Towards sustainable disease management in northeastern apples using risk forecasts and cultural controls

View the project final report

• 2012 annual report
• 2013 annual report
• 2014 annual report

Commodities

• Fruits: apples, general tree fruits

Practices

• Crop Production: application rate management
• Education and Training: decision support system, demonstration, extension, on-farm/ranch research, participatory research, workshop
• Pest Management: biorational pesticides, chemical control, cultural control, eradication, integrated pest management, sanitation, weather monitoring
• Soil Management: organic matter

Apple growers in the Northeast have maintained excellent working partnerships with researchers, Extension and private professionals over the past thirty years, making their orchards more environmentally and economically sustainable through use of integrated pest management. However, management of the most threatening disease, apple scab caused by the fungus Venturia inaequalis, continues to depend exclusively on fungicides. Reductions in the number of fungicide sprays were achieved by a switch from prophylactic applications made before infection periods to use of newer DMI and strobilurin fungicides with postinfection activity. But scab strains resistant to the postinfection fungicides have evolved and they are no longer reliably effective. As a result, over the past decade fungicide use for scab management has increased, returning to frequent, protective applications. Measuring the amount of scab inoculum, and reducing scab inoculum using sanitation, combined with weather-based decision support tools to track infection risk, have been effective at managing scab with fewer fungicide applications. Growers and crop advisors worry that these methods require more effort and expense, and that reducing the number of fungicide applications will expose them to unacceptable risk. Without additional confirmation of the efficacy and demonstrated practicality of these methods in controlled research settings and in commercial orchards, these methods will continue to be underutilized. This project will give growers an understanding of the feasibility and reliability of these practices through education, research evaluation, and grower demonstrations. Adopting these tactics will allow New England apple growers to reverse the trend of increasing fungicide use, and serve as a model for implementation of reduced fungicide methods in organic and conventional orchards throughout the Northeast.

Fifty apple growers will document adoption of scab management alternatives on a total of 500 acres, reducing their fungicide use and maintaining or reducing scab incidence in those blocks. Our calculations indicate that this should save a total of from $50,000 to $75,000 in production costs per year.