• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.235-241
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• 1997

This study was performed to investigate the behaviour of root zone environments under the control of soil temperature and tension of soil moisture near the root Bone of 'Kyoho' grapes tree grown on restricted root zone system in plastic greenhouse. Maximum diurnal air temperature inside plastic greenhouse ranged between 25.1 and 32.7$^{\circ}C$, and the average of nocturnal air temperature inside plastic greenhouse maintained at 18$^{\circ}C$ in winter season. Also the minimum diurnal relative humidity ranged between 50 and 55%, and the maximum nocturnal relative humidity ranged between 84 to 87%. At a depth of 15cm from soil surface, the average soil temperature maintained at 25.6$^{\circ}C$ for under-ground heating, and appeared to 17.4$^{\circ}C$ for unheated condition. Although the tension of soil moisture just after irrigation sharply decreased to pF 1.5, the tension of soil moisture at the depth of 15cm maintained at pF 2.0~2.2. It is suggested that the tension of soil moisture at the depth of 15cm might be used as the standard for the determination of irrigation set point. Effective drainage system is needed to prevent the spindly and succulent growth of vine trees grown in restricted root zone system.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.63-72
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• 2004

This study was carried out to analyze effects of soil, water level and shading on growth of sweet flag(Acorus calamus var. angustatus). Three types of soil were used, which included sandy, silty loam and paddy loam soil. Three levels of shading were applied in the experiment: no shading, 55％ shading and 75％ shading. The water levels were also adjusted to three levels in the experiment. The results are summarized as follows; 1. The cultivation of sweet flag in sandy soil with low water level resulted in decreased fresh weight compared to that at planting. This result indicates that the water level should be maintained higher than the soil surface for sweet flag growth in sandy soil. 2. 5 out of 72 sweet flags died in paddy loam soil. Water saturation of soil easily reduced paddy loam soil, and root growth of sweet flags in reduced soil condition were restricted, resulting in the dead plants. 3. The growth of sweet flag in paddy loam soil was worse than those in silty loam, indicating that reduced soil conditions in paddy loam is harmful to root growth. In planting sweet flags in paddy loam, improved soil aeration in paddy loam soil is necessary for good growth of sweet flag. 4. The maintaining of high water levels is better than that of low water levels in sweet flag cultivation. During winter, soil near the water surface froze and sweet flags in frozen soil were stressed physiologically. Maintaining high water levels prevents soil from being frozen which is good for the growth of sweet flags. 5. There was not significant difference in the growth of the sweet flag between non-shading and 55％ shading. It thus appears that sweet flags can grow soundly under shading rate lower than 55％.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.737-752
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• 2013

This study was conducted to evaluate the allelopathic effect of aqueous extract of Ganghwa domestic mugwort (Artemisia spp.) on vegetables and its related allelo-chemicals. When the receptor vegetables, such as Chinese cabbage, lettuce, and red radish, were treated with aqueous extract obtained from Sajabalssuk (A. $sp^*I$), Ssajuarissuk (A. $sp^*II$) or Ssajarissuk (A. $sp^*III$), their germination rate, leaf number, plant height, and root length were restricted with increasing concentration of aqueous extract. Allelopathic effect was the highest in radish, than lettuce and Chinese cabbage in order. The growth of topplant were more inhibited then root growth observing in restriction of plant height, root length, and chlorophyll contents. The plant height, the root length of red radish were 53.3 and 61.2% and their fresh weights were 19.8 and 26.4% compared to those of controls, respectively. A. $sp^*III$ showed the highest allelopathic effect among the donor plants. In HPLC analysis, 7 phenol compounds were identified in A. $sp^*I$ and A. $sp^*II$, and, in A. $sp^*III$, and hydroxybenzoic acid and phenylacetic acid were further identified as allelochemicals. It is considered that their plant growths were variously inhibited by the amounts and types of allelochemicals in aqueous extracts. To increase the productivity of farm land after cultivation of mugwort, these results can be useful to select the following field crops.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.472-500
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• 1996

