Effect of Light Receiving rate on Growth and Quality of Ginseng Cultivated in Plastic House
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- Proceedings of the Plant Resources Society of Korea Conference
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- 2020.12a
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- pp.62-62
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- 2020
Ginseng is a shade-plant cultivated using shading facilities. However, at too low light levels, root growth is poor, and at high light levels, the destruction of chlorophyll reduces the photosynthesis efficiency due to leaf burn and early fall leaves. The ginseng has a lightsaturation point of 12,000~15,000 lux when grown at 15 to 20℃ and 9,500 lux at 25℃. This study was conducted to select the optimal light intensity of 3-year-old ginseng grown in blue-white film plastic house. The seeds were planted in the blue-white film plastic house with different light receiving rate (March 17, 2020). Between April and September, the average air temperature in the house was 20.4-20.7℃. Average soil temperature was 18.3℃-18.5℃. The chemical properties of the test soil was as follows. The pH level was 7.0-7.4, EC was 0.5-0.6 dS/m, OM was at the levels of 33.6-37.7 g/kg, P2O5 was 513.0-590.8 mg/kg, slightly higher than the allowable 400 mg/kg. The amount of light intensity, illuminance, and solar radiation in the blue-white film house was increased as the light-receiving rate increased and the amount of light intensity was found to be 9-14% compared to the open field, 8-13% illuminance and 9-14% solar irradiation respectively. The photosynthesis rate was the lowest at 3.1 µmolCO2/m2/s in the 9% light blue-white plastic house and 4.2 and 4.0 µmolCO2/m2/s in the 12% and 14% light blue-white plastic house, respectively. These results generally indicate that the photosynthesis of plants increases with the amount of light, but the ginseng has a lower light saturation point at high temperatures, and the higher the amount of light, the lower the photosynthetic efficiency. The SPAD (chlorophyll content) value decreased as the increase of light-receiving rate, and was the highest at 32.7 in 9% light blue-white plastic house. Ginseng germination started on April 11 and took 13-15 days to germinate. The overall germination rate was 82.9-85.8%. The plant height and length of stem were long in the 9% light-receiving plastic house. The diameter of stem was thick in the 12-14% light-receiving plastic house. In the 12% and 14% light-receiving plastic house, the length and diameter of taproot was long and thick, so the fresh weight of root per plant was 20 g or more, which was heavier than 16.9 g of the 9% light-receiving plastic house. The disease incidence (Alternaria blight, Gray mold and Damping-off etc.) rate were 0.9-2.7%. The incidence of Sclerotinia rot disease was 7.5-8.4%, and root rot was 0-20.0%. The incidence ratio of rusty root ginseng was 34.4-38.7% level, which was an increase from the previous year's 15% level.
In this study, we investigated the electromagnetic properties and microwave absorption characteristics of M-type hexagonal ferrites, which are known as millimeter-wave absorbing materials, according to their calcination temperature. The M-type ferrites synthesized using a molten salt-based sol-gel method exhibited a single-phase M-type crystal structure at calcination temperatures above 850℃. The synthesized particle size increased as well with the calcination temperature. Saturation magnetization increased gradually with increasing calcination temperature, but coercivity reached a maximum at 1050℃ and then rapidly decreased. After preparing a thermoplastic polyurethane (TPU) composite containing 70 wt% of M-type ferrites, we measured the complex permittivity and permeability in the Q-band (33-50 GHz) and V-band (50-75 GHz) frequency ranges, where ferromagnetic resonance occurred. Strong magnetic loss from ferromagnetic resonance occurred in the 50 GHz band for all composite samples. Based on the measured results, we calculated the reflection loss of the TPU/M-type ferrite composite. By calculating the reflection loss of the M-type ferrite composite, the M-type ferrite calcined at 1250℃ showed excellent electromagnetic wave absorption performance of more than -20 dB at 52 GHz with a thickness of about 0.5 mm.
