• The Plant Pathology Journal
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• v.23 no.3
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• pp.161-165
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• 2007

Cultivation of a biocontrol agent on a certain medium often results in reduced biocontrol efficacy and alters physiological state. In our previous study, Burkholderia gladioli strain B543 with long-term subculture on tryptic soy agar resulted in significantly reduced biocontrol ability against cucumber damping-off caused by P. ultimum. Therefore, we investigated the influence of laboratory culturing media on biocontrol activity and physiological state of Burkholderia gladioli strain B543 by using long-term repeated culture on a certain medium. When isolate B543 were successionally cultured on King's B agar (KBA), tryptic soy agar, nutrient agar (NA), or soil extract agar more than 20 times, the isolate cultured on KBA or NA showed a significantly enhanced biocontrol efficacy and higher population density in the rhizosphere of cucumber compared to that of the others. However, the isolates cultured on KBA more than 20 times showed the lowest production of protease, siderophore, or antifungal substance(s), measured by skim milk agar, Chrome-Azurol-S agar, and potato dextrose agar amended with 10% of the culture filtrate, respectively. Our results suggest that adaptation to proper culturing medium can alter biocontrol ability and physiological state, and we must consider laboratory media in optimizing the use of biocontrol agents.

• Mycobiology
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• v.40 no.3
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• pp.189-194
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• 2012

Four Cladobotryum isolates were collected from four different commercially grown mushroom types infected with cobweb disease in Cheongdo-gun and Chilgok-gun of Gyeongbuk Province, Korea in 2010. The isolates were identified as C. mycophilum from Agaricus bisporus and Pleurotus eryngii, C. varium from Flammulina velutipes and Hypsizygus marmoreus. The cultural characteristics of the four isolates were investigated using potato dextrose agar (PDA) media under nine different temperatures ranging from $5{\sim}32^{\circ}C$. Rapid growth of the isolates to colony diameters of 47~82 mm was observed at conditions of $18{\sim}22^{\circ}C$. No growth was observed at $32^{\circ}C$. C. mycophilum produced a yellowish red pigment while C. varium produced a cream colored pigment after cultivation for 25 days on PDA. Phylogenetic analysis of the internal transcribed spacer region and partial 28S rDNA from the four isolates confirmed they were C. mycophilum and C. varium. Cross pathogenicity tests revealed that the two isolates of C. mycophilum were highly pathogenic toward three mushroom types, but not toward H. marmoreus. The two isolates of C. varium were less pathogenic than those of C. mycophilum, but were pathogenic toward all mushroom types evaluated.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.180-183
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• 2001

A corynespora leaf spot of pepper, which has not been reported previously in Korea, occurred severely at the major pepper cultivation area of Chinju, Gyeongnam province in 2001. Infection rate ranged from 48.2 to 84.7% in eight fields surveyed. The causal fungus was identified as Corynespora cassicola based on the following cultural and morphological characteristics. The fungi grew well on potato dextrose agar, showing gray to brown color with cultural age. Conidia formed solitary or catenary were obclavate to cylindrical in shape, and pale olivaceous brown or brown in color. They had 420 pseudoseptate and isthmus, and measured 42.7-197.6 x 9.3-$23.5\mu\textrm{m}$. Septate conidiophores were pale to light brown in color, and measured 116.5-836.0 x 4.2-$11.0\mu\textrm{m}$. Conidia germinated as a bi-polar type. Optimal temperature for mycelial growth and conidial germination was $30^{\circ}$ and 25-$30^{\circ}$, respectively. The fungus showed strong pathogenicity to pepper plant, and the symtoms on pepper by the artificial inoculation were similar to those observed in the field. This is the first report on the corynespora leaf spot on pepper (Capsium annuum) caused by Corynespora cassicola in Korea.

