The invention relates to a preparation containing at least one chemical fungicide. In addition to the at least one chemical fungicide, a mixture is included which contains at least the strains of Aureobasidium pullulans DSM 14940 and DSM 14941. The at least one chemical fungicide and the mixture of the strains Aureobasidium pullulans are present in the preparation in synergistically active quantities, and the at least one chemical fungicide is selected from fludioxinil or a combination containing fludioxinil and at least one second chemical fungicide. The invention also relates to the use of the preparation and to a method for the prophylaxis or the reduction of the spread of at least one plant disease which is produced by a fungal pathogen.