Ecology and control of tomato bacterial canker and detection methods of its pathogen.
The density of Clavibacter michiganensis subsp. michiganensis required to cause bacterial canker of tomato was >106 c.f.u./g tomato leaves. No disease was observed at a density of <103-105 c.f.u./g. The disease was more severe in an open field than in a field sheltered from rain by a plastic film. It is concluded that the multiplication and dissemination of C. michiganensis subsp. michiganensis increased in wet weather conditions and that cultivation under plastic film could help to control the disease. A selective medium, developed for the isolation of C. michiganensis subsp. michiganensis from plant material or soil, was particularly useful for determining population density. It is concluded that ELISA was a useful technique for detecting the pathogen and for rapidly diagnosing the disease.