• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.382-386
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• 2000

This study was conducted to know the optimum conditions for overwinter culture of sweetpotato stems in PE film house. The stems will be used as transplant shoots in the next year instead of sprouts produced from storage roots. Sweetpotato stems were cut at field on harvest season and planted in PE film house under three different conditions of PE film mulching, tunnel, or mulching plus tunnel in comparison with the non-treatment of PE film on October 10 and November 10. The survival rate of sweetpotato stems, which was evaluated on April 10 after overwinter, was higher in the treatment planted on October 10 than that on November 10, and with PE film treatments, it was higher in tunnel or mulching plus tunnel than that of the non-treatment of PE film. The survival rate of sweetpotato stems to planting densities was 95-96% in 10$\times$2cm (333 stems/$m^2$) or in 10$\times$4cm (250 stems/$m^2$) when compared with 10$\times$2cm (500 stems/$m^2$). The survival rate under low temperature showed 95% until 20 days at 5$\pm$1$^{\circ}C$, and 0% within 5 days at 2$\pm$1$^{\circ}C$. From these results, it was concluded that there were optimum conditions that cutting time is middle October, planting density is 10$\times$3cm, and minimum maintenance temperature is 5$^{\circ}C$ in growing conditions of sweetpotato stems. Root yield produced by trans-planting shoots using the stems was similar to yield by shoots produced from roots, and the survival rate was not different among varieties.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.427-434
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• 2020

This study was performed to compare nutritional compounds and physiological functions of five domestic and imported green tea cultivars at three time points. The five cultivars were compared for theanine, γ-aminobutyric acid, and catechin content by LC-MS/MS and HPLC. Furthermore, the five tea cultivars were functionally characterized with respect to antioxidant activity, brain cell protective effect, and inhibitions of α-glucosidase and HMG-CoA reductase activities. Among green tea cultivars, Chamnok had the highest content of catechins (198 mg/g DW), theanine (11.89 mg/g DW), and tannin (23.6 mg/g DW). Considering functional properties, Chamnok treatment resulted in the maximum viability of brain cells and reduced the cortisol content of SH-SY5Y cells. The inhibition of α-glucosidase and HMG-CoA reductase was the strongest following Chamnok treatment (72.9% and 69.8%, respectively). These results indicate that Chamnok could be optimal for consumption or favorable processing owing to its high nutritional compounds, such as theanine and catechin, and remarkable brain cell protective effects.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.407-412
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• 2011

The germination of the buds in 'Hongisul' grapes is poor and especially the high ratio of shoots where the flowers failed to emerge it was difficult to secure a sufficient amount of harvest. Thus, in this study, the necrosis and the periodical change in the buds were observed morphologically and also the cause of necrosis of the bud was investigated in order to understand what was causing the low germination and flowering. There was no change in the size of the bud after June and based upon external observation, there wasn't any retrogression or withering. However, based on a microscopic examination, the ratio of whole bud and main bud necrosis of the 'Hongisul' grapes continued to increase after August, and specially the ratio of the main bud necrosis continued to increase up to October. As for the size of the buds on the shoots, the buds located on the $1^{st}-3^{rd}$ nodes from the basal part were small whereas the buds located on the $4-10^{th}$ nodes were comparatively larger in its size. The ratio of necrosis of the bud was the highest at the $1^{st}$ and $2^{nd}$ bud, meaning that the buds located at the basal part of the shoot were defective compared to those located at the end of the shoot. It was also found that when the growth of the shoot is active and the shoot diameter is thick, it hindered the development of the buds. Therefore, it was judged that long pruning of 'Hongisul' grapes would help the emergence of the flowers as you could use the buds that have comparatively developed better.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.28-32
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• 2012

This study was conducted to improve year round production of onion sets for pickles and increase their yield by using different cell sizes of plug trays. 'Josaeng sseondeobol' and 'Daeji' were seeded in 105-cell tray, 128-cell tray, and 162-cell tray on March 27, 2010. 'Josaeng sseondeobol' showed the maximum number of leaves on May 23, but 'Daeji' showed the maximum in late June. Bulbing of 'Josaeng sseondeobol' was already initiated on May 23, but 'Daeji' was initiated on June 6. Growth of both varieties was better in 105-cell tray than the others. There wasn't a difference in bulbing between two varieties by the number of cells, but bulb size was larger in the low number of cells than high ones. 'Josaeng sseondeobol' was all harvested in July, but more than 50% of 'Daeji' was harvested in August. The result of this study is as follows. Harvest time was delayed as the number of cells is increasing. There was a wide range of small onion sets distribution in both varieties as the number of cells is increasing.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.15-22
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• 1990

The efects of application time on the persistence of chlorothalonil in sesame plants and its persistence in soil were studied in the field. A procedure was used which permited the analysis of residues of Chlorothalonil (DACONIL 2787) in sesame(Sesamum indicum L.)and soil. The procedure was based on the multiresidue analytical method using an polarized acetonitrile solution or acidified acetone as the extracting solvent. The DACONIL 2787 is separated from the fat in the extracts by using an activated alumina and Florisil chromatogaphic column. Residues of DACONIL 2787 were determined by subjecting the alternate eluate from the Florisil column to gas chromatographic analysis(ECD). Residue of chlorothalonil in sesame are proved to 0.06 ppm for six sprays, 3rd day before harvest The half-life of chlorothalonil in soil proved to be 8.9 days and residues of chlorothalonil was only 0.03 ppm 100 days after application of 15 ppm.

