In the framework of OPTIMA H2020 project, a freely accessible DSS has been developed and is accessible in http://dss.optima-h2020.eu/. Pathogens incorporated into the tool are the following, Alternaria leaf blight for carrots, Downy mildew for vineyards, and Apple scab for apple orchards in Spain (Aragon region), France (Bordeaux region), Italy (Piemonte region) and Greece (Thessaly, Evia and Attica regions). The DSS provides users with a 5-day prediction, in an escalation step of 3 hours, of disease outbreak based on meteorological data, which is presented in a coloured interactive map, based on the risk level: Green for no risk (0%), Yellow for low risk, Orange for medium risk, and Red for maximum risk (~100%). Thus, producers and other stakeholders operating in the agricultural production sector and carrot production can freely access this early prediction system, and consequently organize the agricultural applications such as spraying applications for their cultivations. This tool enables fast decision-taking that leads to reduced qualitative and quantitative product degradation and yield loss that may derive by severe disease outburst. The additional benefits are the reduced and more cost-effective use of PPPs, the lower residues and the reduced environmental and human health impacts that derive from the over-use of PPPs during spraying applications that may not be needed or/and effective.