• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.104-109
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• 2019

The crops recommended for the plant factory system are diverse. The importance of planting density in the plant factory is being recognized. The objective of this study was to determine the optimal planting density for growth and quality of kohlrabi in a closed-type plant factory system. The kohlrabi was grown under fluorescent lamps and nutrient film technique system. The growth and quality of kohlrabi were investigated under four different planting densities ($22plants/m^2(15{\times}30cm)$, $27plants/m^2(15{\times}25cm)$, and $33plants/m^2(15{\times}20cm)$). There were no significant interactions between Shoot fresh and dry weights per plant or bulb stem fresh and dry weights per plant and planting density. Shoot fresh and dry weight per area or bulb stem fresh and dry weight per area were the highest at $33plants/m^2$. There were no significant interactions between plant height, leaf area, photosynthetic rate, hardness, and chlorophyll content and planting density. Significant differences in Bulb stem height and diameter, and brix were observed. Bulb stem height and diameter and brix of kohlrabi were the highest at $22plants/m^2$. Based on our results, we conclude that the optimal planting density is $33plants/m^2$ for growth of kohlrabi, however, the optimal planting density is $22plants/m^2$ for quality of kohlrabi in a closed-type plant factory system.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.506-509
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• 2014

This study was conducted to identify transition characteristics of mercury in several selected medicinal plants and to find the appropriate management for production of safety food. Cultivated soils and medicinal plants were collected at 29 sites for Angelica gigas (Korean angelica root), 68 sites for Platycodon grandiflorum (Balloon flower), 35 sites for codonopsis lanceolata (Deoduck), 36 sites for Dioscorea batatas (Chinese yam), 32 sites for Rehmannia glutinosa (Foxglove), 16 sites for Cnidium officinale makino (cnidium), and 26 sites for Astragalus membranaceus (milk vetch root) during the harvest season of 2013. Mercury in the soils and medicinal roots were analyzed with a Direct Mercury Analyzer. Average content of mercury in soils cultivated medicinal plants was $0.023mg\;kg^{-1}$ (range: from 0.003 to $0.074mg\;kg^{-1}$) and average content of mercury in medicinal plants was $0.003mg\;kg^{-1}$ (range: from 0.001 to $0.011mg\;kg^{-1}$), indicating that mercury in the surveyed soils and medicinal plants were not exceeded the Korean regulation.

• Journal of Environmental Science International
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• v.30 no.1
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• pp.29-43
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• 2021

This study analyzed the status of climate-change indicator plants native to the main islands of the Korean peninsula, while elucidating their distribution characteristics. Information on flora from over 129 island locations, comprising more than 100 species of native plants, was collected, compiled into a database, and utilized as raw data. The distribution of 193 climate-change indicator plants was confirmed. The distribution area of broadleaf evergreen trees and ferns, including Mallotus japonicus and Cyrtomium falcatum, was relatively wide. In contrast, the distribution of common northern plants such as Corydalis turtschaninovii and Malus baccata was limited. If global warming persists, northern plant distribution is expected to decrease rapidly in the Korean Peninsula island region, while the northern limit line of the southern plants is expected to migrate further northward. During this process, it is likely that the plant congregation structure and species diversity within the island region will change dynamically. In this study, comparative analyses between species and regions were conducted by assessing the relative frequency of their occurrence, and six types of botanical geographic distribution patterns were noted.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.1
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• pp.16-39
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• 1995

From July 8 to September 2 1994, asbestos exposure level among asbestos textile workers was surveyed. Six plants out of plants in Korea were selected for this study. In addition to the exposure level, the relationship between the level of exposure and some factors affecting exposure were studied. Also, using historical data of asbestos concentrations in asbestos textile plants plus current data, trend of asbestos exposure level could be introduced. Historical exposure level was estimated on the basis of these data. The main results of this study are follows. 1. Average concentration of all six plants surveyed was 1.54 f/cc, and range of those concentrations was 0.03 - 11.58 f/cc. The minimum average concentration was 0.32 f/cc and the maximum was 8.04 f/cc which is four times higher than the Korean standard. A wide difference of exposure level among the workers of different plants was observed. In three plants, the half of all the plants surveyed, their average concentrations exceeded the Korean standard, and those in all the plants exceeded the ACGIH TLV. 2. Among total 56 samples, 22 samples(39%) were in excess of the Korean standard, and 53 samples(95%) were above the ACGIH TLV. Among 32 personal samples, 15 samples(47%) exceeded the Korean standard, and 30 samples(94%) exceeded the ACGIH TLV. Among 24 area samples excluding a few samples collected in office area, seven samples exceeded the Korean standard, and 23 samples( 96%) exceeded the ACGIH TLV. 3. Distributions of concentrations were observed by processes. In weaving, the highest, average concentration was 4.29 f/cc, and range was 2.61 - 11.58 f/cc. In spinning, average concentration was 2.22 f/cc, and range was 0.41 - 8.93 f/cc. In carding, average concentration was 1.98 f/cc, and range was 0.23 - 10.93 f/cc, In twisting, average concentration was 1.65 f/cc, and range was 0.21 - 9.83 f/cc. In mixing, the lowest, average concentration was 0.48 f/cc, and range was 0.22 - 1.20 f/cc. 4. All the samples from basic processes of asbestos textile plants were above the ACGIH TLV. Nineteen samples(45%) out of all these 42 samples exceeded Korean standard. Fourteen samples(58%) of total 24 personal samples, and five samples(28%) of total 18 area samples exceeded the Korean standard. Considering processes, all the samples in weaving process exceeded the Korean standard and 50 did 54% of those in spinning, 40% in carding, and 27% in twisting. 5. Trend of decreasing asbestos concentrations in asbestos textile plants was observed by time. 6. Asbestos concentrations in asbestos textile plant in 1975 were estimated to be 11.0 - 92.4 f/cc.

• 한국균학회소식:학술대회논문집
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• 2009.10a
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• pp.70-75
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• 2009

• Journal of Plant Biology
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• v.14 no.1
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• pp.33-35
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• 1971

After topping, axillary buds of haploid plants derived from cultured anthers were treated with 0.4% aqueous solution of colchicine. Due to the high temperature and dry air at the time of treatment, most of the buds perished. A few months after the colchicine application, however, several shoots arose from the places where the dead buds were originally located. These shoots were mostly diploid. Induction of adventive shoots from the colchicine-treatedaxils was supposed to be rather effective method of obtaining diploid shoots from haploid plants. The diploid plants had larger floral organs than the haploid plants, and had good pollen fertility and seed setting. 24 bivalent chromosomes were observed at MI of the PMC's.

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.162-163
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.81-82
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.118-119
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.213-214
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• 2012