• The Plant Pathology Journal
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• v.19 no.6
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• pp.280-283
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• 2003

A soybean-sprout rot epidemic occurred in a mass production soybean sprout factory in 2000 and 2001 in Korea, which caused up to 20% production loss. Among the causal pathogenic bacteria and fungi, Pythium deliense was found to be the dominant pathogen of severe root and hypocotyls rot, particularly in recirculating water system. An average of 90% of the isolated fungi from the rotted sprout on potato dextrose agar were Pythium sp. The fungal density of Pythium in the sampled water was monitored in the recycled water system for 1 year using a selective medium (com meal agar with Pimaricin, 10 mg； Rifampicin, 10 mg； and Ampicillin, 100 mg per 1 liter). The drained water from the soybean-sprout cultivation always had a certain amount of fungus in it. The removal of Pythium from the recycling water system must be thorough, safe, and environment friendly. However, the pathogen in the water was easily found even after ozone and chlorine treatments, which were devised on the recycling system for the removal of microorganisms. 5-$\mu\textrm{m}$ pore size filter was applied and was able to successfully control the disease. As the sprout industry increasingly shifts into mass production, the demand for water will increase continuously. Recycling water for sprout production is eco-friendly. However, a process must be devised to be able to first decompose organic matters before Pythium zoospores are filtered.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.137-148
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• 2012

During investigating of shiitake mushroom competitors, 289 isolates of Trichoderma spp. were collected from shiitake mushroom farms in different districts and the Forest Mushroom Research Center of Korea, among which 29 representative strains were selected. Based on the DNA sequences of the rpb2 and tef1 genes and the ITS rDNA, and their morphological characteristics, they were identified as T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, and two undescribed species, Trichoderma spp. 1 and 2, which are considered to be the candidate of new species. Competition tests between Lentinula edodes (Sanjo302) and the Trichoderma species indicated that the six species of Trichoderma were significantly different from each other in terms of their ability to invade the mycelial blocks of shiitake. In both of dual cultures on potato dextrose agar and sawdust media, Trichoderma spp. 1 and 2 strongly invaded the mycelial blocks of shiitake. Our results suggest that the two Trichoderma species may cause potentially serious economic losses in shiitake cultivation of Korea.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.279-283
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• 1986

The ginseng residue, a by-product of ginseng tea manufacture, was used as growth promoting substance in the submerged cultivation of Basidiomycetes for its effective utilization. Ginseng residue contained about 46％ of total sugar, 14％ of crude protein, 12％ of ash, and 0.16％ of crude saponin. Among inorganic substances in ginseng residue, amount of Mg, Na, K and Ca were much more than other inorganic substances. All ginsenosides existed in red ginseng residue. Ganoderma lucidum and Pleurotus ostreatus could be excellently cultured in potato dextrose broth. Most effective additional concentration of residue extract for growth of these fungi was shown to be 0.2％, and the contents of crude protein and amino acid in mycelium were increased when 0.5％ of residue extract were added to the medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.418-423
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• 2012

Field experiments were carried out to improve the cultural practice of potato by analysing its tuberization patterns. Tuberization patterns affected by different altitudes was analyzed at two potato cultivation regions, Jinbu (600 m) and Daegwallyung (800 m) using two potato cultivars, 'Superior' and 'Atlantic'. To analyse tuberization patterns affected by different planting time, seed potatoes were planted at every 10 days from April 19 to May 19 in Daegwallyung. Total dry weight was greater in plant grown at the altitude of 800 m than 600 m during the entire growth period and the highest increase was observed at the early growth period, July 6, comparing to other growth period. The total dry weight was the greatest at 110~112 days after planting (DAP) at the altitude of 800 m and 108~111 DAP at 600 m. There was no significant differences between altitudes and between cultivars. Tuber dry weight per plant at the altitude of 600 m was lower than 800 m on July 6 (58 DAP), but it increased rapidly from July 21 (73 DAP). At both altitudes, the increase of tuber dry weight per plant from July 6 to August 8 was higher than the other growth period. The time of growth period at which tuber dry weight per plant was the highest was similar at both altitudes that was 118~125 DAP at the altitude 800 m and 118~124 DAP at the altitude 600 m. Dry weight per tuber at the altitude 800m was higher than 600 m due to the number of tubers per plant. A higher increase of crop growth rate (CGR) was shown at the altitude 600 m on July 6 (58 DAP), comparing to at 800 m. The highest tuber dry weight per plant of each cultivar was shown when the planting time was April 29 for 'Superior' and was April 19 for 'Atlantic'. Both the tuber dry weight of plant and the total dry weight were lower at a later planting time. Dry weight per tuber increased quickly during the period between June 30 to August 8. Tuberization period was shortened as the planting time was delayed.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.486-491
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• 2009

