Risk Management Proposal: 
 
Malus  spp. nursery stock  
from all countries 
 
  
 
 
 
 
June 2011 
 
 
 
 
Plant Imports 
Import & Export Standards 
Ministry of Agriculture & Forestry 
Pastoral House 
25 The Terrace 
PO Box 2526 
Wellington 6011 
New Zealand 
 
 
Tel: +64 4 894 5541 
Fax: +64 4 894 0662 
Email: plantimports@maf.govt.nz  
    
 
 
 
 
  
2  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock Purpose 
The purpose of this document is to:  
 summarise the biosecurity risks associated with Malus spp. nursery stock from all 
countries;  
 recommend measures for the effectiv e management of these risks; and, 
 seek stakeholder feedback on the proposed ma nagement options and import requirements 
as outlined in the draft import health standard schedule.  
 
This import health standard (IHS) schedule ha s been developed in accordance with Section 22 
of the Biosecurity Act (1993).   
Background 
The IHS schedule for Malus sylvestris var. domestica budwood/cuttings (stems only) was 
previously issued in hard copy format on 12 June 1998, and has not been reviewed or converted to an electronic version since that time.  
 Recent reviews of the import requirements have identified a number of gaps in the current 
Malus  nursery stock IHS schedule. The scope of th e import health standard has been extended 
to include all species of Malus  approved for import into New Zealand, and to allow the import 
of tissue cultures. 
Objective 
The objective is to effectively manage bi osecurity risks posed by the importation of Malus  
spp. nursery stock, in a way that  is consistent with New Zealand’s domestic legislation and 
international obligations.  
Analysis 
This analysis draws on the significant body of  information that already exists for Malus  spp. 
propagative material, which includes: 
 the nursery stock IHS schedule for Malus sylvestris var.  domestica budwood/cuttings 
(stems only), under the IHS 155.02.06: Importation of Nursery Stock  (available on 
request); 
 subsequent reviews of the import requirements for Malus  spp. nursery stock, for the 
accreditation of MAF-approved offshore facilities  in Canada, France, Italy, and the United 
States of America; 
 the MAF Post-Entry Quarantine Testing Manual for Malus  (Apple) ; 
 the MAF Import Risk Analysis: Viruses, Viroid s, Phytoplasmas, Bacteria, and Diseases of 
Unknown Aetiology on Malus  Nursery Stock from all Countries  (draft version available on 
request). 
1. COMMODITY DESCRIPTION 
Approved species of Malus  nursery stock (dormant  cuttings and plants in-vitro  only) as listed 
on the MAF Plants Biosecurity Index , imported into New Zealand for the purpose of 
propagation.  
 
 
3  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock 2. REGULATED ORGANISMS REQUIRING MANAGEMENT 
2.1 Insects and mites 
The pest list has been updated to remove speci es of insects and mite s that are now known to 
be present in New Zealand. MAF have not attemp ted to produce a full list of insects and mites 
known to be associated with Malus spp nursery stock. 
 
The proposed management steps for insect s and mites are discussed in section 4. 
2.2 Fungi 
The pest list has been updated to remove species  of fungi that are now known to be present in 
New Zealand.  
 A MAF Plant Health & Envir onm
ent Laboratory (PHEL) myco logist conducted a partial 
review of the regulated fungi associated with Malus  spp. and has advised that Sphaeropsis 
pyriputrescens (Sphaeropsis rot) should be added as a regulated pest.  S. pyriputrescens has 
been described as causing a canker and twig di eback disease in commercial apple orchards in 
the USA (Xiao and Boal 2005). In addition, th is fungus has also been found to cause 
postharvest fruit ro t in apples (Xiao et al., 2004) and pears (Xiao and Rogers 2004) in the 
USA and Canada (Sholberg et al., 2009). 
 The proposed management steps for fungi are discussed in section 4. 
2.3 Bacteria 
The pest list has been updated to remove species  of bacteria that are now known to be present 
in New Zealand. MAF have classified the followi ng regulated bacterium
 as a risk associated 
with imported Malus  spp. nursery stock: 
 Pseudomonas syringae  pv. papulans   
 
