N-[(1,3,5-traizin-2-yl)-aminocarbonyl]-benzenesulfonamides of the general formula I ##STR1## where R.sup.1 is methyl or ethyl;R.sup.2 is hydrogen or methyl;R.sup.3 is substituted or unsubstituted alkyl;a group OR.sup.5 or SR.sup.5 where R.sup.5 is unsubstituted or fluorine-substituted alkyl, with the exception of difluoromethoxy; nitro or hydroxyl; andR.sup.4 is hydrogen, methyl, ethyl, methoxy, ethoxy, methylthio, ethylthio, C.sub.1 - or C.sub.2 -haloalkoxy, fluorine or chlorine, with the exception of 6-chloro and 6-fluoro when R.sup.3 is alkyl or C.sub.1 - or C.sub.2 -alkoxy;and agriculturally useful salts thereof, processes for their preparation and the use thereof.