To develope appropriate soil base for planting on the artificial ground, 9 kinds of soil types(varying the components and mixing ratios) and 3 levels of soil depths(10cm, 15cm, 20cm) were chosen. And their plant growing effects were tested and analysed from the test plant Zoysia japonica. The results of the research are as follows. 1. Among the 9 type of soil mixtures, the "sandy loam" soil type gave the worst effects on germination, disease contamination and ground covering. 2. The soil types like VSH(vermiculite20%+sand70%+humus sawdust10%), VSS(vermiculite 40%+sand 50%+humus sawdust 10%) and VS(vermiculite 70%+sand 30%), where vermiculite and sand were added to, show better germination effect promoted from the better condition of aeration and saturation. 3. The plant growing effects(leaf length and ground covering ratio) was evident under the soil types like VSH(vermiculite20%+sand70%+humus sawdust10%) and VSS(vermiculite40%+sand50%+humus sawdust10%), where organic matters were added to. 4. Vermiculite added soil types effect fast leaf decolorization on the tested Zoysia japonica plant, on the contrary to organic matter mixed soil types including SCS(sandy loam 50%+carbonized rice husk30%+sand20%) and SHS(sandy loam 50%+humus sawdust30%+sand20%) with which green leaves subsist longer. S. Soil depth effect to plant growth was found. And a favorable covering rate was accomplished even at the soil depth of 15cm - the limit soil depth for grass survival - from the soil types where organic matters were mixed to. From this result, the soil depth limit for plant survival could be said to be shall owed if appropriate soil type were based.
This study was conducted to investigate the effect of elevated carbon dioxide on the growth and physiological responses of peach 'Mihong' (Prunus persica). We simulated three different carbon dioxide conditions based on climate change scenarios RCP 8.5 in the sunlight phytotron rooms from April 22 to July 6, 2020; 400 µmol·mol-1(present condition), 700 µmol·mol-1 treatment(expecting carbon dioxide concentrations in mid-21st century), 940 µmol·mol-1 treatment (expecting carbon dioxide concentrations in late 21st century). The average of maximum photosynthesis rate at 700 µmol·mol-1(16.06 µmol·CO2·m-2·s-1) was higher than those at 400 µmol·mol-1(14.45 µmol·CO2·m-2·s-1) and 940 µmol·mol-1(15.96 µmol·CO2·m-2·s-1) from May 22 to July 2. However, stomatal conductances at 700 µmol·mol-1 and 940 µmol·mol-1 were lower than those at the control. Also, the carbon dioxide saturation point in all treatments was reduced from 1,200 µmol·mol-1 in the early stage of growth to 600-800 µmol·mol-1 in the late stage of growth. The stomatal densities were decreased as carbon dioxide increased. The shoot lengths were decreased while the carbon dioxide was increased, but the increase of trunk diameter and leaf areas, shoot numbers were not statistically different. The fruit weight at 700 µmol·mol-1(152.5 g) was higher than those at the control(141.8 g) and 940 µmol·mol-1(147.4 g). The soluble solids were higher at 700 µmol·mol-1, 940 µmol·mol-1 compared to the control. These results suggest that a carbon dioxide elevated to 700 µmol·mol-1 in the future may give a positive effect on the yield and fruit quality of peach 'Mihong' while a carbon dioxide elevated above 940 µmol·mol-1 may affect negatively such as early senescence and loss of fruit set.
Introduction: Diffusion is process by which an innovation is communicated through certain channel overtime among the members of a social system(Rogers 1983). Bass(1969) suggested the Bass model describing diffusion process. The Bass model assumes potential adopters of innovation are influenced by mass-media and word-of-mouth from communication with previous adopters. Various expansions of the Bass model have been conducted. Some of them proposed a third factor affecting diffusion. Others proposed multinational diffusion model and it stressed interactive effect on diffusion among several countries. We add a spatial factor in the Bass model as a third communication factor. Because of situation where we can not control the interaction between markets, we need to consider that diffusion within certain market can be influenced by diffusion in contiguous market. The process that certain type of retail extends is a result that particular market can be described by the retail life cycle. Diffusion of retail has pattern following three phases of spatial diffusion: adoption of innovation happens in near the diffusion center first, spreads to the vicinity of the diffusing center and then adoption of innovation is completed in peripheral areas in saturation stage. So we expect spatial effect to be important to describe diffusion of domestic discount store. We define a spatial diffusion model using multinational diffusion model and apply it to the diffusion of discount store. Modeling: In this paper, we define a spatial diffusion model and apply it to the diffusion of discount store. To define a spatial diffusion model, we expand learning model(Kumar and Krishnan 2002) and separate diffusion process in diffusion center(market A) from diffusion process in the vicinity of the diffusing center(market B). The proposed spatial diffusion model is shown in equation (1a) and (1b). Equation (1a) is the diffusion process in diffusion center and equation (1b) is one in the vicinity of the diffusing center.