• Research in Plant Disease
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• v.10 no.4
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.63-71
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• 2011

Pattern recognition of a cucumber were conducted to detect directly the binary images by using thresholding method, which have the threshold level at the optimum intensity value. By restricting conditions of learning pattern, output patterns could be extracted from the same and similar input patterns by the algorithm. The algorithm of pattern recognition was developed to determine the position of the cucumber from a real image within working condition. The algorithm, designed and developed for this project, learned two, three or four learning pattern, and each learning pattern applied it to twenty sample patterns. The restored success rate of output pattern to sample pattern form two, three or four learning pattern was 65.0%, 45.0%, 12.5% respectively. The more number of learning pattern had, the more number of different out pattern detected when it was conversed. Detection of feature pattern of cucumber was processed by using auto scanning with real image of 30 by 30 pixel. The computing times required to execute the processing time of cucumber recognition took 0.5 to 1 second. Also, five real images tested, false pattern to the learning pattern is found that it has an elimination rate which is range from 96 to 98%. Some output patterns was recognized as a cucumber by the algorithm with the conditions. the rate of false recognition was range from 0.1 to 4.2%.

• Journal of Mushroom
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• v.4 no.3
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• pp.111-115
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• 2006

Jinbudlsongyi mushroom (Agrocybe aegerita) was bred in Mushroom Research Institute, Gyonggi Province A.R.E.S in 2005. It was bred with mating between moookarytic strains isolated from Budlsongyi#1 and KME45202. The temperature of optimal mycelial growth was $24{\sim}26^{\circ}C$ on PDA and $18{\sim}20^{\circ}C$ in sawdust medium. To harvest fruiting body of Jiobudlsoogyi the period required for colonization after inoculation was 37days and the period of cultivation was 13days after scratching of inoculum. The major characteristics of the mushroom was shown a lot of primordia, light brown colored stipe and convex-shaped pileus. Compared with Budlsongyi#1, it was shown dark brown-colored pileus and straight stipe. The fruiting body yield was $115g{\pm}6/850cc$ bottle. It was demanded proper circulation at the time of primordia and put it around with cloth that is prevented to be bend the stipes.

• Journal of Mushroom
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• v.15 no.4
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• pp.264-268
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• 2017

In the 21st century, information and communication technology (ICT) worldwide presents a new vision for agriculture. Time and place, as well as the high-tech industry, to overcome barriers to the fusion of the so-called "smart agriculture," are changing the agricultural landscape. Core container production in precision agriculture for mushroom cultivation, optimal temperature, humidity, irradiation, self-regulation of factors such as carbon dioxide, and environment for mushroom cultivation were adopted. Lentinula edodes (shiitake) is an edible mushroom native to East Asia, cultivated and consumed in many Asian countries. It is considered to be medicinal in certain practices of traditional medicine. We used different controlled light sources (Blue-Red-White-combined LED, blue LED, red LED, and fluorescent light) with different LED radiation intensities (1.5, 10.5, and $20.5{\mu}mol/m^2s$ for LEDs) to compare growth and development. Mushrooms were treated with light in a 12-hour-on/12-hour-off cycle, and maintained in a controlled room at $19{\sim}21^{\circ}C$, with 80~90% humidity, and an atmospheric $CO_2$ concentration of 1,000 ppm for 30 days. Growth and development differed with the LED source color and LED radiation intensity. Growth and development were the highest at $10.5{\mu}mol/m^2s$ of blue LED light. After harvesting the fruit bodies, we measured their weight and length, thickness of pileus and stipe, chromaticity, and hardness. The $10.5{\mu}mol/m^2s$ blue-LED-irradiated group showed the best harvest results with an average individual weight of 39.82 g and length of 64.03 mm, pileus thickness of 30.85 mm and pileus length of 43.22 mm, and stipe thickness of 16.96 mm with fine chromaticity and hardness. These results showed that blue LED light at $10.5{\mu}mol/m^2s$ s exerted the best effect on the growth and development of L. edodes (shiitake) mushroom in the ICT-system container-type environment.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.776-779
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• 2012

A new cultivar 'Yeohong' was originated from an artificial cross between 'Jonathan' and 'Fuji' carried out at National Institute of Horticultural & Herbal Science in 1993. The cultivar was preliminarily selected among the elite siblings for its high fruit quality in 2002. After regional adaptability test at five districts for subsequent four years as 'Wonkyo Ga-31', it was finally selected in 2007. 'Yeohong' is characterized by the following. Optimum harvest time is late September. Shape of mature fruit at 278 g on mean weight is oblate a light red skin on a greenish yellow ground and yellowish white flesh. The fruit contains favorable total soluble solids at $14.3^{\circ}Brix$ and titratable acidity at 0.4%, which results in a gustatory harmony between sugars and acids. Safe storage period for the fruit is 3 weeks at room temperature. It is not resistant to Bitter rot. 'Yeohong' also reveals a physiological cross compatibility with leading cultivars such as 'Hongro' and 'Tsugaru', but a physiological cross incompatibility with 'Fuji'. It has weak growth habit.