A synergistic herbicidal composition comprising: (A) at least onecompound of general formula (I) or an agriculturally acceptable salt thereof:(see formula I)wherein Q is a radical Q1:(see formula Q1)； and(B) at least one compound selected from the group consisting of acetochlor,alachlor,atrazine, bromoxynil, carfentrazone-ethyl, dicamba, diflufenzopyr,dimethenamide,flufenacet, flumetsulam, fluthiacet-methyl, imazamox, imazapyr, imazaquin,imazethapyr, metolachlor, metosulam, metribuzin, pethoxamide, pendimethalin,pyridate and thenylchlor, wherein the composition comprises a compound of theformula (I) or a salt thereof and a compound of group (B) in a ratio by weightof from1:2000 to 2000:1. The activity of the composition is superior to that of theherbicidesapplied on their own.
