Pathogenicity testing showed that the injected isolates formed brown spots on the leaves, water soaked lesions and greasy spots on the stem after 4–5 days of inoculation around the sites of inoculation and death of the plant occurred about 15 days after inoculation (Figure 2A, 2B). These symptoms observed are typical of those found in natural papaya dieback infection. Control plants showed no symptoms of the disease. E. mallotivora was recovered from the lesions as pure cultures, supporting our preliminary results that suggest that this bacterium is responsible for papaya dieback disease; the same pathogen has been reported to infect M. japonicus with only mild symptoms exhibiting as small lesions on the stem but not causing dieback of the infected shoot [7]. However, with papaya, E. mallotivora showed severe symptoms and caused dieback of the infected shoot, leading to the destruction of the plants without evidence of canker symptom