Salts of formula (I), wherein n is 0, 1, 2 or 3; R is a halogen, alkyl or alkoxy, independently of one another when n is greater than 1; R1 is a substituted or unsubstituted hydrocarbon radical or a substituted or unsubstituted heterocyclic radical; R2 is an acyl radical; R3 is hydrogen or C¿1?-C5 alkyl; MO is a metal or ammonium ion; X, Y are, independently of each other, a halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkylthio, each of the last three radicals being unsubstituted or substituted by one or more radicals from the group of halogen, C1-C4 alkoxy and C1-C4 alkoxy and C1-C4 alkylthio, or C3-C6 cycloalkyl, C2-C6 alkenyl, C2-C6 alkinyl, C3-C6 alkenyloxy, C3-C6 alkinyloxy, mono- or di- (C1-C4-alkyl)-amino, and Z is CH or N, can be used as herbicides and plant growth regulators. The compounds (I) can be produced by the method disclosed in claims 5-7, for example by hydrogenation of 2-alkoxycarbonyl-5-nitrophenylsulfonyl ureas in the presence of anhydrides.