Occurrence and Host Range of Ascochyta Phaseolorum in Queensland

Abstract

The presence of Ascochyta phaseolorum as a pathogen of Phaseolus vulgaris in Queensland is reported. The fungus has been found to have a wide host range including vegetable crops, pastures, weeds, and indigenous species. Natural infections were found in 48 hosts in 14 families, and an additional 12 species proved susceptible when inoculated experimentally. Pathogenicity of isolates from French bean towards many of the natural hosts has been demonstrated, and in reciprocal inoculations cultures from field·infected hosts produced symptoms on bean typical of those produced by bean isolates. The fungus is shown to be a weak parasite, requiring some form of wounding to initiate infection under Queensland conditions.