• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.547-555
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• 2014

This study was carried out in order to investigate the germination and the early growth characteristics of Parasenecio firmus. Seed pre-treatment before the each experiment was carried out by shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 48 hours). Experiment was performed by shading treatment (full sunlight, 35%, 50%, 75%, and 95% shading). Seeds of Parasenecio firmus were surveyed the highest germination rate (61.1%) in full sunlight with WS (overall 25.7~61.1%). Height was surveyed the highest under 95% shading. And root collar diameter was surveyed the highest in full sunlight. Fresh weights (leaf, shoot, root and total) were the highest under 50% shading. Dry weights (leaf, shoot and total) were the highest under 75% shading. It was indicated the lowest leaf, shoot, root and total under 95% shading. Leaf growth (leaf area, leaf length, leaf width and leaf thickness) and root growth (total root length, root project area, root surface area, root diameter and root volume) were good under 35%~75% shading, but the lowest under 95% shading. As a result of surveying the whole experiment, seed of Parasenecio firmus grows well under 50%~75% shading after germination by high sunlight with water soaking (WS).

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.388-394
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• 2007

To product the edible fresh shoots of Sedum sarmentosum in summer season, 4 local strains were cultivated with cutting propagation under 0, 30, 50, 70, 90% shading. Effect of shading on shoot growth, leaf chroma value, SPAD value, and bitterness were investigated at 35 days after cutting. Plant height, the number of node and leaf stem diameter in $30{\sim}90%$ shading were increased than in the control, and Pohang local strain had little-overgrowth shoot, thicker stem, a few brenches per shoot, and larger leaf compared to the other local strains. Fresh and dry weight under shading were increased than in the control, dry weight of pohang local strain was highest in 50% shading. Hunter L and b values were decreased out of proportion to higher shading rate. SPAD value in $50{\sim}90%$ shading was significantly lower than in the control. The bitterness of fresh shoot was decreased out of proportion to higher shading rate. In Summer season, producing the fresh shoot of S. sarmentosum was excellent in 50% shading, and Pohang local strain among 4 local strains was more stable and good in yield and quality under shading.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.146-154
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• 2014

In the result of effect on freezing damage reduction by the shade net colors and the shade rate to tea trees during wintering period, the high shade ratio decreased tea trees growth and increased freezing damage and 55% of shade ratio based on non treatment developed new leafs and green leaf productivity. By the shade net colors, colorless shade net (55% of shade type) treatment and green shade net treatment increased green leaf productivity and decreased damaged area compare to non treatment shade net and black shade net treatment. Colorless net shade treatment reduced over 50% of freezing damage and increased (10a) 68 kg for green leaf productivity compare to non treatment shade net. The colors of shade net treatments for reduction freezing damaged in order of Black < Green < Colorless but reduction of freezing damage was so high. In the relative microclimates, treatment shade nets were $0.7^{\circ}C$ lower, average relatively humidity 14.9% higher, soil temperature $0.6^{\circ}C$ lower and soil moisture 4.6% higher than non treatment shade net. And treatment shade nets decreased average wind speed 0.7 m/s and it showed us treatment net shades effected to excessive evapotranspiration and soil dry by wind and considered one of good solution for freezing damages.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.153-160
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• 2008

This experiment was conducted to find out an adequate shading level (0, 55, 74, and 95%) on the shoot growth of rooted cuttings of native Hydrangea serrata for. acuminata. New shoot height (NSH), length and width of leaf, and stem diameter under 55% shading were the greatest. Net photosynthetic rate under 55% shading was the greatest, while intercellular $CO_2$ concentration was the least in this treatment. The greatest content of photosynthetic pigments (total chlorophyll, carotenoid) was observed in leaves grown under a 74%, followed by a 55% shading level. Leaf stomata were observed on the abaxial surface, but those on adaxial surface in all shading treatments were not observed. In 95% shading, decreased stomatal density and development were observed. Higher stomatal density and development, however, were observed in 55% shading. Therefore, it is concluded that a 55% shading level was the optimum for growth of new shoots of rooted cuttings of native H. serrata for. acuminata.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.403-408
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• 2010

