This project focused on white blister on brassicas, powdery mildew on cucurbits and downy mildew and anthracnose on lettuce. The project determined the efficacy and economics which could be achieved with weekly fungicide sprays, disease predictive models, irrigation timing and growing a resistant variety, but the latter was the most superior IPM tool.

It evaluated the benefits of nutrient management; developed a disease predictive model for powdery mildew of cucurbits and a detection kit for airborne spores of white blister.

Major outcomes of the research were:

• White Blister of brassicas: The world’s first white blister spore detection kit was developed for use with the white blister disease predictive model (Brassicaspot). This detection kit is a major addition to the current disease control tools. Scientific and economic analysis of field trials demonstrated that the number of fungicide spray applications based on predictions of the Brassicaspot model could be reduced by 12-13, which corresponded to a 77% reduction in disease on broccoli heads and an increase in profits of 13%, during dry conditions. Irrigating broccoli crops in the morning rather than the evening reduced disease by 58% and increased profit by 3%. Growing a broccoli variety with resistance to white blister reduced disease by 99% and increased profit 11%.
• Downy mildew of lettuce: A disease predictive model for downy mildew on lettuce (BREMCAST) showed timing fungicide sprays based on model predictions could reduce spray programs by 1-3, reduce disease by 50-70% and increase profits by 20%. High rates of calcium nitrate applied to lettuce seedlings reduced susceptibility to downy mildew and anthracnose.
• Powdery mildew: The world’s first powdery mildew disease predictive model (PMRI) for powdery mildew of cucurbits grown under Australian conditions was developed and a preliminary trial indicated a reduction of one spray could be achieved.

This project has been funded by Hort Innovation, using the research and development levies listed below and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

• Vegetable Fund