Improving Biopesticide Efficacy of Apple Diseases through Co-application with Natural Products

Project Overview

Project Type: Graduate Student
Funds awarded in 2019: $14,685.00
Projected End Date: 10/31/2022
Grant Recipient: University of New Hampshire
Region: Northeast
State: New Hampshire
Graduate Student:
Faculty Advisor:
Anissa Poleatewich
University of New Hampshire

Information Products


  • Fruits: apples


  • Crop Production: biological inoculants
  • Pest Management: biological control, integrated pest management

    Proposal abstract:

    Apple scab, caused by the fungus Venturia inaequalis, is one of the most destructive diseases of apple worldwide. Managing apple scab is especially challenging in the Northeastern United States due to the ideal climatic conditions for infection that can lead to major yield loss. Growers primarily rely on sanitation and fungicide applications to reduce apple scab in their orchards. There is increasing pressure to decrease the use of synthetic chemicals due to concerns of adverse effects on non-pest species and human health, as well as the risk of pathogen resistance development with regular fungicide applications. Availability of alternative tools that can be incorporated into farmer’s Integrated Pest Management program is crucial to ensure the sustainability of our agricultural systems. One strategy of IPM is to harness beneficial microbes (biopesticides) and natural compounds to promote plant growth and suppress disease. Chitosan is a promising natural compound documented to have antifungal and disease suppressive effects. Chitosan has been used successfully in postharvest applications to prevent storage rot and extend shelf life of perishable fruits and vegetables. Preharvest chitosan application has been effective in vegetable crops but there are limited examples of research evaluating preharvest application of chitosan on tree fruits. Finding synergisms between biopesticides and chitosan will allow us to develop best practices for disease management that capitalize on these synergisms. This research will provide growers with innovations that improve environmental stewardship, profitability, and aid in creating a sustainable production system on New England apple farms.

    Project objectives from proposal:

    The overall goal of this research is to improve biopesticide efficacy in suppressing apple scab through finding synergisms with the natural product, chitosan. Reaching this goal will help farmers to reduce losses, decrease reliance on fungicides, and improve overall yield. The specific objectives are to;

    1. Compare commercial chitosan formulations and application rates for efficacy in controlling foliar apple scab

    2. Investigate synergisms between chitosan-based treatments and microbial biopesticides for suppression of apple scab in laboratory and on-farm studies.

    3. Investigate the potential for chitosan formulations to reduce the quantity and viability of overwintering spores of <i>Venturia inaequalis</i> in orchard leaf litter.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.