Compounds of formula I wherein R 1 is in each case independently selected from C 1 -C 6 -alkyl; R 2 is in each case independently selected from C 1 -C 6 -alkyl; U is N or CR 3; R 3 is selected from H; R 4 is selected from H, C 1 -C 6 -alkyl; Y is O; Z CR 5; R 5 is independently selected from H: X is independently selected from halogen: n is 1; Q 1 is selected from C 1 -C 6 -alkyl, C 1 -C 6 -halogenalkyl; Q 2 is selected from H, C 1 -C 6 -alkyl; W is O, NQ 4; Q 3 is selected from substituted C 1 -C 15 -alkyl, C(=O)C 1 -C 15 -alkyl, C(=O)aryl, wherein the aliphatic moieties of Q 3 except for substituted C 1 -C 15 -alkyl moieties are unsubstituted or substituted with identical or different groups Q 3a which independently of one another are selected from: Q 3a halogen, C 1 -C 6 -alkoxy, phenyl, wherein phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 31a selected from the group consisting of halogen, wherein the carbocycle, heterocycle, heteroaryl and aryl moieties of Q 3 are unsubstituted or substituted with 1, 2, 3, 4, 5 or up to the maximum number of identical or different groups Q 3b which independently of one another are selected from: Q 3b halogen, phenyl, wherein the phenyl, and wherein the phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 311b selected from the group consisting of halogen Q 4 is H, with the proviso that if U is CR 3 W cannot be O and of an agriculturally acceptable salt thereof. R 1 is in each case independently selected from C 1 -C 6 -alkyl; R 2 is in each case independently selected from C 1 -C 6 -alkyl; U is N or CR 3; R 3 is selected from H; R 4 is selected from H, C 1 -C 6 -alkyl; Y is O; Z CR 5; R 5 is independently selected from H: X is independently selected from halogen: n is 1; Q 1 is selected from C 1 -C 6 -alkyl, C 1 -C 6 -halogenalkyl; Q 2 is selected from H, C 1 -C 6 -alkyl; W is O, NQ 4; Q 3 is selected from substituted C 1 -C 15 -alkyl, C(=O)C 1 -C 15 -alkyl, C(=O)aryl, wherein the aliphatic moieties of Q 3 except for substituted C 1 -C 15 -alkyl moieties are unsubstituted or substituted with identical or different groups Q 3a which independently of one another are selected from: Q 3a halogen, C 1 -C 6 -alkoxy, phenyl, wherein phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 31a selected from the group consisting of halogen, Q 3a halogen, C 1 -C 6 -alkoxy, phenyl, wherein phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 31a selected from the group consisting of halogen, wherein the carbocycle, heterocycle, heteroaryl and aryl moieties of Q 3 are unsubstituted or substituted with 1, 2, 3, 4, 5 or up to the maximum number of identical or different groups Q 3b which independently of one another are selected from: Q 3b halogen, phenyl, wherein the phenyl, and wherein the phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 311b selected from the group consisting of halogen Q 4 is H, Q 3b halogen, phenyl, wherein the phenyl, and wherein the phenyl groups are unsubstituted or substituted with 1, 2, 3, 4 or 5 substituents Q 311b selected from the group consisting of halogen Q 4 is H, with the proviso that if U is CR 3 W cannot be O and of an agriculturally acceptable salt thereof.