The proposed management steps for this ba cterium are discussed in section 4. The MAF 
PHEL testing manual for Malus  (Appendix 1 of manual) provide s photos of symptoms caused 
by Pseudomonas syringae  pv. papulans . 
2.4 Viruses, viroids, phytoplasmas, and diseases of un known aetiology 
The 1998 Malus  import health standard included thes e organisms under the generic headings 
‘Virus or Virus-like Organisms’ and ‘Phytopl asma or Phytoplasma-like Organisms’. This 
review has removed a number of organisms from  the regulated pest list, as some organisms 
were no longer classified as risks, due to reviewed host association, limited or obscure 
distribution, and changes in nomen clature. Additions to the pe st list are highlighted in Bold . 
The following regulated organisms and diseases are classified as risks associated with 
imported Malus  spp. nursery stock: 
Viruses
 Cherry rasp leaf virus  
 Clover yellow mosaic virus   Tomato bushy stunt virus   
 Tomato ringspot virus
 
Viroids
 Apple dimple fruit viroid   
 Apple fruit crinkle viroid   Apple scar skin viroid 
Phytoplasmas 
 ‘Candidatus  Phytoplasma asteris’   ‘Candidatus  Phytoplasma mali’
 
Diseases of unknown aetiology
 Apple blister bark agent  
 Apple brown ringspot agent 
 Apple bumpy fruit agent 
 Apple dead spur agent  
 Apple decline agent 
 Apple freckle scurf agent 
 Apple green dimple and ring blotch 
agent 
 Apple junction necrotic pitting agent 
 Apple McIntosh depression agent 
 Apple narrow leaf agent  Apple Newton wrinkle agent 
 Apple pustule canker agent 
 Apple red ring agent 
 Apple rosette agent 
 Apple rough skin agent 
 Apple russet wart agent 
 Apple star crack agent 
 Apple transmissible internal bark 
necrosis agent
 
The proposed management steps for these regula ted organisms and diseases are discussed in 
section 4. The MAF PHEL testing manual for Malus  (Appendix 1 of manual) provides photos 
of symptoms caused by some of the organisms listed above. 
3. MANAGEMENT OF RISK 
All nursery stock imported into New Zealand must  undergo a number of steps to ensure that 
the risk of regulated organisms is reduced to an acceptable level. Table 1 provides a summary of the mitigation and verification steps that Malus  spp. nursery stock must go through to 
ensure freedom from regulated pests and disease.   All Malus nursery stock imported into New Zeala nd must be imported under a permit to 
import, issued by MAF under th e import health standard 155. 02.06: Importation of Nursery 
Stock. The permit to import is used to facilitate the import of the material, and details the specific import requirements for each consignment.  
Table 1. Summary of mitigati on and verification steps for  Malus nursery stock 
Note: Rows highlighted in green apply only to material imported from a MAF-approved offshore facility.  
Step Target organisms Description of measures Related documents 
Pre-export 
growing 
season 
inspection, 
testing, and 
containment 
at a MAF-
approved 
offshore 
facility All; may include 
specific measures 
for bacteria, 
viruses, viroids, 
phytoplasmas, and 
diseases of 
unknown aetiology Specific to material sourced from a MAF-approved 
offshore facility: 
 Offshore facilities are accredited by MAF to 
undertake specified tests, in accordance with the 
import health standard, prior to export of nursery 
stock to New Zealand. Specific testing may include 
herbaceous index, woody indexing, ELISA, and/or 
PCR. 
 Nursery stock undergoes growing season 
inspections and testing by experts familiar with pests 
and diseases associated with Malus . 
 Nursery stock is held in a facility suitable to exclude 
the introduction of regulated quarantine pests.  MAF import health 
standard 155.02.06: 
Importation of Nursery 
Stock  
 MAF operational 
standard 
PIT.OS.TRA.ACPQF: 
Accreditation of 
Offshore Plant 
Quarantine Facilities 
and Operators  
 Agreement between 
MAF and approved 
offshore facility 
Pre-export 
phytosanitary 
inspection All  Prior to issuing a phytosanitary certificate, the 
exporting National Plant Protection Organisation 
(NPPO) must inspect the nursery stock in accordance with appropriate official procedures for 
freedom from visually detectable regulated pests, 
and to ensure the consignment conforms to New  155.02.06: Importation 
of Nursery Stock  
 International Standards 
for Phytosanitary 
Measures  ISPM 12. 
Guidelines for  
 
