• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.167-178
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• 1998

An Aero-NFT nutriculture system using microcomputer for cultivation of greenhouse melon was developed and the performance of the system was evaluated through experiments. The system could control temperature, EC and pH of the nutrient solution within the error ranges of $\pm$ 0.2$^{\circ}C$, $\pm$ 0.2 mS/cm, $\pm$ 0.1 pH, respectively. The results of cultivation experiment showed that temperature, EC and pH of the nutrient solution were generally controlled within the setting ranges during cultivation period. The growth results were good until pinching, but the fruit quality of melons was not high except sweetness and shape. To optimize performance of the system, more techlical information for nutriculture of greenhouse melon was needed.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.190-197
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• 1997

This study was conducted to determine the optimum hydroponic system and nutrient solution for promoting the growth and flowering of hydroponically grown carnation. DFT (deep flow technique) and NFT (nutrient film technique) systems were employed and four kinds of nutrient solution, which are Cooper solution, Yamasaki solution, balanced nutrient solution by Japanese Horticultural Experiment Station and PTG solution in the Netherlands were used and compared. pH was lowest in the PTG solution compared to the other nutrient solutions used. Plant height was highest in the DFT system in the plot of PTG solution as of 53.0 cm at 88 days after transplanting, while lowest in NFT system with Cooper solution. Stem diameter was more thickened in NFT system with PTG solution as of 7.2 mm at 88 days after transplanting. Days to flowering was shortened to 122.3 days in NFT system when PTG solution was used. This results suggested a combination of NFT system with PTG solution as optimum hydroponic system and nutrient solution for cut carnation production. Further trials as to the management of nutrient solution by glowing stages should be followed.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.53-59
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• 1990

Root zone environments in hydroponics are very important factors in crop growth, development and quality. In Korea, improvement of root zone temperature is required because of the continental climate. Therefore, this investigation was carried out to clarify the difference of root zone environments in different hydroponic systems under different climates. Tomato plants were grown in nutrient solutions at Seoul City University and Allen Cooper's. Hydroponic systems in this experiment were aeroponics, nutrient film technique(NFT), rockwool culture, sand culture and smoked rice hull culture(SRH). The decrease in temperature rapidly occured in sand culture while slowly in rockwool culture in low air temperature periods. The internal temperature of substrates of hydroponic bed were slightly changed in rockwool culture under high air temperature periods, while the duration of high temperature was longest in NFT. Electrical conductivity and pH of nutrient solution showed great changes in rockwool and aeroponics. Along the bed, the content of dissolved oxygen in nutrient solution had a tendency to decrease in NFT and DFT(Deep flow technique), while didn`t a change with aeroponics. Root activity measured by triphenyl tetrazolium chloride (TTC) was highest with aeroponics, followed by rockwool culture and NFT.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.686-693
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• 2012

To develop a technique for mass-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plant using nutrient film technique (NFT), the growth characteristics of 4 cultivars as affected by nutrient solution composition and cutting size were investigated. 72 cells (35 mL/cell) plug trays filled with vermiculite and perlite (1:1, v/v) were used. Vine length, fresh and dry weights of virus-free plants were the greatest in the nutrient solution recommended by National Horticultural Research Station in Japan, followed by that recommended by National Institute of Horticultural & Herbal Science in Korea, and Yamazaki's nutrient solution for lettuce. The growth of uppershoot cuttings was the best among 4 subsections of cutting. Vine length, and fresh and dry weights increased in the longer cutting treatments, and were better in 'Shinzami' and 'Yeonhwangmi' than those in 'Mannami' and 'Shincheonmi'. Vine diameter and length of the longest root were not significantly affected by the cutting size and cutting source. The growth characteristics of the single node cutting were not significantly different from those in 2-node cutting. The efficiency of rapid mass-propagation could be promoted with single node cuttings and uppershoot cuttings grown in NFT system.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.71-77
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• 1998

The root-zone environment is an important factor to the plant growth and it is closely related to the thermal characteristics of the root media. In this study thermal characteristics of root media with ambient environmental conditions were analyzed. The temperatures of nutrient solution as well as inside air of culture bed were measured in Nutrient Film Technique(NFT) and Deep Flow Technique(DFT) systems, and also the temperatures of root media measured in aggregate culture systems , The temperature of nutrient solution of NFT system with as low as 3$\ell$/min of flow rate was 3$^{\circ}C$ higher than that with 5 $\ell$/min of flow rate in the daytime, and the temperature of inside air was 2$^{\circ}C$ higher at night. And the temperature of nutrient solution of DFT system with as low as 0.8 cm of water level was 1-2$^{\circ}C$ higher than that with 1 8 cm in the daytime, and the temperature of inside air was almost same at night. The root-zone temperatures in the perlite and rockwool granulate systems with film mulching were 3$^{\circ}C$ higher than those without film mulching in the daytime. However, the rockwool slab system with film mulching showed the same trend as rockwool granulate system, but relatively higher temperature than any other medium because of the exposure of media surface to the ambient air. Additionally the temperature below the plant was measured 3$^{\circ}C$ lower than that between plants.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.299-309
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• 1997

