Survival in soil of bacteria causing common and halo blights of French bean in Victoria

Abstract

Survival of Pseudomonas phaseolicola and Xanthomonas phaseoli in soil between successive bean crops was studied in a field situation at Bairnsdale. P. phaseolicola and X. phaseoli survived on nylon netting for maximum periods of 6 and 3 weeks, respectively, on the soil surface, and for 6 and 2 weeks when buried. On infected leaf, stem and pod tissue P. phaseolicola survived for 20 weeks on the soil surface and for 11 weeks when buried; X. phaseoli survived up to 11 weeks on the soil surface and for 3 weeks when buried. In heavily infected bean plots neither pathogen was carried over from one growing season to the next. It is concluded that infected bean debris in the soil from the previous growing season is not a source of common and halo blight infection in East Gippsland.