Researches on mineral nutrition, physiology and phyrsiological diseases, . cultivaction methods. brceding. pest control quality management and extension during 1976-1995 in Korea were reviewed Review in brceding and pest control was restricted to the researches directely related to cultivaction. Mineral nulrient up take. partion and varicos factors such as top dreasing. Light intersity etc. and interrelationship between minerals were investigated. Top dressing was not effective due to low minera1 requorement Physiological characteristics on tempelature light and water were well elucidated and applied to assess traditional cultivation method and its inovation. Photosyrnthetic pigments. light harvest proteins and activity of related enzymes were studied. In nitrogen metabolism arginine, praline, ammonium, threonine appeared to have important role in re growth of shoot Saponin metabolism was studied in relation to growth and new ginsenosides were found but physiological role of saponin was not clearly elucidated yet Endogenous growth regulators were reported and various erogenous growth regulators were studied for growth stimulation. short stem and seed pruning etc. Various physiological diseases were investigated for cause and control measures were established. Water culture was little studied Forest culture was studied but not retched the recommendable stage Drip irrigation straw mulching. seasonal shading and soil preparation method including soil fertility adjustment were established for practical application. Shading materials completely changed to polyethylene net and materials of polymers The research on ginseng cultivation in paddy field opened the way to establish the permanent ginseng cultivation plantation Ginseng harvester and seeder were developed in the late 1950s. Transplanted and many other machines were developed in the early 1990s. In ginseng breeding only pure line selection was of practical significance several verities were at the stage of seed propagation at ginseng plantations. Mutation breeding (${\gamma}$-ray. X-ray chemicals) was not successful. The research on plantlet formation through tissue culture was a little progressed but still far behind to vegetative propagation. Disease control research was concentrated in the isolation and identification of pathogans. their ecological charactelistics and biological control and soil humigation. Potato root rot nematodes was found and control method was established. Insect and small animal control research was greatly progresses in identification, ecological investigation, and ecological and physical control. Weed control was less important due to the development of mulching method of ridge and ditch. Quality factors of raw ginseng in relation to red ginseng process were extensively studied. Traditional quality measures were elucidated in accordance with modern analytical chemistry resulting in the importance of peptides in the centrat part rather than ginsenosides For large root production growth promoting rootzone micrcorganisms (PGPRM) were isolated and active compounds were identified. Field test on PGPRM was on going. Varictus methods formality improvement through cultivation were developed. Management research of ginseng production was rare Extension was active throuch official and private organizations and through workshop for the extension specialists, and direct lectures to grower's. Extension services made the researcher to understand the existing problems at grower's fields. Research environment for ginseng production was in prime time only for three years when Korea Ginseng Research Institute was established then gradually aggravated.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.61-66
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• 2002

Double cropping system in a year in Kyoho grapes (Vitis labruscana L.) has currently been attempted in the plastic greenhouse. One of the problems in double cropping system is the promotion of bud break in summer season and shoot fertility. Effects of the control of soil moisture tension near the root zone and treatments of bud dormancy breaking agents on bud breaking in summer were examined to promote the bud break for the second fruiting. The lignification of shoots was induced in July or August by the control of soil moisture tension in root zone environment. The first shoot growth was almost the same as that in common plastic greenhouses. The highest bud break value appeared in the plot of cyanamide chemicals mixed with merit blue as over 75% bud break rate. The bud break rate in the discontinuing plot in irrigation showed significantly higher in bud break than that in the continuing plot in irrigation. Despite of the final high bud break rate, the time of bud break was irregular.

• Journal of Ginseng Research
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• v.44 no.4
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• pp.627-636
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• 2020

Background: Cultivation of medicinal crops, which synthesize hundreds of substances for curative functions, was focused on the synthesis of secondary metabolites rather than biomass accumulation. Nutrition is an important restrict factor for plant growth and secondary metabolites, but little attention has been given to the plasticity of nutrient uptake and secondary metabolites synthesis response to soil nitrogen (N) change. Methods: Two year-field experiments of Sanqi (Panax notoginseng), which can synthesize a high level of saponin in cells, were conducted to study the effects of N application on the temporal dynamics of biomass, nutrient absorption, root architecture and the relationships between these parameters and saponin synthesis. Results: Increasing N fertilizer rates could improve the dry matter yields and nutrient absorption ability through increasing the maximum daily growth (or nutrient uptake) rate. Under suitable N level (225 kg/ha N), Sanqi restricted the root length and surface and enhanced the root diameter and N uptake rate per root length (NURI) to promote nutrient absorption, but the opposite status of Sanqi root architecture and NURI was found when soil N was deficient. Furthermore, increasing N rates could promote the accumulation of saponin in roots through improving the NURI, which showed a significant positive relationship with the content of saponin in the taproots. Conclusion: Appropriate N fertilizer rates could optimize both root architecture and nutrient uptake efficiency, then promote both the accumulation of dry matter and the synthesis of saponins.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.358-358
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• 2017

