Fungicidal substituted amino acid amides

A substituted amino acid amide derivative of the formula:

• ##STR225## in which R.sup.1 represents straight-chain or branched alkyl having 1 to 6 carbon atoms, straight-chain or branched alkenyl or alkynyl having 2 to 6 carbon atoms, straight-chain or branched halogenoalkyl having 1 to 6 carbon atoms and 1 to 9 identical or different halogen atoms, straight-chain or branched halogenoalkenyl or halogenoalkynyl having 2 to 6 carbon atoms and 1 to 9 identical or different halogens atoms, or unsubstituted or substituted cycloalkyl or cycloalkenyl having 3 to 7 carbon atoms;
• R.sup.3 represents hydrogen;
• and
• R.sup.4 represents i-propyl, s-butyl or 3-pentyl;
• or
• R.sup.3 and R.sup.4, together with the carbon atom to which they are bonded, form a cycloalkyl ring having 3 to 7 carbon atoms;
• R.sup.5 represents hydrogen or alkyl having 1 to 6 carbon atoms;
• and
• R.sup.6 represents pyridyl or pyridyl-C.sub.1-4 alkyl, each of which is optionally substituted in the pyridyl part by one to three identical substituents selected from the group consisting of halogen, alkyl, alkoxy or alkylthio, each of which has 1 to 4 carbon atoms, halogenoalkyl, halogenoalkoxy, or halogenoalkylthio, each of which has 1 to 4 carbon atoms and 1 to 9 identical or different halogen atoms, hydroxyl, cyano, nitro, amino, alkylamino or dialkylamino, each of which has 1 to 4 carbon atoms in the alkyl part, and carboxyl.