Plum pox virus (PPV) is considered to be one of the most serious diseases of stone fruit plants (Prunus sp.). Several strains of the virus have been detected, with varying host ranges within the stone fruit species and varying levels of tree and fruit damage. Infected plants can quickly become uneconomic, and fruit symptoms can make the fruit drop early or become unmarketable. The virus is spread by means of propagation and by aphid vectors.
The first discovery of PPV in North America was in Pennsylvania in 1999. It was discovered in Ontario and Nova Scotia, Canada in 2000, followed by findings in Michigan and New York in 2006.
In Canada seven quarantine areas were created to contain PPV since 2000. Eradication has been achieved in six of those areas now, with the only remaining quarantine area existing in the Niagara region of the Province of Ontario.
Extensive survey and tree removal actions have been in place since 2000, with a trend to progressively lower infection levels being discovered year over year. In 2007 over 570,000 samples were taken from Canadian orchards and residences resulting in the discovery of 261 positive trees. These trees and positive blocks of trees with infection levels above a specified percentage were ordered removed. This has resulted in the removal of approximately 20,000 trees based on the results of the 2007 summer survey. Plans and funding are in place to continue an eradication effort in Canada until at least 2011. Extensive research continues into improved detection methods, potential for disease spread by aphid vectors and the development of resistant cultivars.
Under IPPC Standards (e.g., ISPM No. 8), Plum pox virus is considered present (only in some parts of Ontario) and subject to official control in Canada.
For more information on Plum pox virus, please visit the CFIA website at http://www.inspection.gc.ca.