Agrometeorological Models For Downy And Powdery Mildew Of Grapevine

The problem of crop protection has assumed a primary importance because of the necessity of reducing the quantity of chemicals requested for the control of pests and pathogens. The every increasing doses of sprayed chemicals have not allowed a satisfactorily level of protection, also causing a wide range of primary and secondary effects. The relationships between biotic and abiotic factors inside the cropping systems seem to be very useful for the improving of crop protection (1). On these basis a research programme was started in our institutes to formulate agrometeorological models for the simulation of grapevine (Vitis vinifera) diseases. First of all downy mildew (Plasmopara viticola) was considered because of its development is deeply analysed and it is strongly related to environmental conditions. A model was proposed (2, 3), called PLASMO (Plasmopara Simulation Model), for the simulation of the ontogenesis of Plasmopara on the basis of weather parameters. However the results of several vineyard tests indicated the need of a quantitative evaluation of fungus infections to assess the real intensity of every infection cycle. So a new version was proposed, integrating the growth of grapevine with the development of pathogen infections. In this way every infectious cycle was identified by temporal and quantitative elements (Eunita). According to the same approach, grapevine powdery mildew (Uncinula necatrix) was modelled to draw a global model of the main diseases (tesi). All this information can represent a complete basis, available in real time for the technical operators, to manage and rationalise crop protection.