• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.42-48
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• 2016

Angelica gigas, belonging family Apiaceae, is a perennial and famous medical plant growing in Korea, Japan, and China. The aims of this study was to analyze the growth and accumulated Decursin and its precursor Decursinol angelate of A.gigas grown under fluorescent lamp and LED. A. gigas 'Manchu' were sowed and managed for seedlings stage in a glass house for 4 weeks. One hundred twenty seedlings with 3 true leafs were transplanted at an ebb & flow system with fluorescent lamp and LED [red: peak wavelength 660nm, blue: peak wavelength 455 nm, white = 3:2:4 ratio] irradiated at $180{\pm}7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at the top of plant canopy for 5 weeks. The number of leaves increased by 13.5% in the LED treatment, though it is not statistically significant. Leaf length/width ratio of A. gigas grown under the fluorescent lamps was 24% bigger than the LED treatment and also the stem was 13% larger. Maximum root length was similar to both groups. Fresh weight and dry weight of shoots grown under the LED increased by 50% and 42% and the both weights of roots increased by 125% and 45%, respectively. The contents of Decursin and Decursinol angelate grown under the florescent lamps were larger than LED by 188% and 27% in shoot and 78% and 8% in root. The contents of Decursin and Decursinol angelate per plant grown under LED and florescent lamps were 132mg and 122mg. In conclusion, functional materials in A. gigas were increased by florescent light and its growth was promoted by LEDs light.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.149-154
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• 2005

It is very important to make shorter and healthier pot plants with increased numbers of branch at a growing stage before short-day exposure. Especially light and nutrient conditions directly affect the growth and quality of the plants as described above. In this study, the effects of nutrient strength and light intensity on the nutrient uptake and growth of young Kalanchoe plants (Kalanchoe blossfeldiana 'Marlene') during this growth stage were investigated. The plants were grown under two radiation integral (15.8 and 7.9 $mol{\cdot}m^{-2}{\cdot}d^{-1}$, PPF) and three EC (0.8, 1.6 and 2.4 $dS{\cdot}m^{-1}$) conditions. Leaf area, fresh weight, dry weight and number of branch were higher at a higher PPF, and this tendency was more evident at an EC above 1.6$dS{\cdot}m^{-1}$. The plants became higher at a lower PPF. When the EC was at 0.8 $dS{\cdot}m^{-1}$, the plants did not grow so healthy regardless of PPF conditions. EC decrement in the nutrient solution was increased with increase of nutrient strength. With growth stage, the nutrient uptake was increased with increases of nutrient strength and PPF. At a higher PPF, $NO_3-N,\;K^{+}\;and\;Ca^{2+}$ were much more absorbed, and especially the uptake of $K^{+}$ was 1.1 to 1.5 times greater than that or $NO_3-N$. From the results, the EC needed above 1.6 $dS{\cdot}m^{-1}$ during the seedling stage in order to make more healthy Kalanchoe plants having more leaf area, fresh weight, dry weight and number of branches under adequate light conditions.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.187-194
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• 2011

The objective of this study was to determine the effects of light intensity and electrical conductivity (EC) of nutrient solution on the growth and nutrient uptake of potted kalanchoe plants (Kalanchoe blossfeldiana 'Marlene') with growth stage in ebb and flow subirrigation systems. The plants were grown at four ECs of 0.5, 1.0, 1.5, and 2.0 $dS{\cdot}m^{-1}$ for seedling stage and four ECs of 1.0, 1.5, 2.0, and 3.0 $dS{\cdot}m^{-1}$ for short day stage under three daily photosynthetic photon flux (PPF) of 6.5, 10.3, 18.2 $mol{\cdot}m^{-2}{\cdot}d^{-1}$. At seedling stage, plant height was the longest under the lowest light intensity, and particularly dry weights and leaf areas were the highest at PPF 10.3 $mol{\cdot}m^{-2}{\cdot}d^{-1}$. Dry weights and leaf areas were the highest at EC 1.5 $dS{\cdot}m^{-1}$ regardless of light intensity. At short day exposure, plant height was the longest under the lowest light intensity. Dry weights, leaf areas, and number of pedicels of the plants significantly increased as light intensity increased. Under all light intensity conditions, dry weights, leaf areas, and number of pedicles increased until EC becomes to 1.0 - 2.0 $dS{\cdot}m^{-1}$. And after reached the highest at EC 2.0 $dS{\cdot}m^{-1}$, they decreased at EC 3.0 $dS{\cdot}m^{-1}$. By comparing the ion uptakes at EC 1.5 $dS{\cdot}m^{-1}$ of seedling stage and EC 2.0 $dS{\cdot}m^{-1}$ of short day stage in which the plants grew better, we confirmed that ion balance of nutrient solution among $NO_3{^-}$-N, $H_2PO_4{^-}$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were significantly changed at short day stage compared to seedling stage. For better growth of the plants, both ion balance and EC of nutrient solution should be considered under different light intensities at short day stage while control of EC is enough at seedling stage.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.112-117
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• 2008

