Abstract: The invention relates to a method for inducing systemic resistance in plants, thereby protecting plants against a broad range of plant pathogens and disease. The method of the invention comprises the application of a biologically active formulation, comprising a diphenyl ether, to a plant. In accordance with the invention, it has been observed that use of this formulation results in induced systemic resistance in a target plant. Also in accordance with the method of the invention, the formulation has been shown to trigger long-lasting, non-specific systemic resistance in the plant to a variety of pathogens and disease. Furthermore, the method of the invention results in an increase in the levels of plant isoflavones.