This experiment was conducted to determine the mineral absorption character and develop the optimum composition of nutrient solution for dill(Anethum graveolens L.) in hydroponics. Dill(Anethum graveolens L.) plants were grown in nutrient film technique(NFT) supplied with 1/4, 1/2, and 1 strength of the nutrient solution developed by National Research Station in Japan(HRS). Plants grown in 1/2 strength showed the best growth in plant height, fresh weight, and dry weight compared with those grown in 1/4 or 1 strength. In 1/2 strength solution, pH and EC changed little and proper nutrient contents were observed in the leaves as compared to plant nutrient diagnosis standard. Based on these results, optimum macronutrients were composed by nutrient- water absorption rate(n/w) with 1/2 strength: NO$_2$―N 8.85, NH$_4$―N 0.55, P 2.1, K 6.2, Ca 2.8, and Mg 1.7 me L$^{-1}$ To examine the suitability of the nutrient solution developed(SCU) , dill plants were grown in NFT supplied with two different kinds of solution and concentration. 1/2, 1, 3/2 and 25 of SCU and 1/2S of HRS. Changes of pH and EC were not distinct in 1S, but a significant change of pH was shown in low concentrations-HRS 1/2S and SCU 1/2S. Shoot fresh and dry weight were much higher in the plants grown in SCU IS as compared with HRS 1/2S. There were no significant differences in growth of plants grown in SCU IS, 3/2S, and 25. In addition, nutrient contents in the leaves grown by SCU 1S were in proper levels as compared with plant nutrient diagnosis standard. SCU 1S developed in this experiment was found to be optimum for dill in hydroponics.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.165-167
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• 1998

식물은 생육에 필요한 특정양분의 요구도가 환경요인, 품종 및 생육단계에 따라 좌우된다. 양액내 특정양분의 부족과 축적은 NFT같은 순환식 재배시스템에서 많은 문제점으로 나타나고 있는데 이는 식물생육이 주로 근권내 EC 조절에 의존하기 때문이다. 일반적으로 Ca, Mg, SO$_4$, Cl, Na, HCO$_3$$^{-}$등이 축적되기 쉬워 대규모 엽채류 재배농가와 식물공장에서 작물생육에 영향을 주는 것으로 알려져 있다. (중략)

• Horticultural Science & Technology
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• v.28 no.4
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• pp.580-584
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• 2010

The effect of planting densities on the growth of $Sedum$ $samentosum$ (4 collections) was investigated using nutrient film technique (NFT) with Yamazaki' lettuce nutrient solution (1982) from September 5th to October 24th in non-heating plastic film house. At 40 days, the plant height of 4 collections showed the range of 15.0-18.9 cm, and mean plant height was high the order of $10{\times}10$, $2.5{\times}2.5$, and $5{\times}5cm$. The growth of 'Pohang' and 'Wando' collections was better compared to that of 'Gunsan' and 'Wanju' collections. Number of node, stem diameter, and fresh and dry weight per plant were decreased in higher planting density. Despite the lower fresh weight per plant obtained, the fresh yield per $m^2$ was significantly increased in higher planting density. The mean fresh yield was $14.9kg{\cdot}m^{-2}$ in $2.5{\times}2.5cm$, and 'Pohang' collection showed the highest fresh yield ($17.6kg{\cdot}m^{-2}$). The first optimized harvesting time base on plant height was 30-40 days after NFT culture during autumn season. In eating quality, compression force of stem and bitterness of shoot were decreased in higher planting density. However, the heavy labor demanding high density cutting needs to be improved for hydroponic culture of $S.$ $samentosum$.

• Research in Plant Disease
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• v.11 no.2
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• pp.193-197
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• 2005

The effect of pH on the survival of R. solanacearum and its transmission via roots of tomato in hydroponic culture were studied in laboratory and greenhouse. In laboratory experiment, R. solanacearum could not survive for 24h in nutrient solution with pH of $4{\cdot}0;or\;4{\cdot}5$, while 1, 14, 51 and $62\%$ of inoculum survived at pH $5{\cdot}0,\;5{\cdot}6\;and\;6{\cdot}5$, respectively. When tomato plants were inoculated with R. solanacearum through wounds on the stems, the bacteria moved downward from the inoculation site to the roots and infectious bacteria were released from the roots into the nutrient solution. Of two pH regimes tested in greenhouse nutrient-film technique(NFT) culture, the R. solanacearum population was significantly lower in pH 5.0 than in pH 6.5 in most sampling data. In treatments in which R. solanacearum was introduced by transplanting two root-inoculated plants, significantly move plants developed wilt at pH $6{\cdot}5$(34 out of 48 plants) than at pH 5.0(11 out of 48 plants). In addition, when the bacterium was introduced by transplanting two stem-inoculated plants at pH $6{\cdot}5$, seven out of 24 plants developed wilt.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.195-200
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• 2011

The growth, yield and quality of Sedum sarmentosum between soil and hydroponic cultivation were compared to produce high-quality shoots in summer season. The plants were collected from four places in Korea and cultivated in a plastic film house with 50% shading. A 1:1:1 mixtures of sand, upland soil and substrate (N-P-K: 330-220-400 $mg{\cdot}L^{-1}$) was used for soil cultivation, and a nutrient film technique (NFT) with Yamazaki-lettuce nutrient solution used for hydroponics. After 30 days of cultivation, plant height ranged from 18.4 to 21.8 cm and showed no significant difference between soil and hydroponic cultivation. Number of shoot, leaf length, leaf width, number of leaf, fresh weight, and dry weight significantly increased in hydroponics compared to those in soil cultivation. Fresh and dry weights in hydroponics were greater in 'Gunsan' and 'Wando' collections than those in other collections. Stem diameter and compression-force significantly increased in soil cultivation rather than hydroponics with significant differences among collections. However there were no significant differences in shoot bitterness and vitamin C content between cultivation methods or among the collections. Most mineral contents except Fe in hydroponics were higher than those in soil cultivation. K, Na, Zn contents in hydroponics were over 2 times higher than those in soil cultivation.