Conservation of sugarcane germplasm: survey of Papua New Guinea, Indonesia and northern Australia.
New Guinea is considered as a centre of diversity for the genus Saccharum with S. officinarum (noble cane), S. edule (edible pitpit), S. robustum and S. spontaneum present in Papua New Guinea (PNG). Both exotic and native pests and diseases may erode this important germplasm for future plant improvement programs locally and worldwide. Identifying these pest and disease problems, and assessing the extent of their distribution in the centre of diversity and their impact on the germplasm, are essential for the development of management strategies to minimize their impact. Surveys were conducted in PNG, northern Australia and eastern Indonesia during 2001-2003. Ramu stunt disease was widespread in PNG, while suspected symptoms of the disease and the insect vectors were observed in Indonesia. Fiji disease was also widespread in PNG, while an unknown sugarcane mosaic was observed in S. edule at Keravat. The moth borers, Chilo spp. and Scirpophaga spp., were observed in both PNG and Indonesia, while Sesamia grisescens, a serious borer pest, was found mainly in PNG. Sugarcane smut was not present in PNG. Eumetopina flavipes, the leafhopper vector of Ramu stunt disease, was recorded at Bamaga (mainland Australia), signalling the need an eradication program, to prevent the Ramu stunt disease affecting the Australian sugar industry.