• Title/Summary/Keyword: Yi Se-${\Box}$

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Scientists of the Gwansang-gam, the Royal Observatory of Joseon Dynasty (1)

  • Nha, Il-Seong;Nha, Sarah;Cho, Haman
    • Journal of Astronomy and Space Sciences
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    • v.30 no.1
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    • pp.69-77
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    • 2013
  • We have uncovered 14 Korean royal astronomers and one scientist who worked in the early and mid-18th century. In spite of their high positions in the government office, all of them but one were not recorded anywhere in the major histories, such as WangjoSillok(王朝實錄) and JeungboMunheonBigo(增補文獻備考). Our search of Bon'gwans for each person has been carried successfully for 13 scientists. Their family relations are also uncovered finding five eminent astronomy families.

In vitro Antifungal Activities of Fungicides against Japanese Plum Fruit Anthracnose Fungi (자두 탄저병균에 대한 살균제의 활성)

  • Jeong, Byeong-Ryong;Lee, Tae-Yi;Park, Min-Jung;Ha, Da-Hee;Chung, Jong-Bae;Lee, Yong-Se
    • Korean Journal of Environmental Agriculture
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    • v.37 no.1
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    • pp.34-40
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    • 2018
  • BACKGROUND: In order to select a fungicide that can effectively control anthracnose disease in Japanese plum fruit, mycelial growth inhibition effect and spore germination inhibition effect of six fungicides were tested in vitro against six isolates of Colletotrichum acutatum and five isolates of C. gloeosporioides that were isolated from diseased Japanese plum fruit. METHODS AND RESULTS: Inhibitory effects of fungicides on mycelial growth were investigated after inoculating each isolate on potato dextrose agar amended with four discriminatory concentrations of each fungicide for 7 days at $25^{\circ}C$. For spore germination inhibitory effect, each isolate of the Colletotrichum spp. was cultured in potato dextrose agar for 7-14 days at $25^{\circ}C$. After adjusting the concentration of spores of each isolate to $1{\times}10^6mL^{-1}$ by diluting with 0.025% PDB, the spore suspension was mixed with each fungicide (1:4, v/v), and $60{\mu}L$ aliquots were dispensed to sterile hole slide glass. Hole slide glasses were placed in a humidified box and incubated for 15 hours at $25^{\circ}C$. Then, spore germination was observed under an optical microscope. At recommended concentration of fungicide prochloraz manganese showed the highest mycelial growth inhibitory effect and dithianon showed the lowest mycelial growth inhibition. The $EC_{50}$ values for the inhibition of spore germination by dithianon and pyraclostrobin were $0.069-0.126{\mu}g/mL$ and $0.37-1.59{\mu}g/mL$, respectively. Although benomyl, prochloraz manganese, azoxystrobin, and tebuconazole did not inhibit the spore germination, they appeared to restrain mycelial growth by abnormal growth of germ tube and mycelium after germination. CONCLUSION: Dithianon seemed to have preventive effect. Prochloraz manganese, azoxystrobin, and tebuconazole were likely to have control effect. Pyraclostrobin is considered to have both preventive and control effect against anthracnose disease of Japanese plum fruit.