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 R1 is difluoromethyl or trifluoromethyl; Y is -CHR2- or and R2 is hydrogen or C1-C6alkyl; 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.