Plum Pox Virus aka Sharka Most feared viral disease of Prunus Photo by M. Nemeth Photo by Dr. Ken Hickey

History of PPV Perhaps first noticed in 1910 in Macedonia, Greece Observed by plum growers in Bulgaria between 1915 and 1918 First paper 1932 called it “Sarka po slivite” meaning Pox of Plum Spread throughout Europe by 1960 Found in the US in 1999 in Pennsylvania

PPV Hosts Apricot, Peach, Nectarine, Plums, Cherries, Almond Wild & Ornamental flowering cherries and plums Many herbaceous plants from various families

Plum Pox Virus Biology Causal Agent- PPV, D (Dideron) strain a Potyvirus (named for potato virus Y)- see the filamentous particles Vector: 20+ aphid species, esp. Green Peach aphid - virus carried in stylets Spreads rapidly in springtime Photo courtesy of APS

Major PPV Strains PPV-D the Dideron Strain from apricot in SE France. Now also the US strain. Apricot, Peach and Plum (not cherries) Not seed transmitted, mild form, & non-epidemic PPV-M the Marcus Strain from Greece and France. Very virulent, seed transmitted, very aggressive, causes necrosis in tree, spread very easily, epidemic. Also infects cherries

Plum Pox Virus in North America 2000 New York July 2006 2000 August 2006 October 1999 Declared Eradicated 2010 PPV in Michigan