Dihydropyridazinones, pyridazinones and related compounds as fungicides

A compound of the formula ##STR90## wherein A is --(CHR.sup.2).sub.n --CHR.sup.7 --Z--;

• D is CR.sup.6 or nitrogen;
• Q is an aromatic group selected from ##STR91## X is oxygen (O) or sulfur (S);
• Z is carbonyl (C=O), or thiocarbonyl (C=S);
• wherein (i) R.sup.1 is alkynylalkenyl, alkynyl, haloalkynyl, phenylalkynyl, dialkynyl,
• heterocyclylalkynyl, cycloalkylalyl, alkenylalkynyl, hydroxyalkynyl, alkoxyalkynyl, alkanoyloxyalkynyl, formylalkynyl, trialkylsilylalkynyl, trialkyltinalkynyl, haloalkenylalkynyl, carboxyalkynyl, or alkoxycarbonylalyl;
• R.sup.2 is hydrogen, (C.sub.1 --C.sub.3)alkyl, phenyl, or halogen;
• R.sup.7 is hydrogen, (C.sub.1 -C.sub.3)alkyl, phenyl, halogen, alkynylalke nyl, alkynyl, dialkyyl, haloalkynyl, or alkenylalkynyl;
• R.sup.3 and R.sup.6 are independently hydrogen, alkoxy or halogen;
• R.sup.4 is hydrogen, halogen, alkoxy or nitro;
• and
• R.sup.5 is hydrogen, halogen, nitro, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, haloalkylthio, phenyl, phenoxy or cyano;
• or
• (ii) R.sup.2 and R.sup.3 together form a (C.sub.1 -C.sub.3)alkyl, (C.sub.2 -C.sub.3)alkylene or carbonyl link and R.sup.1, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are as above;
• or
• (iii) R.sup.2 and R.sup.7 together form a fused phenyl ring and R.sup.1, R.sup.3, R.sup.4,
• R.sup.5 and R.sup.6 are as above;
• n is 2;
• R.sup.6 is hydrogen, (C.sub.1 -C.sub.3) alkyl, phenyl, CN or halo and agronoxnically acceptable salts thereof.