Summary.Linuron, 2,4‐D‐aniine, propachlor, pyriclor and cypromid, singly and mixture with atrazine, were compared with atrazine and fluromidine alone for effectiveness of weed control in maize on Oxford clay soil. Pre‐emergence applications were made under wet conditions and atrazine, even at 0·28 kg/ha a.i. gave an excellent control of three main weeds,Stellaria media, Veronicaspp. andPolygonum aviculare, and at 0·56 kg/ha also killedAethusa cynapium.Fluromidine was comparable with atrazine, but linuron,2,4‐D‐amine, propachlor and pyriclor were less effective. Post‐emergence treatments were less satisfactory. High doses of atrazine were needed for good weed control.Acynapiumwas resistant to pyriclor and cypromid andP. aviculareto fluromidine. 2,4‐Daminewas ineffective, but atrazine/2,4‐D‐amine mixtures were more effective than the individual components for the control ofP. aviculare.Pyriclor, at 0·56 kg/ha pre‐emergenceand cypromid at 2·24 kg/ha post‐emergence directly reduced the yield of the crop.Utilisation de I'atrazine à faible dose, seule et en mélange avec d'autres herbicid