The OPTIMA DSS is a tool developed under the EU’s Horizon 2020 program (Grant 773718-2) that helps farmers across Europe predict infection risks for three major fungal diseases: downy mildew in vineyards, alternaria leaf blight in carrot fields, and apple scab in orchards. Using weather data, the system provides a 5-day forecast on potential disease outbreaks, displaying risk levels on a color-coded map. This early warning system allows farmers and agricultural stakeholders to plan preventive actions like spraying at the optimal times, helping to protect crops from disease damage. By offering this proactive tool, the OPTIMA DSS reduces crop loss and improves product quality, while also minimizing the use of plant protection products (PPPs), lowering residues, and decreasing environmental and health impacts from unnecessary chemical applications. This integrated, precise approach supports smarter and more sustainable agriculture across Europe.