Plug seedlings of vinca (Catharanthus roseus L. 'Pacifica Punch') and salvia (Salvia splendens F. Sellow ex Roem & Schult 'Maestro') were transplanted into square plastic pots (145 mL volume) filled with a soilless growing medium. To determine the effect of application rate on the growing medium EC and growth of plants, 0, 0.5, 1.0, 1.5, 2.0 and 4.0 g per pot of a controlled release fertilizer (14-14-14 Osmocote, 14N-6.2P-11.6K) were mixed with the growing medium. Plants were subirrigated daily with tap water. In both vinca and salvia, growing medium EC increased as application rate was elevated. Growing medium EC was relatively constant over a whole crop period when the application rate was less than 1.5 g per pot, while it decreased throughout the experiment at higher application rates such as 2.0 to 4.0g per pot in both species. The greatest leaf area, plant height, and shoot dry weight of vinca were obtained when plants were fertilized with 2.0 to 4.0 g per pot of the fertilizer, resulting in a growing medium EC of $1.0{\sim}1.7dS{\cdot}m^{-1}$ throughout the experiment. Leaf area, shoot dry weight, and chlorophyll content of salvia increased with elevated application rates. Leaf area, shoot dry weight, and chlorophyll content of salvia were the greatest when plants were fertilized with 4.0 g per pot, resulting in growing medium EC of $1.0{\sim}4.0dS{\cdot}m^{-1}$ throughout the experiment. Plant height of salvia was the greatest when plants were fertilized with 2.0 to 4.0g per pot. Concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and sulfur (S) in the shoots of vinca increased, while concentration of calcium (Ca) decreased with elevated application rates. Concentrations of boron (B) and manganese (Mn) in the shoots of vinca increased as the application rate decreased.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Journal of Bio-Environment Control
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• v.33 no.3
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• pp.163-171
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• 2024

This study was aimed to investigate the effects of layer-by-floor environmental conditions and lower shelf supplemental lighting on the productivity of fresh shoots when growing rosemary in multi-layer cultivation. The 10-cm cuttings from stock plants of common rosemary (Rosemarinus officinalis) were planted in a 128-hole tray, rooted, and then transplanted into pots of 750, 1,300, and 2,000 mL. Afterwards, they were placed on multi-layer shelves (width × length × height: 149 × 60 × 57 cm, 3-layer) in a two-linked greenhouse and cultivated using the sub-irrigation. The productivity of young shoots by layer of the multi-layer shelf was the highest on the third floor (top floor), but productivity decreased sharply after September due to stem lignification caused by excessive light during the summer. Conversely, the lower two layers exhibited faster growth rate of young shoots until the late cultivation period, but the quality decreased due to stem softening and leaf epinasty. To address the excessive light problem on the third floor during the summer, shading was implemented at 30% opacity in July and August, resulting in a 210% increase in rosemary young shoots count and a 162% increase in fresh weight per unit area compared to the unshaded control. To improve the lighting deficiency on the lower layer, supplemental lighting with LED at 30 W increased rosemary young shoot harvest by 168% from June to September compared to no supplemental lighting, but it decreased productivity after September. Therefore, when growing rosemary in multi-layer, it is judged that intensive production of young shoots is possible if the third floor (top layer) is shaded with 30% of light from July to August to prevent stem lignification, and the lower layer is temporarily supplemented with LED 30 W from June to September to increase young shoot growth.