October 2010. From Rabaul, PNG, images of discoloured Abelmoschus leaves (aibika). The problem is worse during dry spells. It was thought likely that a virus was the cause, transmitted by the aibika jassid, Amrasca devastans).
The only definitive virus recorded on Abelmoschus is Hibiscus chlorotic ringspot virus (HCRSV), and this has been reported from Fiji, PNG, Solomon Islands and Vanuatu. This is assumed to be beetle transmitted. See:
Brunt A A, Spence NJ (2000) The natural occurrence of Hibiscus chlorotic ringspot virus (Carmovirus; Tombusviridae) in aibika or bele (Abelmoschus manihot) in some South Pacific Island countries. Plant Pathology 49: 798.
There is a photo of Abelmoschus with HCRSV at: http://www.pestnet.org/PhotoGallery/DiseasesofSolomonIslandscrops/tabid/3702/AlbumId/123/PhotoId/2328/Default. And the photo (left, below) was taken during a disease survey in PNG. The leaf tested positive for HCRSV.
However, it was thought more likely that the symptoms in the photos were caused by the jassid. The symptoms are common in aibika throughout PNG. The plant will recover after the dry spell. Also, sprays with Karate (permethrin) at 100-150ml/20L will control the jassids. The jassid also affects peanuts, especially during dry spells.
|