Draft Import Risk Analysis - Biosecurity New Zealand

appealing. These social impacts, while being significant on there own, are of less significance
given the wide number of pests and diseases already associated with these hosts in New Zealand.
The potential environmental impact of CRLV in New Zealand should therefore be considered to
have a low likelihood of being low.
Human health consequences
This organism is not known to be of any significance to human health.
5.3.2.4. Conclusion of consequence assessment
From the assessment above it is concluded that CRLV has a low likelihood of causing low to
moderate unwanted economic consequences and low environmental consequences to
New Zealand.
5.3.2.5. Risk estimation
The likelihood estimate is low that CRLV would be associated with Malus nursery stock on
entry into New Zealand, high that any CRLV that does enter would successfully establish in
New Zealand, and low that the establishment would result in low to moderate unwanted
economic consequences and low environmental consequences to New Zealand. As a result the
risk estimate for CRLV associated with imported Malus nursery stock is non-negligible and
should be considered a hazard.
5.3.2.6. Assessment of uncertainty
There is some uncertainty around the biology, distribution and epidemiology of this virus. As
such this risk assessment should be reviewed once further relevant information becomes
available.
5.3.3. Risk management
5.3.3.1. Risk evaluation
Since the risk estimate for CRLV associated with imported Malus nursery stock is nonnegligible,
options for phytosanitary measures are provided for consideration.
5.3.3.2. Option evaluation
There are conceivably a number of points on the importation pathway that phytosanitary
measures could be implemented to meet the aforementioned management objectives. The
following risk management options should be assessed:
a. Pest free area (PFA) (see section 4.3.7 for background): Malus nursery stock is imported
from areas that they are free of CRLV;
b. Pest free place of production (PFPP) (see section 4.3.7 for background): Malus nursery
stock is imported from a place of production that is free of CRLV;
c. Virus indexing of mother plants either prior to export to New Zealand or on arrival in
New Zealand in a post entry quarantine facility.
d. Inspection of mother plants.
Pest free area (PFA)
In crops that show symptoms and do not show latency, such as varieties of cherry and apple, the
virus could be detected by visual inspection of the growing crop for typical symptoms.
Inspections would need to occur at the appropriate times of the year when symptoms would be
most obvious. Sampling and laboratory testing would then be required to confirm the identity of
DRAFT Import Risk Analysis: Viruses, Viroids, Phytoplasma, Bacteria and Diseases of
Unknown Aetiology on Malus Nursery Stock
August 2009 Page 39 of 203