• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.773-786
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• 2016

Grape cultivar "Campbell Early" account for 70% of table grape in Korea and Leaf Spot Disease caused by Pseudocercospora vitis is one of a major disease in greenhouse and field grown area during late summer season in both of organic and conventional grape farm. Leaf spot disease can cause lowing of sugar content in fruit and vine growth and very difficult to control especially in organic field. Photosynthesis ability and chemical components are compared between leaf spot disease infected leaves with degree of necrotic area. With increase of disease necrotic area, $CO_2$ differential value, water use efficiency and $CO_2$ assimilation and respiration ratio are decreased proportionally and on the other hand, stomatal conductance value is not affected by disease necrotic area. Chlorophyll contents are also decreased by 50% in heavily infected leaves and imply decrease of chlorophyll contents is a major source of photosynthesis ability decline. With increase of disease necrotic area in leaves, total nitrogen and phosphate contents are decreased and on the other side, total carbon, potassium, calcium and magnesium contents are increased. From this research, we can infer that not only chemical control program is important in control of leaf spot disease but also fertilizing program is significant especially in organic agronomical control of fungal disease in grape cultivar "Campbell Early".

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.258-265
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• 2004

The experiment was conducted to investigate the effect of EC and pH of nutrient solution on the growth and quality of the single-stemmed rose grown in a rose factory installed with hydroponic system. The growth and quality of the single-stemmed rose were not significantly different from each other with the EC of the nutrient solutions $1.0\~3.5dS{\cdot}m^{-1}$, which resulted in concluding high concentration of the nutrient solution was not necessary. The optimum range of the EC for single-stemmed rose was $1.5\~2.0dS{\cdot}m^{-1}$ considering plant growth, photosynthetic and transpiration rates. The optimum range of the pH for good plant growth without any visible physiological disorder was $4.0\~6.0$. Therefore, to keep the pH of the nutrient solution for rose low compared to other plants was beneficial for plant growth and uptake of the mineral ions.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.1-7
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• 1989

To enhance the capability of starch fermentation of the transformant TSD-14, the heat treated protoplasts of TSD-14 were fused with the protoplasts of C. tropicalis (lys$^-$) in the presence of 30% (w/ v) PEG and 20 mM CaC1$_2$. Fusants were selected by nutritional complementation on minium medium and the fusion frequency was 4.4$\times$10$^{-5}$. All fusants tested were possessed of complemented traits concerning carbon compound assimilation, and the cell volumes of the fusants were approximately 1.5 times larger than the parental strains. The fusants were genetically very stable, and were able to hydrolyze alpha 1,4-glucosidic linkage as well as alpha 1,6-linkage of starch contrary to one of parents TSD-14, The most promising fusant FSC-14-75 produced 8.7% (v/v) of ethanol from 15% liquefied potato starch medium, but the result was enhanced to 9.3% (v/v) by addition of 0.3% peptone. The corresponding fermentation efficiency was 86.0%.

• Journal of Korean Society of Forest Science
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• v.69 no.1
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• pp.28-35
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• 1985

To estimate the aboveground biomass of Pinus rigida and Pinus rigida ${\times}$ taeda 22-year-old plantations, the experimental plots of $200m^2$ in size located in Kwangju of Jeonlanam-do were selected. Nine sample trees selected at each plot taking account of DBH distribution were felled and the diagram of oven-dry weight distribution of stem, branch, and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component (stems, branches, and needles) and the variable of $(DBH)^2{\cdot}H$ were obtained. The aboveground standing crops was estimated to be as much as 71.61 and 142.32 tons of dry matter per hectare in P. rigida and P. rigida ${\times}$ taeda stand respectively. The net production was estimated as 10.81 and 10.46 t/ha/yr and the net assimilation rate 1.32 and 1.00 kg/kg/yr in P. rigida and P. rigida ${\times}$ taeda stand respectively. And the efficiency of needles to produce stem was 0.97 and 0.81 kg/kg/yr in same order.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.33-39
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• 1985

