Multiple-strain biological control agents and their impact on soil borne plant diseases

Soilborne plant pathogens cause significant crop losses worldwide. The use of biological control agents (BCAs) to suppress plant diseases has gained much interest as an alternative to chemical pesticides. Single-strain BCAs have demonstrated efficacy against some soilborne pathogens, but multiple-strain mixtures may provide greater and more consistent disease control. This review examines current research on Multiple-BCA strain mixtures, including their mechanisms of action, compatibility, field efficacy, and potential risks. Numerous studies indicate mixtures can provide broad-spectrum suppression through complementary and synergistic interactions among strains. Compatibility testing protocols have enabled the development of effective multi-strain products. Field trials demonstrate these products often perform comparably or better than single strains or chemical fumigants. However further research optimizing formulation, delivery, and environmental fit of mixtures is needed. Ultimately, multi-strain BCAs offer an promising sustainable tool for integrated management of soilborne crop diseases.