Heterocyclyluracils

A heterocyclyluracil of the formula:

• wherein
• R1 represents formyl, hydroximinomethyl, alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy moiety, carbamoyl, thiocarbamoyl or CF3
• R2 represents hydrogen, cyano, halogen or unsubstituted or halogen-substituted C1-C4-alkyl and
• Het represents pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, pyrazolyl, oxazolyl, isoxazolyl or thiazolyl, where these radicals are unsubstituted or mono- to trisubstituted by identical or different substituents selected from the group consisting of hydroxyl, mercapto, amino, cyano, nitro, carboxyl, carbamoyl, thiocarbarnoyl, halogen, alkyl having 1 to 6 carbon atoms, alkoxyalkyl having 1 to 4 carbon atoms in the alkoxy moiety and 1 to 6 carbon atoms in the alkyl moiety, alkoxy having 1 to 6 carbon atoms, halogenoalkoxy having 1 to 6 carbon atoms and 1 to 5 halogen atoms, alkoxyalkoxy having 1 to 6 carbon atoms in each alkoxy moiety, alkylthio having 1 to 6 carbon atoms, halogenoalkylthio having 1 to 6 carbon atoms and 1 to 5 halogen atoms, alkylsulphinyl having 1 to 6 carbon atoms, halogenoalkylsulphinyl having 1 to 6 carbon atoms and 1 to 5 halogen atoms, alkysulphonyl having 1 to 6 carbon atoms, halogenoalkylsuphonyl having 1 to 6 carbon atoms and 1 to 5 halogen atoms, alkylcarbonyl having 1 to 6 carbon atoms in the alkyl moiety, halogenoalkylcarbonyl having 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkyl moiety, alkoxycarbonyl having 1 to 6 carbon atoms in the alkoxy moiety, halogenoalkoxycarbonyl having 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkoxy moiety, alkylamino having 1 to 6 carbon atoms, dialkylamino having 1 to 6 carbon atoms in each alkyl moiety, halogenoalkylamino having 1 to 5 halogen atoms and 1 to 6 carbon atoms, alkylaminocarbonyl having 1 to 6 carbon atoms in the alkyl moiety, dialkylaminocarbonyl having 1 to 6 carbon atoms in each alkyl moiety, alkylsulphonylamino having 1 to 6 carbon atoms in the alkyl moiety, halogenoalkylsulphonylamino having 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkyl moiety, N,N-bis-alkylsulphonylamino having 1 to 6 carbon atoms in each alkyl moiety, N,N-bis-halogenoalkylsulphonyl-amino having 1 to 5 halogen atoms and 1 to 6 carbon atoms in each halogenoalkyl moiety, N-alkyl-N-alkylsulphonylamino having 1 to 6 carbon atoms in the alkyl moiety and 1 to 6 carbon atoms in the alkylsulphonyl moiety, N-halogenoalkyl-N-halogeno-alkylsulphonyl-amino having 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkyl moiety and 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkylsulphonyl moiety, N-alkylcarbonyl-N-alkylsulphonyl-amino having 1 to 6 carbon atoms in the alkyl moiety of the alkylcarbonyl group and 1 to 6 carbon atoms in the alkylsulphonyl moiety, N-halogenoalkylcarbonyl-N-halogenoalkylsulphonyl-amino having 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogenoalkyl moiety and 1 to 5 halogen atoms and 1 to 6 carbon atoms in the halogeno-alkylsulphonyl moiety and N-alkylsulphonyl-N-phenyl-carbonylamino having 1 to 6 carbon atoms in the alkylsulphonyl moiety and being unsubstituted or mono- to trisubstituted by identical or different substituents selected from the group consisting of halogen, alkyl having 1 to 4 carbon atoms, dialkylamino having 1 to 4 carbon atoms in each alkyl group and alkoxy having 1 to 4 carbon atoms.