Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-22430-003-067-N
Project Type: Non-Funded Cooperative Agreement
Start Date: Jun 1, 2025
End Date: May 31, 2026
Objective:
1. Determine if predator-exclusion effects of nets can be mitigated without loss of codling moth control by:
a. Delaying net deployment
b. Leaving nets partially opened
2. Determine if predator releases can mitigate aphid pressure under netting.
3. Determine the level of reduction in spray penetration/efficacy caused by netting.
Approach:
All objectives will be performed in commercial, organic orchards where drape netting has been installed, in a two-year trial.
For Objectives 1-2, treatments will be compared to each other by sampling: aphids (time counts and number on two most infested shoots), natural enemies (beat trays and sticky cards), codling moth (pheromone traps), and codling moth damage (number of visible stings per fruit, measured at the end of each generation). Each treatment will be replicated five times at the row level (1 plot = 1 row).
1a. Compare net deployment timing, treatments are: (1) petalfall, (2) delay partway into first generation codling moth, (3) delay until second generation codling moth, (4) unnetted control.
1b. Compare net closure level: (1) completely closed, (2) partway closed with bottom loose, (3) unnetted control
2. Compare: (1) releases under net, (2) releases without net, (3) netting with no releases, (4) no netting and no releases. The release program tested will be a grower recommended program of 20,000 lacewing larvae/acre applied twice and 20,000 ladybeetle adults/acre applied twice, on alternating weeks.
3. Compare spray penetration through netting using water-sensitive paper. Six papers will be used per tree at different heights and depths, on five trees per row and five rows per treatment. We will compare penetration on netted and unnetted rows.