The result showed that the papaya seedlings treated with 40 mg L-1 of chitosan at
7 days interval for 8 weeks could increase the plants height 1.1-1.6 fold higher than the control (18.7 cm.)
Moreover, Necrosis test on papaya leaves treated with 40 mg L-1 of chitosans clearly indicated the plant resistanceagainst Phytophthora palmivora