• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.358-365
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• 2019

An agrivoltaic systems (AVS) is mixed systems associating photovoltaic panels (PVPs) and crop cultivation at the same time on the given land area. It is receiving attention to improve rural economy. However, it is likely that, the crop yield should be decreased due to the reduced absorption of solar radiation by leaves. Thus, before popularizing the AVS, it is necessary to comprehend the degree of shading by PVPs in AVS. In this study, the change of radiation condition under AVS mimic shading net was investigated. The minimum and maximum of difference of photosynthetically active radiation (PAR) between under and outside shading net were 3.03 mol/㎡/day on a cloudy day and 17.08 mol/㎡/day on a sunny day. This difference decreased when the ratio of diffuse irradiance to global irradiance increased. Such a shading effect resulted in the increase of rice height and decrease of rice tillering.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.247-252
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• 2014

The study was conducted to investigate the effect of shading treatment on the uniform primordium formation and development of fruit body during incubation of major cultivated oyster mushrooms (Pleurotus ostreatus). Oyster mushrooms cultivars Suhan No. 1 and Gonji No. 7 were incubated while shading during different times in the incubation room wherein temperature of $20^{\circ}C$ was maintained. Substrate temperature during incubation was increased to $24{\sim}25^{\circ}C$ in 11~12 days for Suhan No. 1 and to $25{\sim}26^{\circ}C$ in 11~12 days for Gonji No. 7 regardless of shading times. The $CO_2$ generation was the highest as 9~11% for Suhan No. 1 and 9~10% for Gonji No. 7 at the time of temperature increase the highest, while $O_2$contents became decreased, thus constructed good environment for the growth of hyphae. Therefore, ratio of ununiformal primordia formation was reduced by 20% as against control for Suhan No. 1 and by 13% for Gonji No. 7 when shading was applied from $10^{th}$ day of inoculation with no difference in fruit body yield.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.218-229
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• 1987

This study was carried out to investigate all the parts' weight growth under the different light intensity and root-cutting. As results : ${\cdot}$ Fresh and dry weight of leaf, shoot, root and seedling treated under 63% R.L.I showed the largest growth. ${\cdot}$ The largest growth in fresh and dry weight of shoot arid seedling appeared at 1/4 root cutting plot. ${\cdot}$ The value of T/R ratio was increased in low light intensity and high root-cutting. ${\cdot}$ The simple nonlinear relationship between light intensity, root-cutting and T/R ratio was recognized, respectively.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.178-186
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• 2015

This study was carried out to determine the effects of environment controls (temperature and shading level) on germination responses and early growth of Allium thunbergii. Germination experiment was performed by pre-treatment (with low temperature and wetting treatments for 0, 20, 40 and 60 days) and temperature controls (5, 10, 15, 20, 25 and 30). And growth experiment was performed by containers (128 and 200 cavities containers) and shading level (full sunlight (control), 35%, 50% and 75% shading). Germination rate of A. thunbergii seeds were, 20 days of seed pre-treatment, the highest at $10^{\circ}C$ (81.7%) and the more temperature went up, the more germination rate went down. As a result of surveying container and shading treatments, the height, leaf area, leaf length, leaf aspect ratio (L/W) were higher under 50% shading of 128 (24.2cm, $2.76cm^2$, 22.3cm and 223.4, respectively) and 200 (22.6cm, $2.29cm^2$, 19.4cm and 190.5, respectively) cavities container. The root was grown well under full sunlight. Specially, fresh weight of shoot (leaves+stem) was higher under 50% shading of 128 (0.241g) and 200 (0.212g) cavities container. As a result of surveying the whole experiment, A. thunbergii seeds need to pre-treatment (with low temperature and wetting treatments for 20~40 days) for high germination rate. And it is judged better growth and higher yield by maintaining 50% shading of 200 cavities container.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.101-105
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• 1997

Most of the mulberry saplings in Korea have been produced by grafting. But the production of mulberry sapling by this method is very complex process and requires high level of technique and two years to produce saplings. Therefore, to develop the mulberry sapling production system by softwood cutting method which is suitable for mass production, several conditions on rooting and growth of cuttings were investigated. The rooting ability of cuttings varied according to mulberry varieties, showing the highest rooting ratio of 93.3% in cultivar of Shingwangppong. Of different soil texture as for rooting media, the clay was found to be the best; other media decreased in order as follows; sand, sand loam and vermiculite. The shading ratio by 70% with polyethylene film showed the highest rooting ratio of the cuttings. Optimum day of cutting was around 50th day after sprouting, whereas the ratio of stem thicker than 7mm at the base of saplings in diameter was highest at 44th day.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.183-188
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• 1975

