1-aryl-naphthoic acid amide and microbicides containing these

1-Aryl-2-naphthoylamines of the formula I are described,wherein R1, Halogen, nitro, cyano, unsubstituted or by halogen and / or Ci-C3-Alkoxy mono- or polysubstituted Ci-C6Alkyl, C3-C6Cycloalkyl, OR4, NR5R6,] CO2R5, CONRsR6 or NHCOR7 or wherein two adjacent positions in the nucleus are bridged by an unsubstituted or fluorine mono- or polysubstituted methylenedioxy or ethylenedioxy group, wherein further R4 Hydrogen or C1-C6Alkyl means unsubstituted or by C1-C3Alkoxy or mono- or polysubstituted by halogen, or for C is3-C4Alkenyl, 2-propynyl, 3-halo-2-propynyl,or COR7 stands,Rs and R6 independently of one another H or C1-C4Alkyl,R7 for C1-C4Alkyl andZ is O or NH,a and b represent the number of occupied positions in each ring anda stands for the numbers 1-3, b stands for the numbers 0-3, whereby the individual groups R1 are the same or different if the sum of a and b is greater than 1,X is 0, S or NH,R2 and R3 independently unsubstituted or by C1-C4Alkoxy, halogen, cyano substituted C1-C6Alkyl or else C3-C7-Cycloalkyl, C3-C7Alkenyl or the restrepresents, in whichn = 0 or 1, furtherR2 and R3 also together a C4-C7Alkylene chain, which with the nitrogen atom connecting them unsubstituted or by C1-C4Alkyl mono- or di-substituted heterocycle can form, with a methylene group from this chain by 0, S or NR7 can be replaced. The compounds of formula I have microbicidal activity and can be used advantageously for crop protection.