• Horticultural Science & Technology
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• v.33 no.4
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• pp.518-524
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• 2015

The objective of this research was to investigate the influence of various depths of expanded rice hull (ERH) medium and fixation dates of runner plantlets of 'Seolhyang' strawberry on the growths in nursery field and in plastic house soil after transplanting. The five treatments in medium depths (30, 50, 70, 90, and 110 mm) and four treatments in fixation dates (1st and 15th July and 1st and 15th August) were tested. The growths of runner plantlets were investigated before transplanting to plastic house soil. The early growth and inflorescence rates of crops after transplant to plastic house soil were also investigated. The plant height and fresh weight of runner plantlets were the highest in the medium depths of 50, 70, and 90 mm. The medium depth of 30 mm had higher numbers of first roots, but lower root fresh weight compared to those of 70, 90, and 110 mm. The treatment of 30 mm in medium depth showed poorer growth in all indexes except root length and root weight compared to those of 70, 90, and 110 mm. The runner plantlets fixed on July 1 and July 15 showed good root growth and the weights of ERH adhered to form root balls were 18.3 g and 13.9 g, respectively. The detached amount of ERH was less than 40% in the two treatments when root balls were shaken by a vibratory sieve shaker. The plant growth at 45 days after transplanting to plastic house soil were not significantly different when the runner plantlets were fixed in the period from July 1 to Aug. 1. The inflorescence rates of the first cluster were 93 to 100% when runner plantlets were fixed in the period from July 1 to Aug. 1. By contrast the runner plantlets fixed on the Aug. 15 had a 67% in florescence rate for the first cluster. These results indicate that optimum depth of ERH medium was 7 cm and the ranges of optimum fixation dates are from July 20 to 25.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.526-534
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• 2010

The prevalence rate for chronic diseases such as obesity, diabetes, hypertension etc. caused by the increment of national income and the change of food life according to the globalization in Korea have been increased. Especially excess sodium intake may contribute to the development of hypertension, increasing cardiovascular disease risk. The objective of this study was to investigate sodium intake of nursery school meals in Gyeonggi-Do, and to construct database for lesser sodium intake policy. Survey consisted of 601 sample intakes of sodium in summer and in winter. A food weighed record method was used for measuring food intakes. Average intakes of ten children per nursery school were measured. The sodium contents of meals were analyzed by ICP-OES (inductively coupled plasma-optical emission spectrometer) after acid digestion by microwave. The sodium contents on food groups showed that sources (693 mg/100 g), grilled foods (689 mg/100 g) and kimchies (643 mg/100 g) had respectively higher sodium contents and the average sodium intake per meal was $582\pm204$ mg. The sodium contents of soups & hot soups and kimchies had 37.5% and 15.8% of total sodium intakes per meal, respectively. Sodium intakes per meal in summer and winter showed 572.3 mg and 592.3 mg, respectively. Regional ranking of sodium intakes showed the ascending order of apartment (514.3 mg/meal), rural region (540.5 mg/meal), multiplex house (635.9 mg/meal) and industrial complex (696.4 mg/ meal). A habit of excessive sodium intakes in childhood will threaten their health when they grow up to be adults; thus lesser intake of sodium per meal is needed for children in nursery school.

• Journal of Environmental Science International
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• v.25 no.3
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• pp.337-343
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• 2016

The present study aimed to determine the influence of various root restriction media on seedling quality and early growth of strawberry after transplanting. The root activity of the seedlings, measured 20 days after fixation, was considerably higher (0.096, 0.090, and $0.063mg{\cdot}g^{-1}{\cdot}h^{-1}$ at 420, 450, and 480 nm, respectively) in expanded rice hull (ERH) treatment than in the sandy loam and loamy sand treatments. The volumetric water content (VWC) of the root media tested across 3 irrigation regimes (15 d, 30 d, 45 d) in the nursery field was highest in sandy loam (65.0-66.8%), followed by 59.4-61.3% in loamy sand and 38.6-45.3% in ERH. When growth parameters of runner plantlets were compared, ERH treatment was found to result in the highest crown thickness and fresh weights of root and above-ground parts. This had a favorable influence on above-ground tissue growth after transplanting to plastic house soil. As mentioned above, ERH treatment resulted in the highest seedling quality and early growth after transplanting. The results of this study would serve as useful on-site data for the production of high-quality strawberry seedlings.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.163-168
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• 2012

