• Journal of Environmental Science International
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• v.22 no.9
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• pp.1181-1186
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• 2013

Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, Chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This study examined the influence of air temperature during seedling growth on the time required to reach the first fruit maturity and yield of hot pepper. Seedling plants of 'Super Manita' hot pepper was grown in temperatures $2.5^{\circ}C$ and $5.0^{\circ}C$ lower than the optimum temperature (determined by the average of temperatures for the past 5 years). Seedlings were transplanted into round plastic containers (30-cm diam., 45-cm height) and were placed in growth chambers in which the ambient temperature was controlled under natural sunlight. The growth of seedlings under lowered temperatures was reduced compared to the control. The mineral (K, Mg, P, N) concentrations in the leaf tissues were higher when plants were grown with the ambient temperature $2.5^{\circ}C$ lower than the optimum, regardless of changes in other growth parameters. Tissue calcium (Ca) concentration was the highest in the plants grown with optimum temperature. The carbohydrate to nitrogen (C/N) ratio, which was the highest (18.3) in the plants grown with optimum temperature, decreased concomitantly as the ambient temperature was lowered $2.5^{\circ}C$ and $5.0^{\circ}C$. The yield of the early harvested fruits was also reduced as the ambient temperature became lower. The first fruit harvest date for the plants grown with optimum temperature (June 27) was 13 days and 40 days, respectively, earlier than that in plants grown with $2.5^{\circ}C$ (July 10) and $5.0^{\circ}C$ (Aug 6) lower ambient temperatures. The fruit yield per plant for the optimum temperature (724 g) was the greatest compared to those grown with $2.5^{\circ}C$ (446 g) and $5.0^{\circ}C$ (236 g) lower temperatures. The result of this study suggests that the growers should be cautioned not to transplant their hot pepper seedlings too early into the field, since it may delay the time of first harvest eventually reducing total fruit yield.

• Culinary science and hospitality research
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• v.8 no.1
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• pp.55-69
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• 2002

Sedum Sarmentosum Bunge has been used as medical material and food in Korea. To upgrade it's value as a materials of beverage, I research and analysed nutritive substance and taste. Inorganic components content was included in the order of Ca, mg, P, K, Na, in line, and there were little Fe, Cu, Zn. It appeared much Ascorbic acid contents in May sample for March sample, but it was included less than other Green Vegetables. Chlorophyll contents decreased about 37.8% and 37.6% to the first each contents after seven days resulting measuring May sample and March sample in room temperature. There was much difference in appearance. Sedum Sarmentosum Bunge included a little polyphenol contents. Polyphenol contents decreased a little in five days in May sample and March sample. I measured phenol compounds of garlic acid, vani11ic acid, caffeic acid, p-coumaric acid, ferulic acid, most of consisted in corrected forms. Fragrance components were confirmed 9 kinds in March sample, 11 kind in May sample the common components in May sample and March sample were 7-octen-4-o1.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.177-185
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• 2016

Fertilization is required to keep the balance of tissue nutrients and to produce high quality seedlings at the permanent nursery. This study was conducted to verify the optimum fertilization method for Fraxinus rhynchophylla, F. mandshurica, Pinus koraiensis, and Abies holophylla seedlings with vector diagnosis method. Seven treatments include nitrogen (N, $13.8g{\cdot}m^{-2}$), phosphorus (P, $6.1g{\cdot}m^{-2}$), potassium ($7.5g{\cdot}m^{-2}$) fertilization and 1x (N $6.9g{\cdot}m^{-2}$, P $3.05g{\cdot}m^{-2}$, K $3.65g{\cdot}m^{-2}$), 2x (twice of 1x), 4x (four times of 1x) fertilization and no fertilization. Soil pH decreased as fertilization increased. Nitrogen and NPK fertilization decreased exchangeable $Ca^{2+}$ and $Mg^{2+}$ concentrations. Height and root collar diameter of F. rhynchophylla and F. mandshurica significantly increased with N and NPK fertilization, but those of P. koraiensis and A. holophylla did not. The biomass of F. rhynchophylla and F. mandshurica was about twice higher at NPK fertilization compared to the control. The responses of vector diagnosis were different by tree species and fertilization treatment: F. rhynchophylla was in the status of N "dilution", which means the N concentration decreases with N content. Phosphorus and K were "sufficiency" state with 4x fertilization. F. mandshurica showed "retranslocation" as N content decreased without change of dry weight at N, P, K fertilization, but "dilution" state at NPK fertilization. This result suggested that optimal fertilization was required for F. rhynchophylla and F. mandshurica in seedling production stage, but was not essential for P. koraiensis and A. holophylla.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.296-300
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• 2015

