• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.250-256
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• 2006

This experiment was conducted to investigate the hydroponic culture possibility and the optimal solution strength of 'Pechika' ever-bearing strawberry in summer highland. Maximum room temperature and minimum root zone temperature of plastic house were $30.8^{\circ}C\;and\;19^{\circ}C$ in highland respectively and $4^{\circ}C\;and\;3^{\circ}C$ lower than in level and. The growth of 'Pechika' was better in highland. There was effective in producing the good yield and fruit quality in highland and the deformed fruits also were decreased. The soluble solid and titratable acidity content increased in highland. Early growth was the most effective in standard solution $(EC\;0.75dS\;m^{-1})$ and had a tendency to be inhibition with increasing nutrient concentration. Standard solution was also the highest to yield about 2,064kg/10a among treatments, and 2/3S, 4/3S, 5/3S by turns. The browning roots and root activity increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and acidity content of fruits were increased with higher solution strength. Therefor, the summer hydroponic culture of 'Pechika' ever-bearing strawberry was suitable in highland and effective in standard solution $(EC\;0.75dS{\cdot}m^{-1})$ in solution control.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.235-242
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• 2015

The objective of this study was to determine the effects of soluble potassium silicate by soil drenching application on watermelon growth, yield, and nutrient uptake. The potassium silicate rates were control (No potassium silicate), 1.63mM, 3.25mM, 6.50mM. The potassium silicate were treated 6 times (twice before fruit forming and 4 times after fruit forming per 7 day. Soil chemical properties, such as soil pH, EC, available phosphorus and silicate, exchangeable K, nitrate-N levels were increased after potassium silicate treatment, while the concentrations of soil organic matter, exchangeable Ca and Mg were similar to control. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for increased potassium silicate treatment than the control, while number of node, and plant length were same for all treatments. With increased potassium silicate treatment, nutrient concentrations, such as P and K in the watermelon leaf at harvest were increased, N concentration in the leaf was decreased, and Ca and Mg concentrations in the leaf were same. Chlorophyll content was increased with increased potassium silicate application. The occurrence of powdery mildew was lower for the potassium silicate treatments than the control. Fresh watermelon weight for the potassium silicate treatments was 0.1 to 0.5kg per watermelon heavier than the control, sugar content was 0.5 to $0.6^{\circ}Brix$ higher than control, and merchantable watermelon was 2 to 4% increased compared to the control. These results suggest that potassium silicate application by soil drenching method in the greenhouse can improve watermelon nutrient uptake, merchantable watermelon and suppress the occurrence of powdery mildew.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.280-286
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• 2009

To investigate anti-phytopathogenic fungal activity of Coptis chinensis, the methanol extract and its organic solvent fractions were prepared. Using the extract and the fractions, in-vitro spore-germination inhibition and mycelial-growth inhibition activities were evaluated against Colletotrichum gloeosporioides, Phytohpthora capsici, Pyricularia grisea, Rhizoctonia solani, Botryosphaeri dothidea, Glomerella cingulata, respectively. Treatment of the methanol extract (500 mg/mL) into the spore of phytopathogenic fungi completely inhibited germinations for 5 days, except B. dothidea, and showed strong antifungal activities against P. grisea and B. cinerea, and antioomycetes activity against P. capsici. The minimal growth inhibition concentrations of the methanol extract against P. grisea, B. cinerea and P. capsici were 300, 300, and 500 mg/mL, respectively. For practical application of C. chinensis in red-pepper field, the hot-water extract (1,000 mg/mL) was prepared in commercial facility, after evaluation of heat stability and solvent-extraction yields of antifungal substances. The 3-times leaf-spray of the extract from June to August, 2008 did not show any deleterious effect to red-pepper. In fact, the leaf-spray promoted plant growth including leaf, root and fruit. The average weight and rind of each fruit were increased to 119% and 117% comparison to those of without treatments. Our results suggest that C. chinensis is a useful source for control of red-pepper diseases and plant growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1484-1490
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• 2014

