Evaluation of the Peacock Eye Disease Management (PedMan) System in Highly Susceptible Olive Cultivar and Using the System for Addressing Key Biological Questions

Peacock eye disease, caused by Venturia oleaginea, is a major foliar disease of olive (Olea europaea) in Mediterranean regions, resulting in defoliation, reduced tree vigor, and yield losses. Effective disease management relies on precise fungicide timing. In this study, we evaluated a decision support system (DSS) named PedMan (Peacock eye disease Manager), designed to predict infection events and optimize fungicide application timing in highly susceptible olive cultivars based on rainfall and temperature conditions. PedMan recommendations were examined in seven independent grove experiments conducted during the 2023/24 and 2024/25 growing seasons in commercial olive orchards in Israel. In addition, simulation analyses were performed using weather data from 11 meteorological stations representing diverse climatic regions. Field evaluation showed that fungicide applications timed according to PedMan recommendation significantly reduced leaf abscission by approximately 60% compared with untreated controls. Applications made contrary to system recommendations did not improve disease control, confirming the reliability of both positive and negative recommendations. Multi-season analyses indicated cumulative disease suppression, with up to 85% reduction in leaf abscission after three consecutive years of correctly timed applications. The system was implemented by olive growers in 2025/6 with applicable success. Simulation results showed that most infection alerts occurred in autumn and early winter. Across all regions and seasons, PedMan recommended 0-3 fungicide applications per season, comparable to or fewer than conventional spray programs. These findings demonstrate that PedMan is a robust, field-validated DSS that improves fungicide timing, enhances disease control efficiency, and supports sustainable management of peacock eye disease without increasing spray instances under Mediterranean conditions.