Occurrence of Prunus necrotic ringspot virus and Prune dwarf virus in wild cherries in the locality velehrad (South Moravia, Czech Republic)

The occurrence and spatial distribution of PDV and PNRSV in a seed wild cherry (Prunus avium) orchard were studied during the period 1996 - 1999. Each year any newly infected trees were immediately removed. The cumulative infection rate of PDV-positive trees reached 4.7% and number of new infections per year was 1.2 %, on average. Although the number of centers was found to be decreasing (from 22 in 1996 to 10 in 1999), eradication of PDV was not achieved. Only one case of PNRSV infection was found in 1997.