Phomopsis viticola, pathogenicity and management

In Australia, the fungi Phomopsis type 1 and type 2 are associated with Phomopsis cane and leaf spot on grapevine. Currently, fungicides are applied to control the disease but these may be unwarranted if vineyards are infected solely by type 1. Experiments were conducted in the glasshouse and at four vineyards, in the Adelaide Hills and Southern Fleurieu Peninsula, SA to assess the effect of type 1 on grapevine. It was shown that Phomopsis type 1 did not cause injury to vines and is not associated with bud loss. It is recommended that the application of fungicides is not warranted for the control of type 1. To eliminate confusion between Phomopsis type 1 and type 2, the term Diaporthe should be used for type 1 as it does not cause disease.