• 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.

• Asian Journal of Turfgrass Science
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• v.18 no.3
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• pp.129-139
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• 2004

This study conducted to find out the best way to prolong green period of Zoysiagrass and Cool-season grass from 1999 to 2001 in Korea. Treatments were control, vinyl, black shade net, green shade net, black shade net+vinyl, green shade net+vinyl, vinyl+black shade net, and vinyl+green shade net for Zoysiagrass. For cool-season grass, treatments were control, non-punched vinyl and punched vinyl. Data on temperature, light intensity, humidity, leaf color and chlorophyll were collected. Plot size was 2 by 2 and the experiment was conducted using completely randomized design with three replication. Zoysiagrass Green period of Zoysiagrass depended on temperature and light intensity than humidity. Effective method of prolongation of green period in Zoysiagrass was to covered it with vinyl during early October to early November, and then using vinyl+black shade net from end of November. Cool-season grass Effective method of prolongation of green period in Cool-season grass was by covering it with vinyl during mid-November to mid-December, and then using vinyl+black shade net from end of December.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.307-316
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• 1994

To investigate the effect of light pretreatment on photosynthetic characteristics of leaf blade of rice, 2 varieties of japonica type and 2 varieties of tongil type were grown under 30% or 70% shading conditions from tillering stage to heading stage. Shading treatment of 70% at the heading stage produced low dry matter, and higher LAR and SLA compared with other combination of shading treatment and growing stage did. Photosynthetic activity was lower in order of 0%, 30% and 70% shading treatment under the low light intensity(5Klux) but significantly high in 30% shading treatment under the high light intensity (33Klux) at tillering stage. Photosynthetic activity under low(5Klux) and high(33Kluk) light intensity were higher in order of 70%, 30% and 0% shading treatment at heading stage. Respiration /photosynthesis ratio was lower in shading treatment than in control. CGR, RGR and NAR decreased in shading treatment. Shading treatment reduced the number of ripened grain per panicle and decreased the harvesting index.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.227-232
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• 2015

This experiment was carried out to investigate the effects of shading materials (aluminum specific-shading screen and polypropylene non-woven fabric) and shading ratio (50% and 70%) on climatic changes, cut-flower quality, and yield of spray rose cultivars for export during high temperature periods. The daily cumulative solar radiations were higher with the aluminum specific-shading screen, especially with 50% shading compared to polypropylene non-woven fabric. Air temperature and root zone temperature within rockwool media greatly decreased with the aluminum specific-shading screen, but relative air humidity was not different among shading methods. Chlorophyll contents (SPAD values) were slightly higher with aluminum-specific shading screen than with polypropylene non-woven fabric, and were higher with 50% than with 70% aluminum specific-shading screen. Except for 'Lovely Lydia', marketable and exportable yields of all cultivars were higher with 50% than with 70% aluminum shading treatment. In addition, flowers talk length, stem diameter, number of node and 7ea-leaflet, and floret number tended to be better with aluminum specific-shading screen. Flower stalk length was higher with 70% than with 50% aluminum shading treatment. Chromaticity of petals slightly increased, and vase life was 0.5-2.5 days longer for each cultivar with aluminum specific-shading screen than with polypropylene non-woven fabric.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.419-427
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• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.30-30
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• 2021

빌레나무는 국내에서 제주도 서부 곶자왈 지역에서만 자생하는, 어두운 환경을 선호하며 개체수가 희소한 종이다. 본 연구는 광 환경이 빌레나무 묘목 생장에 미치는 영향을 파악하고자 수행되었다. 서귀포시 난대아열대산림연구소 내 양묘장에 차광막을 이용하여 35%, 55%, 75% 차광 처리구를 설치하였고 노지에 비차광 처리구를 비교구로 설정하였다. 2019년 7월에 삽목 증식시킨 빌레나무를 2020년 5월에 각 처리구에 이식하였다. 2021년 3월에 각 차광 처리구의 모든 묘목의 묘고, 잎의 수, 줄기 수를 측정하고 생육이 건전하고 평균적인 묘목을 각 9본씩 굴취하여 건중량을 측정하였다. 35%, 55%, 75% 차광 처리구별 평균 묘고(cm)는 각각 53.2, 51.3, 41.4, 평균 잎의 수(개)는 41.3, 42.1, 24.4, 평균 줄기 수(개)는 3.1, 2.7, 2.2로 나타났다. 평균 묘고, 잎의 수, 줄기 수는 35% 차광 처리구와 55% 차광 처리구에서 75% 차광 처리구보다 높은 경향을 보였다. 건중량 분석 결과, 35%, 55%, 75% 차광 처리구별로 평균 잎 건중량(g)은 각각 11.3, 9.5, 5.5, 평균 줄기 건중량(g)은 5.6, 5.3, 2.6, 평균 뿌리 건중량(g)은 4.5, 3.6, 2.6으로 차광률이 낮을수록 증가하였으며 모든 부위별 건중량은 처리에 따른 통계적 유의성을 보였다(p<0.05). 지상부 대비 지하부 비율은 75% 차광 처리구에서 0.35로 가장 높았으며 35%, 55% 차광 처리구에서 0.27, 0.26로 나타났다. 한편, 비차광처리구의 모든 묘목들은 2021년 1~2월경 지상부가 고사하였다. 본 연구결과, 빌레나무 묘목은 노지에서 생존률이 불량하고, 차광 처리 시 차광률 증가에 따라 생장에 부정적인 영향을 받는 것으로 판단된다. 빌레나무의 건전한 생육 및 유무성증식을 통한 보급 증대에 기여하기 위하여 향후 온도, 수분 등 여러 환경 인자를 조절하는 연구가 필요한 것으로 사료된다.

