In the Philippines the focus of research is integrated disease management (IDM) of Bacterial Crown Rot (BCR) which is caused by bacteria of the genus Erwinia. Aspects of IDM that are being investigated include identification of Erwinia strains, disease transmission, identification of resistant strains of papaya plants, natural defence mechanisms, and in-field management.
A developing theory for the transmission of BCR is that it is spread with windblown rain between plants and that infection is facilitated by wind damage, which provides an entry point for the bacteria in previously disease-free plants. So both dwarf plants (which are likely to suffer less damage from strong winds) and those with less susceptibility to the bacteria will most likely suffer less from the disease.
|Aira Waje screening papaya breeding lines for resistance to BCR disease under glass-house conditions in the Philippines. Photo: David Hall |
|Putative BCR-resistant papaya breeding lines growing in big plastic bags inside a net house. Photo: David Hall|
While in Queensland, Aira also visited commercial papaya plantations to learn how a commitment to hygiene and sanitation is a prime strategy for pest and disease management.
The research is part of ACIAR project HORT/2012/113 ‘Integrated disease management strategies for the productive, profitable and sustainable production of high quality papaya fruit in the southern Philippines and Australia’ which is being conducted by Queensland’s DAF.