• 식물병연구
• /
• 제29권4호
• /
• pp.377-383
• /
• 2023

In 2020 and 2021, we surveyed diseases of three-leaf ladybell (Adenophora triphylla) plants grown in fields at two locations in Korea. During the disease surveys, severe leaf rot symptoms were observed on the young plants in Hongseong, and stem rot symptoms on the adult plants in Cheolwon. The incidence of leaf rot was 5-60%, and that of stem rot 1-10%. We obtained 6 fungal isolates each from the leaf rot lesions and the stem rot lesions. All the isolates were morphologically identified as Rhizoctonia solani. Anastomosis test and investigation of cultural features of the fungal isolates revealed that the isolates from the leaf rot lesions corresponded to R. solani AG-1(IB), and those from the stem rot lesions to R. solani AG-2-2(IIIB). Two isolates each of R. solani AG-1(IB) and AG-2-2(IIIB) were used for DNA sequence analysis and pathogenicity test to three-leaf ladybell plants through artificial inoculation. The anastomosis groups and cultural types of the R. solani isolates were confirmed by the sequence analysis. The pathogenicity tests revealed that the isolates of R. solani AG-1(IB) caused only leaf rot symptoms on the inoculated plants, and those of R. solani AG-2-2(IIIB) leaf rot and stem rot symptoms. The induced symptoms were similar to those observed in the fields investigated. Leaf and stem rot of three-leaf ladybell caused by the two anastomosis groups and cultural types of R. solani is first reported in this study.

• The Plant Pathology Journal
• /
• 제24권4호
• /
• pp.439-446
• /
• 2008

A fungicidal spray program for effective control of three major apple diseases in Korea (white rot, bitter rot, and Marssonina blotch) was developed. This was based on our previous studies showing that application of ergosterol biosynthesis inhibitors (EBIs) in early or mid-August can eradicate white rot infection in fruit and that some protective fungicides show after-infection activity against white rot. The basic spray program focused on control of white rot, the main target disease, and the fungicides were sprayed at 15-day intervals from petal fall to late August using fungicides that show after-infection and EBI activity. The basic spray program was modified over 4 successive years to improve control efficacy against bitter rot and Marssonina blotch, which sometimes cause as much damage as white rot. Modifications to the regime were made every year by replacing one fungicide in the basic program at a specific spraying time. Substitution of only one fungicide in the spray program, even early in the growing season, greatly influenced the final disease incidence at harvest. Applying this principle, a moderately efficient spray program for cv. Fuji that increased the spray interval from 10 to 15 days and thus reduced the number of sprays required per crop season was developed.

• The Plant Pathology Journal
• /
• 제33권4호
• /
• pp.434-439
• /
• 2017

Incidence rates of diseases in kiwiberry orchards were investigated monthly from late June to late September in Gwangyang and Boseong in 2015 and 2016. The impact of postharvest fruit rot was investigated during ripening after harvest. Bacterial canker was only observed on one single tree in 2015, but black rot, powdery mildew, leaf spot and blight, and postharvest fruit rot diseases were problematic throughout the study period in both 2015 and 2016. Incidence rates of the diseases varied with kiwiberry cultivar, region and sampling time. Incidence rates of powdery mildew, leaf spot and blight diseases increased significantly during the late growing stages near fruit harvest, while black rot peaked in late August. Incidence rate of postharvest fruit rot on fruit without fruit stalks was less than half of fruit with fruit stalks, regardless of kiwiberry cultivars. Among the four cultivars, Mansu was relatively resistant to black rot and postharvest fruit rot diseases. In our knowledge, this is the first report of various potential pathogens of kiwiberry in Korea.

• Journal of Ginseng Research
• /
• 제5권1호
• /
• pp.73-84
• /
• 1981

Effect of environmental factors and host on the growth and outbreak of various ginseng diseases was reviewed Environmental lectors included hydrogen ion concentration, moisture content, temperature, nutrition, and microbiol populations. Age of the ginseng plants in relation to several ginseng disease occurrence was also included in order to formulate the effective control measure for ginseng diseases. Damping-off caused by Rhizoctonia, Pythium, and Phytophthora, greymold by Botrytis, sclerotinia by Scleretinia, and phytophthora blight caused by Phytophthora were usually prevalent during the early growing season of ginseng when temperature is below 20$^{\circ}C$, while anthrac se caused by Colletotrichum, alternaria blight by Alternaria, and bacterial soft rot by Erwinia were so during the latter growing season when temperature is above 25$^{\circ}C$. However, the root rot incited by Fnarium and Cylindrocarpon caused severe damages throughout the growing season. Growth range of the temperature for a pathogen was highly related to the corresponding disease outbreak. Hydrogen ion concentration was highly related to the outbreak of sclerotinia, root rot, and red rot. Most severe outbreak of those diseases where the soil acidity was pH 4.7, pH 6.5- 7.5, and pH6.0-6.5, respectively. Nitrogen content in the soil was also related to outbreak of root rot and red rot. More red rot occurred where NH,-nitrogen is above 30 ppm and more root rot obtained when excessive nitrogen fertilizer applied. Yellow necrosis apparently was related to magnesium especially its ratio with potassium or calcium content in a soil. Fusarium Population showed significant .relations to missing rate of ginseng Plants in a Implanting ginseng field, while that of total bacteria showed similar relations in all ginseng field, However, in six year old ginseng fields, the more the Streptomyces population was, the less the Fusarium obtained. Consequently, less missing rate observed in a field where Streptomyces population was high. Damping-off, root rot, Rhytophthor a blight were mose severe on the nursery and on 2-3 years old ginseng plants, whereas sclerotinia, and grey cod, alteraria blight, anthracnose were severe on 4-6 years old ginseng plants. Root rot caused by Fusarium and Erwinia, however, was also severe regardless of the age of the plants when the roots were injured. Therefore, for the effective control of ginseng root rot most careful control of the disease during the early year should be rendered.

• 식물병연구
• /
• 제24권2호
• /
• pp.113-122
• /
• 2018

Ripe rot, Botrytis storage rot and Sclerotinia rot are major fungal diseases that lead to deterioration of fruit quality in Korea. Ripe rot, which is caused by Botryosphaeria dothidea, affects harvested fruits during post-storage ripening, while Botrytis storage rot, caused by Botrytis cinerea, affects harvested fruits during cold storage, and Sclerotinia rot, caused by Sclerotinia sclerotiorum, mainly affects immature fruits on the trees. Major fungal fruit rots tend to affect yellow- and red-fleshed cultivars of kiwifruit more severely because of the sharp increase in their cultivation acreage in recent years in Korea. In this review, we summarize symptoms and epidemiological characteristics of the major fungal fruit rots and propose integrated management methods of the diseases that can be practically utilized at the farmers' orchards in order to prevent the diseases based on our research works and field experiences and the research works of others conducted during the last three decades worldwide.