• Title/Summary/Keyword: 농업환경

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Dissipation and Processing Factor of Etofenprox and Fenitrothion Residue in Chinese Matrimony Vine by drying (건조에 따른 구기자 중 etofenprox와 fenitrothion의 잔류량 변화 및 가공계수)

  • Noh, Hyun Ho;Lee, Jae Yun;Park, Hyo Kyoung;Jeong, Hye Rim;Lee, Jung Woo;Jo, Seung Hyeon;Kwon, Hyeyoung;Kyung, Kee Sung
    • Korean Journal of Environmental Agriculture
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    • v.37 no.3
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    • pp.213-220
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    • 2018
  • BACKGROUND: This study was carried out to determine characteristics of residual pesticides in time-dependent manner and calculate half-lives of the residual pesticides in fresh and dried Chinese matrimony vine. In addition, processing factors were calculated based on the residual concentrations in them. METHODS AND RESULTS: The test pesticides, etofenprox and fenitrothion, were sprayed onto the Chinese matrimony vine plants at once or twice (at seven-day interval) and then samples were collected at 0 (after 3 hours), 1, 3, 5 and 7 days after the last spraying. Dried samples were prepared in hot-air drying oven at $60^{\circ}C$ for 48 hours until water content of less than 20%. Residual concentrations of etofenprox in fresh and dried samples decreased by 54.0-60.9% after 7 days of the last pesticide-application. In case of fenitrothion, the concentrations were found to have decreased by 69.2-76.5%. Processing factors of etofenprox were 2.6-3.0 for the one-time spraying and 2.5-3.0 for the two-time spraying and those of fenitrothion were found to be 1.5-22 for the one-time spraying and 1.6-2.0 for the two-time spraying. First half-lives of etofenprox and fenitrothion in fresh and dried samples ranged from 5.0 to 6.3 and from 3.4 to 4.0 days, respectively. The third half-lives were found to be 15.0-18.9 and 10.2-12.1 days, respectively. CONCLUSION: Residual concentrations of the tested pesticides in the studied crop decreased, but those in the dried samples appeared to have increased. In addition, processing factor and half life were constant regardless of spraying times.

Sclerotinia Rot of Peucedanum japonicum Thunb. Caused by Sclerotinia sclerotiorum (Sclerotinia sclerotiorum에 의한 갯기름나물 균핵병 발생)

  • Jung, Won-Kwon;Lim, Yang-Sook;Kim, Min-Ki;Kim, Jong-Su
    • Research in Plant Disease
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    • v.27 no.3
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    • pp.115-119
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    • 2021
  • Sclerotinia rot was occurred on the leaf and stem of Peucedanum japonicum Thunb. in greenhouse field of Pohang city of Gyeongbuk province in Korea. The typical symptom of the disease was light brown spot and tipburn on infected leaves. The colony of the isolated fungus was white to light gray in color. Asci were cylindrical shape and 75-240×5.9-17.3 ㎛ in size. Apothecia were cup-shaped with numerous asci and 0.5-0.9 cm in size. Ascospores were aseptate and ellipsoid in shape, and 8.4-10.7×4.8-5.8 ㎛ in size. Sclerotia formed on the plants and potato dextrose agar medium were globose to irregular in shape and black in color. Partial sequencing of rDNA of this isolate showed that it was 100% consistent with that of Sclerotinia sclerotiorum. It was confirmed that the same lesion was formed by reinoculating this pathogen on a healthy P. japonicum Thunb. and the same strain was isolated. This is the first report on the Sclerotinia rot of P. japonicum Thunb. caused by S. sclerotiorum in Korea.