This study was carried out to investigate the physiological responses of $Rhododendron$ $mucronulatum$ Turcz. and $R.$ $indicum$ (L.) Sweet seedlings with 0%, 35%, 55% and 75% shading of full sunlight in polyethylene film house. The shading treatments were performed during the late growth season for each species (from Sept. 9 to Nov. 5, 2008). The shading treatment was effective in reducing the daily temperature by 0.9 to $1.7^{\circ}C$ during September and by 0.8 to $1.7^{\circ}C$ during October. Before the shading treatments, the water content of $R.$ $mucronulatum$ and $R.$ $indicum$ amounted to 68.5% and 66.3%, respectively. The water contents of two species after 75% shading treatment period decreased to 66.2% (3.4% reduction) and 65.9% (0.6% reduction), respectively. Notably, both species had a similar tendency indicating less reduction rate of water content with 75% shading. $R.$ $indicum$ showed higher photosynthetic capacity with higher level of shading, and its photosynthetic capacity reached the highest level ($9.63{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). On the other hand, shading-treated $R.$ $indicum$ showed higher intercellular $CO_2$ concentration, stomatal conductance and transpiration rate (55% shading > 35% shading > 75% shading) than non-treated ones. In addition, non-treated seedlings showed higher water use efficiency than treated ones. In particular, it was found that the leaf color of $R.$ $mucronulatum$ turned equivalent to purple under full sunlight, while its leaf color kept equivalent more to green with higher level of shading, as evidenced even in naked eyes. According to comprehensive analysis using Munsell Color Chart on potential leaf color variations of $R.$ $mucronulatum$ depending on the level of shading, it was found that relatively many leaf colors under full sunlight were equivalent to R (red) and Y (yellow) chart, while relatively many leaf colors with higher level of shading were equivalent to G (green) and Y chart, where the latter still showed green color.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.146-154
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• 2021

This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to the growing season of the typical viscous sweetpotato 'Hogammi' and the powdery sweetpotato 'Jinyulmi'. Shading was provided using commercially available shading nets (55% and 75% shading level), and the treatments were applied at the following stages of storage root growth: SFS: the storage root formation stage (planting-50^th day), SSS: the storage root swelling stage (50-90^th day), and SAS: the storage root actively swelling Stage (90-120^th day). The growth characteristics according to shading treatments during each growth period, the number of tubers obtained at harvest, and sugar contents were investigated. For both assessed cultivars, there was no significant difference between the control group and the 55% shading treated group with respect to the maximum quantum yield (Fv/Fm) of photosystem II under different shading treatments, whereas the 75% shading group showed slightly higher values than the control group. In both cultivars, the contents of chlorophyll a and b tended to increase in plants subjected to shading treatments compared with the control plants, particularly that of chlorophyll b. Compared with the control group, the chlorophyll b content of 'Hogammi' subjected to 55% and 75% shading increased by 47% and 41%, respectively, whereas that of 'Jinyulmi' increased by 39% and 34%, respectively. We also detected reductions in the dry weights of the above- and belowground parts of the two varieties in response to shading compared with the control, with the reduction in the dry weight of belowground parts being significant. Furthermore, in both varieties, the T/R rate tended to increase in response to shading treatment. Owing to the lack of sunlight, both cultivars tended to suppress the formation and enlargement of tuber roots. Consequently, post-harvest yield analysis revealed that under shading treatments, both cultivars were characterized by poor tuber root growth according to growing season, with the yield of 'Hogammi' showing a greater reduction compared with that of 'Jinyulmi'. In addition, we found that the higher shading level also significantly reduced yields. Compared with the storage root formation and storage root actively swelling stages, shading treatments during the storage root swelling stage significantly affected yield reduction in both varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.1-11
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• 2007

Light is an environmental component inevitably regulating photosynthesis and photo-morphogenesis, which are involved in the plant growth and development. Studies were conducted at the International Rice Research Institute, Philippines in 2004 and 2005, with aims to investigate 1) morphological responses of rice plants to low radiation, 2) morphological alteration of shade-grown plants when exposed to high light intensity, and 3) photosynthetic responses of shade-grown rice plants. Reduction in solar radiation by 40% induced increases in the area on a single leaf basis, biomass partitioning to leaves, and chlorophyll meter readings but brought about retardation of tiller development and decrease in above-ground biomass production of rice varieties. When the shade-grown plants from two weeks of transplanting to panicle initiation were exposed to full solar radiation after panicle initiation, they demonstrated less increase in chlorophyll meter readings and more decrease in leaf nitrogen concentrations from panicle initiation to flowering than control plants that were grown under the ambient solar radiation for whole growth period after transplanting. Shade-grown rice plants exhibited lower carbon assimilation rates but higher internal $CO_2$ concentrations on a single leaf basis than control plants, when measurements for shade-grown rice plants were made under the shading treatments. But when the measurements for shade-grown plants were made under the full solar radiation, light-saturated carbon assimilation rates were similar to control plants. Response of photosynthetic rates to varying light intensities was not considerably different between shading treatments and control. Yield reduction was observed in the shading treatments from panicle initiation to flowering and from flowering to physiological maturity, mainly by less spikelets per panicle and poor grain filling, respectively.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.321-326
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• 2003

