Disclosed herein are herbicidal compositions comprising a synergistically herbicidal effective amount of (a) aminocyclopyrachlor, or an agriculturally acceptable salt or ester thereof, and (b) 2,4-D, or an agriculturally acceptable salt or ester 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) aminocyclopyrachlor, or an agriculturally acceptable salt or ester thereof, and (b) 2,4-D, or an agriculturally acceptable salt or ester thereof, wherein (a) and (b) are each added in an amount sufficient to produce a synergistic herbicidal effect.本文揭示除草組成物，其包含協同性除草有效量之(a)環丙嘧啶酸或其農業上可接受的鹽類或酯類，及(b)2,4-D或其農業上可接受的鹽類或酯類。本文亦揭示控制非所欲的植被之方法，其包含施用下述之物至該植被或鄰接該植被的區域，或是施用下述之物至土壤或水，以預防該植被的萌芽或生長，該物係指(a)環丙嘧啶酸或其農業上可接受的鹽類或酯類，以及(b)2,4-D或其農業上可接受的鹽類或酯類，其中(a)及(b)各自添加足夠產生協同除草性效應的量。
