• Title/Summary/Keyword: photosynthesis experiment

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Comparison of Photosynthesis between Treatment and Non-treatment of Lime Bordeaux Mixture in 3 Year Old Root in Panax ginseng C. A. Meyer

  • Ahn, Deok-Jong;Jung, Won-Kwon;Choi, Jin-Kook;Jang, Myeong-Hwan;Kwon, Tae-Ryong;Shin, Yeon-Hwa;Lee, Sang-Chul
    • Korean Journal of Plant Resources
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    • v.26 no.3
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    • pp.370-373
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    • 2013
  • Korean ginseng has been used for thousands of years as an important medicinal plant. Lime-Bordeaux mixture (LBM) was made with copper sulfate and quicklime, which was sprayed instead of pesticides in ginseng field. Net photosynthesis ($P_N$) was compared between Treatment and Non-treatment of LBM in 3 Year Old Ginseng. $P_N$ in control plot recorded $2.94{\mu}mol\;(CO_2)\;m^{-2}s^{-1}$ at the first day of experiment, which was similar until the last day of experiment. However, The $P_N$ in LBM recorded $2.23{\mu}mol\;(CO_2)\;m^{-2}s^{-1}$, which was lower than that in control plot. As time goes by, The $P_N$ in LBM was gradually increased up to $3.21{\mu}mol\;(CO_2)\;m^{-2}s^{-1}$ and finally, it was similar with that in control plot at 7th day as a $3.20{\mu}mol\;(CO_2)\;m^{-2}s^{-1})$.

The Effect of Soil Flooding on Photosynthesis and Water Relations of Carpinus cordata and Carpinus laxiflora (까치박달과 서어나무의 광합성과 수분관계에 미치는 토양 침수의 영향)

  • 박용목
    • The Korean Journal of Ecology
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    • v.20 no.3
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    • pp.175-179
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    • 1997
  • To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

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The Analysis of Elementary Pre-service Teachers' Reflective Thinking and Experiment Performance Ability on Photosynthesis Experiment (광합성 실험에서 나타난 초등 예비교사들의 반성적 사고와 실험 수행 능력 분석)

  • Kim, Dong-Ryeul
    • Journal of Korean Elementary Science Education
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    • v.34 no.4
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    • pp.502-518
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    • 2015
  • In order to find out Elementary pre-service teachers' reflective thinking and experiment performance ability related with Photosynthesis Experiment in the Korea Elementary School Science Textbook, the research is conducted targeting Elementary pre-service teachers. They are asked to carry out the experiment and write their own report about the difficulties and solutions of exploration process. This study aims to analyze Elementary pre-service teachers' reflection and experiment performance ability on Photosynthesis experiment based on 10 groups' reports and presentation materials. Reflective thinking extracts 108 statements which is associated with the four types of the sentence 'Knowledge, Procedure, Orientation, Attitude' in 10 reports. There are many sentences about reflective thinking acquired through analysis of the photosynthesis experiment. reflective thinking about the newly discovered type or changed concepts through experimentation in Knowledge is at the highest frequency. 56 sentences in relation to the ability to perform experiments are extracted by adding 4 different types of reflective thinking in 10 groups shown the highest frequency group and the lowest frequency group's report through analyzing 4 steps 'Experimental preparation and safety accident prevention', 'Experiments performance', 'Experimental results and generalization', and 'Experimental results and feedback.' Results of the analysis showed that there are the biggest difference between the two groups in 'experiment results supplement and feedback step.' In the lowest group's report, there's no contents related with 'Computer-assisted information processing' in the 'Experimental results summary and generalization stage', 'Alternative reagents and materials research', and 'Devising alternative experiment methods'.

Characteristics of Photosynthesis and Leaf Growth of Peucedanum japonicum by Leaf Mold and Shading Level in Forest Farming (임간재배지 내 부엽토 및 차광수준에 따른 갯기름나물의 광합성과 엽생장 특성)

  • Song, Ki Seon;Jeon, Kwon Seok;Choi, Kyu Seong;Kim, Chang Hwan;Park, Yong Bae;Kim, Jong Jin
    • Korean Journal of Medicinal Crop Science
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    • v.23 no.1
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    • pp.43-48
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    • 2015
  • This study was carried out in order to investigate the photosynthesis response and leaf characteristics of Peucedanum japonicum growing in forest farming. The experiment was performed by leaf mold (pine tree and chestnut tree) and shading levels (0%, 35%, 50% and 75% shading). Light relative intensity was 100% (full sunlight), 60.3% (35% shading), 35.1% (50% shading), and 17.4% (75% shading) respectively. Light response curves of pine-leaf mold and chestnut-leaf mold were the highest in control (full sunlight) and these were getting lower in the higher shading level. Photosynthesis capacity and light saturation point were indicated higher in chestnut-leaf mold within the same shading level. As the shading level increased, maximum photosynthesis rate decreased. And apparent quantum yield was not indicated statistically significant difference from all treatment. Leaf area, leaf length and leaf width were significant higher in 35% shading and control under chestnut-leaf mold in all treatment. As the shading level increased, LAR (leaf area ratio), SLA (specific leaf area) and SPAD value decreased in pine-leaf mold and chestnut-leaf mold. As a result of surveying the whole experiment, P. japonicum is judged better growth and higher yield by maintaining 35% shading (relative light intensity 60%) under chestnut-leaf mold in forest farming.