• Journal of Bio-Environment Control
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• v.2 no.1
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• pp.53-57
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• 1993

This study was carried out to investigate the appropriate hydroponic system when cherry tomatoes were grown in summer. The base diameter of the trunk, leaf length, leaf width, and the length of cluster were good in deep flow culture(DFC), and not different between NFT and rockwool culture. The first time of flowering and the fruit coloring per cluster were not different among cultural systems, but the marketable yields were good in DFC. In DFC, ％ dry weight, firmness, the content of organic acid and sugar were low, and the ratio of sugar/organic acid and vitamin C were high. So DFC is recommended for the summer cultivation of cherry tomatoes.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.114-118
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• 2005

The experiment was conducted to establish the blanching culture of chicon expected to become exporting crop, for preventing Korea fiom importing the ffreign chicon and increasing the growers' profits, the days of blanching culture are based on the 5 treatments such as 10 days, 15 days ,20 days, 25 days, and 30 days. In the blanching culture days of chicory, the growth was good as blanching culture days were longer, there were too many outer leaves, and the ratio of bolting was $16\%$ on the 25 days, $30\%$ on the 30days. On the 10th day, the weight of chicon was light, the hardness was low, the density was low. The quality of chicon had no differences among the treatments. Therefore, the optimal condition for blanching culture of chicory is that the days of blanching culture is 20 days.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.137-141
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• 2009

This experiment was investigated to effect of divided rhizome size and medium type on survival rate and growth of wasabi for 60 days in controlled growth room. In divided rhizome size of 5mm above, survival rate was 100% and their growth (plant height of 12cm and leaf number of 3${\sim}$4 per plant) was good at 30 days after wrapped-sphagnum treatment. Plant height was 20cm above and number of leaves increased in 1-2 per plant at 60 days after treatment. Survival rate and growth didn't show any effect on plant regulator of root-tone. In inorganic media (saprolite and aerated light stone) treatment, survival rate of wasabi in divided size of 5${\sim}$10mm showed 83% or above at 30 days in deep flow culture. Growth did not show significant difference of inorganic support media treatments. Therefore, it is possible for divided rhizome size of 5mm above to do production of seedlings by acclimatize for 30 days in hydroponics under controlled growth chamber.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.79-84
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• 2000

The growth and quality differences between common thyme(Thymus vulgaris L.) and lemon thym (Thymus$\times$citriodorus) were investigated. They were grown in a hydroponics culture system (DFT) with a nutrient solution developed by the European Vegetable R&D Center in Belgium. Nutrient solution ionic strength used were 1.2, 2.4, 4.8 and 7.2 mS.cm-1. The dry matter of two thymes were increased with increasing ionic strength, while shoot length, root length and fresh weight were decreased. Chlorophyll content was higher in lemon thyme, while vitamin C content and essential oil content were higher in common thyme. The essential oil content showed a similar trend as those of growth. The main compostion of essential oil were thymol and carvacrol in common thyme, and geraniol and $\alpha$-citral in lemon thyme. The highest content of these compounds was obtained in 1.2mS.cm-1 treatment. Consequently, the ionic strength of 1.2mS.cm-1 was suitable for the production of quality thymes.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.1
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• pp.55-64
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• 1995