In the present study, we examined the effects of a mixture of three strains, Lactobacillus plantarum CECT 7527, 7528, and 7529 (L. plantarum mixture), on body weight and lipid metabolism in Sprague-Dawley rats fed a high-fat diet. Rats were fed a high-fat diet and subjected to oral gavage with vehicle or the L. plantarum mixture ($0.6{\times}10^9$, $1.2{\times}10^9$, $2.4{\times}10^9$ colony-forming units (CFU)/day/rat, respectively) for 8 weeks. In rats fed a high-fat diet, oral administration of $2.4{\times}10^9CFU/day$ of the L. plantarum mixture significantly reduced body weight gain as well as weights of liver and epididymal fat. Leptin levels in sera were significantly reduced by oral administration of $2.4{\times}10^9CFU/day$ of the L. plantarum mixture. The L. plantarum mixture ($1.2{\times}10^9$ or $2.4{\times}10^9CFU/day$) also reduced the concentrations of total cholesterol and LDL-cholesterol in sera when it administered orally. Further, the L. plantarum mixture significantly reduced the atherogenic index and cardiac risk factor. In addition, oral administration of $2.4{\times}10^9CFU/day$ of the L. plantarum mixture markedly reduced levels of total lipids, triglycerides, and total cholesterol in the liver. The results of this study indicate that the L. plantarum mixture may exhibit anti-obesity and cholesterol-lowering effects, which suggest that the L. plantarum mixture has the potential to be a probiotic in the management of obesity and hypercholesterolemia.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.83-87
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• 2014

The objective of this study was to examine the changes in carbon dioxide ($CO_2$) concentration due to application of solid $CO_2$ generator (Tansansol) in plastic greenhouses during winter cultivation of Korean melon. The experimental treatments consisted of four levels, namely, 0 (control) 10, 20 and 30bags with solid $CO_2$ generator per $600m^2$ of plastic greenhouse. $CO_2$ concentration in plots with solid gas generators was higher by 3.0-3.2% compared to control. Fruit weight, sugar content and color parameter were also enhanced due to application of solid $CO_2$ generator. The fraction of fermentated and unmarketable fruits were decreased by 2.9-3.9% and 5.4-7.3%, respectively, in plots where solid $CO_2$ generators were applied. The marketable yield increased by 10.3, 14.8 and 16.2% in plots with 10, 20 and 30bags with $CO_2$ generators, respectively. As a result, $CO_2$ concentration within the greenhouses was increased by applying $CO_2$ generators and it is positively affected the rate of photosynthesis.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.317-323
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• 2017

In this study, the heating performance and the energy saving effect of the heat pump system using hot waste water(waste heat) of the thermal power plant discharged from a thermal power plant to the sea were analyzed. The greenhouse area was $5,280m^2$ and scale of the heat pump system was 120 RT(Refrigeration Ton), which was divided into 30 RT, 40 RT and 50 RT. The heat pump system consisted of the roll type heat exchangers, hot waste water transfer pipes, heat pumps(30, 40, 50 RT), a heat storage tank and fan coil units. The roll type heat exchangers was made of PE(Poly Ethylene) pipes in consideration of low cost and durability against corrosion, because hot waste water(sea water) is highly corrosive. And the heating period was 5 months from October to February. During the heating performance test(12 hours), the inlet water temperature of evaporator was changed from $32^{\circ}C$ to $26^{\circ}C$, and heat absorption of he evaporator was changed from 175 kW to 120 kW. The inlet water temperature of the condenser rose linearly from $15^{\circ}C$ to $50^{\circ}C$, and the heat release of condenser was reduced by 40 kW from 200 kW to 160 kW. And the power consumption of the heat pump system increased from 30 kW to 42 kW. When the inlet water temperature of condenser was $15^{\circ}C$, the heating COP(Coefficient Of Performance) was over 7.0. When it was $30^{\circ}C$, it dropped to 5.0, and when it was above $40^{\circ}C$, it decreased to less than 4.0. It was analyzed that the reduction of heating energy cost was 87% when compared to the duty free diesel that the carbon dioxide emission reduction effect was 62% by recycling the waste heat of the thermal power plant as a heat source of the heat pump system.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.181-187
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• 2017

The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. The climatic conditions around seven major reclaimed land areas with a plan to install advanced horticultural complexes in Korea were analyzed. The characteristics of natural ventilation and temperature rise through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. Results of comparing the ventilation rate of the greenhouse according to the presence or absence of plants showed the greenhouse with plants had the lower ventilation rate, but the smaller rise of indoor temperature due to the evapotranspiration of plants. In the greenhouse with plants, the number of air changes was in the range of 0.3 to 0.9 volumes/min and the average was 0.7 volumes/min. The rise of indoor temperature relative to outdoor temperature was in the range of 1 to $5^{\circ}C$ and the average $2.5^{\circ}C$. The natural ventilation performance of the experimental greenhouse constructed in the reclaimed land almost satisfied the recommended ventilation rate in summer and the rise of indoor temperature relative to outdoor temperature did not deviate considerably from the cultivation environment of plants. Therefore, it was determined that the greenhouse cultivation in Saemangeum reclaimed land is possible with only natural ventilation systems without cooling facilities. As the reclaimed land is located in the seaside, the wind is stronger than the inland area, and the fog is frequent. This strong wind speed increases the ventilation rate of greenhouses, which is considered to be a factor for reducing the cooling load. In addition, since the fog duration is remarkably longer than that of inland area, the seasonal cooling load is expected to decrease, which is considered to be advantageous in terms of the operation cost of cooling facilities.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.328-335
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• 2012

