Alternative Strategies for Controlling Plant Diseases Caused by Pseudomonas syringae

Abstract

The most common strategy for controlling diseases caused by Pseudomonas syringae is, as it has been for more than 5 decades, to spray bactericides. These mainly include a variety of copper compounds or other heavy metals, with or without various combinations of fungicides or other pest-control chemicals. Spraying with antibiotics or other organic bactericides have also been used, but to a lesser extent. Unfortunately, these strategies have never been satisfactory, resulting in heavy crop losses during severe epidemics. Over the last years, pathogenic strains that are resistant to copper spraying have been detected globally and are threatening the continuation of this strategy. Three different strategies are slowly being introduced into the field, (i) seed disinfection by heat or a combination of heat and bactericides, (ii) biological control by antagonistic microorganisms, and (iii) soil solarization especially against pathogens that spend part of their life cycle in the soil. Additional minor strategies include: (i) spraying infested plants with natural-occuring antibacterial compounds, and (ii) various techniques of sustainable agriculture without the use of chemicals (organic farming).