Improving Orchard Productivity Using Novel Disease Management Practices for Control of Apple Powdery Mildew in the Northeast USA

View the project final report

Commodities

• Fruits: apples

Practices

• Pest Management: biorational pesticides, chemical control, genetic resistance, weather monitoring

Apple powdery mildew is an endemic foliar disease of apple in the northeastern United States. The pathogen, Podosphaera leucotricha, is largely managed by programs for apple scab, the primary fungal pathogen of concern to apple growers in the northeast. However, global climate change projections forecast that the northeast US region will experience greater periods of heat and increased variability in precipitation in the coming decades; environmental conditions that are conducive to the development of powdery mildew. Fungicides are the primary means of disease management, and application schedules are routine and prophylactic, resulting in unnecessary applications that leads to increased production costs and off-target environmental consequences. This project will develop new methods with which to manage apple powdery mildew using biopesticides and reduced-risk single-site fungicide products, improved management timing based on disease forecasting, and a robust molecular assay to screen for fungicide resistance should it develop. Outreach activities will include providing on-farm fungicide resistance risk consultations based on our molecular assays, presentation of results at regional grower schools and field days, and the development of extension deliverables.

The goal of this multi-year project is to leverage novel technologies and ideas to better manage the disease apple powdery mildew in the northeast USA, and proactively develop methods to assess resistance to highly effective single-site fungicides so that these tools are not lost in later years. Specific objectives include:

(1) Evaluate fungicide management programs that integrate commercially available biopesticide and reduced-risk single-site fungicide products for effective management of apple powdery mildew.

(2) Innovate timing of management practices using weather metrics as a form of disease forecasting to improve control and reduce fungicide inputs.

(3) Continued support for development of a robust PCR assay to identify mutations in target genes involved in single-site fungicide resistance in Podosphaera leucotricha.