2018 Fiscal Year Final Research Report

Elucidation of population dynamics of glyphosate-resistant Italian ryegrass and its application to Integrated Weed Management

Research Project

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Project/Area Number	15K07324
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Plant protection science
Research Institution	Shizuoka University
Principal Investigator	Yamashita Masayuki 静岡大学, 農学部, 教授 (30252167)
Co-Investigator(Kenkyū-buntansha)	澤田均静岡大学, 農学部, 教授 (10183831) 宮田祐二静岡県農林技術研究所, その他部局等, 研究員 (80426452) 亀山忠静岡県農林技術研究所, 静岡県農林技術研究所, 科長 (00542630)
Project Period (FY)	2015-04-01 – 2019-03-31
Keywords	総合的雑草管理（IWM） / ネズミムギ / グリホサート除草剤抵抗性
Outline of Final Research Achievements	Italian ryegrass, which has become a problem weed as a source of spotted rice bugs in the paddy field margins, has acquired glyphosate resistance in Shizuoka Prefecture in recent years, making it more difficult to control them. Glyphosate resistant Italian ryegrass was found in some paddy fields margins in major paddy fields in Shizuoka Prefecture, and resistant individuals were found at more than half (59%) of all survey sites, especially in Chuen area. The authors focused on mowing grass, which can be an important component option of Integrated Weed Management (IWM), and devised mowing methods timed to the high flowering season. Field experiments were conducted in paddy fields, and it was shown that mowing during the flowering period was more effective in reducing the frequency of resistant ryegrass than early mowing that has been conventionally used in this area.
Free Research Field	雑草科学
Academic Significance and Societal Importance of the Research Achievements	最も高頻度で使用されているグリホサート系除草剤に対する抵抗性雑草を研究対象とする本研究の成果から、難防除雑草ネズミムギの管理法だけではなく、日本における雑草管理技術の発展に寄与するものと考えられる。また、研究で調査対象とするグリホサート抵抗性ネズミムギは、世界で初めて水田畦畔の雑草集団から見つかった。このことは、世界全体における水田面積が極めて広く、今後も除草剤により管理される水田畦畔がアジアの途上国を中心に増加すると予想されることから、本研究で得られる成果は、日本のみならず世界全体においてグリホサート系除草剤に過度に依存しない総合的雑草管理技術（IWM）の確立に貢献するであろう。