This paper presents analytic results of energy sequestered for the forcing cultural Cu- cumber and the others production system with the input-output tables method in the suthern parts of Korea. In this study an attempt is made to evaluate input of direct and indirect energy, output of yield energy and net energy in order to achieve increased energy productivity under P E greenhouse. Cultural practices were grouped soil and soilless with perlite for vegetable production. The results from this study are summarized as follows : 1. Total energy inputs in cucumber production were calculated to be 510 GJ/l0a(di- rect energy : 480 GJ/lOa, indirect energy : 30 GJ/lOa) from soil culture and 440 GJ/ 10a(direct energy : 420 GJ/lOa, indirect energy : 20 GJ/lOa) from soilless culture in perlite hydroponics. 2. Energy outputs from cucumber and biomass were 7 GJ/lOa and 120 GJ/lOa at a uniform rate respectively. 3. Heating fuel as diesel is a major energy inputs approaching 90% of the total energy requirements for cucumber production. 4. Net energy in cucumber production was calculated to be 503 GJ/lOa from soil cul- ture and 431 GJ/lOa from soilless culture. Net energy productivity was maintained costantly as 0.98. 5. Energy productivity in cucumber was calculated to be 0.029 kg/MJ from soil culture and 0.043kg/MJ from soilless culture, while energy efficiency was 0.012 and 0.015 respectively. It is expected that a soilless cultural production system seems to be reduc- tive in seguestered energy input by 13%.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.1-7
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• 2011

An experiment was conducted to test different heights of drainage level sensors in an irrigation management system for perlite bag culture of cucumber and paprika. The sensors were placed at 4, 8, 12, and 16 mm from the bottom of the container. Both cucumber and paprika did not show any significant difference in growth and yield among the treatments. However, placing the sensor at 4 mm seemed to be the best in order to prevent over-supply of water at the beginning of the day.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.92-94
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• 1998

최근 도시근교 시설재배토양의 염류 과다집적과 연작장해 발생으로 생산성이 저하되고 있다. 그리고 고품질 연중생산이 가능한 양액 재배 면적이 '93년 23ha에서 '97년 414ha로 급속히 증가되고 있는데 이 중 약12%가 담액경이나 박막수경의 순수 수경재배 방식이 차지하고 있다. 순환식 담액수경 상추재배를 기준으로 할 때 농가 300평 재배시 약 100ton의 양액이 소요되며 이 양액은 1회 재배가 끝난 후 상당량이 폐기되고 있고 고형 배지경 양액 재배의 경우에도 대부분 비 순환식 재배로 1회 관수 후 나오는 배액이 그대로 버려지고 이어 토양 및 지하수 등 환경오염, 자원 낭비 등의 여러 가지 문제를 야기시키고 있다. (중략)

• The Plant Pathology Journal
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• v.17 no.5
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• pp.311-314
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• 2001

Phytophthora root rot of lettuce, which has not been reported in Korea before, occurred severely in liquid hydroponic culture. The disease occurred in all seasons and was most severe in summer from June to August, showing over 90% infection rate in some farms. A total of 51 isolates collected from various farms were all identified as Phytophthora drechsleri. The fungus showed strong pathogenicity to lettuce and Chinese cabbage, moderate pathogenicity to cucurbits and tomato, and weak pathogenicity to pepper. However, the fungus was not pathogenic to other leafy vegetables namely: chicory, kale, endive, garland chrysanthemum, spinach beet, and perilla. Among 10 species of Phytophtora inoculated to lettuce, only P. drechsleri and P. cryptogea were found pathogenic.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1117-1125
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• 1996

A low-cost and precise metering device, which is suitable to automatic mixing of nutrient-solution for hydroponic culture, was developed for small-scale growers. The metering accuracy of the metering device developed was compared with commercial metering pumps. The mixing performance through the control of EC and pH was also evaluated. The accuracy of the metering device in terms of the full -scale error was $\pm$0.3% , which was much better compared to $\pm$2.45% and $\pm$1.38% for the two types of commercial metering pumps. The mixing system of nutrient-solution with the metering device showed a satisfactory control performance with the accuracies of $\pm$0.05mS/cm and$\pm$0.2pH for EC and pH, respectively.

• Plant Resources
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• v.8 no.1
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• pp.48-51
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• 2005

Optimmum cultivation period was determined for producing seed bulb of Korean native Allium wakegi Araki in vitro in hydroponic culture. The growth gradually increased during cultivation period. In general, plants grown for 5 months produced significantly the highest bulb number and bulb fresh weight per plant. Raising the cultivation period from 1 to 5 months remarkably increased seed bulb yield.