The plant type is generally one of the most important factor for crop production and be influenced by nitrogen absorption. Soybean plants have nodules in their roots, supplying nitrogen at the vegetative and reproductive stages. Root nodules seem to effect plant type of soybean plants, but there are few reports on the relation nodules and plant type. We tried to clarify the effects of root nodules on the plant type, especially internode length and petiole length, comparing non-nodule soybean with normal soybean. The pot experiment and field experiment were carried out at Mie University and Utsunomiya University in 2015 and 2016. Enrei, a popular cultivar in central Japan, and En1282, non-nodulating isogenic line of Enrei, were used. The petiole length on main stem was measured after defoliation and internode length and yield components were measured after harvest. In the field experiment, the patterns of the final length in internode and petiole on main stem were consistent in both cultivars, and a positive correlation was found between the Nth petiole length and the N-1th internode length, belong to the same phytomere. Therefore, the petiole and internode on the main stem make similar response for environmental factors. In pot experiment, Enrei grew with the same pattern as field experiments, but in En1282, the elongation of petiole and internode in the upper part was suppressed, especially the petiole was suppressed greatly. The main stem becomes the basis of the plant type. These results were considered that the nitrogen is distributed preferentially to the internode than the petiole. It seems that the pot cultivation restricted the rhizosphere and caused nitrogen deficiency in En1282. These results suggested that the slight nitrogen deficiency provided from the root nodules was compensated by the increase of the amount of inorganic nitrogen absorption due to the expansion of the rhizosphere, and the severe nitrogen deficiency suppressed elongation of petiole and internode. It is clear that root nodules effect the plant type by supplying nitrogen to internodes and petioles.

• Horticultural Science & Technology
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• v.18 no.1
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• pp.9-13
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• 2000

Cultivation of onions in Korean peninsula is so restricted to Southern region, mainly due to inadequate air temperature for the growth of onions in this region. This sometimes resulted in unstable supply of onions. The fluctuation of market prices mainly results from the limited production of onions in such restricted areas. Onions are usually transplanted at the end of fall and cultivated until the beginning of next summer. This study was designed to examine the possibility of extending production region of onions by adopting the plug seedling system, and the effects of plug seedling age, transplanting date, plug cell volume, and variety on the yield of onions were investigated. Transplanting date (Mar. 15 or Apr. 15) did not affect the yield of onions. However, 60-day-old seedlings produced significantly greater bulb yield (107.2 ton/ha) than those of 30- or 90- day-old seedlings. Bulb yields of seedlings raised in 128 and 72 cell trays were 125.0 and 120.8 ton/ha, which were significantly greater than those in other cell trays. Yield of seedlings raised in 406 cell trays was the lowest. Seedlings of mid-late 'Chenjuwhang' yielded 130.5 Ton/ha, which was significantly higher than those of other varieties. Considering the rainy season during early summer, we suggest that seedlings of onions raised for 60 days and transplanted on Mar. 15 should be advantageous in producing of marketable bulbs and that an early 'Yongbongwhang' should be the best variety.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.404-408
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• 2014

Three type of Lime Bordeaux mixture (LBM) that has been used since 1800's for control plant disease are used for eco-friendly ginseng (Panax ginseng) disease control. But it was restricted the use in the crops cultivation in some countries of Europe recently, because there is a possibility that the copper component is concentrated in the soil and plants with using LBM containing copper. According to the concentration and number of LBM spraying treatment, it was investigated copper and other components in soil and ginseng root. In case of LBM sprayed 33 times for three years, copper concentration was increased up to 75.9 ppm in the soil. However copper concentration of ginseng root was increased with 9.9~23.0 mg/kg in comparison with 8.38~11.39 mg/kg at LBM non-treatment. It has shown that the copper components can be concentrated to in the soil if used continuously in the long term.