Background
Phomopsis cane and leaf spot caused by the fungus Phomopsis viticola is a disease of grapevines that can be highly destructive if weather conditions are favourable. It is not known to occur in Western Australia but is present in other grape growing regions of Australia and overseas.
The disease is favoured by extended periods of rainfall post budburst that can lead to yield losses of up to 30%. Yield loss can occur through reduction of viable canes, reduced budburst and bunch infection. This leads to reduced production of bunches, lower quality of fruit and reduced yields.
The introduction of DNA sequencing methods has resulted in extensive taxonomic revision of the Phomopsis group of fungi in recent times and name changes have occurred. This information has supported prior studies showing that P. viticola is absent from WA.
Hosts
Vitis vinifera is the primary host of this pathogen. Secondary hosts are other Vitis spp. including sand grape (Vitis rupestris), fox grape (Vitis labrusca) and Virginia creeper (Parthenocissus quinquefolia). This fungus is known to infect leaves, stems, inflorescences, canes, rachis and berries.
Distribution
Phomopsis cane and leaf spot has been recorded in Victoria, New South Wales and South Australia. Phomopsis viticola is present in the viticultural areas of Coonawarra, Mildura, Rutherglen, Mudgee, the Hunter Valley and the Barossa Valley.
Phomopsis viticola is present throughout other viticultural areas in Asia, Europe, Africa, North America, parts of South America and New Zealand. Countries where it is present include China, India, Japan, Turkey, Belgium, Serbia, Montenegro, France, Germany, Greece, Hungary, Italy, Netherlands, Portugal, Romania, Switzerland, Ukraine and the UK.
In North America, P. viticola is found in California, New York and Canada, and in South America it is found in Venezuela and Chile.