To evaluate the potential value of the major bioenergy crops which are wheat, canola, barley, corn, and sweet potato in Korea, we investigated the production of biomass and calorific value of crops, and also compared input and output factors among bioenergy crops during the cultivation period. There was difference between the biomass values in Agricultural and Forestry statistical yearbook(2006) and the one investigated in this experiment, also there was difference in crops and in species. Among the crops investigated, sweet potato(Jinhongmi, Yulmi) was shown the highest amount of biomass production and corn(Gangdaok) was shown the highest amount of the total biomass which is the total aboveground biomass at harvest. Oilseed canola which is presently a major source of bio-diesel had highest calorific value as $6,673{\sim}6,725cal\;g^{-1}$. Wheat and corn grains which are source of bio-ethanol were in the range of $3,879{\sim}4,317cal\;g^{-1}$. Gangdaok(Corn) produce the highest total calorific value in unit cultivating area among the crops as $8,263kcal\;m^{-2}$. Corn was shown that the input and output factors were the highest level among bioenergy crops during cultivation period. Sweet potato also was shown that output factor was the highest level though its input factors were average level. It is needed to be investigated more crops for collecting the higher potential value of bioenergy production further considering small land area and its effective utilization in Korea.

• Journal of Mushroom
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• v.6 no.1
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• pp.20-26
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• 2008

The stromatal forms of T. fuciformis and the mycelia of Hypoxylon sp. were collected. The DNA sequence in the ITS region of the 5.8S ribosomal genes of isolated strain KG103 was very similar to that of T. fuciformis AF042409 with a homology of over 98% in the EMBL/GenBank database through BLAST searching. A second isolate, No KG201, one of the symbiotic strains for cultivating T. fuciformis also exhibited high homology with Annulohhypoxylon stygium AJ390406. Potato Dextrose Medium exhibited the best mycelial growth of 14 mm/14 days and 85 mm/14 days for T. fuciformis and its symbiotic fungi, respectively. Optimum culture conditions for the micelial growth were pH 5 at $25^{\circ}C$. For the optimization of artificial cultivation of T. fuciformis in bottle with sawdust medium, several conditions such as type of sawdust, supplements, pH, moisture content, and incubation temperature were investigated. T. fuciformis and symbiotic fungi showed fast mycelial growth on corn cob media (77 and 52%) followed by oak tree sawdust and cotton seed meal. The optimal temperature for mycelial growth of T. fuciformis and symbiotic fungi on corn cob media was $25^{\circ}C$ at 55% of moisture content.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.131-138
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• 2016

Recently, the cultivated area is reduced, the ratio of upland-field in the total cultivated area is increasing relative appeared in 36.2% in 1990 from 43.7% in 2013. If upland-field can be applied well designed-infrastructure, good income crop production is possible, however, maintenance of infrastructure and a significant portion of the upland-field is maintained under insufficient infrastructure. While imports of agricultural products expanded since the 2000s in progress, looking at the self-sufficiency of upland-field crops, it is reduced to from 90% to 42% for the pepper, it is from 90% to 74% for the garlic, cereals is reduced from 42% by 26%. As a result of these conditions, the competitiveness of farmers has weakened, the risk to meet the challenges of this area of production and supply reduction increased. This study was the first to conduct a basic evaluation index, data analysis and evaluation of indicators to diagnose the agricultural production capacity of the upland field. 12 kinds classified index of producing conditions from the natural environment and eight factors for the cultivation and production capabilities have developed for the assessment of productivity of upland-field (especially Kimchi cabbage). Through this regional imbalance was found, based on the production capabilities conditions are good in Haenam, Gangneung, Pyeongchang. 3 Regions have been low and the lowest Youngwol to 0.8992. Climate(Cultivation conditions) indicators of Mungyeong region is the highest, relatively low areas were in Taebaek. In particular, it is determined to be preferred that the area required for the enhancing the production environment based on providing the convenience for the producing and maintenance of the first production area. It is necessary Increasing part of mechanization, agro-industrial competitiveness through aggressive management plans for facilities as required in the process of post-harvest storage, processing, distribution line can be improved.