Biocontrol of Plant Diseases by Means of Antagonist Microorganisms, Biostimulants and Induced Resistance as Alternatives to Chemicals

Abstract

Plant diseases are one of the biggest problems in conventional agriculture as they reduce both yield and crop value. Therefore, it is necessary to establish systems that protect against pests to maintain or improve yields while ensuring high food quality. The chemical pesticides used in conventional agriculture over the last 50 years can contaminate the environment, including soil and water; may leave residues in food; and affect other beneficial organisms that are not targeted by treatment. Therefore, researchers are searching for natural and ecofriendly alternatives for crop protection that avoid the problems associated with chemical pesticides. In recent decades, the natural compounds and beneficial microorganisms for use as biological control agents (BCAs) or plant biostimulators have attracted interest. These treatments have several advantages compared to classic pesticides; for example, they usually exhibit low toxicity, leave zero residue in foods, and their modes of action often allow their use to be preventive or curative. These advantages make them suitable for sustainable agriculture, for fulfilling new demands from the agro-food sector of the Euroregion, as well as for society in the frame of the European Green Deal. The term biocontrol comprises a group of treatments that are based on natural compounds, extracts or microorganisms.