5-(Dioxabicyclohept-6-yl)cyclohexenone oxime ethers of the formula I ##STR1## where: R.sup.1 is hydrogen, the equivalent of an agriculturally useful cation, C.sub.1 -C.sub.10 -alkylcarbonyl, C.sub.1 -C.sub.10 -alkylsulfonyl, C.sub.1 -C.sub.10 -alkylphosphonyl, benzoyl, benzenesulfonyl or benzenephosphonyl;R.sup.2 is C.sub.1 -C.sub.6 -alkyl;R.sup.3 is in each case, independently of the others, hydrogen or C.sub.1 -C.sub.4 -alkyl;Z is a C.sub.1 -C.sub.6 -alkylene, C.sub.3 -C.sub.6 -alkenylene or C.sub.3 -C.sub.6 -alkynylene chain which may carry an exo-methylene substituent (.dbd.CH.sub.2) and/or in each case one to three additional substituents selected from the group consisting of C.sub.1 -C.sub.3 -alkyl substituents and halogen atoms, is a C.sub.3 --C.sub.6 -alkylene or C.sub.4 --C.sub.6 -alkenylene chain which may carry one to three C.sub.1 -C.sub.3 -alkyl substituents and which contains, in addition to methylene or methine units, one of the following bridge members: oxygen, sulfur, --SO--, --SO.sub.2 -- or --N(R.sup.i)--, where R.sup.i is hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.3 -C.sub.6 -alkenyl or C.sub.3 -C.sub.6 -alkynyl;R.sup.4 is hydrogen, halogen or phenyl, where the phenyl group may be unsubstituted, partially or fully halogenated and may carry, if it is not fully halogenated, one to three substituents which are as defined in the claims,and the preparation and use thereof.