ABSTRACT
Competitive interactions among microbes on plant surfaces can influence disease development, and considerable efforts are concentrated towards increasing the effectiveness of resource competition in reducing pathogen populations and disease. Pseudomonas syringae is used as a model to consider the types of ecological information needed to enhance competition-based biocontrol. Competition between coexisting populations can be broken down into at least two distinct categories: competition for limiting resources; and interaction through some form of physical or chemical attack. Despite the difficulties in definitively resolving mechanisms, competitive interactions have been implicated in biocontrol on a wide range of different plant parts. Niche overlap is a prerequisite for effective competition-based biological control. Theory suggests that the intensity of competitive interactions between coexisting populations will be partly a function of the degree of niche overlap that exists between them. Successful biocontrol will also depend upon the diversity of resource needs within the pathogen population.
