Characterization of a bacterial collar and rhizome rot of banana (Musa paradisiaca) caused by strains of Erwinia chrysanthemi pv. paradisiaca

A serious collar and rhizome rot disease of banana was observed in the north region of Maharashtra state in post rainy season. The disease was caused by the bacterial strains of Erwinia chrysanthemi pv. paradisiaca identified and characterized by morphological, physiological, biochemical and pathogenicity tests. The infection occurred on new banana plantation of one month old in poorly drained soil. In post rainy season, banana plantations of 8 to 10 weeks were found severely infected. E. chrysanthemi pv. paradisiaca produced soft rot symptom on healthy banana rhizomes within three weeks. Two strains were isolated from the collar and rhizome rotted diseased samples which were similar in morphological, physiological and biochemical characteristics, however they differed in the virulence aggressiveness to cause the disease in banana. Strain II caused soft rot symptoms within 19 days, however strain I produced it within 23 days of inoculation with suspension of 3×10 8 CFU ml -1 . The result of this study revealed that strain II was more aggressive as compared to strain I of E. chrysanthemi pv. paradisiaca.