Substituted guanidines as fungicides

A fungicide comprising, as an active ingredient thereof, at least one selected from a compound of formula [I]:

• or a salt thereof,
• wherein:
• A1represents heterocyclyl, arylene optionally substituted with C1-6 alkyl or halogeno, or —N(H)—;
• A2 represents heterocyclyl, arylene optionally substituted with C1-6 alkyl or halogeno, or —N(H)—;
• Q1represents a single bond, phenylene, —CH═CH—, —C≡C—, —O—, —S —, —S(O)—, —S(O)2—, or —N(H)—;
• Q2represents a single bond, phenylene, —CH═CH—, —C≡C—, —O—, —S —,S(O)—, —S(O)2—, or —N(H)—;
• X represents alkylene, alkenylene, alkynylene, -Ta-O-Tb, -Ta-S-Tb, or -Ta-N(H)-Tb-;
• Z represents alkylene, alkenylene, alkynylene, -Ta-O-Tb, -Ta-S-Tb, or -Ta-N(H)-Tb-;
• Ta represents a single bond or alkylene optionally substituted with C1-6 alkyl, halogeno, or oxo;
• Tb represents a single bond or alkylene optionally substituted with C1-6 alkyl, halogeno, or oxo;
• R7 represents hydrogen or hydrocarbon;
• R8 represents hydrogen or hydrocarbon;
• and
• R9 represents hydrogen or hydrocarbon;
• or
• R8 and R9, bonded together, form a divalent organic group;
• or
• R8 and a substituent on X, bonded together, form a divalent organic group.

A plant disease-controlling agent comprising, as an active ingredient thereof, at least one selected from a compound of formula [I]:

• or a salt thereof,
• wherein:
• A1represents heterocyclyl, arylene optionally substituted with C1-6 alkyl or halogeno, or —N(H)—;
• A2 represents heterocyclyl, arylene optionally substituted with C1-6 alkyl or halogeno, or —N(H)—;
• Q1represents a single bond, phenylene, —CH═CH—, —C≡C—, —O—, —S —, —S(O)—, —S(O)2—, or —N(H)—;
• Q2represents a single bond, phenylene, —CH═CH—, —C≡C—, —O—, —S —,S(O)—, —S(O)2—, or —N(H)—;
• X represents alkylene, alkenylene, alkynylene, -Ta-O-Tb, -Ta-S-Tb, or -Ta-N(H)-Tb-;
• Z represents alkylene, alkenylene, alkynylene, -Ta-O-Tb, -Ta-S-Tb, or -Ta-N(H)-Tb-;
• Ta represents a single bond or alkylene optionally substituted with C1-6 alkyl, halogeno, or oxo;
• Tb represents a single bond or alkylene optionally substituted with C1-6 alkyl, halogeno, or oxo;
• R7 represents hydrogen or hydrocarbon;
• R8 represents hydrogen or hydrocarbon;
• and
• R9 represents hydrogen or hydrocarbon;
• or
• R8 and R9, bonded together, form a divalent organic group;
• or
• R8 and a substituent on X, bonded together, form a divalent organic group.