• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.53-58
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• 2001

Jeju Italian millet was grown at five planting densities(5$\times$5, 15$\times$15, 20$\times$20, 25cm) form May 13 to Aug. 14, 2000 at jeju island to determine influence of planting density on agronomic characters, forage yield and quality. Days to heading increased from 87 to 89 days as planting density was decreased. In 5$\times$5cm planting density plot, plant height was 185.4cm and it was gradually decreased as planting density was increased. So in 30$\times$30cm planting density plot, plant height was 173cm. As planting density increased, stem diameter, the number of nodes per plant, the umber of leaves, leaf width and SPAD reading values was increased, the longer leaf length as the broader planting density. Fresh forage yield increased from 29.99 to 55.01MT/ha, dry matter(DM) yield from 8.04 to 15.59MT/ha, crude protein(CP) yield from 0.78 to 2.26MT/ha and total digestible nutrients(TDN) yield from 3.65 to 7.93MT/ha as planting density was decreased. Crude protein content increased from 9.8 to 14.5% ether extract comtent from 1.4 to 1.9%, nitrogen free extract content from 38.4% to 38.9% and TDN content from 45.4 to 50.9%, but crude fiber content decreased from 34.5 to 30.1% and crude ash content from 9.1 to 8.0% as planting density was decreased.

• Journal of Plant Biology
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• v.13 no.1
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• pp.56-64
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• 1970

The present experiments differning from that conducted by agriculturists with the first consideration of food or seed production were performed in order to investigate the density effect on dry matter production in the artified population of maize. Three experimental plots were established and one seed was sown in the first plot, 2 seeds in the second plot and 3 seeds in the third plot, respectively. The space of each ridge was designed with 30cm in width and 50cm in length. The space of each seed was 4cm and the growth amount by density was measured through three times. The results obtained are as follows: 1) The total growth amount per unit area was in the order of the third, second and first plots until the second sampling. At the third sampling the whole plots showed almost the same growth amount except the first plot which showed a slightly smaller amount. 2) The growth amount per individual plant was in the order of the third, second and first plots until the second sampling, while the first plot showed drastic growth compared with the other two plots at the third sampling. 3) The growth amount by each organ(leaf, stem and root) of the plant body was markedly abundant in the stem of the non-productive part compared with that in the leaf of the productive part. Especially the root was affected remarkably by density and the first plot showed an abundant growth in comparison with the other plots which were too poor to resist the gound surface.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.57-63
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• 1979

This study has been carried out to find out the optimum plant density and number of seedling per hill in the late season culture of rice at Chung Buk. P.O.R.D. Up to the level of 33 hills per m2 and 6 number of seedling per hill, rice yield was increased as the number of seedling per hill and plant density per unit areas increased. However it is recommendable to have a plant density of 28~33 hills per m$^2$ with 4~6 number of seedling per hill for the late season culture.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.16-20
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• 2004

Aphis gossypii Glover(Homoptera: Aphididae) is an serious pest on various crops. This experiment was conducted to evaluate the effect of A. gossypii Glover on the growth of oriental melon and the plant recovery after removing A. gossypii. Visible damage symptom caused by A. gossypii feeding to oriental melon was leaf distortion and stunting. A. gossypii feeding for 20 days on oriental melon significantly reduced the growth of oriental melon with increasing A. gossypii density level. Plant growth was decreased by 63${\sim}$69%, 62${\sim}$88% and 49${\sim}$70% in plant height, leaf area and dry weight, respectively. During 10 day after aphids removal, the infested leaves remained stunt, however, new shoot and leaf recovered gradually. By 20 day, plant height, leaf area and dry weight substantially increased in 5 aphid per plant. Plant recovered rapidly with day and among aphid density level, 5 aphid per plant showed rapid recovery. When plant were infested with several density of aphid per plant, sugar contents of total leaves were not significantly different between aphid density level. Whereas, sugar contents of lear infested with aphid per leaf were decreased with increasing cumulative aphid-days.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.127-132
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• 2008

In bioreactor cultures of plants, inoculum density is an important factor affecting growth and proliferation of the plantlets. To maximize shoot growth and proliferation of grape rootstock '5BB' in bioreactors, inoculum density varied at 15, 30, 45 and 60 single nodes in a 3-liter scale balloon type bioreactor, respectively and cultured for 40 days. Results suggested that the growth and the photosynthesis of the plantlet were greatly affected by inoculum density in the bioreactor. The inoculum density of 45 nodes resulted in the greatest growth (910.4 mg/shoot FW, 764.4 mg/root FW) followed by 30 nodes. $CO_2$ assimilation rate, stomatal conductance, transpiration rate of the plantlet were also highest at the inoculum density of 45 nodes. Significant reduces in shoot and root growth (426.5 mg/shoot FW, 248.4 mg/root FW) were observed at the inoculum density of 60 nodes. When the inoculum density decreased by 15 nodes, plantlets were malformed due to hyperhydricity, resulting in the highest transpiration rate and the lowest $CO_2$ assimilation rate. The plantlets stressed by the inoculum density at 15 nodes and 60 nodes showed larger number and irregular shape of stomata compared to the plantlets inoculated with 45 nodes.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.315-324
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• 1996