 
5  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock Step Target organisms Description of measures Related documents 
Zealand’s import requirements. phytosanitary 
certificates (2001)  
Specific to material sourced from a MAF-approved 
offshore facility: 
 The NPPO must also verify that the nursery stock 
has been: 
 held and tested for/classified free from specified 
regulated pests as required in the agreement 
between MAF and the MAF-approved offshore 
facility 
AND 
 held in a manner to ensure that infestation/ 
reinfestation does not occur following inspection and 
testing at the accredited facility, and certification.  155.02.06: Importation 
of Nursery Stock  
 Agreement between 
MAF and approved 
offshore facility 
Pesticide 
treatments 
for cuttings Insects and mites  All cuttings shall be treated for regulated insects and 
mites. Where treatments are completed prior to 
export, the NPPO verifies this by recording the treatment details on the “Disinfestation and/or 
Disinfection Treatment” section of the phytosanitary 
certificate.  155.02.06: Importation 
of Nursery Stock  
Packaging 
requirements 
for cuttings All  Following certification, cuttings shall be held and 
packaged in a manner to prevent infestation/ 
reinfestation by regulated pests. Cuttings shall be 
packaged in inert/ synthetic materials.  155.02.06: Importation 
of Nursery Stock  
Packaging 
requirements 
for tissue 
culture All  Containers shall be pest proof. Growing media shall 
not contain fungicides or antibiotics.  155.02.06: Importation 
of Nursery Stock  
On arrival 
verification/ inspection All  A 600 unit sample is inspected to verify compliance with the import requirements, and to achieve a 95% confidence level for freedom from visually detectable 
regulated pests. 
 Documentation is inspected to ensure that appropriate pre-export activities have been verified 
by the exporting NPPO.  155.02.06: Importation 
of Nursery Stock  
 MAF Border Clearance 
Procedures (internal 
MAF document) 
 Nursery stock is held in a level 3 PEQ facility for a 
minimum growing period of 36 months, with tissue 
cultures exflasked into a PEQ greenhouse at the beginning of the PEQ period.  
 The minimum 36 month PEQ period is required for the completion of all serological, molecular and 
herbaceous indictor testing prior to samples being 
transferred to Level 1 PEQ for woody indicator tests. 
 Nursery stock undergoes growing season inspection 
for visual symptoms of disease expression, and 
testing for pests and diseases of significant biosecurity concern.  Post entry 
quarantine 
(PEQ) All 
Specific to material sourced from a MAF-approved 
offshore facility: 
 Nursery stock is held in a level 2 PEQ facility for a 
minimum growing period of six months, with tissue 
cultures exflasked into a PEQ greenhouse at the 
beginning of the PEQ period.  
 Nursery stock undergoes growing season inspection 
for visual symptoms of disease, and testing for 
regulated organisms of significant biosecurity 
concern, which were not tested for at the approved  MAF operational 
standard 
PBC.NZ.TRA.PQCON: 
Specification for the 
Registration of a Plant 
Quarantine or 
Containment Facility, 
and Operator  
 155.02.06: Importation 
of Nursery Stock  
 MAF Operational 
Standard 155.04.03: 
Diagnostic Facilities 
which undertake the 
identification or new 
organisms, excluding 
animal pathogens  
 MAF Post Entry 
Quarantine Testing 
Manual for Malus  
(Apple)  
 Border Clearance  
6  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock Step Target organisms Description of measures Related documents 
offshore facility.  
 The minimum six months PEQ period is required for 
the completion of all serological, molecular and 
herbaceous indictor testing. 
Note , currently all required woody indexing is 
undertaken at the approved offshore facility. Procedures 
3.1 MAF-approved offshore facility 
Malus nursery stock may be sourced from a facility that has been approved by MAF as a 
supplier of high health Malus  budwood. A list of approved offshore facilities for Malus  spp. 
nursery stock can be viewed on the website: 
http://www.biosecurity.govt.nz/r egs/im ports/plants/off-shore . 
 
