• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.61-66
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• 2004

To investigate the effect of charcoal on the physico-chemical characteristics in the growing media and the growth of oriental melon, six treatment, 0%, 10%, 20%, 30%, 40%, and 50% charcoal, were added into the growing media, Baroker. The value of pH in the charcoal contained growing media (CGM) was recorded higher and further increased by raising the charcoal ratio and by growing period. In 20% CGM, the range of pH was adequate to grow crop as 5.2${\sim}$5.8. Contents of Ca and K in CGM increased by raising the ratio of charcoal, while contents of Mg and Na decreased. The growth of oriental melon seedlings in 20% and 30% CGM was better than in other treatments, in terms of fresh and dry weight of shoot, plant height, leaf area, lear width and relative growth rate. Both the physico-chemical properties of growing media and the growth of oriental melon seedlings were changed by the addition of charcoal. These results suggest that charcoal can be used as mixing material with other potting media for producing the seedling of good quality.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.21-25
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• 2004

This experiment was carried out to investigate the effect of apex removal at different leaf ages on the growth and yield of broccoli in pinching cultivation. Apex was pinched when 2, 3 or 4 true leaves were spread during nursery bed, and non-pinching was conventional method. The plant height was not different among treatments but the fresh weight was decreased as the pinching days were delayed. The numbers of leaves and lateral shoots were increased compared to those of non-pinching by pinching. Days to central budding were shortended by 3 days when pinched at 2 true leaves spreading stage than those of non-pinching. Central (1st) head weight was heaviest when pinched at the time of 2 true leaves spreading (157g). Total head weight was heaviest when pinched at the time of 2 true leaves spreading (378g), and lowest at 4 true leaves spreading stage (196g). Marketable yields were increased by 48% when pinched at the time of 2 true leaves spreading (1,754kg) as compared with those of non-pinching (1,184kg) and lowest when pinched at the time of 4 true leaves spreading (820kg). Also, first harvest was shortended by 6 days by pinching at 2 true leaves spreading stage.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.107-111
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• 2008

This experiment was carried out to examine the effect of silicate on the rooting of cuttings and growth of cut chrysanthemum. In the first experiment, cuttings of chrysanthemum 'Pink Pixie Time' were grown in a 3 L medium which was supplemented with silicate at 0, 30, 60, or 90 g for examination of its effect on rooting of cuttings. In the second experiment, chrysanthemum 'Backwang' was grown in medium supplemented with silicate at 0, 60, 90, 120 or 240 g per 20 L medium. In the first experiment, the promotional effect of silicate increased with increasing silicate concentration in the medium, resulting in increased length of shoot and root. However, root dry and fresh weights were not affected by silicate concentration in the medium. In the second experiment, number of branches, plant height, number of nodes, and stem diameter in the silicate-supplemented treatments were greater than those in the control. However, dry matter was not affected significantly by silicate concentration in the medium. Fresh weights of the leaf, stem and root in the silicate-supplemented treatments were greater than those in the control.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.211-217
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• 2008

To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1731-1738
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• 2021

The objective of this study was to extract individual trees and tree heights using UAV drone images. The study site was Gongju national university experiment forest, located in Yesan-gun, Chungcheongnam-do. The thinning intensity study sites consisted of 40% thinning, 20% thinning, 10% thinning and control. The image was filmed by using the "Mavic Pro 2" model of DJI company, and the altitude of the photo shoot was set at 80% of the overlay between 180m pictures. In order to prevent image distortion, a ground reference point was installed and the end lap and side lap were set to 80%. Tree heights were extracted using Digital Surface Model (DSM) and Digital Terrain Model (DTM), and individual trees were split and extracted using object-based analysis. As a result of individual tree extraction, thinning 40% stands showed the highest extraction rate of 109.1%, while thinning 20% showed 87.1%, thinning 10% showed 63.5%, and control sites showed 56.0% of accuracy. As a result of tree height extraction, thinning 40% showed 1.43m error compared with field survey data, while thinning 20% showed 1.73 m, thinning 10% showed 1.88 m, and control sites showed the largest error of 2.22 m.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.511-519
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• 2020

For camera calibration, a checkerboard is generally used to determine the principal point, focal length, and lens distortions. The checkerboard has a planar and three-dimensional shape, and camera calibration parameters are affected by the size of the checkerboard, the placement of the target, and the number of target points. In this study, the accuracies of the types of checkerboards were compared using checkpoints for stereo camera calibration, and the purpose of this study was to propose the best performance checkerboard. The checkerboard with large flat shape showed comparatively high accuracy through comparison with the check points. However, due to the size of the checkerboard, it was inconvenient to move and rotate, and there was a disadvantage in that it was difficult to shoot so that the target points could all appear in the stereo camera. The checkerboard, which was manufactured in a small size in a flat shape, was easy to move and rotate but had the lowest three-dimensional accuracy. The checkerboard with targets with height values had the hassle of having to determine the three-dimensional coordinates of the target points by using observation equipment for camera calibration, but it was small in size, convenient to move and rotate, and showed the highest three-dimensional accuracy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.57-64
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• 1991

