Fungicides for the control of take-all disease of plants

A method of controlling disease in a plant caused by Gaeumannomyces sp. comprising applying to the plant locus a fungicidally effective amount of a fungicide of the formula ##STR3## wherein Z.sub.1 and Z.sub.2 are C and are part of an aromatic ring which is benzothiophene;

• and
• A is selected from --C(X)-amine wherein the amine is an unsubstituted, monosubstituted or disubstituted nonheterocyclic amino radical, --C(O)--SR.sub.3, --NH--C(X)R.sub.4, and --C(.dbd.NR.sub.3)--XR.sub.7 ;
• B is --W.sub.m --Q(R.sub.2).sub.3 or selected from o-tolyl, 1-naphthyl, 2-naphthyl, and 9-phenanthryl, each optionally substituted with halogen or R.sub.4 ;
• Q is C, Si, Ge, or Sn;
• W is --C(R.sub.3).sub.p H.sub.(2-p) --;
• or when Q is C, W is selected from --C(R.sub.3).sub.p H.sub.(2-p), --N(R.sub.3)mH(.sub.1-m), --S(O)p--, and --O--;
• X is O or S;
• n is 0, 1, 2, or 3;
• m is 0 or 1;
• p is 0, 1, or 2;
• each R is independently selected from
• a) halo, formyl, cyano, amino, nitro, thiocyanato, isothiocyanato, trimethylsilyl, and hydroxy;
• b) C1-C4 alkyl, alkenyl, alkynyl, C3-C6 cycloalkyl, and cycloalkenyl, each optionally substituted with halo, hydroxy, thio, amino, nitro, cyano, formyl, phenyl, C1-C4 alkoxy, alkylcarbonyl, alkylthio, alkylamino, dialkylamino, alkoxycarbonyl, (alkylthio )carbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylsulfinyl, or alkylsulfonyl;
• c) phenyl, furyl, thienyl, pyrrolyl, each optionally substituted with halo, formyl, cyano, amino, nitro, C1-C4 alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, dialkylamino, haloalkyl, and haloalkenyl;
• d) C1-C4 alkoxy, alkenoxy, alkynoxy, C3-C6 cycloalkyloxy, cycloalkenyloxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, dialkylamino, alkylcarbonylamino, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylcarbonyl, alkylcarbonyloxy, alkoxycarbonyl, (alkylthio)carbonyl, phenylcarbonylamino, phenylamino, each optionally substituted with halo;
• each R.sub.2 is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl and phenyl, each optionally substituted with R.sub.4 or halogen;
• and wherein, when Q is C, R.sub.2 may also be selected from halo, alkoxy, alkylthio, alkylamino, and dialkylamino;
• or
• wherein two R.sub.2 groups may be combined to form a cyclo group with Q which is 1-methylcyclopropyl, 1-methylcyclobutyl, 1-methylcyclopentyl, or 1-methylcyclohexyl;
• R.sub.3 is C1-C4 alkyl;
• R.sub.4 is C1-C4 alkyl, haloalkyl, alkoxy, alkylthio, alkylamino, or dialkylamino;
• and
• R.sub.7 is C1-C4 alkyl, haloalkyl, or phenyl, optionally substituted with halo, nitro,
• or R.sub.4 ;
• or an agronomic salt thereof.