BIOLOGICAL CONTROL AGENTS OF FIRE BLIGHT: SUCCESSES AND CHALLENGES

Abstract

Because of the limited number of products available for control of fire blight, the search for alternative methods of control has been a dynamic and productive field of scientific research. Today, only a few biological control agents are registered for control of this disease, representing a relatively small part of the market for products to control fire blight. This is in spite of fire blight being an economically important bacterial disease whose impact could be significantly lowered by simply protecting the flowers from the pathogen, a task that many biological control agents seem able to do. The number of new biological control agents being commercialised might be restricted by problems linked to the registration process. This is especially true for biological control agents that belong to species containing poorly characterised strains of medical or environmental interest. Furthermore, the biological control agents available in the USA were reported to exhibit a much lower and more variable efficacy than streptomycin. This may contribute to the choice by growers to use antibiotics more often than they use biological control agents. The future of biological control agents for the control of fire blight might rest in the ability to incorporate such products in new strategies of control. These strategies might include the use of several biological control agents, but may also include antibiotics or some elicitors.