This study was one of a series of studies on application of machine vision and image processing to extract the geometrical features of plants and to analyze plant growth. Several algorithms were developed to measure morphological properties of plants and describing the growth development of in-situ lettuce(Lactuca sativa L.). Canopy, centroid, leaf density and fractal dimension of plant were measured from a top viewed binary image. It was capable of identifying plants by a thinning top viewed image. Overlapping the thinning side viewed image with a side viewed binary image of plant was very effective to auto-detect meaningful nodes associated with canopy components such as stem, branch, petiole and leaf. And, plant height, stem diameter, number and angle of branches, and internode length and so on were analyzed by using meaningful nodes extracted from overlapped side viewed images. Canopy, leaf density and fractal dimension showed high relation with fresh weight or growth pattern of in-situ lettuces. It was concluded that machine vision system and image processing techniques are very useful in extracting geometrical features and monitoring plant growth, although interactive methods, for some applications, were required.

• Korean Journal of Medicinal Crop Science
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• v.21 no.3
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• pp.179-183
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• 2013

This study was carried out to investigate the variation of growth and yield using different planting densities and vinyl mulching in S. miltiorrhiza cultivation. Top plant growth was observed in the $30{\times}30cm$ planting density of S. miltiorrhiza;, plant height, leaves and branches were larger than in the other treatments. Root length, root diameter, and supporting roots of underground part were increased as planting density was wide, and dry root weight was increased in $30{\times}30cm$. However, yield was highest at 294 kg/10a in the planting density of $30{\times}10cm$. The use of 30-31cm white and black vinyl mulching had no significant effect on the plant height of S. miltiorrhiza, as compared to non-mulching. However, the highest volume of leaves and plant weight was observed in plants using 24.7 black vinyl mulching. Dry underground root weight was highest in black vinyl mulching at 21.7 g compared to 17.0 g for non-mulching. Yield per 10a increased by 28% using black vinyl mulching compared to non-mulching. Based on the results of this study, planting density of $30{\times}10cm$ and black vinyl mulching are the most suitable in the cultivation of S. miltiorrhiza.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.27-37
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• 2007

This study is to analyse the feasibility for providing Co-generation plant in Apartment Complex for 4 typical Apartment Complexes located Seoul metropolitan area, The selected complexes are three midium-large size Apartment[nearby 35pyoug of floor area] and one complex of small size Apartment[below 25 pyoung of floor area] for comparison. The necessary data for the study were collected with visitation of each site. The study showed very positive result for the three medium-large size Apartment Complexes of which the average floor area is more than 25 pyoungs, while negative result for the Complex of which average floor area is less than 25 pyoungs. Other than floor size it was found that the electric consumption density also influence the economic feasibility. In study the unit fixed cost of the energy produced from Co-generation plant is one third of the unit variable cost[fuel cost] and it seems better to select high thermal efficiency machine for Co-generation plant even with some higher cost of the plant.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.4
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• pp.219-235
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• 2013

In order to investigate the changes in sea water characteristics and stratification due to operation of Shihwa tidal power plant, three dimensional numerical model is used. In summer, the density of inner part of Shihwa Lake is more affected by salinity than water temperature due to fresh water discharge. Before tidal power plant operation, the sea water characteristics in Shihwa Lake shows relatively high temperature and low salinity. After tidal power plant operation, water temperature decreases slightly and salinity tends to increase in Shihwa Lake. Also, density increases and stratification tends to weaken by mixing with sea water.

• Journal of Ecology and Environment
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• v.41 no.1
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• pp.1-8
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• 2017

Background: Though the biomass of floral vegetation in understory plant communities in a forested ecosystem only accounts for less than 1% of the total biomass of a forest, they contain most of the floral resources of a forest. The diversity of understory honey plants determines visitation rate of pollinators such as honey bee (Apis mellifera) as they provide rich food resources. Since the flower visitation and foraging activity of pollinators lead to the provision of pollination service, it also means the enhancement of plant-pollinator relationship. Therefore, an appropriate management scheme for understory vegetation is essential in order to conserve pollinator population that is decreasing due to habitat destruction and disease infection. This research examined the diversity of understory honey plant and studied how it is related to environmental variables such as (1) canopy density, (2) horizontal heterogeneity of canopy surface height, (3) slope gradient, and (4) distance from roads. Vegetation survey data of 39 plots of mixed forests in Chuncheon, Korea, were used, and possible management practices for understory vegetation were suggested. Results: This study found that 113 species among 141 species of honey plant of the forests were classified as understory vegetation. Also, the understory honey plant diversity is significantly positively correlated with distance from the nearest road and horizontal heterogeneity of canopy surface height and negatively correlated with canopy density. Conclusions: The diversity of understory honey plant vegetation is correlated to vegetation structure and human impact. In order to enhance the diversity of understory honey plant, management of density and height of canopy is necessary. This study suggests that improved diversity of canopy cover through thinning of overstory vegetation can increase the diversity of understory honey plant species.