| Abstract: | The forecasting and warning system in Portugal started in 1964 with a control programme applied against Plasmopara viticola, the most important pathogen of grapevine. Since then, studies and new techniques have been developed and applied to other important pests of vineyards and orchards, on the basis of epidemiological and climatic data that supports technical evaluation of the risk. In the last few years, mathematical models have been evaluated as an important part of the control strategy, integrated with biological data from field monitoring. At the moment, forecasting models are available for Plasmopara viticola, Venturia pirina, Venturia inaequalis and Cydia pomonella. The integration of forecasting models with field observations is used to formulate warnings that are sent out to farmers about the need to spray or not. |