This study was conducted to investigate optimal crop loads of 'Jinok' grape for unheated plastic house culture. The crop loads of 'Jinok' grapes were managed to be 1.3, 1.8, 2.2, 2.4, and 2.6t per 10a from 2012 to 2014. We measured vine growth and berry qualities. Crop loads were not significantly affected on plant height, trunk diameter, shoot length, and the internode length of 'Jinok'. However, the maturation of berries was delayed when the crop load was higher. And the harvest date was earlier about three weeks in an unheated plastic house compared to in an open field. The average berry weight was decreased by the higher crop load although higher crop loads made higher yields showing the lowest weight at 342g with the treatment of 2.6t per 10a and the highest weight at 363g with the treatment of 1.3t per 10a. Also, the soluble solids content showed a tendency that higher crop loads brought to lower degree Brix. The contents of P, K, Ca, and Mg in grape leaves and shoots were not significantly different by crop loads. To sum up, when crop loads were under the 2.4t per 10a, the berries were harvested as a marketable fruit having $15^{\circ}Brix$ in the cultivar 'Jinok' grape. This result could help to increase grower's benefit having improved quality of fruit for the sustainable production by the established cultivation techniques for the newly developed cultivar 'Jinok'.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.395-406
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• 2007

The twenty seven wrap-up vegetables (13 Compositae, 14 Brassicaceae) and seven herbs (6 Labiatae, 1 Umbelliferae) were cultivated with a deep flow technique (DFT) hydroponic beds and treated with 3 levels of nutrient solution concentrations of 1.2, 2.4, and $3.6dS{\cdot}m^{-1}$ in summer and autumn season. The pH and electrical conductivity (EC) change of nutrient solution, fresh weight, and mineral contents of plants were investigated. The pH was maintained lower in high electrical conductivity (EC) treatment and in summer than autumn. EC of nutrient solution in EC $3.6dS{\cdot}m^{-1}$ treatment increased up to $4.8dS{\cdot}m^{-1}$ during the growing period in summer season. The growth of tested plants showed high variations by plant species and nutrient solution concentrations. The coefficient variation (CV) of the shoot fresh weight of plants was higher in summer than autumn. The growth of Compostiae and herbs was better at EC $1.2dS{\cdot}m^{-1}$, and 14 Brassicaceae was better at EC $2.4dS{\cdot}m^{-1}$ in summer. In autumn, the growth was better at EC $2.4dS{\cdot}m^{-1}$ in all plants except kale 'TBC F1' and red rape 'honchaetae'. In mineral contents, total nitrogen and potassium were higher in autumn than summer. Total nitrogen, potassium, calcium, magnesium were higher in Brassicaceae than others. Iron and manganese, however, were higher in Compositae. As the results, this study suggests that mixed planting of 27 wrap-up vegetables and 7 herbs in DFT hydroponics in two seasons was possible and EC $1.2dS{\cdot}m^{-1}$ in summer and EC $2.4dS{\cdot}m^{-1}$ in autumn be recommended as for the nutrient solution concentration to produce them safely year round.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.904-909
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• 1996

To investigate effects of sugars on the retrogradation of rice flour gels, sucrose and isomaltooligosaccharide (1, 2, and 5%, w/w on the flour basis were added to 50% Dongjinbyeo rice flour gels and stored at different temperature $(20^{\circ}C,\;4^{\circ}C)$ far 1, 3 and 6 days. Changes on the degree of retrogradation (DR) of these rice flour gels were measured by α-amylase-iodine method, DSC and X-ray diffractometry. DRs of rice flour gels increased over storage and showed a rapid increase up to 3 days and then decreased thereafter. DRs of rice flour gels with sucrose or oligosaccharide also increased rapidly until 3 day storage but these values were lower than those of rice flour gels without sugar. DRs of rice flour gels with oligosaccharide were lower than those of gels with sucrose. Changes in enthalpy of rice flour gels measured by DSC showed the same tendency with those in DRs of rice flour gels by ${\alpha}-amylase-iodine$ method, but varied with sugar levels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.167-173
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• 2002