• Food Science and Preservation
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• v.8 no.4
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• pp.362-366
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• 2001

This study was conducted to reduce degradation of marketability by the rot and discolor of onion bulbs under room temperature from 1977 to 1998. Allium cepa cv. Changnyungdeago, late strain, was used for the test at the storage condition of non-shading, 55% and 95% shadings. The results obtained are as follows: The mean temperature was maintained lowly 1.0∼2.9$\^{C}$ in 55% and 2.0∼3.8$\^{C}$ in 95% shadings in contrast to nun-shading, but the relative humidity was a tittle higher in high shading than other shading condition. The illumination and color density maintained lowly in high shading. After 21 days of storage, the rate of discolored onion bulbs was significantly higher in non-shading(90.0%) than 55%(35.7%) and 95%(13.3%) shadings. The rotting rate by the end of August was a little decreased at 55%(25.4%) and 95% shadings(26.5%) in contrast to non-shading(28.9%), and total weight loss was maintained lowly in high shading.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.63-72
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• 2016

A study was conducted to evaluate the effect of collected region(Bongpyeong in Gangwon, 690 m, Mt. Halla in Jeju, 1,085 m), pre-treatment (stratification, soaked in distilled water or $GA_3$) and shading (control, 50%, 80%) on seed emergence and seedlings growth of Ligularia fischeri. The result showed that seed emergence (%) of L. fischeri were 6.9~75.5% (Gangwon : 6.9~32.8%, Halla : 22.2~75.5%). Maximum seed emergence (%) of 32.8 (Gangwon) and 75.5 (Halla) were achieved for seeds were stratified, soaked in distilled water, and under non-shading for L. fischeri (Gangwon), whereas seeds were stratified, soaked in $GA_3$ 100 ppm, and under 80% shading for L. fischeri (Halla). In this study, the best seedling vigor index (SVI) of L. fischeri (Gangwon) and L. fischeri (Halla) were obtained when seeds were stratified, soaked in distilled water, and under 50% shading. The survival rate of potted seedlings for L. fischeri (Halla) were 100% of all shading conditions, but there were decreased by 77.8%, 61.1%, 55.6%, as an increasing shading rate (con, 50%, 80%) for L. fischeri (Gangwon). Therefore, good seedlings were obtained when seed (Mt. Halla) of L. fischeri were stratified, soaked in distilled water, and under 50% shading, and then seedlings were transferred in pot.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.304-311
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• 2021

This Experiment was conducted to determine the effects of light shield materials when melon grown inside a plastic greenhouse in summer season. The average temperatures were 36.6℃, 34.5℃ and 34.0℃ respectively for the control(non-shield), coating agent, and the white net. The light transmittances were 69% and 75%, respectively inside the greenhouse treated with the coating agent and white net immediately after applicants, compared with that inside the control greenhouse. At the 40 and 80 days after treatment, the light transmittances for the coating agent were 92% and 98%, respectively, indicating it was slowly decomposed and removed, but there was no change in the transmittance for the white net. While the leaf number did not differ among the treatments, the plant height was higher in the white net and shading agent than in control. The weight of the leaves, fresh-weight and dry-weight were no different from that of shading, but it became heavier in the later stages. The marketable fruit yield was increased by 6% for white nets and 5% for the coating agent compared to control, there was no statistical significance. Therefore, coating agent is considered as an effective method to lower temperature during high temperature period, but it is preferable to use it in consideration of cultivation period, because the coating agent is gradually removed.

• Asian Journal of Turfgrass Science
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• v.15 no.2
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• pp.51-64
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• 2001

Summer stress is one of the serious problems on cool-season grass at the soccer fields in Korea during heavy rainy season. This study was conducted to intestigate the effect of shade net with regard to its percent (0, 50, 75), color (black, green), height (0 cm, 30 cm) and time (7 hr, 24 hr) on turf canopy temperature, light intensity, leaf color, turf performance, clipping yield and root dry weight of cool-season turfgrass. Turf canopy temperature was 6~13$^{\circ}C$ under black and green shade net when temperature was over 4$0^{\circ}C$. Light intensity was also decreased from 40 to 94% under black and green shade net compared to control. Black shade net was more effective than green net in reduction of temperature and light intensity. Green shade net was found to be better for photosynthesis of cool-season grass. Leaf color, turf performance, clipping yield, and root dry weight were better and increased under 50% and 75% shade net. 50% black shade net with 30cm height and 7 hr treatment showed the best turf performance. It can be concluded that 50% and 75% green shade net can be used fur reducing summer stress on cool-season grass after soccer marches during heavy rain season. The shade net decreased the turf canopy temperature and reduced heating damage of cool-season turfgrass.