Disclosed herein are herbicidal compositions comprising a synergistic herbicidally effective amount of (a) penoxsulam or an agriculturally acceptable salt thereof and (b) acetochlor or an agriculturally acceptable salt thereof. Also disclosed herein are methods of controlling undesirable vegetation, which comprise applying to vegetation or an area adjacent the vegetation or applying to soil or water to prevent the emergence or growth of vegetation (a) penoxsulam or an agriculturally acceptable salt thereof and (b) acetochlor or an agriculturally acceptable salt thereof, wherein (a) and (b) are each added in an amount sufficient to produce a synergistic herbicidal effect.於本文中揭示出一種除草劑組成物,其包含協同性除草有效量之(a)五氟磺草胺或其農藝上可接受的鹽及(b)乙草胺或其農藝上可接受的鹽。亦於本文中揭示出一種控制非所欲的植被之方法,其包括將(a)五氟磺草胺或其農藝上可接受的鹽及(b)乙草胺或其農藝上可接受的鹽施用至植被或一毗連該植被的區域,或施用至土壤或水以防止植被萌芽或生長,其中該(a)及(b)每種係以足以產生協同性除草效應之量加入。