1-cycloalkenyltetrazolinones
1-cycloalkenyltetrazolinone derivatives of the following herbicidal formula <IMAGE> R1 is cycloalkenyl which may optionally be substituted by halogen C1-4 alkyl, or bicycloalkenyl which may optionally be substituted by halogen or C1-4 alkyl, and R2 and R3 each independently is alkyl, cycloalkyl, phenyl (optionally substituted by a member selected from the group consisting of nitro, cyano, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy and alkylthio), alkenyl and alkynyl, or R2 and R3 together with the N-atom to which they are bonded form, a 5- or 6-membered heterocyclic ring which may optionally contain a further hetero atom, said heterocyclic ring optionally being benzo-condensed, or a C-1-4 alkyl, and intermediates therefore of the formula <IMAGE>