A decision support system for management of organic vineyards against downy mildew

A DSS (Decision Support System) called Vitebio.net is described for guiding decision about tactical management of downy mildew in organic vineyards. The DSS is available for registered users via the internet in an interactive way. It is based on: (i) a network of weather stations that measure environmental variables; (ii) a 72-h weather forecast system; (iii) a file repository that stores weather data; (iv) a set of mathematical models that use weather data and vineyard-specific information to predict the biological events relevant for decision making; (v) a user interface that makes it possible to readily input vineyard-specific information and obtain supports for decision making; and (vi) a register of the vine-management options already applied that could influence future decisions (e.g., fungicides used, rates, etc.). Output provides information on: (i) current weather conditions and 3-days forecasts; (ii) model output for primary and secondary infections of Plasmopara viticola; (iii) optimum dose of copper to be applied depending on disease risk, residual coverage of the previous fungicide application, and grapevine growth and development. Different users can access information at different levels of complexity, depending on their role (i.e., providers, advisors, or growers). Each year, experimental sites are managed so as to compare advantages arising from using the DSS in comparison with the usual grower’s practice.