Sero-groups ofErwinia carotovoraassociated with water, soil, tuber, and stems of potato plants in Western Australia

Soft-rot erwinias were isolated from irrigation water, soil, tubers, and stems from spring (1986) and summer (1987) crops of potato at a field in Manjimup, Western Australia. Most of the isolates from all environments in both seasons belonged to Erwinia carotovora pv. carotovora (Ecc), with the exception of those from stems of the summer crop which were predominantly (68%) Erwinia carotovora pv. atroseptica (Eca) and belonged to sero-group SGI. In spring, SGIII was recorded from all environments tested, while SGI was found only in stems and tubers. SGVI was recorded from stems (8%) and soil (15%) only in summer and in water (6.4%) only in spring. In spring, SGV, which was the predominant (28.2%) sero-group isolated from stems, was also found in water, soil, and tubers. In summer, of the SGs isolated from stems, SGIII occurred in soil and tubers and SGVI in soil. Although SGXXIX was the most common in water in both seasons, it was isolated from stems only in summer. In a pathogenicity test, repres...