An agricultural or horticultural chemical according to the present invention is an agricultural or horticultural chemical containing a plurality of active ingredients, the agricultural or horticultural chemical comprises, as one of the active ingredients, an azole derivative represented by general formula (I), and can be used as a plant disease controlling agent that can reduce the content of an active ingredient: wherein, R1 represents an alkyl group having from 1 to 6 carbons, R2 represents a hydrogen atom, an alkyl group having from 1 to 3 carbons, an alkenyl group or an alkynyl group having from 2 to 3 carbons, A represents a nitrogen atom or a methine group, Y1 represents a halogen atom, and n represents either 0 or 1.