• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.264-269
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• 2006

This experiment has investigated the effect of growth, yield and fruit quality of fig plant by different concentration of nutrient solution. Nutrient solution for pig plant were three concentrations of the balanced nutrient formula development by Japanese Horticultural Experiment Station. Plant height, number of leaves, stem diameter and number of fruit per plant were the best at 1/2 concentration. However, leaf length and leaf width did not show any difference in other treatment. Fruit length, fruit diameter and soluble solids did not differ from the different concentration of nutrient solutions. However, the fruit weight of fig plant was heavier by hydroponics than by soil culture in 2nd experiment. Early stage growth of fig plant was better at low concentration of nutrient solution and yield was better at high concentration. The result of this experiment will be utilized in the new application for fig plant hydroponics.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1994.05a
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• pp.9-19
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• 1994

Hydroponics, Nutriculture, Soilless culture 라고 불리워지는 양액재배는 결코 새로운 기술은 아니지만 최근 집약적 생산을 위한 공장적 재배 등을 통해서 다시 주목을 받고 있다. 과거에는 재배관리의 어려움 때문에 전문가 이외에는 재배가 곤란했지만, 최근 재배관리의 자동화경향 때문에 비전문가에 의한 관리도 가능하게 되고 있다. 양액재배는 토양재배에 비하여 여러가지 장점을 가지고 있다. 양액관리를 위한 장치의 개선과 적용작물의 선택, 생력관리기술이 확정되었고, 연작장애 대책, 안정적 계획생산, 무공해식품의 평가가 높기 때문에 양액재배 면적은 서서히 증가하는 추세라 할 수 있겠다. (중략)

• The Plant Pathology Journal
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• v.18 no.3
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• pp.142-146
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• 2002

The effect of potassium phosphonate ($KH_2PO_3 or $K_2 HPO_3$) on the control of Phytophthora root rot of lettuce was evaluated in a liquid hydroponic culture. Phosphonate 100 ppm strongly inhibited mycelial growth of Phytophthora species in vitro but did not affect normal growth of lettuce in a greenhouse test. Application of the chemical before infection showed over 94% control value, while it was less than 35% when applied after infection. In a field trial, phosphonate 100 ppm, which was directly supplemented into the nutrient solution, satisfactorily controlled the disease as it did not develop until 28 days after transplanting and remained at less than 2% infection rate at the end of cultivation. Meanwhile, in the control plot, the disease initiated at 7 days after transplanting and developed rapidly reaching over 70% infection rate at 28 days. Population density of the causal pathogen, R drechsleri, in a heavily infested farm was 22.0-25.0 cfu/100 ml of nutrient solution. However, it decreased to 1.3-2.0 cfu/100 ml at 7 days after treatment with phosphonate 200 ppm.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.52-57
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• 1994

The external qualities of cherry tomato fruits(Lycopersicon esculentum) grown in circulating deep flow hydroponic culture were non - destructively estimated in 1992 under warm climate conditions and evaluated in 1993-1994 under cool season. The fruit size of ‘Minicarol’ was by far the smallest compared to ‘Chelseamini’ and ‘Popo’. There were high correlations between external qualities of fruits-lengthwise growth harmonized with widthwise growth. The volume and/or weight of fruit could be non -destructively estimated by length and width of fruit. Volume=0.071$\times$ (length+width)$^3$＋0.451, Fresh weight=0.072$\times$ (length+width)$^3$＋0.542. These models were accurately evaluated by fruits harvested in 1994.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.489-496
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• 2017

