Erwinia papayae, the bacterial pathogen responsible for the disease, was first identified in 1931 in Java, Indonesia (Gardan et al. 2004), and has since spread to papaya growing countries worldwide—from the Caribbean to South America to South East Asia (Ollitrault et al. 2007).

Papayas are significant cash crops for the papaya-growing countries because of their rapid generation, high yields, and large market demand both locally and internationally (Ollitrault et al. 2007).

In Malaysia, where the disease has plagued farmers for over a decade, papayas have an export value of approximately 24-28 million USD per year (Maktar et al. 2008).

With bacterial crown rot affecting approximately 800 hectares of papaya on the Malaysian Peninsula alone (Maktar et al. 2008), this results in a huge loss in profit for the agricultural industry.

Symptoms of bacterial crown rot begin as angular water-soaked lesions on leaf surfaces and eventually spread through veins and petioles to cause death to the canopy layer of leaves.

Erwinia papayae is a Gram-negative, straight rod bacterium with peritrichous flagella, so diagnosis can be made using a Gram stain.

Thus far, seed-borne transmission is the predominant method of spread and infection; in fact, studies indicate the pathogen has the ability for long-range dispersal via seed (Ramachandran et al. 2015).

Although symptoms can be seen year round, rain and splashing water aid in the transmission and exacerbate the disease (Webb 1985).

E. papayae causes a systemic infection—coalescing brown angular lesions spread from the stem lamina to the crown meristems.

Ollitrault, P., Bruyére, S., Ocampo, J., de Lapeyre, L., Gallard, A., Argoud, L., Duval, M.F., Coppens d’Eeckenbrugge, G., Le Bellec, F. (2007).