Submitted to: Acta Horticulture Proceedings
Publication Type: Book / Chapter
Publication Acceptance Date: 7/24/2003
Publication Date: 9/24/2006
Citation: Gottwald, T.R. 2006. Plum pox - review of PPV epidemiology in North America. European and Mediterranean Plant Protection Organization Bulletin. 36:269-286. Interpretive Summary: Plum pox virus (PPV) was discovered in North America in Pennsylvania in September 1999, in the Niagara peninsula region of Canada and in Nova Scotia in 2000. The paper is a review article that examines the current knowledge of the epidemiology (increase and spread) of Plum Pox. The disease is caused by a virus and is spread by insects (aphids) as well as by human movement of plant material. The disease affects peach, apricot and a few other commercial stone fruits. Since discovery the disease, both the US and Canada have begun eradication programs to eliminate the disease. Survey methods were developed by studying the patterns of disease that were found to design the best ways to find and detect the disease. These have developed into national surveillance programs in both Canada and the US. The rate od PPV increase and how it spreads has been studied and contrasted with information from Europe where the disease is believed to have originated. The understanding of the dynamics of this disease helps to predict outcomes if the disease is introduced into the US and also will help regulatory agencies to develop eradication/containment strategies.
Technical Abstract: Plum pox virus (PPV) was discovered in North America in Pennsylvania in September 1999, in the Niagara peninsula region of Canada and in Nova Scotia in 2000. In response to the discovery of PPV-infection in Adams County, a Plum Pox Virus National Surveillance Program was implemented in the United States. Following the confirmation of PPV in Ontario, Nova Scotia and Pennsylvania, USDA, APHIS and the Canadian Food Inspection Agency (CFIA) began using a Hierarchical Survey method which led to identification of additional PPV-positive sites and continues in use to elucidate areas for eradication. The epidemiology of PPV strain D is reviewed by this paper and contrasted with previous work from Europe when PPV strain M is the most prevalent pathogen. Methods of vector spread and distances over which spread have occurred are discussed as well as the interaction of human movement of propagating material as a mode of disease conveyance. The disease seems to be easily spread within localized areas by vectors but there seems to be an outer range beyond which vector-related spread cannot be documented.