This experiment was conducted to elucidate the effect of plant growth regulators (PGR) on the root -mat formation of infant seedling (8- to 10-day-old seedling) of rice in machine transplanting. The rice seeds of Odaebyeo were socked in water with different concentrations of PGRs for 48 hours at room temperature. Seeding rate was 220 g per seed tray (30x60x3cm). Metalaxyl (25% wettable powder) was used for a fungicide. Generally, the metalaxyl-treated seeds markedly promoted the root growth of the rice seedling, while tetracy-cle, pachlobutrazol and NTN -821 reduced the seedling height and root length, and thickened the shoot diameter at higher concentation levels. Tetracycle decreased root length of the rice seedlings but increased root number per seedling, and root-mat formation was poor. Whereas, metalaxyl concentrations of 200 and 1,000 ppm markedly increased root length and number of root hairs without decreasing root number, thus root-mat formation was excellent. The optimum concentration of metalaxyl seed treatment to increase the root-mat formation of infant seedling of rice was about 200 ppm. Metalaxyl seed treatment could be advanced one to two days of the duration of root-mat formation compared with control.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.19-26
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• 2011

The machine transplanted rice has highly extended in the Republic of Korea due to a wage rise since 1976 and thus rice seedling raising nursery method has shifted from field into polyethylene film house. The rice seedling grown under a polyethylene film house was weak and tall because of limited sunlight and wind and so there was so complained among rice growing farmers in terms of missing hill and broken seedling after machine transplanting. In recent iron-coated seedling has reported on healthier and stronger than that of polyethylene film house. These seedlings were more stiff and thus more easy to handle during transplanting and less missing hills. The Iron-coated seed was proven to more stiff like seedling height, root growth and weight of shoot and root growth. This was more convenient during transfer of seedling raising box im machine transplanting. Thus, this study was carried out to grow a stiff and healthy seedling growth and development for machine transplanting. There were a normal seed germination and sprouting after iron-coated seeds treatment and this seedling was smaller and stiffer than that of untreated control. The leaf number and root growth of seedling which was iron-coated seeds would be better and total seedling fresh weight was greater than that of untreated control.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.408-417
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• 2023

This study aimed to investigate the effects of an aquaponics system utilizing catfish recirculating water on the growth and water quality in lettuce and chicory cultivation. After 60 d of catfish cultivation in the BFT-AP, the survival rate was 96.0% and average weight gain was 178.5 g. The WGR grew by 241.4% and the SGR was 3.0%. A comparison between lettuce and chicory cultivation using BFT-AP and hydroponics revealed significant increases in shoot height, leaf count per week, and biomass of the cultivated lettuce and chicory. The SPAD values also increased significantly by 15.4-43.3%. Water quality analysis of the BFT-AP systems and crop cultivation beds showed significant differences, except for K and Na. The average NO₃^- concentration in the sediment pond was significantly higher at 45.3±1.0. Comparison of water temperature, pH, EC, DO, and ORP in the BFT-AP system and crop cultivation beds revealed similar monthly water temperatures from July to September. The pH in the catfish culture pond was 0.3-1.2 lower than that in the crop cultivation beds, and the EC was approximately 0.01- 0.03 dS/m lower in the catfish culture pond than the crop cultivation beds. The monthly average ORP in the catfish culture bed steadily increased to 479.9 mV in October. Bacillus velezensis (AFB2-2) and Chlorella fusca (CF) were applied to the biological activation bed; the population density of CF showed a continuous increase, whereas that of AFB2-2 decreased after 15 d and gradually increased thereafter. Thus, the application of the recirculating aquaponics cultivation technology with catfish (BFT) enhances catfish cultivation and promotes the growth of lettuce and chicory. Therefore, it is considered suitable for the environment-friendly cultivation of lettuce and chicory.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.353-358
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• 2023

This study aimed to investigate the growth and phenol content changes of basil (Ocimum basilicum L.) under five different light intensities and photoperiods, maintaining the same Daily Light Integral (DLI) conditions in a plant factory. Basil seeds were sown on a rockwool medium for four weeks and then transplanted. To maintain a DLI 17mol·m^-2·d^-1, light intensity and photoperiod were set at 16h-295, 18h-260, 20h-235, 22h-215, and 24h-200μmol·m^-2·s^-1 and cultivated for four weeks. The harvested results showed that basil plant height, number of lateral branches, and leaf number tended to decrease from the 16h-295 treatment to the 24h-200 treatment. Shoot fresh weight, dry weight, leaf area, leaf width, and leaf length were significantly higher in the 18 h-260 treatment. The total phenolic contents in the 18h-260 treatment was significantly higher by 51.3%, 172.7%, 111%, and 119.7% compared to the 16h-295, 20h-235, 22h-215, and 24h-200 treatments, respectively. Therefore, it is anticipated that cultivating basil under the condition of 18h-260 treatment could yield enhanced growth quality and an increase in total phenolic contents.