• Journal of Bio-Environment Control
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• 제7권2호
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• pp.151-158
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• 1998

This study was carried out to evaluate the effect of substrates and nutrient solution supplying methods in the media culture using perlite and its mixtures with rice hull, carbonized rice hull. cocopeat on the growth and fruit qualify of hydroponically grown cucumber. Three substrates. Perlite(70%) +rice hull(30%) perlite(70%) +carbonized rice hull(30%) and perlite(70%)＋cocopeat(30%) were compared with perlite medium. Supplying methods of nutrient solution were composed of drip irrigation, modified drip irrigation(covered with cheesecloth between drip hose and substrate) and mist system Leaf area of cucumber Plants was lowest in perlite medium while it was highest in mixture of perlite and cocopeat. NAR was higher in the plot of mixture with cocopeat. and same trend was observed in LAI and CGR. T/R ratio was higher in Perlite and perlite mixture with rice hull. Fruit Yields increased in the plot of modified drip irrigation system. When perlite mixture with rice hull used as a substrate. mist system was recommended. Perlite mixture with carbonized rice hull was observed favored in conventional drip irrigation system. Marketable yield and the number of fruit per plant increased and the malformed fruit decreased in the plot of modified drip irrigation system with the mixtures of Perlite and cocopeat.

• Journal of Bio-Environment Control
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• 제5권2호
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• pp.131-137
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• 1996

This analysis has been conducted to get some basic data of the composition of culture solution mostly in inorganic ions, and water quality in hydroponic farms in Chollabuk - do. pH range was shown from 6.00 to 7.65 and the average was 6.58. EC range was shown from 0.01 to 0.94 mS/cm and the average was 0.28 mS/cm. Na concentration ranged from 4.71 to 145.44 ppm and Cl concentration ranged from 0 to 171.80 ppm were shown and their average were 24.24 ppm and 26.33 ppm, respectively. Na and Cl concentrations were higher as 7.7%, compared to those of other farms, which could cause the salt accumulation in the substrate mats. K, Ca and Mg concentrations were ranged from 0.93 to 17.38 ppm, 2.29 to 34.30 ppm and 0.70 to 18.61 ppm, respectively. Average concentrations were 3.06 ppm in K, 13.00 ppm in Ca and 4.91 ppm in Mg. 50, and PO$_4$ concentration ranged from 0.63 to 59.79 ppm and 0 to 4.28 ppm were shown and their average were 18.11 and 0.51 ppm. Cu concentration was ranged from 0 to 0.32 ppm and 0 to 6.22 ppm in Zn concentration. Their average were 0.02 ppm and 0.52ppm, respectively.

• Journal of Bio-Environment Control
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• 제29권1호
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• pp.28-35
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• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.

• Korean Journal of Plant Tissue Culture
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• 제27권3호
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• pp.213-217
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• 2000

To investigate the cucumber regeneration from embryogenic calli, shoot tips of aseptically-grown cucumber seedlings were used as explants for establishing tissue cultures. Growth and differentiation of callus were studied by using Murashige and Skoog's (MS) medium containing 0.5 to 2 mg/L 2,4-D. Plantlets were induced from shoot tip culture on the plant growth regulators-free MS medium. Non-embryogenic calli and viscous calli were induced on the medium supplemented with 0.5 to 2 mg/L 2,4-D, but embryogenic callus was not induced on the same medium. Segments (ca. 5∼10 mm) of aseptically-grown hypocotyl from five to seven days old seedlings after germination were placed on MS medium supplemented with 1 mg/L 2,4-D for 50 days. Embryogenic calli and embryoids were induced only from the seedlings grown in dark condition, and hypocotyl was placed on the media explanted in light condition. Foully-five point one percent of white fragile calli and 0.6% yellowish compact calli formed roots. Yellowish callus lines were investigated to have a considerably higher concentration of crude proteins than white callus lines. Plantlets derived from embryogenic calli or embryoids have been transferred to pots containing sterile vermiculite and perlite. Normal fruits were harvested from nutrient culture on aggregated hydroponics in the F-clean house.

• Journal of Bio-Environment Control
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• 제7권1호
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• pp.43-54
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• 1998

This experiment was conducted to develop optimal nutrient solution for tomato plants, according to the plant growth stages in closed system. Perlite substrate was supplied with 1/2 and 1 strength of the solution of National Horticultural Research Station in Japan. Plants grew better and the nutrient_contents in the leaves were also proper in 1 strength. Based on these results, optimal nutrient solution in perlite was composed by n/w of 1 strength according to the plant growth rates ： N 13.5, P 3.3, K 7.0, Ca 7.0, Mg 3.5 me.L$^{-1}$ in seedling stage, N 14.2, P 3.3, K 8.0, Ca 7.5, Mg 4.0 me.L$^{-1}$ in vegetative stage and N 10.0, P 3.0, K 7.0, Ca 6.0, Mg 3.0 me.L$^{-1}$ in reproductive stage. To examine the suitability of the nutrient solution developed in this experiment, tomato plants were grown in rockwool and supplied with two different composition and concentration of nutrient solution composed by n/w of 1 strength in perlite (SCUT) and by Research Station for Greenhouse Vegetable and Floriculture on the Netherlands (PBG). PH and EC in SCUT were changed little in 1 strength but a significant change of PH was shown in 1/2 strength. Later, drained solutions in rockwool were also analyzed according to the Plant growth stages. Low concentrations of N and P in root zone were shown in early growth stage but N was increased in reproductive stage, while, K, Ca, Mg concentration was consistent through the whole growth stage. Considering these results, we found that the rebalance of N and P was needed, that is, reduction of N concentration in reproductive stage and increasing of P concentration in vegetative stage.

