Biological control agents: the importance for specific and targeted screening techniques to enable their effective and successful implementation

Abstract Biological control agents (BCAs) provide a successful and environmentally beneficial alternative to synthetic pesticides for plant pathogen control. Despite this, the identification of BCAs through screening techniques, has not been widely defined and understood. One of the research gaps for BCAs, is that many current screening techniques used for BCAs, have minimal replicated studies, resulting in limited research to demonstrate their success and viability for commercial application. This review identifies current literature of two key BCA components required for their successful use in global agriculture. The first is defining the current BCA screening techniques, encompassing direct and indirect methods of phenotypic and genotypic screening. The second is how current screening techniques can be developed in conjunction with new screening methods of BCAs for success. There exists in agriculture, a demand to improve BCAs identification through screening techniques due to many synthetic chemicals for pest and disease mitigation becoming restricted globally. Methods currently used for screening techniques of BCAs were originally developed for synthetic pesticides and may not be appropriate for BCAs. Incorrect screening methods may result in many potential BCAs being defined as ineffective against target pathogens. The review develops an understanding of the current gap in research and literature in the screening techniques for BCAs, which highlights the importance of BCAs to be screened correctly. The complexity of screening BCA candidates, coupled with difficulties in repeatable protocols for effective practical screening, highlights that for a successful future with BCA adoption, increased research is critical to address both components.