A method of using a beef extract or a protein hydrolisate or a mixture of beef extract and protein hydrolisate, as active substance, for treatment and/or prophylaxis of plants against the action of pathogens is described. A composition including a beef extract or a protein hydrolisate or a mixture of beef extract and protein hydrolisate, as active substance, for treatment and/or prophylaxis of plants against the action of pathogens is also described.
