A method of controlling phytopathogenic diseases on useful plants or on propagation material thereof, which comprises applying to the useful plants, the locus thereof or propagation material thereof a combination of components A) and B) in a synergistically effective amount, wherein component A) is a compound of formula (I), wherein R<；SUB>；1 <；/SUB>；is difluoromethyl or trifluoromethyl and R<；SUB>；2 <；/SUB>；is C<；SUB>；1<；/SUB>；-C<；SUB>；6<；/SUB>；alkyl, C<；SUB>；1<；/SUB>；-C<；SUB>；4<；/SUB>；alkoxy-C<；SUB>；1<；/SUB>；-C<；SUB>；6 <；/SUB>；alkyl or C<；SUB>；1<；/SUB>；-C<；SUB>；6 <；/SUB>；haloalkyl； or a tautomer of such a compound； and component B) is a compound selected from compounds known for their fungicidal and/or insecticidal activity, is particularly effective in controlling or preventing fungal diseases of useful plants.一種控制在有用植物或其繁殖物質上的植物致病性疾病之方法，特別有效控制或預防有用植物的真菌疾病，該方法包含以協同有效量之成分A)與B)之組合施予有用植物、其所在地或其繁殖物質，其中成分A)為式I化合物：其中R1為二氟甲基或三氟甲基，及R2為C1-C6烷基、C1-C4烷氧基-C1-C6烷基或C1-C6鹵烷基；或這種化合物之互變體；及成分B)為選自已知其殺真菌及/或殺昆蟲活性之化合物的化合物。