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was investigated the residue property of fungicide dimethomorph and pyraclostrobin in green onion, a stem-crop. After pesticides were applied 2 times with 1 week interval in that day of harvest, 3 days, 7 days, 10 days and 14 days before harvest, a green onion was harvested. The residue of dimethomorph in a green onion was 26.31 and 39.08 mg/kg in that day of harvest, however, in according to elapse time, it was reduced to 6.86 and 9.34 mg/kg in 14 days before harvest. In case of pyraclostrobin, it was also reduced from 13.46 and 39.08 mg/kg to 3.57 and 5.21 mg/kg. Based on the residue in that day of harvest, the deposit of spray solution in a green onion was calculated. The deposit of spray solution of dimethomorph was 274.35~345.84 mL/kg, in case of pyraclostrobin, it was calculated 213.65~343.33 mL/kg. When the amount of the deposit of both pesticides was compared in a green onion, it was so similar. On the other hand, it was estimated the predicted dissipation curve of pesticides in the green onion during cultivation. The half-life of dimethomorph was 6.95~7.45 days, in case of pyraclostrobin, 7.15~7.45 days. When both pesticides were compared with the residue property, the deposit of spray solution and half-life of dissipation were so similar.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.294-301
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• 2012

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was compared a green onion with a scallion on the residue property of insecticide bifenthrin and chlorfenapyr. After pesticides were applied 2 times with 1 week interval in that day of harvest, 3 days, 7 days, 10 days and 14 days before harvest, vegetables were harvested, and the residue of pesticides was investigated. Base on the residue in that day of harvest, the deposit of spray solution in vegetables was calculated. The deposit of spray solution of bifenthrin was 123.0 mL/kg in a green onion, and 74 mL/kg in a scallion. In case of chlorfenapyr, it was calculated 126.5 mL/kg in a green onion, and 70.0 mL/kg in a scallion. When the amount of the deposit of both pesticides was compared a green onion with a scallion, it was higher in a green onion. On the other hand, it was estimated the predicted dissipation curve of pesticides in a green onion and a scallion during cultivation. The dissipation curve of bifenthrin was y = 1.0334 $e^{-0.0602x}$ ($R^2$= 0.8606) in a green onion, and y = 0.7693 $e^{-0.1823x}$ ($R^2$= 0.9756) in a scallion. In case of chlorfenapyr, it was y = 2.2603 $e^{-0.0519x}$ ($R^2$= 0.9043) in a green onion, and y = 1.2940 $e^{-0.1051x}$ ($R^2$ = 0.9782) in a scallion. The half-life of bifenthrin was 11.51 days in a green onion, and 3.80 days in a scallion, respectively. Also, it was estimated half-life in chlorfenapyr, it was 13.35 days in a green onion, and 6.59 days in a scallion, respectively. The half-life of both pesticides in a green onion was longer than in a scallion. When both vegetables were compared with the residue property, the deposit of spray solution and half-life of dissipation in a green onion were more than those in a scallion.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.9-16
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• 2016

To investigate the effect of soluble silicate zeolite dressing of the rice against bakanae disease, field trial in reclaimed land and in vitro were carried out. The coated rice seeds (SCS) which were dressed with the mixture of 25% silicic acids (binder), and the zeolite (coating powder). In wet direct seeding, uniform scattering of rice seeds on the soil surface and the better seedling establishment were shown in SCS treatment plots. The incidence of bakanae disease began from the mid tillering stage toward the heading stage. Around heading stage, the ratio of infected tillers reached its highest point by 9.9% in non-SCS treatment plots. While, in SCS treatment plots, the ratio of infected tillers was no more than 0.01%. The vitality of the pathogenic fungi of bakanae disease in the SCS and non-SCS samples were assessed. Samples were incubated for one week keeping proper humidity at $30^{\circ}C$ after inoculated with panicles of infected rice plants from experimental field plots. In non-SCS treatment, pinkish colonies were formed on the grain surface of panicle of infected plants, and mycelium, macro-conidia and micro-conidia were developed actively inside part of infected grain inoculated. While in SCS treatment, micro-conidia and mycelium were not survived and the growth of macro-conidia, mycelia were greatly inhibited and withered. Based on the results, it is concluded that the environmental friendly control of bakanae disease by use of SCS is possible and soluble silicate can be applied as agents for replacement of seed disinfection.