• Horticultural Science & Technology
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• v.19 no.3
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• pp.315-319
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• 2001

The study was carried out to develop a simple and efficient system to regenerate plants from cotyledon and hypocotyl tissues of Chinese cabbage (Brassica campestris L. ssp. pekinensis cv Seoul). Among the various combinations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) tested, the best shoot induction medium for cotyledon, with 2.67 shoots per explants, contained $2.0mg{\cdot}L^{-1}$ NAA, $1.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$. The shoot induction medium with $1.0mg{\cdot}L^{-1}$ NAA, $5.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$, was best for shoot induction from hypocotyl explants, with 1.87 shoots per explants. After shoot induction, regenerated shoots were excised and rooted on rooting medium. Rooted plantlets were then hardened in the high humidity growth chamber and transplanted to pots, and then grown in the greenhouse. Regenerated plants appeared phenotypically normal and there were no changes in chromosome number.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.636-641
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• 2011

Four different green manure crops, hairy vetch, Italian ryegrass, crimson clover, orchard grass were cultivated to test the differences in their effects on soil improvement. After plowing to incorporate the green manure crops, tomato plants were grown as a succeeding crop to investigate the effects of green manure on the soil physical properties and plant growths. The experimental results showed that green manure could decrease the soil hardness. Italian ryegrass and hairy vetch as the green manure were especially effective in decreasing the soil hardness. Orchard grass and Italian ryegrass provided more void in soil matrix, resulting increased soil moisture contents. After two months, bulk density was decreased in the plots of Italian ryegrass and orchard grass. However, there were no significant differences between green manure plots and control after the cultivation of the succeeding crop. The results indicated that the growing Italian ryegrass and hairy vetch as green manure helped growing tomato plants. Orchard grass also improved the soil characteristics, comparable to Italian ryegrass in spite of their relatively small biomass.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.352-357
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• 2007

We investigated effects of concentration and duration were investigated in order to promote efficiency of $CO_2$ enrichment in winter. The treatments were conducted with two levels of $CO_2$ concentration, namely 400 ppm, 700 ppm, two levels of duration, 3 h (9:00-12:00), 6 h (9:00-15:00), and control (nonenrichment $CO_2$). Fresh weight of leaves increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Fresh weight of stem and root increased under longer exposure to $CO_2$, but decreased under higher $CO_2$ concentration. Total dry weight increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Combination treatment of longer exposure to $CO_2$ and higher $CO_2$ concentration showed the largest decrease of Root : Shoot dry weight ratio. The $700ppm{\times}6h$ treatment showed higher fruit number and yield than control. The results suggested that the growth under longer exposure to 400 ppm $CO_2$ was better than that under higher $CO_2$ concentration.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.334-342
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• 2016

In order to evaluate the modified installation methods of roof ventilation devices, derived from the previous experiment ('investigation into the optimum capacity of roof ventilation devices and their deployment'), the conventional and modified (improved) roof ventilation systems were installed in the single-span plastic greenhouse for growing oriental melons. The roof vents ($60{\varphi}$) and roof fans (maximum air capacity of $38m^3/min$) were installed in the spacing of 15m (FT, modified 'side vent+roof fan' ventilation) and 6m (TT, modified 'side vent+roof vent' ventilation) respectively on the roof of greenhouses for the modified roof ventilation treatments, and 20m (FC, conventional 'side vent+roof fan' ventilation) and 8m (TC, conventional 'side vent+roof vent' ventilation) for the conventional ones. The stem diameter, leaf blade lengh, petiole length, and leaf width were lower in the FT and TT treatments than those in the conventional treatments, FC and TC. Although the fruit weight and total yields were slightly lower in the FT and TT treatments, the marketable fruit ratio (%) were higher, as a result of increased fruiting ratio (%) in these treatments, than those of FC and TC. The marketable yields (kg/10a) in the FT and TT treatments were 8,391 kg/10a and 7,283 kg/10a, which were respectively 661 kg/10a and 487 kg/10a higher than those in the treatments of FC and TC. The modified installation methods of roof fan resulted in production of more female flowers and lower fruit drop ratio (%) compared to conventional meathods. In the treatment of the conventional ventilation with roof vent, the fruit weight, fruit length & width, and flesh thickness were higher than in other treatments, but there were no significant differences in the fruit width and flesh thickness among the treatments.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.306-316
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• 2006