The objective of this study is to quantify the levels of ammonia and hydrogen sulfide inmechanically ventilated slurry-pit swine house according to pig's growth stage and seasonal condition. Mean concentrations of ammonia and hydrogen sulfide in the housing room of gestation/farrowing pigs were 5.60 (${\pm}2.48$) ppm and 178.4 (${\pm}204.8$) ppb in spring, 2.51 (${\pm}3.08$) ppm and 86.6 (${\pm}112.5$) ppb in summer, 4.96 (${\pm}2.84$) ppm and 182.3 (${\pm}242.6$) ppb in autumn, and 6.82 (${\pm}3.42$) ppm and 206.3 (${\pm}356.8$) ppb in winter, respectively. Mean concentrations of ammonia and hydrogen sulfide in the housing room of nursery pigs were 7.18 (${\pm}3.26$) ppm and 486.0 (${\pm}190.2$) ppb in spring, 4.23 (${\pm}2.95$) ppm and 206.4 (${\pm}186.9$) ppb in summer, 7.02 (${\pm}2.65$) ppm and 465.4 (${\pm}156.8$) ppb in autumn, and 9.25 (${\pm}3.68$) ppm and 618.4 (${\pm}298.3$) ppb in winter, respectively. Mean concentrations of ammonia and hydrogen sulfide in the housing room of growing/fattening pigs were 9.26 (${\pm}3.02$) ppm and 604.4 (${\pm}186.8$) ppb in spring, 6.78 (${\pm}3.88$) ppm and 312.5 (${\pm}215.4$) ppb in summer, 9.34 (${\pm}2.14$) ppm and 578.2 (${\pm}248.1$) ppb in autumn, and 14.65 (${\pm}3.15$) ppm and 825.3 (${\pm}316.9$) ppb in winter, respectively. As a result, mean concentrations of ammonia and hydrogen sulfide in terms of pig's growth stage were highest in growing/fattening housing room followed by nursery housing room and gestation/farrowing housing room (p<0.05). The swine house showed the highest levels of ammonia and hydrogen sulfide in winter followed by spring, autumn and summer. However, there was no significant difference of ammonia and hydrogen sulfide among seasons (p>0.05).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.1-8
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• 2017

We investigated the effect of silicate coating of rice seeds on bakanae disease incidence and the quality of seedlings raised in seedling boxes and transplanted into pots. The silicate-coated rice seed (SCS) was prepared as follows. Naturally infested rice seeds not previously subjected to any fungicidal treatment were dressed with a mixture of 25% silicic acid at pH 11 and 300-mesh zeolite powder at a ratio of 50 g dry seed - 9 mL silicic acid - 25 g zeolite powder. The following nursery conditions were provided : Early sowing, dense seeding in a glass house with mulching overnight and no artificial heating, which were the ideal conditions for determining the effect on the seed. The nursery plants were evaluated for Gibberella. fujikuroi infection or to determine the recovery to normal growth of infected nursery plants in the Wagner pot. Seedlings emerged 2-3 days earlier for the SCS than they did for the non-SCS control, while damping-off and bakanae disease incidence were remarkably reduced. Specifically, bakanae disease incidence in the SCS was limited to only 7.8% for 80 days after sowing, as compared to 91.6% of the non-SCS control. For the 45-days-old SCS nursery seedlings, the fresh weight was increased by 11% and was two times heavier, with only mild damage compared to that observed for non-SCS. Even after transplanting, SCS treatment contributed to a lower incidence of further infections and possibly to recovery of the seedlings to normal growth as compared to that observed in symptomatic plants in the pot. The active pathogenic macro-conidia and micro-conidia were considerably lower in the soil, root, and seedling sheath base of the SCS. In particular, the underdeveloped macro-conidia with straight oblong shape without intact septum were isolated in the SCS ; this phenotype is likely to be at a comparative etiological disadvantage when compared to that of typical active macro-conidia, which are slightly sickle-shaped with 3-7 intact septa. A active intact conidia with high inoculum potential were rarely observed in the tissue of the seedlings treated only in the SCS. We propose that promising result was likely achieved via inhibition of the development of intact pathogenic conidia, in concert with the aerobic, acidic conditions induced by the physiochemical characteristics associated with the air porosity of zeolite, alkalinity of silicate and the seed husk as a carbon source. In addition, the resistance of the healthy plants to pathogenic conidia was also important factor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.586-591
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• 1996

