• Title/Summary/Keyword: 생육 시기

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Impacts of Climate Change on Rice Production and Adaptation Method in Korea as Evaluated by Simulation Study (생육모의 연구에 의한 한반도에서의 기후변화에 따른 벼 생산성 및 적응기술 평가)

  • Lee, Chung-Kuen;Kim, Junwhan;Shon, Jiyoung;Yang, Woon-Ho;Yoon, Young-Hwan;Choi, Kyung-Jin;Kim, Kwang-Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.4
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    • pp.207-221
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    • 2012
  • Air temperature in Korea has increased by $1.5^{\circ}C$ over the last 100 years, which is nearly twice the global average rate during the same period. Moreover, it is projected that such change in temperature will continue in the 21st century. The objective of this study was to evaluate the potential impacts of future climate change on the rice production and adaptation methods in Korea. Climate data for the baseline (1971~2000) and the three future climate (2011~2040, 2041~2070, and 2071~2100) at fifty six sites in South Korea under IPCC SRES A1B scenario were used as the input to the rice crop model ORYZA2000. Six experimental schemes were carried out to evaluate the combined effects of climatic warming, $CO_2$ fertilization, and cropping season on rice production. We found that the average production in 2071~2100 would decrease by 23%, 27%, and 29% for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were fixed. In contrast, predicted yield reduction was ~0%, 6%, and 7%, for early, middle, and middle-late rice maturing type, respectively, when cropping seasons were changed. Analysis of variation suggested that climatic warming, $CO_2$ fertilization, cropping season, and rice maturing type contributed 60, 10, 12, and 2% of rice yield, respectively. In addition, regression analysis suggested 14~46 and 53~86% of variations in rice yield were explained by grain number and filled grain ratio, respectively, when cropping season was fixed. On the other hand, 46~78 and 22~53% of variations were explained respectively with changing cropping season. It was projected that sterility caused by high temperature would have no effect on rice yield. As a result, rice yield reduction in the future climate in Korea would resulted from low filled grain ratio due to high growing temperature during grain-filling period because the $CO_2$ fertilization was insufficient to negate the negative effect of climatic warming. However, adjusting cropping seasons to future climate change may alleviate the rice production reduction by minimizing negative effect of climatic warming without altering positive effect of $CO_2$ fertilization, which improves weather condition during the grain-filling period.

Changes of Essential Oils from Mentha piperita L. Influenced by Various Cultivation Conditions and Harvesting Time (박하의 재배조건 및 수확시기에 따른 정유성분의 변화)

  • Shin, Kyung-Eun;Park, Hong-Ku
    • Korean Journal of Food Science and Technology
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    • v.26 no.5
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    • pp.512-519
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    • 1994
  • To investigate the effects of cultivation on the aroma characteristics of essential oil of peppermint (Mentha piperita L.), experimental peppermints were cultivated with different treatments of field mulching, soil fertilization, and harvesting time. Aroma characteristics of the different mint oils were analyzed by gas chromatography (GC) and GC/mass spectrometry (MS)/infrared spectroscopy (IR). Growth of peppermint with vinyl muching was faster in the early stage of cultivation, but became almost same in the harvest date. The higher amounts of rainfall and sunshine hour resulted in the better growth of stem and leaf of the peppermint. Contents of menthone in the essential oils from the peppermint cultivated in 1990 increased as harvest date delayed from late June 25 to late July 26 the same period. In 1991 menthone decreased from June 25 to August 5, but l-menthol increased from June 25 to august 5. The results indicated that the sunshing hour affected biosynthesis of the components. Contents of menthofuran increased significantly from early June to late July. The optimum cutting date resulting best oil production was late July 7 in 1991.

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Effects of Cutting Dates on Hay Production of Italian Ryegrass in Paddy Field (예취시기가 답이작 이탈리안라이그라스의 건초생산에 미치는 영향)

  • Kim, Young-Doo;Chae, Jae-Suk;Park, Tae-Ill;Chang, Young-Sun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.4
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    • pp.372-376
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    • 1992
  • This experiment was conducted to determine hay making time on the drying period, hay moisture content, hay loss content, yield and forage quality of Italian ryegrass in paddy field. Plant height increased rapidly from middle of April, and leaf weight rate were 55.6% at April 20 and 18.9% at May 30. Moisture content and loss content of hay were 17.1-20.5% and 10.2-15.0%, respectively, at drying for 4 days from May 10 to May 30. As the growth stage later, crude protein, fat and ash contents reduced, but crude fiber and NFE contents increased. Dry matter and TDN yield at the cutting of May 20 and May 30 increased to 17-18% and 5-11%, respectively, than those of April 20+May 30.

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Effects of Planting Date and Density on Growth Characteristics and Saikosaponins Content in Bupleurum falcatum L. (파종시기 및 재식밀도가 시호의 생육 및 Saikosaponin 함량에 미치는 영향)

  • Lee, Ho;Kim, Kil-Ung;Son, Tae-Kwon;Lee, Sang-Chul
    • Korean Journal of Medicinal Crop Science
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    • v.10 no.5
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    • pp.317-326
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    • 2002
  • This study was conducted to determine the optimum planting dates and density of one year old Bupleurum falcatum L. to improve its productivity and quality. Two cultivars of B. falcatum, originated from Jeongseon, Korea and Mishima, Japan were used. Some of the results obtained are as follows : Jeongseon cultivar showed less stem branches and shoot weight compared to Mishima. However, Jeongseon cultivar showed tall plant height, high root fresh and dry weight, and high levels of saikosaponin, but low saikosaponin content than that of Mishima. Both cultivars seeded on March 20 had long main root, big stem diameter, few stem branch, and high saikosaponin c content compared to those of late seeded one, April 30. Growth characteristics such as plant height, stem diameter, stem branch number, shoot weight, root diameter, root fresh and dry weight, and root branch number were increased in a low planting $density(30\;{\times}\;15cm)$, but the content of saikosaponin was not affected by planting density. Jeongseon and Mishima cultivars seeded on April 10 with $30\;{\times}\;15cm$ planting density and April 30 with $30\;{\times}\;10cm$ planting density contained the highest total saikosaponin levels, respectively. However, average root dry weight were not affected by planting time or density in both Bupleurum cultivars.

Harvesting Date and Cultivar Effect on the Growth Charateristics , Forage Yield and Quality of Spring Sown Oats (수확시기와 품종이 춘파연맥의 생육특성 , 사초수량 및 사료가치에 미치는 영향)

  • 김종근;김동암
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.14 no.3
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    • pp.247-256
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    • 1994
  • This experiment was carried out to determine harvesting date and cultivar effects on growth characteristics, forage yield and quality of spring sown oats(Avena surivu L.) at the forage experimental field, College of Agricultural and Life Sciences, Swul National University, Suwwn from March 22 to June 20, 1993. The experiment was arranged in a split plot design with three replications. The main plots consisted of the harvesting dates such as early(24 May), mid(8 June) and late(20 June). The subplots consisted of different maturities of oat cultivm such as Speed oat, Cayuse, Foothill, Sv841034 and Magnum.

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