Downy mildew is a major disease of grapevines caused by the fungus Plasmopara viticola. This species is unique to grapevines and is established in all Australian grapegrowing districts. The fungus is spread by wind and water and favourable conditions for infection and disease development occur in warm wet weather, especially in late spring and early summer. In most districts, vines are at greatest risk from 3–6 weeks after budburst until berries are pea-sized. Inadequate control of downy mildew can result in severe crop losses. Most commercial varieties are susceptible to this disease. Essential components for strategic management of downy mildew include prediction of infection based on weather events, monitoring the vineyard for symptoms of infection, knowing the disease cycle, and understanding how cultural management practices and available fungicides impact on disease control. This page provides links to help growers understand and manage this grapevine disease.
Fact sheets and website links