Investigation on the Incidence of Plum Pox Virus in Fruit Nurseries of the Czech Republic

Polák J., Komínek P. (2016): Investigation on the incidence of Plum pox virus in fruit nurseries of the Czech Republic. Plant Protect. Sci., 52: 158–163. Nine different visual evaluations of Plum pox virus (PPV) presence were carried out in four nurseries during 2012–2015. Results of visual evaluation were verified by ELISA. The presence of PPV was confirmed by ELISA in all the trees showing PPV symptoms. PPV has never been detected by ELISA in trees without PPV symptoms on leaves. A very low occurrence of PPV was proved in plums in all the four nurseries. There were two cases of higher occurrence of PPV in plum cultivars, where PPV originated from infected grafts. The PPV occurrence was 0.126 and 1.59%. The average occurrence of PPV in plums was 0.075%, 93 trees out of 123 630 inspected were PPV-infected. All the PPVinfected trees were destroyed immediately. No new PPV infection was proved later in season (August–September). In comparison with the situation in the 60s of the last century, the PPV occurrence in plums was 2.48% in one nursery in 1963 and there were nurseries with PPV occurrence exceeding 5%. All growing plants were destroyed in this case. The occurrence of PPV in the Czech fruit nurseries today is more than hundred times lower in comparison with the situation fifty years ago. The incidental occurrence of PPV in nurseries cannot be excluded in countries and areas with the endemic presence of PPV (in the Czech Republic and in most European countries). Visual inspection of PPV symptoms in nurseries confirmed by ELISA testing is sufficient. Infected plants must be removed immediately.