This study was conducted to investigate and effects of shading treatment on photosynthetic activity of Acanthopanax senticosus. We investigated plant growth, light response curve and A-Ci curve to photosynthesis of A. senticosus at 55%, 75%, and 90% shading treatment. As results, the ratio of above-ground/under-ground biomass was increased at 75% shaded condition and showed highest dry biomass. Under shaded conditions, plants had lower chlorophyll a+b content and a/b ratio and also showed thinner leave. But shaded plants showed higher leaf area and higher total leaf area per a plant. This apparently indicates adapted responses to shaded treatment. Effects of shading treatments on photosynthetic activity were higher in apparent quantum yield, carboxylation efficiency, re-phosphrylation but lower in light compensation point. These results suggested that higher photosynthesis rates in shaded treatments were due to activated carboxylation efficiency. Shading treatment had lower water use efficiency thatn controls but still higher than other tree species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.87-91
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• 2016

Recently, rice growth and production have been influenced by climatic change worldwide. In particular, under low solar radiation and cloudy weather, rice plants show abnormal physiological responses. In this experiment, plants of the rice cultivar Samgwangbyeo grown 40% and 70% shading and natural conditions at the primordium initiation stage (PI) for 30 days and the booting stage for 10 days up to heading were compared. After shading treatments, culm lengths were significnatly longer than that in natural condition plots, and panicle lengths were shorter in the 40% and 70% shading treatment plots compared to control plots. After heading, the production of dry matter treated at the PI stage was significantly lower than that at the booting stage. SPAD values of the leaf color and N concentration of leaves treated with shading were greater than those under natural conditions. In the shading treatment, the lodging index at 20 days after heading was significantly higher than that in natural condition. For yield components, number of panicles, spikelet number per panicle, and ripened grain ratio significantly decreased with shading treatment; thus, rice yield decreased significantly. For rice quality, the protein content of the head rice treated with shading was significantly higher than that in the control plot, but the amylose content of rice treated with shading was signifiantly lower than that in rice in control plots.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.50-50
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• 2019

잇꽃(Carthamus tinctorius L.)은 국화과에 속하는 두해살이 초본 식물로 한자명은 홍화(紅花), 영명으로는 Safflower를 사용하고 있다. 잇꽃의 원산지는 이집트, 아프카니스탄 등의 서남아시아가 원산지로 알려져 있으며, 우리나라의 잇꽃 재배면적은 2010년 39 ha 수준이 재배되다가 2016년에는 67 ha로 재배면적이 증가한 것으로 보고되고 있다. 우리나라에서 잇꽃 이용은 잇꽃 종실을 위주로 이용되고 있으나 일본의 경우 잇꽃의 경관적 가치를 활용하여 산형현(山形縣)에서는 홍화축제가 매년 개최되고 있으며, 미국 등에서는 잇꽃의 저온압착유가 기능성 건강식품류로 판매되고 있다. 본 연구는 일조시수가 짧은 표고 500 m의 준고랭지에서 잇꽃의 경관적 가치 활용도를 평가하기 위해 차광조건에 따른 개화특성 및 종실 수량성을 평가하기 위해 수행되었다. 비가림 하우스에서 5월 9일 파종후 생육 54일차인 7월 5일 개화기에 지상부 발육량을 조사한 결과 차괄비율이 강해질수록 엽장폭비가 감소하여 세장형에서 장타원형으로 성장함을 알수 있었고, 분지수는 30% 차광조건에서 증가하는 경향을 보였다. 같은 시기에 조사한 엽면적에서는 30% 차광에서 증가하다가 차광비율이 높아질수록 감소하였으며, 식물체당 총 착화수는 30% 차광조건에서 20.3화/주로 가장 많았고 2차 화경의 착화수도 많은 경향을 보였다. 착생된 꽃의 개화단계를 3등급으로 구분하여 비율을 조사한 결과 차광 조건에서는 개화 2, 3단계의 비율이 무차광에 비해 낮아 개화가 지연됨을 알수 있었고, 건조한 관상화의 색도에서는 차광비율이 높아질수록 b 값이 증가하여 황색값이 높아지는 것을 알수 있었다. 파종 후 생육 94일 차인 8월 13일 종실을 수확하여 식물체당 100립중을 조사한 결과 무차광 4.9 g에 비해 차광조건에서는 감소하는 경향을 보였고, 종실수량성에서도 무차광에서 201.1 kg/10 a로 가장 높아 차광조건에서 잇꽃 재배는 개화지연에 의한 등숙률의 감소로 종실수량성이 감소하는 것으로 판단되었다.