More Ecological Research Needed for Effective Biocontrol of Plant Pathogens

Abstract

Effective use of biocontrol agents (BCAs) is a potentially important component of sustainable agriculture. The ecological processes determining the success of biocontrol are complex, which may explain that there has been a limited amount of success in biocontrol of plant diseases in field crops. Even for successful biocontrol cases in cultivation under protection, control efficacies are often variable. To improve efficacies achieved through use of single BCA products, there has been increasing interest in using mixtures of BCAs. Despite the frequent claim in the literature that synergy between two BCAs was observed, true synergy is rarely observed. Recent theoretical modelling studies suggested that in order to predict the biocontrol outcomes we need to understand not only the main biocontrol mechanisms involved but also the extent of environemntal patchiness, the level of biocontrol activity and survival of individual BCAs in relation to external conditions. This chapter reviewed recent research findings on the interaction outcomes between pathogens and BCAs in relation to genetics and external factors, illustrating the complex nature of microbial interactions. We propose that research on the ecological aspect of microbial interactions should be an integral part of biocontrol research and development to improve effective use of microbial BCAs in commercial agriculture.