This study was conducted to test the applicability of hydroxy radical reactor system, which applied advanced oxidation processes, to sterilize pathogenic bacteria for nutrient solution recycling in closed hydroponics. Removal efficiency was tested on 25 L of nutrient solution maxed with 10 mL culture solution of bacteria, E. coli, and R. solanacearum in a pilot tank. The testing conditions included various levels of hydroxy radicals resulting from air flow rates of 40, 80, and $120L\;min^{-1}$, and 12 hours processing time. The removal of bacteria, E. coli, and R. solanacearum by hydroxy radical in nutrient solution was significantly increased with an increase in the flow rate of the air from $40L\;min^{-1}$ to $120L\;min^{-1}$. The optimum removal efficiency was achieved at an air flow rate of $120L\;min^{-1}$ for 2 hours treatment. There were no significant differences in removal efficiency among bacteria, E. coli, and R. solanacearum for tested level and time of hydroxy radical. These results verified the efficiency of hydroxy radical in removing the pathogenic bacteria and the applicability of hydroxy radical reactor system in the field.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.183-188
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• 2010

It is necessary to develop an efficient and affordable cooling technology and apply the practical system to rural farmhouse, control to adequate growth environment by adjusting temperature of root zone. A study on managing medium temperature of the hydroponics for strawberry cultivation was conducted and feasible evaporative cooling system for the media cooling were as follows: Characteristics of temperature drop were investigated for the evaporative cooling devices using microporous film duct, felt mulching on media surface, and water permeable sheet in culture tank. The evaporative device with water permeable sheet in culture tank was the most efficient and economic on media cooling system.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.4
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• pp.76-89
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• 2023

One of the technologies in urban agriculture, hydroponics cultivation, has primarily focused on technological development, resulting in a lack of research on urban agriculture's cultural utilization aspects, encompassing cultural values associated with urban residents' leisure activities. Therefore, this study aimed to identify the participation constraints perceived by school community members when implementing urban farming activities using hydroponics and understand the structural relationships between the variables that influence decision-making from the perspective of leisure activities in urban farming. As a result, participation constraints in urban farming activities utilizing hydroponics were first categorized into intrinsic, interpersonal, and structural factors. Second, the results of hypothesis model verification showed that interpersonal constraints significantly influenced the participants' willingness to participate and their expected behavior. This study found the multidimensional perceptions of school community members regarding hydroponic urban farming conducted in urban spaces, particularly rooftops, and revealed the influence of decision-making factors on participation when conducting urban farming activities using hydroponic cultivation.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.23-26
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• 2010

Commercial fibers such as two kinds of micro-fiber, flannel, and cotton were analyzed for their nutrient solution absorption capacity to select hydrophilic mat used for the irrigation management by drainage level sensor in perlite bag culture. The selected mat was evaluated in terms of absorption capacity. Cotton had the highest absorption capacity and was revealed to be the most appropriate for the control system.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.325-329
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• 2008

This study was conducted to compare the postharvest physiological characteristics of 2 paprika cultivars; 'Special', 'Fiesta' grown in 2 regions: Chuncheon(plain region) and Hwacheon(semi-high land region), and by 2 cultural methods; soil and hydroponic(rock wool culture). Respiratory rate of paprika fruit was higher in soil culture, and ethylene production was higher in Chuncheon region of both cultivars. As the thickness of fruit flesh showed thicker in Hwacheon region and hydroponic culture, the firmness of fruit was in proportion to thickness. Vitamin C content was higher in red-cultivar, 'Special'. and in Chuncheon region. Soluble solids was higher in 'Special', but there was no different between cultural regions. The fruit of both cultivars was grown smaller in Chuncheon region, and the fruit shape of 'Fiesta' progressed faster in soil culture. The surface color of fruit was higher in Hwacheon, and although there was no significantly different between cultural method, both cultivars grown by hydroponics was shown vivid color. As above results, for the long term circulation and high quality of fruit, paprika may be cultivated by hydroponics in high-altitude region.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.12-18
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• 2010

Irrigation management methods controlled by integrated solar radiation (ISR) or drainage level sensor were evaluated in rockwool or coir bag culture as tomato (Solanum lycopersicum L.) production system. Substrate water content and drainage percentage were more stable in the drainage level sensor method than in the ISR method regardless of substrate type. Total yield and marketable yield were high in the drainage level sensor method, but not between substrates in the same irrigation management method. Sugar content was affected more by the substrate type than irrigation method. The drainage level sensor method was elucidated to be better than the ISR method regardless of substrate type.