This study was performed to investigate the damage to the primary production of Pinus thunbergii forest from air pollution around the Yeochon Industrial Estate. The data were observed at 6 sites in the vicinity of the above area. The vitality of pine trees and the accumulation of the soluable sulfur and the fluorine were analyzed. Their value was generally increased near the source of air pollutants. The biomass density and annual net production were $1.01kg/m^3$, 5.90 t/ha/yr in the stand 4 respectively and $0.66kg/m^3$, 0.32t/hr/hr in the stand 3 respectively. The net assimilation rate was 0.4 - 1.6 kg/kg/yr and the efficiency of leaf to produce stem was 0.3 - 1.3 kg/kg/yr. The annual growth percentage of volume was 16.0% at the slightly damaged area and 4.0% at the severly damaged area. The maximum mean annual increment per tree was $0.0040m^3$ and $0.0008m^3$ in same order.

• Journal of Korea Foresty Energy
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• v.7 no.1
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• pp.1-10
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• 1987

This study was carried out to estimate the aboveground biomass of Cryptomeria japonica and Chamaecyparis obtusa which was planted in Changsong district, the southern part of the Korean peninsula. Nine sample trees at each plot(20m x 20m drom C. japonica of 20-year-old and C. obtusa of 25-year-old, according to DBH distribution. were felled to measure the dry weights of stem, branches and leaves sectioned respectively. Since it is very difficult to separate leaves from twigs. all green parts including pure leaves and twigs were tentatively treated as 'leaves'. 1. The logarithmic regression equations between dry weight of each component (stem. branches. leaves land the variable of $(DBH)^2{\cdot}H$ were obtained (Table 6). The aboveground standing crops was estimated 108. 75ton/ha in C. japonica and 112.56 ton/ha in C. obtusa. Percentage of each part based on the aboveground standing crop in stand was and in order of stem >leaves>branches for C. japonica and in order of stem> branches> leaves for C. obtusa repectively. 2. Net production of each stand was estimated as 1:3.32ton/ha/yr in C. japonica and 11.69ton/ha/yr in C. obtusa. and its composition was in order of stem>leaves>branches for both species. 3The net assimilation rate was estimated as 1.10 and 1.2lkg/kg/yr, the efficiency of leaves to produce stem was 0.71 and 0.75 kg/kg/ha and biomass accumulation ratio was 8.16 and 9.63kg/kg/yr in each stand of C. japonica and C. obtusa respectively.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.293-303
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• 2008

Reservoir turbidity flows degrade the efficiency and sustainability of water supply system in many countries located in monsoon climate region. A decision support system called RTMMS aimed to assist reservoir operations was developed for the real time monitoring, modeling, and management of turbidity flows induced by flood runoffs in Daecheong reservoir. RTMMS consists of a real time data acquisition module that collects and stores field monitoring data, a data assimilation module that assists pre-processing of model input data, a two dimensional numerical model for the simulation of reservoir hydrodynamics and turbidity, and a post-processor that aids the analysis of simulation results and alternative management scenarios. RTMMS was calibrated using field data obtained during the flood season of 2004, and applied to real-time simulations of flood events occurred on July of 2006 for assessing its predictive capability. The system showed fairly satisfactory performance in reproducing the density flow regimes and fate of turbidity plumes in the reservoir with efficient computation time that is a vital requirement for a real time application. The configurations of RTMMS suggested in this study can be adopted in many reservoirs that have similar turbidity issues for better management of water supply utilities and downstream aquatic ecosystem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.104-108
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• 1998