• Journal of Bio-Environment Control
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• 제23권3호
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• pp.229-234
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• 2014

We analyzed drainage water from coir substrate in which cucumber plants were grown in winter and elucidated changes in pH, EC, and major nutrients according to the growth stages to recommend nutrient solution management appropriate to each growth stage. From the analysis of drainage solution the growth stages of cucumber were desirable to be divided into two, planting to fruit setting and fruit setting to harvest in case of nutrient solution management. The time required was about 3 weeks from planting to the first fruit setting and thereafter 7~10 days more until the first harvest. Approximately every 3~4 days were needed until the upper flowers bloomed. The time required from fruit setting to harvest was not different much among flowers as cucumber plants grew. From the experimental results, EC of supplied solution was recommended to maintain a little high to $3.0dS{\cdot}m^{-1}$ until before fruit setting and lower a little to $2.0{\sim}2.3dS{\cdot}m^{-1}$ after that. Of course, the amount of solution supply should be increased as plants grew. In case of each nutrients, the recommendation of concentrations of nitrogen, phosphorus and calcium were 700, 60, and $110mg{\cdot}L^{-1}$ each until before fruit setting, and then 660, 50, and $100mg{\cdot}L^{-1}$ each after fruit setting. The concentrations of potassium and magnesium are recommended to start from 400 and $80mg{\cdot}L^{-1}$ until fruit setting and lower a little after that.

• Journal of Bio-Environment Control
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• 제25권1호
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• pp.63-70
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• 2016

Water drainage from the open hydroponics often causes significant environmental pollution due to agrochemicals and loss of water and nutrients. The objectives of this study were to show the potential application of an irrigation schedule based on threshold values of volumetric substrate water content for tomato (Solanum lycopersicum L. 'Samsamgu') cultivation in a commercial hydroponic farm during spring to summer cultivation. This study was performed for minimizing effluent from coir substrate hydroponics using a frequency domain reflectometry (FDR) sensor-automated irrigation, as compared with an integrated solar-radiation (IR) and conventional timer-irrigation (TIMER) after transplanting. In results, no significant difference in daily irrigation volume was found among the treatments until 88 days after transplant (DAT). However, during the 88 to 107 DAT, the daily irrigation volume was in the order of IR (2125 mL) > TIMER (2063 mL) > FDR (1983 mL), and during the 108 to 120 DAT, it was in the order of IR (2000 mL) > TIMER (1664 mL) > FDR (1500 mL). The lowest drainage volume was observed in the FDR treatment with the order of IR (12~19%) > TIMER (4~12%) > FDR (0~7%) during the entire growing period. A lower irrigation volume in the FDR treatment after 88 DAT may be due to the sensor's detecting capacity for less water absorption by plant after completing fruit maturity with apical pruning and removal of lower leaves, while a higher irrigation volume in the IR treatment may be due to gradual increase in integrated solar-radiation amount as closer to summer season. There was no significant difference in plant growth and fruit yield among the treatments; however, a 11% and 18% of higher soluble sugar content was observed in the FDR than that of TIMER and IR treatment. respectively.

• Journal of Bio-Environment Control
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• 제14권3호
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• pp.203-211
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• 2005

The experiment was conducted to investigate the nutrition absorption pattern in the growth stages and develope the optimal nutrient solution hydroponically grown the tomato in closed substrate culture system with the nutrient solution of National Horticultural Research Station in Japan into 1/2S, 1 S, and 2S. When plant was grown in 1/2 S, the growth and yield were high and the pH and EC in the rooting zone were stable. Suitable composition of nutrient solution for tomato was $NO_3-N$ 7.1, $PO_{4}$-P 2.1, K 4.0, Ca 3.1, Mg 1.2, and $SO_{4}-S\;1.2\;me{\cdot}L^{-1}$ in the early growth stage and $NO_3-N$ 6.5, $PO_4-P$ 2.3, K 3.4, Ca 3.1, Mg 1.1, and $SO_4-S\;1.1\;me{\cdot}L^{-1}$ in the late growth stage by calculating a rate of nutrient and water uptake. To estimate the suitability for the nutrient solution of tomato in a development of optimum nutrient solution of tomato developed by Wonkwang university in korea (WU), plant was grown in perlite substrate supplied with different solution and strengths(S) by research station for greenhouse vegetable and floricultuin in the Netherlands (Proefstation voor tuinbouw onder glas te Naaldwijk; PTG) of 1/2 S, 1 S and 2 S, respectively, The growth was good at the PTG and WU of 2 S in early growth stage, and at the WU 2S in late growth stage. The highest yield of tomato obtained in the WU of 2 S, although blossom-end rot was appeared in all treatments. pH and EC in root zone of WU of 2 S were stable during the early and late growth stage. Therefore when plant was grown in WU of 2 S, N and P content in the nutrient solution need to low, according N and P content of their leaves were high in WU of 2 S.