December 15, 2008
Plum pox declining in Ontario
The Canadian Food Inspection Agency (CFIA) has completed its 2008 plum pox virus (PPV) survey activities. The agency noted a significant drop in the number of positive findings, despite collecting 35 per cent more samples compared to 2007.
The CFIA collected over 750,000 samples from commercial orchards and residential properties. Only 131 samples tested positive this year, compared to 261 samples found positive in 2007.
This year’s survey also detected a new strain of PPV (PPV-Rec) in three trees on a Grimsby, Ont. residential property within the Niagara PPV quarantine area. However, it is felt that this new strain is not likely to hinder the eradication of PPV in Canada.
Additional surveys in the area suggest PPV-Rec has not spread outside of that property and the detection is an isolated occurrence. The positive trees were plum rootstocks with grafted apricot, peach and plum branches. The trees were detected as part of the homeowner’s survey activities.
CFIA will continue to monitor for the presence of PPV-Rec, a strain only recently discovered and only known to occur in Europe. At this time, very little is known about the biology of the strain. Preliminary research seems to indicate that it could be aphid transmissible, however, the specific host range of this strain still needs to be determined.
This is not the first time a new strain of PPV has been found. In 2002, a new strain (PPV-W) was discovered at a residence in Stoney Creek, Ont. Survey activities were enhanced in the surrounding area and no further positives were detected. The infected tree was removed and the strain type was never detected again in Canada. This was considered an isolated incident with no impact on the eradication program.
The CFIA collected over 750,000 samples from commercial orchards and residential properties. Only 131 samples tested positive this year, compared to 261 samples found positive in 2007.
This year’s survey also detected a new strain of PPV (PPV-Rec) in three trees on a Grimsby, Ont. residential property within the Niagara PPV quarantine area. However, it is felt that this new strain is not likely to hinder the eradication of PPV in Canada.
Additional surveys in the area suggest PPV-Rec has not spread outside of that property and the detection is an isolated occurrence. The positive trees were plum rootstocks with grafted apricot, peach and plum branches. The trees were detected as part of the homeowner’s survey activities.
CFIA will continue to monitor for the presence of PPV-Rec, a strain only recently discovered and only known to occur in Europe. At this time, very little is known about the biology of the strain. Preliminary research seems to indicate that it could be aphid transmissible, however, the specific host range of this strain still needs to be determined.
This is not the first time a new strain of PPV has been found. In 2002, a new strain (PPV-W) was discovered at a residence in Stoney Creek, Ont. Survey activities were enhanced in the surrounding area and no further positives were detected. The infected tree was removed and the strain type was never detected again in Canada. This was considered an isolated incident with no impact on the eradication program.