In this study, the effect of the shade level, water flow rate applied to the shades and the temperature of water on the greenhouse cooling was investigated depending on the shade level of 0, 35, 55, 75%, and water flow rate and water temperature by the test on the small wooden frames to find out the low cost cooling method. With increasing of the dry bulb temperature of outside air, the dry bulb temperature in the wooden frames increased. For the frames with the shade and water, inside temperatures of the frames were lower of -0.2$\sim$-1.2$^{\circ}C$ than the temperature of the outside air and higher than the water temperature. For the frames without water, inside temperatures of the frames were higher of 1.7$\sim$4$^{\circ}C$ than the outside and not affected by the shade level very much. The water flow rate and the temperature of the water were not the important factors to decrease the inside temperatures in the frames. The black globe temperature became lower with increasing of shade level. The shade frames with water curtain showed the best cooling effect because of reducing thermal radiation and cooling the plastic film cover. The surface temperatures of the plastic film cover for the water supplied modules became lower with increasing of the shade level. The relative humidity was decreased with the dry bulb temperature in the frame increasing and not affected by the dry bulb temperature of the outside air for the frames with the shade and water.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.57-62
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• 2015

Manual grafting is a labor-intensive operation and highly susceptible to human error. Development of grafting robot has been considered as an effective alternative to manual grafting. The study was conducted to investigate the grafting efficiency between the domestically produced automated grafting robot and traditional manual grafting performed in a commercial plug seedling greenhouse. Plug seedlings of pepper (Capsicum annuum L.) 'Buchon' and 'Anseongmatchum' were sown as scions and rootstocks, respectively on March 29, 2013. The grafting was performed by a grafting robot, amateur grafters, and professional grafters on May 31, 2013. After grafting, the seedling efficiencies and seedling characteristics were compared in terms of plant height, the number of success as well as failure of seedling grafts produced in an hour. The results showed that plant heights were most uniform in the grafts performed by the professionals that had a 0.6 cm difference whereas an uneven difference of 2.1 cm difference was observed in plug seedling grafted by an amateur. However, plug seedlings grafted by the grafting robot were found to be uniform with 1 cm plant height difference. Moreover, the maximum number of grafting processed plug seedlings per hour (667 plants) was achieved by the grafting robot on compared with the seedlings grafted (466 plants) by the professionals. Furthermore, the least failure rate of 21.7% was noted upon the usage of grafting robot than the manual grafters. Thus, the results demonstrate that the technology of automated grafting robots is the most appealing and can be employed in commercial plug seedling greenhouses to overcome the drawbacks of manual grafting.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.424-432
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• 2016

This experiment was carried out to compare growth and fruit setting characteristics in ten winter-planted paprika (Capsicim annuum L.) cultivars. Five red line paprika cultivars ('Maduro', 'Maranello', 'Nagano', 'Sirocco' and 'Special') and five yellow line paprika cultivars ('Coletti', 'Sven', 'Thialf', 'Volante' and 'Zagato') were used for this study. The experiment was performed for 42 weeks, from winter of 2013 to autumn of 2014. Based on the growth stages of paprika, growth characteristics were investigated six times, and each investigation was categorized from group 1 through group 6. The relative internode ratio showed a normal range at the early growth stage, but tended to gradually decline as growth progressed. This trend was greater in red line paprika than in yellow line paprika. Among the cultivars used for this experiment, 'Special' and 'Zagato' showed growth inhibition, whereas 'Maranello' and 'Volante' kept a balanced growth during summer cultivation. The fruit set percentage in yellow paprika was 10.8% higher than in red paprika, while the number of branches in yellow paprika was 4.1% less than in red paprika. When measured after the full fruiting age, from June to July, the number of fruit set in group 4 was much lower in 'Sirocco' and 'Coletti' than in any of the other cultivars, indicating that they were more sensitive to the growth environment during the rainy season. These findings suggest that 'Maranello', 'Nagano', 'Sven', 'Thialf', and 'Volante' could be effectively used for summer cultivation in a high-plastic-film greenhouse, and 'Maranello', 'Special', 'Volante', and 'Zagato' could be good candidates for a low-plastic-film greenhouse.

