Draft Import Risk Analysis - Biosecurity New Zealand

Executive summary
The risks of viruses, viroids, phytoplasma, bacteria and diseases of unknown aetiology
associated with the importation of Malus nursery stock from all countries have been examined.
An initial list of 64 viruses, viroids, phytoplasma, bacteria and diseases of unknown aetiology
recorded on Malus nursery stock that are exotic to New Zealand or are the subject of a national
eradication campaign in New Zealand, were included in a preliminary potential hazard list.
Forty of these were considered potential hazards and were subjected to a risk assessment. A list
of the final hazard status of the potential hazards is provided in table 1.1 below, along with a
brief description of the phytosanitary measures considered in the analysis as potential options for
managing the identified risks. Further details on the phytosanitary measures options are
provided in chapter 4 of this risk analysis and in the chapters relating to each of for the hazards
or hazard groups as listed. In addition to the options presented, no phytosanitary measures may
also be considered.
Of particular note within the table are 12 of the hazards marked with an asterisk (*). While these
organisms and diseases are considered hazards, their impacts are largely limited to the
production sector. The production sector is the greatest beneficiary of trade in Malus nursery
stock material and in these cases has the ability to limit any consequences associated with the
establishment of these hazards in New Zealand. In consultation with affected domestic sectors
the biosecurity risks from these hazards may managed by industry alone rather than using
official quarantine controls.
Table 1.1: Potential hazards – Status determination and identified phytosanitary measures options
Organism (Name and Hazard? Phytosanitary measures that could be considered options for the effective
organism type)
Viruses (Chapter 5)
management of the identified hazards, subject to effective implementation.
Horseradish latent virus
Sowbane mosaic virus
No Assessed as not being a hazard therefore no phytosanitary measures are required.
Apple latent spherical virus
Tulare apple mosaic virus
Carnation ringspot virus
Tomato bushy stunt virus
Cherry rasp leaf virus
Clover yellow mosaic virus
Tomato ringspot virus
Viroids (Chapter 6)
Yes
Yes
Yes
a. No phytosanitary measures if risk considered acceptable;
DRAFT Import Risk Analysis: Viruses, Viroids, Phytoplasma, Bacteria and Diseases of
Unknown Aetiology on Malus Nursery Stock
b. Virus indexing: Inoculation (onto a susceptible Malus cultivar or other host plant)
followed by testing of symptomatic material.
a. Virus indexing: Inoculation (onto a susceptible Malus cultivar or other host plant)
followed by testing of symptomatic material.
a. Pest free area (PFA): Malus nursery stock is imported from areas that are free of
these viruses;
b. Pest free place of production (PFPP): Malus nursery stock is imported from
places of production that are free of these viruses;
c. Virus indexing: Inoculation (onto a susceptible Malus cultivar or other host plant)
followed by testing of symptomatic material.
Peach latent mosaic viroid No Assessed as not being a hazard therefore no phytosanitary measures are required.
Apple dimple fruit viroid Yes*
Apple fruit crinkle viroid Yes
a. Risks managed by industry without official controls;
b. Viroid indexing: Inoculation (onto a susceptible Malus cultivar or other host
plant) followed by testing of symptomatic material.
a. Viroid indexing: Inoculation (onto a susceptible Malus cultivar or other host
plant) followed by testing of symptomatic material.
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