New diseases caused by virus, fungi and also a bacterium on rubber from Brazil and their impact on international quarantine.

More recently, leaf diseases attributable to virus, other fungi and possibly a bacterium were well recorded as a new disase of the rubber tree. In the state of Amazonas, symptoms of a systemic infection caused by virus (being identified), typified by leaf mosaic, little leaf, malformation and tree stunt were confirmed in clonal nurseries and field plantings in several clones at CNPSD. In tests, the symptoms of virus appeared more distinct at temperatures below 22oC. The new fungal leaf pathogens discovered in the nurseries and fields are Corynespora cassiicola, Periconia manihoticola (previously of minor importance), and an Ascomycete (Dothideaceae) in association with Phyllachora huberi yet to be identified. Also discovered were leaf symptoms in the form of tiny lesions, followed by premature leaf yellowing and fall, suggestive of a bacterial infection. These were reproduced in artificial inoculation with a culture of the bacterium repeatedly isolated from fields of clones Fx 3864, PFB 5, IAN 873 and PA 31. Relating these potentially dangerous new diseases to the welll-being of the rubber industry worldwide, international quarantine measures adopted today against Microcyclus ulei alone must now be reviewed. These should include additional measures for the inspection, identification and preventive pre and postquarantine treatment against the virus, bacterium and hitherto unknown fungi