Effect of Composts On Field Soils Affected by Bacterial Wilt of Edible Ginger In Hawaii

Bacterial wilt caused by Ralstonia solanacearum is the most important disease affecting edible ginger (Zingiber officinale) in Hawaii.  Serious outbreaks began occurring in 1993 and large losses continue every year.  R. solanacearum is persistent in soil and following crop failure, fields are abandoned and left unsuitable for ginger production for many years. We are able to detect this pathogen in environmental samples including field soil using SMSA liquid culture enrichment followed by PCR.  This detection method is being used for developing strategies for reclaiming fields for ginger production and we are working towards developing a more quantitative assay using combination of enrichment and real-time PCR.   We are also performing controlled greenhouse studies to evaluate soil amendments including enriched compost and vermicompost preparations, for their ability to reduce pathogen populations in naturally infested field soil prior to planting.