Case study: Managing potyvirus disease of zucchini in Australia
Virus disease is a major limiting factor to zucchini production and is mostly caused by one or more potyvirus species.
Papaya ringspot virus-type W (PRSV-W) is the main virus found in Queensland, zucchini yellow mosaic virus (ZYMV) dominates in Western Australia and watermelon mosaic virus (WMV) occurs in all regions, but particularly in the Swan Hill area in northern Victoria.
Rapid spread of these viruses by aphids (less than one minute) frequently results in very high disease levels.
Affected crops have reduced fruit set and high numbers of deformed unmarketable fruit. The rapid spread by aphids means insecticides are not effective for disease control.
In previous years, seed companies have invested considerably in developing zucchini varieties with virus tolerance.
As part of the strategic levy investment Area Wide Management of Vegetable Diseases: viruses and bacteria (VG16086), trials of the different varieties in three different Queensland production districts were set up.