Analysis of energy budget in Neomysis awatschensis exposed to PCB toxicity was carried out by measurement of bioassay, growth, oxygen consumption, nitrogen excretion at 10 and $20^{\circ}C$. Energy contents of the body, molted exoskeleton and eggs, which measured to understand used energy for growth, molt and oxygen consumption were 5.52cal/mg, 2.17 cal/mg and 6.15 cal/mg, respectively. Feeding energies at $10^{\circ}C$ were 3.755ca1 in control group and 3.420 cal at 2.0 ppb concentration, of them, $70.19\%$ and $67.53\%$ of their energies were assimilated. At $20^{\circ}C$, feeding energies were 5.998 cal in control group and 4.166 cal at 2.0 ppb concentration. The assimilation efficiency of the mysid estimated by ash-ratio method ranged between $11.5\~67.5\%$ and $73.4\~70.5\%$ with PCB toxicity at $10^{\circ}C$ and $20^{\circ}C$ respectively. Energy used by respiration of total assimilated energy was $45.18\%$ in control group and $62.27\%$ in 2.0 pub concentration at $20^{\circ}C$, and energy used by metabolism was high 2.0 ppb concentration than control group.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.203-213
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• 2024

In this study, we investigated the growth and physiological responses of Iris laevigata Fisch. to shading treatments in order to suggest optimal light conditions for ex-situ conservation of the northern lineage plants. For this purpose, a control plant receiving full sunlight and different shading treatments (50%, 75%, 95%) were installed, and leaf mass per area, chlorophyll content and fluorescence response, and photosynthetic characteristics were investigated. I. laevigata developed leaves with higher photosynthetic efficiency to adapt to lower light intensity as shading levels increased. Chlorophyll content increased with increasing shading levels, and leaf mass per area decreased with increasing leaf area. The chlorophyll fluorescence responses Fv/Fm and NPQ did not change with shading, and the activity of the carbon fixation system did not differ between treatments. I. laevigata exhibited a light-saturation point equivalent to that of sun plants and maintained photosynthetic capacity similar to that of controls up to 75% shading. The apparent quantum yield of I. laevigata decreased significantly at 95% shading, indicating adaptation to lower light conditions. It seems that the photosynthetic capacity of I. laevigata decreases when grown under 95% shading level compared to full sunlight, and it is judged that the longer the light is restricted by continuous shading, the more unfavorable the growth will be.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.61-71
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• 2007

The photosynthetic characteristics and primary production by phytoplankton in open waters of two wetlands (the Banwol and the Donghwa wetland) of Sihwa Constructed Wetland with different water chemistry were investigated to provide the information for the wetland management considering the water treatment efficiency. During the study period (from March to October, 2005) the primary productivity in open waters ranged from 481 to 11,275 mgC $m^{-2}$ $day^{-1}$, which is very high compared with the eutrophic level of 600mgC $m^{-2}$ $day^{-1}$. From the analysis of the photosynthesis-irradiance (P-I) model parameters, the photosynthetic characteristics may be affected by different concentration and ratio of nutrient (N and P) between two wetlands. Assimilation number (AN) was higher in the Donghwa wetland (average AN: 8.5gC $gChl^{-1}$ $hr^{-1}$) with high P and low N/P ratio than the Banwol wetland (average AN: 5.8gC $gChl^{-1}$ $hr^{-1}$) with high N and high N/P ratio. This result indicates that AN may be concerned with phosphorus than nitrogen and low NIP ratio. Positive correlation (R=0.81) was observed between the initial slope and AN, implying that AN was high in case of phytoplankton having more active photosynthesis ability under low light. On the other hand, maximum photosynthesis (Pmax) was related positively with chlorophyll a concentration showing correlation coefficient of 0.47. In this study, considering the high primary production through phytoplankton photosynthesis in open waters of Sihwa Constructed Wetland, the produced organic matter by phytoplankton may affect the water quality within wetland and its efficiency of water treatment. Also, the photosynthetic characteristics may be affected by different nutrient enrichment (especially phosphorus) of wetlands. This study suggests that the production by phytoplankton and its characteristics in open water of constructed wetland for water treatment should be considered to improve the removal efficiency of organic matter.