PROBLEM TO BE SOLVED: To provide a herbicide showing sufficient safety on important crops and a compound useful for it.SOLUTION: The present invention provides a herbicide for agricultural and horticultural use containing a pyrazolidinone derivative represented by formula (I) or a salt thereof as an active ingredient (R1 is a substituted phenyl group R2 and R3 independently represent H or a (C1-C6) alkyl group R4 is H R5 is a substituted phenyl group).SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】重要作物に対して十分な安全性を示す除草剤及びそれに用いられる有用な化合物の提供。【解決手段】式(I)で表されるピラゾリジノン誘導体、又はその塩類を有効成分とする農園芸用除草剤。{R1は置換フェニル基;R2及びR3は各々独立にH又は(C1-C6)アルキル基;R4はH;R5は置換フェニル基}【選択図】なし
