Novel herbicides and plant growth regulants of the formula ##STR1## in which R.sup.1 represents hydrogen alkyl, alkenyl, alkinyl, halogenoalkyl, halogenoalkenyl, halogenoalkinyl, alkoxyalkyl, alkoxy, cycloalkylalkyl or cycloalkyl, or represents in each case optionally substituted aralkyl or aryl,R.sup.2 represents a radical ##STR2## or represents a radical --S(O).sub.n --R.sup.7, R.sup.3 and R.sup.4 independently of one another each represent hydrogen, alkyl, alkenyl, alkinyl, halogenoalkyl, halogenoalkenyl, halogenoalkinyl, cyanoalkyl, hydroxyalkyl, alkoxyalkyl, alkylaminoalkyl, alkoxyacarbonylalkyl or aldoxycarbonylalkenyl, or represent in each case optionally substituted cycloalkyl, cycloalkylalkyl, cycloalkenyl or cycloalkenylalkyl, or represent optionally substituted heterocyclylalkyl, or represent in each case optionally substituted aralkyl, aroyl or aryl, or represent alkoxy, alkenyloxy, alkinyloxy, aralkyloxy or aryloxy, or, together with the nitrogen atom to which they are bonded, represent an optionally substituted heterocyclic radical,X represents oxygen or sulphur andY represents oxygen or sulphur,whereinR.sup.5 and R.sup.6 independently of one another each represent alkyl, alkenyl, alkinyl, halogenoalkyl, halogenoalkenyl, halogenoalkinyl, alkoxyalkyl, alkoxy, cycloalkyl or cycloalkylalkyl, or represent in each case optionally substituted aryl, aralkyl or heteroaryl, or, together with the nitrogen atom to which they are bonded, represent an optionally substituted heterocyclic radical,R.sup.7 represents alkyl, alkenyl, alkinyl, cycloalkyl or cycloalkylalkyl, or represents in each case optionally substituted aralkyl or aryl andn represents the number 0, 1 or 2,but wherein R.sup.2 only represents a radical --S(O).sub.n --R.sup.7 if R.sup.3 and R.sup.4 do not simultaneously represent methyl.Intermediates therefor where NR.sup.3 R.sup.4 is replaced by C1 are also new.