• FLOWER RESEARCH JOURNAL
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• v.19 no.3
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• pp.144-150
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• 2011

This study was carried out to develop the soil amendment practice by phosphate solubilizing bacteria application in greenhouse chrysanthemum cultivation area with high salt accumulation. The experimental site (ShinWoo Flower, GwangJu) has been cultivated chrysanthemum for 15 years and showed significant salt accumulation. The phosphate solubilizing bacteria, Pseudomonas putida (KSJ11), Acinetobacter calcoaceticus (KSJ3) and Acinetobacter calcoaceticus (WP20) formulated on vermiculite for easy use, were applicated. Each 250L of phosphate solubilizing bacteria was applied for $82m^2$ before planting. Acinetobacter calcoaceticus (KSJ3; WP20) increased the amount of soluble phosphorus in an effective level. Particularly, Acinetobacter calcoaceticus (WP20) increased not only the level of soluble phosphorus but also potassium, calcium and magnesium resulting in the increase of EC in the soil. The level of nematode was also decreased with the non-treated increased. As a result, we suggest that selected phosphate solubilizing bacteria (WP20) could be a useful practice for soil amendment in chrysanthemum plantation soil and provided an opportunity to reduce the use of the fertilizer during the cultivation period.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.175-182
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• 2021

This experiment was conducted to find out the possibility of use of reused rockwool and comparison of growth, productivity and quality of tomatoes according to the use of rockwool and coir medium. The experiment was conducted in an automatic controlled greenhouse at Andong National University, College of Life Science, located in Andong, Gyeongsangbuk-do.. As a result of the experiment, there was no difference in the number of leaves, plant height, and leaf area between treatments, and the crown diameter was slightly higher in rockwool medium, also there was no difference between reused rockwool and coir medium. Fruit productivity showed different responses depending on the cultivation environment, but there was no significant difference between rockwool, reused rockwool and coir medium. In addition, the quality of fruit was observed to be different according to the concentration of EC in the medium. Therefore, in tomato hydroponic cultivation, there was no difference in the type of medium in growth, productivity, fruit quality and the environmental and water management had a great effect, and it is expected that the reuse of rockwool will have a positive effect on the economic point of view.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.1-7
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• 2023

Understanding the light environment in greenhouse cultivation and the light utilization characteristics of crops is important in the study of photosynthesis and transpiration. Also, as the plant grows, the form of light utilization changes. Therefore, this study aims to develop a light extinction coefficient model reflecting the plant growth. To measure the extinction coefficient, five pyranometers were installed vertically according to the height of the plant, and the light intensity by height was collected every second during the entire growing season. According to each growth stage in the early, middle, and late stages, the difference between the top and bottom light intensity tended to increase to 69%, 72%, and 81%. When leaf area index and plant height increased, the extinction coefficient decreased, and it showed an exponential decay relationship. Three-dimensional model reflecting the two growth indexes, the paraboloid had the lowest RMSE of 1.340 and the highest regression constant of 0.968. Through this study, it was possible to predict the more precise light extinction coefficient during the growing period of plants. Furthermore, it is judged that this can be utilized for predicting and analyzing photosynthesis and transpiration according to the plant height.