We investigated rhizome yield and growth characteristics of wasabi variety, Daioichigo and Daruma cultured by flowing water from Trout nersery in Pyong Chang. Average temp. of air and water during a year was 14.3, 12.3$^{\circ}C$, respectively in PE film house. Wasabi growth was good and healthy in May and October. Rhizome weight of main stem in Daioichigo was 78.78g per plant and 608kg per l0a, while those of the Daruma was 37.1g per plant and 287kg per l0a. Rate of marketable rhizome was 90% in Daioichigo and 37.5% in Darurna. Rhizome weight of main stem in Daioichigo was increased, up to 21% of the control by the remove of floral axis with two times a year.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.226-232
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• 2017

Dhup (Canarium resiniferum) is an economically and aesthetically important rare native tree species of Bangladesh. In natural condition 78.5-98.7% seeds do not germinate due to inhibition by hard seed coat, seed predation and unfavorable environmental conditions. A study was conducted in the Seed Research Laboratory and nursery of Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh in 2013 to find out appropriate pre-sowing treatments for maximizing germination and initial seedling growth. Eleven pre-sowing treatments were provided in both the seeds sown in polybags and seeds sown in propagator house. Results revealed that, germination started at first (after 20 days of seed sown) in seeds immersed in water at room temperature for 24 hours and germination completed within 38 days. Significantly higher (p<0.05) germination percentage (33%), germination energy (16.7%), plant percent (33%) and germination value (0.4) was found with seeds immersed in water at room temperature for 24 hours. Seedling height measured at three, four and five months after the seed germination in case of seeds treated by immersion in water for 24 hours was also greater than others. Therefore, pre-sowing treatment by immersion in water at room temperature for 24 hours was more effective in germination and production of quality vigor seedlings of Dhup.

• Research in Plant Disease
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• v.9 no.4
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• pp.213-216
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• 2003

A bacterial disease of tea plants(Camellia sinensis L.) was found in the graftage nursery grown under vinyl house conditions in Suncheon city, Korea, in spring of 2002. The primary symptoms of the disease include small, water-soaked and dark brown spot development on the young leaves. This spot gradually increases in size, especially taking on elongate shape along the midrib or vein of the leaf, and then turns black. The diseased leaves were defoliated easily. Ten strains were isolated from the infected leaf. Inoculation on tea leaf with these isolates produced the same symptoms of naturally infected plants. On the basis of stain reactions, morphological characterization, colony pattern, physiological and biochemical reactions, the bacterium was identified as Pseudomonas syringae pv. theae. This is the first report of brown blight of tea plant in Korea.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.587-591
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• 2004

Blood samples from 622 pigs of 44 farms which were sero-positive to Mycoplasma hyopneumoniae (M. hyo) by ELISA method were collected from May 2003 to July 2004. And they were divided into 2 categories : M. hyo-vaccinated group (7 swine farms) and M. hyo-non-vaccinated group (37 swine farms). Then, each swine farm was analysed by sero-positive percentage per weeks of age. It was observed that the sero-positive percentage to M. hyo is directly proportional to weeks of age in the 44 swine farms that were selected. This meant that there has been a chronic infection of M. hyo in Korean swine herds and control of M. hyo infection did not have worked efficiently. In 7 M. hyo-vaccinated swine farms, there were no reliable patterns between sero-positive percentage to M. hyo and weeks of age. Although the swine farms have been used M. hyo vaccine, they had only little sero-positive percentage that was less than 50% at 6 to 11 weeks of age. This means a present vaccination program does not induce sufficiently a seroconversion expected. In 37 M. hyo-non-vaccinated swine farms, it was observed that sero-positive percentage was higher at above 15 weeks of age. This result showed that infection of M. hyo occurred commonly at between 7 and 12 weeks of age, at which pigs moved to the growing house. Because a risk of natural infection is severe at growing stage as well as nursery stage, it suggested that M. hyo vaccination at several weeks prior to the growing stage will give efficient effect to control the enzootic pneumonia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.69-89
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• 1981

