INCIDENCE OF NECROTIC RINGSPOT AND PRUNE DWARF VIRUSES IN WILD PRUNUS SPECIES

In the fruit belt of the Niagara Peninsula, wild Prunus avium and P. serotina are common along the Niagara Escarpment, the larger streams, and the Niagara River. P. virginiana is somewhat more widespread than the former species and P. pensylvanica is very rare. P. nigra and P. americana are limited in distribution. The necrotic ringspot virus (NRSV) was detected in trees of P. avium, P. serotina, and P. virginiana, whereas the prune dwarf virus (PDV) (sour cherry yellows) was found only in trees of P. avium and P. serotina. Because of the limited incidence and distribution of virus-infected trees, however, and because the bloom periods of the wild species rarely coincide with sour cherry, peach, or plum, wild Prunus species are considered relatively unimportant as potential reservoirs of virus for infection of commercial orchards.