THE VIABILITY AND PERSISTENCE OF ERWINIA AMYLOVORA IN APPLES DISCARDED IN AN ORCHARD ENVIRONMENT
The viability, persistence and possible spread of Erwinia amylovora in apples discarded in an orchard over a 20 day period at flowering were evaluated. The calyxes of 600 apples were each inoculated with c.106 cfu/ml of a strain of E. amylovora resistant to rifampicin and nalidixic acid. The inoculated apples were then systematically distributed throughout a flowering orchard. Quantitative determination by plating on an antibiotic resistance medium showed that there was a X 104 decline in E. amylovora populations over the 20 day period. E. amylovora was not detected on any of the apple flowers or leaves collected from the orchard. E. amylovora was not detected either in rainwater or on insects trapped and tested during the 20 day sampling period. E. amylovora was never detected in the orchard nor were any subsequent symptoms of fire blight observed. The results suggest that E. amylovora is not spread from calyx-infested apples to susceptible hosts.
Taylor, R.K., Hale, C.N. and Marshall, J.W. (2002). THE VIABILITY AND PERSISTENCE OF ERWINIA AMYLOVORA IN APPLES DISCARDED IN AN ORCHARD ENVIRONMENT. Acta Hortic. 590, 153-155
fire blight, Erwinia amylovora, fruit-borne inoculum, dissemination