An evaluation of the wilt-causing bacterium Ralstonia solanacearum as a potential biological control agent for the alien kahili ginger (Hedychium gardnerianum) in Hawaiian forests.
The use of R. solanacearum, collected from diseased rhizomes of ginger in the Hamakuma region of Hawaii, USA, as a biological control agent of a weed species, wild ginger (Hedychium gardnerianum), was evaluated. Host specificity of the isolate was determined and field tests were carried out to determine its efficacy as a biological control agent. The isolate of R. solanacearum caused minor, non-systemic symptoms on Hedychium coronarium, Zingiber zerumbet, Heliconia latispatha and Musa sapientum [Musa paradisiaca]. All of the infected Hedychium gardnerianum plants developed severe chlorosis and wilting within 3-4 weeks of inoculation. It is suggested that the risk of contaminating edible ginger plants is unlikely due to the remote locations of Hedychium gardnerianum infestations.