Unusual incidence of diseases affecting economic plants in Northern Italy.

acer aetiology cercosporiose chestnuts claviceps purpurea crop losses durazno enfermedades de las plantas enfermedades fungosas etiologia etiologie farmland feuille fungal diseases hojas leaves maladie des plantes maladie fongique morbidite morbidity morbosidad peaches plant diseases remolacha azucarera sugarbeet terre agricole trigo virose viroses virosis wheats