This experiment was conducted to figure out the change of soil physical properties, rice growth and yield with the years of continuous cultivation in direct dry-seeding and no-tillage machine transplanting. Experiments were conducted at NHAES(National Honam Agricultural Experiment Station, RDA, Iksan, Cheon Buk Province, South Korea) with a rice variety "Dongjinbyeo" from 1995 to 2000. In no-tillage machine transplanting cultivation, organic matter in soil was higher than that on direct dry-seeding and was significantly high in topsoil. Problematic weed species were E. crus-galli B., A. keisak H., and L. japonica M. Plant height and tiller number m-2 were higher in common-tillage during the total growth duration. The highest weedy rice occurrence of 27.5% was observed in live years' continuous direct dry-seeding and followed by 6.2%, in four years', and 3.7%, in three years'. The highest yield reduction of 38% was observed in five years' continuous direct dry-seeding. The reduction may resulted from the competition between weedy rice and cultivated rice.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.13-23
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• 2001

Bentonite layers are intercalated within the basal conglomerates in the Tertiary sedimentary basins of Kampo, Janggi and Pohang, southeastern Korea. Eighteen samples of the bentonites went through X-ray diffraction, scanning electron microscopy, heavy mineral analyses, chemical analyses and oxygen, hydrogen stable isotope analyses to define the mineralogical characters of the bentonites. Heavy minerals such as zircons, apatites, amphiboles and biotites separated from bentonites show clean and euhedral surfaces, which are the characteristic features of volcanic origin. But biotites from the Chunbook Conglomerate are found as altered and heavily broken flakes which implies longer transportation of these bentonites. $TiO_{2}/Al_{2}O_{3} ratios of <2 $\mu$m particle fractions (the Chunbook Conglomerate 0.031; Janggi 0.029; Kampo 0.025) suggest that those are originated from volcanic tuffs. That is, the higher the value is, the more mafic in chemical compositions of the original tuffs. Authigenic montmorillonite and zeolite minerals were observed by SEM, which indicates diagenesis origin of bentonites. But the samples from the Chunbook Conglomerate showed only chaotically packed clay flakes in the matrix of sands or conglomerates, which implies detrital influence, not authigenic origin. The structural formulae of montmorillonite from these basins reflects their environment of formation. Fe (Ⅵ) can show the redox condition of its past environment and much lower $Fe^{2+}(Ⅵ)/Fe^{3+}(Ⅵ)$ ratios in montmorillonite of the Chunbook Conglomerate imply the greater oxidizing influence. Calculated burial depths from oxygen stable isotope data of the samples from the Chunbook Conglomerate generally fall to the range of 929~963 m whereas the real burial depth of this area is only 530~580 m. This could be explained as the bentonites of the Chunbook conglomerate had not been formed in situ. Discriminant analyses with the data from chemical analyses and structural formulae of montmorillonites show that bentonites from three different basins could definitely be distinguished with each other. This result arises from the different chemical compositions of original volcanic ashes and the difference of sedimentary environments.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.99-107
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• 1992

Effects of the indigenous Vesicular-arbuscular mycurrhizal fungi(VAMF) on early growth response of greenhouse grown crops were experimented. This study was done to evaluate the benefit of indigenous VAMF inoculation on the early growth and the subsequent growth after transplanting of some crops such as cucumber, tomato, hot pepper, eggplant, and melon. Leaf area, shoot dry weight, and plant length of mycorrhizal greenhouse crops showed the tendency of significant or no significant increase over control plants receiving no inoculation. The levels of VA mycorrhizal colonization were increased with plant growth, and infection rates of horticultural crop except hot pepper around one week after transplanting were decreased, while that of 8 weeks after emergence of mycorrhizal seedlings were increased again and infected by around 50% at harvesting time. In spore densities in the rhizosphere soil of craps experimented, the number of spore ranged from $72.7{\pm}26.3$ to $100{\pm}10.3g^1$ on dried soil basis and high density showed in both cucumber and tomato. Total nitrogen contents in shoots were lower in the mycorrhizal plants than non-mycorrhizal one, whereas P uptake in mycorrhizal hot pepper and tomato were highly ramarkable. The K contents in the shoots of mycorrhizal cucumber and eggplent were highly enhanced. Inoculation of the indigenous VAMF enhanced shoot Ca and Mg in both tomoto and melon. The contents of Fe, Zn, Mn and Cu in shoots of mycorrhizal crops were higher than non-mycorrhizal plants and vice versa in case of eggplent. Inoculation of the indigenous VAMF to horticultural crops were effective for alleviation of transplanting shock, and pretransplanting infection improved subsequent growth by reducing the time required for establishment of a functional mycorrhizal symbiosis following transplanting.