Indagini su virus e virosi del peperone in Umbria.

The following viruses were isolated from pepper crops in Umbria: AMV, CMV, PVY, TMV, TRV. The virus found more frequently was CMV: an unusual isolate of CMV was found near the Trasimeno Lake, i n pepper fruits, showing necrotic symptoms. In the same area, TRV showed high incidences; it was also detected in the Alta Valle del Tevere and, in both these areas, it was associated with its vector Trichodorus viruliferus. PVY was isolated i n a few cases. TMV was frequently detected in the cvs "Cuneo" and "Quadrato" but never in the resistant pepper 'Yolo Wonder'. AMV was widespread though it occurred in moderate incidences. The presence of very early AMV infections were suggestive of virus transmission by the pepper seeds but this could not be demonstrated experimentally. In the Alta Valle del Teverer where the cv 'Yolo' is prevalent , the incidences of virus infections were considerably lower than in the other surveyed areas (Trasimeno Lake, Valle Umbra and Media Valle del Tevere), where cvs 'Cuneo' and 'Quadrato' predominate.