HERBIZIDE TETRAHYDROPYRAN-2,4-DIONE

Tetrahydropyran-2,4-diones of the formula in which the substituents and the index have the following meaning: R is hydrogen; C1-C6-alkyl; C2-C6-alkenyl; C2-C6-alkynyl; optionally substituted C1-C6-alkyl; optionally substituted phenyl; C1-C6-alkylsulphonyl; optionally substituted benzenesulphonyl; C2-C6-alkylcarbonyl; C3-C6-alkenylcarbonyl; or optionally substituted benzoyl; R is C1-C6-alkyl; C2-C6-alkenyl; C2-C6-alkynyl; C1-C6-haloalkyl; or C3-C6-cycloalkyl; A, B and D are =CH- or =N-, E is oxygen, sulphur or -NR -, where R is hydrogen, C1-C6-alkyl; C2-C6-alkenyl; C2-C6-alkanoyl; optionally substituted benzoyl; benzyl; or optionally substituted phenyl; X stands for n identical or different substituents from the group comprising halogen, C3-C6-cycloalkyl; optionally substituted C1-C6-alkyl or C2-C6-alkenyl; C2-C6-alkynyl; C1-C6-alkoxy; C2-C6-alkenyloxy; C1-C6-alkylthio; C1-C6-alkoxycarbonyl; C2-C6-alkanoyloxy; optionally substituted benzoyloxy or optionally substituted NR R ; formyl; C2-C6-alkanoyl and its imine, oxime and Schiff's base; or optionally substituted phenyl; R and R are hydrogen, C1-C6-alkyl, phenyl, C2-C6-alkanoyl, benzoyl or benzyl; Z is oxygen or NOR , R is optionally substituted C1-C6-alkyl; C2-C6-alkenyl; C2-C6-alkynyl; C2-C6-haloalkynyl; or optionally substituted thenyl; n is 0, 1 or 2, and their environmentally tolerable salts and compositions containing them.