Stevia (Stevia rebaudiana Bertoni) is a perennial herb widely distributed in the mountainous area of Paraguay. It belongs to the family Compositae and contains 6 to 12 percent stevioside in the leaves. Stevioside is a glucoside having similar sweetening character to surgar and the degree of sweetness is approximately 300 times of sugar. Since Korea does not produce any sugar crops, and the synthetic sweetenings are potentially hazardous for health, it is rather urgent to develop an economical new sweetener. Consequently, the current experiments are conducted to establish cultural practices of stevia, a new sweetening herbs, introduced into Korea in 1973 and the results are summarized as followings: 1. Days from transplanting of cuttings to the flower bud formation of 6 stevia lines were similar among daylengths of 8, 10 and 12 hours, but it was much greater at daylengths of 14 or 24 hour and varietal differences were noticable. All lines were photosensitive, but a line, 77013, was the most sensitive and 77067 and Suweon 2 were less sensitive to daylength. 2. Critical daylength of all lines seemed to be approximately 12 hours. Growth of plants was severely retarded at daylengths less than 12 hours. 3. Cutting were responded to short daylength before rooting. Number of days from transplanting to flower bud formation of 40-day old cuttings in the nursery bed was 20 days and it was delayed as duration of nursery were shorter. 4. Number of days from emergence to flower bud formation was shortest at short day treatment from 20 days after emergence. It was became longer as initiation of short day treatment was earlier or later than 20 days. 5. Plant height, number of branches, and top dry weight of stevia were reduced as cutting date was delayed from March 20 to May 20. The highest yield of dry leaf was obtained at nursery duration of 40-50 days in march 20 cutting, 30-40 days in April 20 cutting, and 30 days in May 20 cutting. 6. An asymptotic relationship was observed between plant population and leaf dry weight. Yield of dry leaf increased rapidly as plant population increased from 5,000 to 10,000 plants/10a with a reduced increasing rate from 10,000 to 20,000 plants/l0a, and levelled off at the plant population higher than 20,000 plants/l0a. 7. Stevia was adaptable in Suweon, Chengju, Mokpo and Jeju and drought was one of the main factors reducing yield of dry leaf. Yield of dry leaf was reduced significantly (approximately 30%) at June 20 transplanting compared to optimum transplanting. 8. Yield of dry leaf was higher in a vinyl house compared to unprotected control at long daylength or natural daylength except at short day treatment at March 20. Higher temperature ill a vinyl house does not have benefital effects at April 20 transplanting. 9. The highest content of stevioside was noted at the upper leaves of the plant but the lowest was measured at the plant parts of 20cm above ground. Leaf dry weight and stevioside yield was mainly contributed by the plant parts of 60 to 120cm above ground but the varietal differences were also significant. 10. Delayed harvest by the time of flower bud formation increased leaf dry weight remarkably. However, there were insignificant changes of yield as harvests were made at any time after flower bud formation. Content of stevioside was highest at the time of flower bud formation and earlier or later harvest than this time was low in its content. The optimum harvesting time determined by leaf dry weight and stevioside content was the periods from flower bud formation to right before flowering that would be the period from September 10 to September 15 in Suweon area. 11. Stevioside and rebaudioside content in the leaves of Stevia varieties were ranged from 5.4% to 14.3% and 1.5% to 8.3% respectively. However, no definit relationships between stevioside and rebaudioside were observed in these particular experiments.