In the recent past, papaya was cultivated primarily as a home garden crop. However, due to the increasing demand in the local market and its increasing export markets, papaya is now grown on a much larger scale and in a more organized manner. Presently, papaya is exported to Maldives, Middle East and, some European countries. To expand the export market of this fruit to the lucrative EU markets, it is important that the postharvest management practices be improved to meet the stringent quality standards of these countries. Common causative agents for post harvest diseases of papaya are the fungi of Colletotrichum species.

In the new method devised by Dr. Hewajulige to improve the post harvest management of papaya, as the first step, Dr. Hewajulige identified the antifungal activity of chitosan extracted from head and shell waste of prawn against Colletotrichum sp Samples of the Rathna variety of papaya, which is one of the two varieties common in the country, were treated with an aqueous solution of chitosan and stored at low temperature at a pre-identified maturity stage. This treatment extended the shelf life of papaya for 14 days without any adverse effect on the flavour.