Plum Pox Virus (PPV) - Questions and Answers

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Plum pox virus | Control & Eradication | Consequences | Compensation

Plum pox virus

Q1. What is plum pox?

Plum pox virus (PPV) is a viral disease that affects the fruit, yield and productive life of peach, plum, apricot and nectarine trees. It can also infect certain ornamental shrubs and trees. The disease does not pose any risk to human health.

Q2. How does PPV spread?

This disease is transmitted locally by aphids to other susceptible plants. It is also transmitted by propagative material, whereby buds are taken from infected trees to grow new trees. These new trees will be infected, but may not show symptoms of the disease until the virus levels rise over time.

Q3. Can PPV be spread through the movement of fruit?

There is no evidence to indicate that movement of fruit can spread the disease.

Q4. How did PPV come to Canada?

PPV likely came to Canada through the introduction of infected propagative material.

Q5. PPV in any provinces other than Ontario?

Four years of testing across Canada has not found PPV in any provinces other than Ontario. The virus has been eradicated in Nova Scotia and surveillance testing has not detected it in other tender fruit producing provinces like British Columbia and Quebec.

Control & Eradication

Q1. How is PPV destroyed?

PPV has no cure. The only method of eradication is the removal and destruction of infected trees. The host trees, including their roots, are destroyed by burning and chipping. There are no chemicals to kill PPV.

Q2. Is eradication of PPV in Canada possible?

International and Canadian experts have stated it is possible to eradicate PPV if Canada acts quickly. The Plum Pox Eradication Program (PPEP) is based on that advice.

Q3. Why was PPV not eradicated under the old program?

The old program was not designed to eradicate PPV. It was designed to suppress the disease and evaluate if eradication was possible. It succeeded in these objectives.

Q4. How will the funding be used?

Detecting the virus to find infected trees is a complex and costly activity. Most of the program costs are to be used for this activity. In its early stages PPV is hard to detect so trees need to be sampled intensively and a few years in a row to find all infected trees.

Q5. Are the industry and the provinces contributing to the eradication program?

The Government of Canada is investing up to $45.6 million in additional funding starting in 2007 until 2011 to eradicate plum pox virus. Agriculture and Agri-Food Canada will contribute $36.16 million and the Canadian Food Inspection Agency will contribute $9.44 million to continue the high level of detection and surveillance of the disease, and financial assistance to affected producers. PPV is a quarantinable pest under the Plant Protection Act and, therefore, falls under the responsibility of the federal government.

The industry is establishing a certification program to provide PPV-free replacement trees.

Ontario is cost-sharing on a 60/40 basis. Ontario is also providing training and support to the research activities.

Q6. Does the Canadian tender fruit industry support the eradication of PPV?

The Ontario Tender Fruit Marketing Board and the majority of Ontario tender fruit growers have expressed their support for the revised eradication plan.

Q7. How can you ensure PPV will be eradicated?

The International Expert Panel (IEP), tasked with reviewing the progress of the PPEP on an annual basis, stated in their most recent report that eradication of the virus should be possible if eradication efforts are maintained at a high level.

Eradication of the virus has been achieved in six of the seven established quarantine areas (Annapolis NS, Wolfville NS, Vittoria ON, Blenheim ON, Fonthill ON and Stoney Creek ON). Niagara ON is now the sole remaining quarantine area.

Eradication of the virus has been successfully achieved in other countries. For example, in Puglia, Italy, PPV monitoring and eradication efforts, similar to the proposed Canadian programs, were pursued and total eradication was achieved after 15 years of sustained efforts.

Consequences

Q1. What negative effects could PPV have on Canada?

While it's difficult to speculate on an exact figure, it is estimated that not eradicating PPV would cost the tender fruit, fruit processing and nursery industries $114 million (M) over 25 years because of:

• continual spread of PPV and possible mutation could affect all of Canada;
• decreased fruit quality and yields would mean a 15% production cost increase;
• signs of PPV on both fresh and processed fruit make them unmarketable; and,
• border movement restrictions on PPV susceptible ornamental plants would affect all of Canada and force nurseries to dramatically change operations.

The Government of Canada would have to spend $0.9 M per year indefinitely to monitor PPV.

Q2. What are the benefits for Canada of eradicating PPV?

If the program is implemented quickly and successfully, PPV will be eradicated in Canada and:

• the growing, processing and nursery industries will be able to return to pre-PPV operations;
• tender fruit production was expanding to meet increasing demand before PPV was discovered and, with eradication, that expansion will resume;
• the benefit to these industries is estimated to be $125 M over 25 years compared to living with PPV;
• the tender fruit industry will remain viable and will avoid future yield loss;
• nursery growers in Niagara and other quarantine areas will be able to go back into production of Prunus ornamentals such as the purple leaf sand cherry;
• other tender fruit growing regions of Canada will be protected;
• international and national movement restrictions on nursery products could be lifted;
• local supply of quality fruit to the processing industry will continue; and,
• related industries will be maintained, generating over seven years, approximately $1.4 billion in sales.

Q3. If we eradicate PPV, can we prevent it from re-entering Canada?

Better management practices, based on Canadian and U.S. expertise and research are being implemented to prevent future resurgence and spread of diseases such as PPV. These practices include a ban on propagation inside quarantine areas and continued research into the role of aphids in spreading the disease.

Continued regulation and increased audit of imported susceptible material in conjunction with new initiatives to control the introduction of invasive alien species will help to ensure that PPV is not re-introduced into Canada.

In addition, the implementation of an industry certification program will provide a reliable source of propagative material tested for PPV and other viruses.

Compensation

Q1. What is the size and value of the tender fruit industry?

PPV is a threat to Canada's $50 M tender fruit, $120 M fruit processing and $25 M Prunus nursery industries, totalling $200 M in sales per year. Over 80% of Canada's stone fruit industry is located in Ontario, mainly in the Niagara region.

Q2. How are you going to mitigate the negative impact to growers from such large tree removals?

The Government of Canada is investing up to $45.6 million in additional funding starting in 2007 until 2011  to pursue the eradication of PPV: Agriculture and Agri-Food Canada - $36.16 million, Canadian Food Inspection Agency - $9.44 million. The Ontario Ministry of Agriculture, Food and Rural Affairs remains committed to contribute its share of financial assistance for the 2011.

Q3. Why are these producers being compensated for lost trees?

Compensation reflects the significant contribution this agricultural sector makes to the Canadian economy and promotes the early reporting of plant diseases and pests.

Q4. Will producers have any recourse to address tree removal orders from the CFIA that are perceived to be unnecessary or excessive?

Once a tree is infected by PPV the only method of eradication is the removal and destruction of the affected tree. The current removal protocol is to remove blocks (a block is made of trees of the same varieties planted at the same time in a contiguous manner) if the level of infection passes a specified threshold.

Government officials have been receptive to the needs of the most affected growers and, where possible, have sought solutions to minimize the impact on individual growers. However, the government's responsibility is to protect the viability of the industry as a whole. Failure to eradicate this virus would ultimately threaten the viability of the entire sector.

Although there is no formal recourse process, growers could seek a court injunction to stop the removal of trees. However, the courts have remained supportive of policy decisions regarding quarantine pests.