Plum Pox Virus in Canada Year 2001

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Plum Pox Virus in Canada Blake
Ferguson Canadian Food Inspection Agency
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Plum Pox Virus

• Plum Pox Virus (PPV) is a virus that infects
  plants in the genus Prunus - plums, peaches,
  apricots etc.
• It causes a disease called plum pox or sharka.
• Plum Pox is the most serious disease of stone
  fruits in Europe.
• The virus has several strains D, M, C, W and EA
  strains.

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Distribution in the World

• First found in Bulgaria around 1917
• Now present in most European countries
• widespread in central eastern Europe
• recently reported in Mediterranean countries
• sporadic reports in northern Europe
• Also in Egypt, India, Syria, Turkey, Argentina
  Chile
• 1999 - Pennsylvania, USA, strain D
• 2000 Canada, strain D

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Background

• Plum Pox Virus (Sharka)
• Decrease yield fruit quality
• Transmitted via aphids or propagation
• Transmissibility and host range vary by strain
• Severe economic impact

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Host Range

• Hosts are mainly in the genus Prunus
• Both fruit stock and ornamental plants may be
  infected
• PPV affects plums, peaches, nectarines, almonds,
  cherries and apricots
• Wild Prunus species are also hosts
• Some herbaceous weeds can be infected

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Stone Fruit Production in Canada

• Canadas Commercial Production of
• PPV-D susceptible stone-fruit
• Ontario 77
• British Columbia 21
• Nova Scotia 1.1
• Quebec 0.6

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PPV survey in Canada2005
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(2004)
(2003)
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24 Positives on 19 Properties (2 properties not
shown on map)
St. Catharines
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Total Ontario Samples Collected
1,041,442
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Positive Blocks - Ontario
infested blocks 2000 246/5121 4.80 2001
211/6125 3.44 2002 215/7474 2.88 2003
235/7911 2.97 2004 302/8158 3.70 2005
168/7293 2.30
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Positive Blocks - Ontario
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Total positive blocks
Total positive trees
Number of samples collected
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Aphid transmission of PPV

• 2004 evidence
• Volunteer seedlings found to be infected
• Newly planted blocks propagated from PPV-tested
  budwood have been found to contain infected trees
• Research indicates peach to peach transmission
  rates as high as 22 using 50 Myzus persicae
  aphids per plant
• 2005 evidence
• 5 residential trees grown from seed were found
  positive
• 103 existing orchard blocks becoming positive
  after 4-5 years of negative testing.

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Niagara Repeat Positive Blocks
In at least one subsequent year. 51 of
positive blocks are repeat positives in
subsequent years.
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Current challenges

• Continuing discovery of newly positive blocks
• Availability of tested/certified replacement
  trees
• Clearer data needed on aphid spread of PPV
• Resistance of growers to mandatory block removals
• Need to consider buffers but
• logistical difficulties
• industry structure considerations
• neighbour effect