More information about plum pox outbreaks in the U.S.
Have trees in the United States been infected?
In September 1999, PPV was found in Adams County, Pennsylvania. It was also found in Franklin, York and Cumberland counties in Pennsylvania. To ensure that the PPV was eradicated, more than 1,600 acres of commercial orchards and homeowner trees had to be destroyed at a cost of more than $50 million and with a loss of fruit production in the affected areas.
In July 2006, USDA confirmed the presence of plum pox virus in New York within five miles of plum pox eradication zones in Canada (The virus was discovered in Canada in 2000.) In August 2006, Plum pox virus was also identified and eradicated in Michigan.
In May 2007, USDA declared an extraordinary emergency in Michigan and New York due to plum pox virus and provided funds to assist with eradication expenses.
Where did plum pox originate and where have infected trees been found?
The disease was originally found in Bulgaria in 1915 and has spread throughout Europe where it has destroyed well over 100 million stone fruit trees. In the past decade, plum pox has spread from Europe to India, Egypt, Lebanon, the Azores, Chile, and most recently, Canada, Argentina, China and the United States (Pennsylvania, Michigan, and New York).
How did the virus get here?
How the virus spread to United States is unknown, but it is most likely to have been through the introduction of infected material.
How are trees infected?
PPV is spread from tree to tree by aphids, which are small insects that feed on sap, and through grafting infected budwood onto non-infected plants.
Are other trees susceptible to the virus?
More than 40 Prunus species are now known to be susceptible to this virus. These include trees native to North American woodlands such as wild black cherry, a valuable lumber species, wild red cherry, sand cherry, choke cherry, big-tree plum, beach plum, chickasaw plum, American plum, and popular flowering Prunus ornamentals such as flowering cherry and dwarf flowering almond.
Commercially-grown stone fruit trees, including peach, nectarine, plum, apricot, and cherries, are also susceptible. *
*Note the terms "stone fruit" and "Prunus" are often used interchangeably. Stone fruit is the common term for commercially produced edible species of the genus Prunus. These Prunus species include plums, peaches and nectarines, apricots, and cherries. The term stone fruit also can be extended to other less commonly cultivated Prunus species grown for their fruits.