Herbicidal substituted 4-amino-5-alkylthio-1,2,4-triazol-3-ones

A substituted 4-amino-5-alkylthio-1,2,4-triazol-3-one of the formula ##STR76## in which R.sup.1 represents straight-chain or branched alkyl, alkenyl or alkenyl, each of which has up to 4 carbon atoms, and

• R.sup.2 represents unsubstituted sec.-butyl, tert.-butyl, C.sub.5 -C.sub.10 -alkyl, C.sub.5 -C.sub.10 -alkenyl or C.sub.5 -C.sub.10 -alkynyl, or substituted alkyl, alkenyl or alkynyl, each of which has up to 10 carbon atoms and each of which is substituted by halogen, cyano, C.sub.3 -C.sub.6 -cycloalkyl, aryloxy having 6 to 10 carbon atoms or C.sub.1 -C.sub.6 -alkoxy, or represents C.sub.1 -C.sub.6 -alkyl substituted by, in each case, piperidyl or morpholinyl or represents cyclopropyl, cyclobutyl, cyclopentyl or cycloheptyl, each of which is optionally substituted by halogen, aryl having 6 to 10 carbon atoms, C.sub.1 -C.sub.6 -alkyl or C.sub.1 -C.sub.4 -halogenoalkyl, or represents cyclo-hexyl which is substituted by halogen, C.sub.1 -C.sub.6 -alkyl, C.sub.2 -C.sub.4 -alkenyl or C.sub.1 -C.sub.4 -halogenoalkyl, or represents phenyl-C.sub.1 -C.sub.2 -alkyl or naphthyl-C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.2 -halogen-alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.2 -halogenoalkoxy, C.sub.1 -C.sub.4 -alkylthio, C.sub.1 -C.sub.4 -aklylsulphinyl, C.sub.1 -C.sub.4 -alkylsulphonyl, phenoxy, and/or phenyl.