Effects of air temperature and 50% shading for 20 days at each growth stages (from 33days before heading, from heading and from 20days after heading) on the productivity of Tongil (IR667-Suweon 214) and Jinheung rice (Oriza sativa.) were as follows. 1. Shading decreased yield by 48, 98 and 18% for Tongil and 73.71 and 12% for Jinheung during ear formation, heading and milky stage, respectively. 2. Shading most severely affected filled-grain ratio in both varieties except shading during milky stage of Jinheung that more affected grain weight. 3. Optimum mean air temperature for maximum crop growth rate appears to be $25^{\circ}C$ and clitical temperature $22^{\circ}C$ for Tongil but these for Jinheung seem to be lower. Solar radiation greater than $300cal/cm^2$ day appears to be enough. 4. Maximum crop growth rate of Tongil always advanced that of Jinheung. 5. Tropical Tongil variety appeared to be more tolerant to high temperature and low solar radiation before heading than temperate Jinheung. Thus Tongil will be more productively adapted to the high temperature-low solar radiation period in rice season which mostly overlaps with ear formation stage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.2
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• pp.79-89
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• 2012

This study was conducted to investigate the chlorophyll contents, photosynthetic characteristics, chlorophyll fluorescence, and growth performance of Parasenecio firmus under changing light environment. Parasenecio firmus was grown under non-treated (full sunlight) and three different shading conditions (88~93%, 65~75% and 45%~55% of full sunlight) for the experiment. Total chlorophyll content, photochemical efficiency (Fv/Fm), T/R ratio, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) were increased with increasing shading level, but decreased dark respiration. Therefore, light absorption and light utilization efficiency were improved under the low intensity light. Plants under 65~75% of full sunlight had best maximum photosynthetic rate and net apparent quantum yield in May. On the other hand, the non-treated plants had lower maximum photosynthetic rate, photochemical efficiency, and chlorophyll content than the treated ones. Parasenecio firmus considered to be a sciophyte, is fairly sensitive to high intensity light. If 88-93% of full sunlight lasts for a long period, photosynthetic capacity will be sharply decreased, though limiting light. These results suggest that growth of Parasenecio firmus adapted to 65~75% of full sunlight.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.68-74
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• 2010

The present study was conducted to investigate growth performance and ascorbic acid contents of Allium victorialis var. platyphyllum, Ligularia fischeri, and L. stenocephala growing under four different light intensity regimes (full sun, and 64~73%, 35~42%, 9~16% of full sun). The leaf area and total biomass of Allium victorialis var. platyphyllum were highest in 35~42% of the full sun. However, the leaf area and total biomass were highest in 64~73% of the full sun in Ligularia fischeri, and L. stenocephala. The leaf thickness decreased with increasing shading in all three wild vegetables. The growth of root comparing to that of shoot decreased as shading increased, and as the result, the ratio of shoot biomass to root biomass increased. Ascorbic acid contents were higher in Allium victorialis var. platyphyllum than in Ligularia fischeri and L. stenocephala. Allium victorialis var. platyphyllum showed the highest contents of ascorbic acid in 35~42% of full sun. Whereas Ligularia fischeri and L. stenocephala showed the highest in 64~73% of full sun.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.181-188
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• 2020

This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

• Journal of Korea Foresty Energy
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• v.19 no.1
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• pp.20-29
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• 2000

This study was carried out to investigate the effects of shading on the growth of 1 -year-old seedlings of Cornus controversa. The height growth was highest in relative light intensities of 100% and 50%, but relative growth rate in 50% was higher than that in 100% treatment. The growth did not occur under 9% relative light intensity. The root collar diameter growth at different light intensities is similar to height growth. The leaf area was highest in 50% relative light intensity, and the leaf area under the light intensity was small compared with the control. SLA and LAI of seedlings increased with decreasing relative light intensity. The LAR and LWR of seedlings increased with decreasing light intensity, but LWR decreased at 9% relative light intensity. The dry weight of root, stem, leaf and branch, and the number of branch and leaf decreased with decreasing relative light intensity. T/R ratio was highest in 17% and 30% relative light intensity. Lateral root growth decreased with decreasing light intensity except for that in 50% light intensity.