The invention concerns a method for prophylaxis of infections by fungi, particularly by oomycetes, and of bacterial infections in crop and ornamental plants. Areas of application are vine, fruit, vegetable and ornamental plant growing. The method of the invention is characterized in that an aqueous solution of a protease, alone or in combination with ß-glucanases and/or chitinases, is prepared, stabilizers, stickers and wetters are added, and the additized solution is applied by conventional techniques to the plants a number of times within the vegetation period, preferably ahead of weather-related phases of high infection threat.
