ABSTRACT
Bacterial pathogens cause destructive diseases and remain a formidable limiting factor to crop production all over the world. The ability of bacterial pathogens to multiply and reach huge population levels rapidly under favorable conditions, poses problems in containing the incidence and spread of bacterial diseases in various crops cultivated in different ecosystems. Soilborne bacterial plant pathogens differ in their virulence, host range, survivability and responses to changes in the existing soil environments and to chemicals applied. Ralstonia solanacearum is a soilborne, xylem-limited pathogen, known to be responsible for bacterial wilt diseases of a wide range of crop plant species and many weed and wild species without necessarily inducing visible symptoms, contributing inoculum for infection of crops. Production of exopolysaccharides by many bacterial pathogens either in culture or in planta has been observed. Potato bacterial ring rot (BRR) caused by Clavibacter michiganensis subsp. sepedonicus has worldwide distribution. Occurrence of BRR has been observed in Asia, Europe and North America and South America.