Material sourced from approved facilities will have some of the required testing completed 
prior to export. Which tests are completed at the offshore facility is determined as part of the 
facility accreditation process. Tests completed at  the offshore facility must be in accordance 
with the testing requirements of the Malus spp. schedule; however, equivalence may be given 
for other internationally recognised testing methods.  It is the responsibility of the importer to ensure that only material that has been produced in 
accordance with the agreement with MAF is selected for importation into New Zealand. 
3.2 Freedom from regulated organisms 
3.2.1 Specific measures for budwood 
Treatment of budwood for insects an d mites is required to ensure  that imported material is 
clean before importation into New Zealand, a nd entry into post entry quarantine. Budwood 
should be treated prior to export in accordan ce with section 2.2.1.6 (p art B) of the import 
health standard. 
3.2.2 Specific measures for tissue culture  
Tissue cultures must be produced in a facility under conditions that prevents contamination 
with regulated pests. The tissue culture media must not contain fungicides or antibiotics, or 
other compounds which will make the media non-transparent, e.g. charcoal. 
3.3 Pre-export phytosanitary inspection and certification 
The exporting National Plant Pr otection Organisation (NPPO) inspects the consignm
ent to 
confirm that it meets New Zealand’s import re quirements. The exporting NPPO must verify 
the following pre-export activities have been completed: 
 Budwood has been treated for insects and mites 
 Budwood and tissue cultures are free from vi sually detectable regulated pests and 
diseases  
 Material sourced from an approved offshore facility has been produced in accordance 
with the agreement with MAF 
 
Where the exporting NPPO has verified that th e consignment is compliant with the import 
requirements, a phytosanitary cer tificate is issued. Following certification the nursery stock 
must be held in a manner to prevent infest ation/reinfestation with regulated pests and 
diseases.  
 
 
7  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock 3.4 On arrival verificati on of pre-export measures 
On arrival in New Zealand, the MAF inspector will inspect the consi gnment to verify the 
required pre-export measures have been met. This verification include s the following steps: 
 Inspection of the phytosanitary  certificate to ensure compliance with the import 
requirements 
 Inspection of 600 units to achieve a 95% c onfidence level for freedom from visually 
detectable regulated pests. 
 
Where the MAF inspector has verified that th e consignment is compliant, the inspector will 
authorise movement of the nursery  stock to post entry quarantine. 
3.5 Post entry quarantine 
All Malus  nursery stock im
ported into New Zealand must undergo a period of post entry 
quarantine to ensure freedom from  regulated pests and diseases. 
3.5.1 Material from MAF-approved offshore facilities 
Due to the pre-export activities undertaken at  approved offshore facili ties, and a history of 
compliance with consignments imported from th ese facilities, it is proposed that Level 2 post 
entry quarantine facility for a minimum growing period of six months is appropriate. 
3.5.2 Material from non-ap proved offshore facilities 
As the history of material from non-approved facilities cannot be accurately assessed, and the 
unknown phytosanitary status (in part icular, fungi), it is proposed th at the material shall enter 
a Level 3 post entry quarantine facility. A mi nimum growing period of 36 months is proposed 
as the time required allowing the imported materi al to undergo serological, molecular, and 
herbaceous indicator testing, prior to woody indexing occurring in a Level 1 post entry 
quarantine facility. 
3.5.3 Growing season inspection 
Material must undergo regular growing season inspections by a MAF Biosecurity Inspector, 
to ensure freedom from visually  detectable regulate d pests. Where visibl e signs of pests and 
disease are detected, samples may be co llected and sent for diagnostic testing. 
 
The operator of the post entry qua rantine facility is also e xpected to undertaken regular 
inspections of the plants dur ing the growing season, and to notify the MAF Biosecurity 
Inspector if pest or dise ase symptoms are observed. 
3.5.4 Testing for regulated organisms of significant biosecurity concern 
Pests and diseases of significant concern require  specific mitigation measures to ensure they 
do not enter and establish in New Zealand.   For nursery stock, the following specific testing may be appropriate to detect regulated bacteria, viruses, viroids, phytoplasma s, and diseases of unknown aetiology: 
 Biological tests: herbaceous indexing and woody indexing 
 Molecular tests: polymera se chain reaction (PCR) 
 Serological tests: enzyme linked immunosorbent assay (ELISA) 
 For viruses, viroids, and phytoplasmas the pr oposed testing requirements are based on the 
level of biosecurity risk associ ated with the organism. Due to the potential biosecurity risk 
posed by some organisms, a combina tion of testing methods is proposed. 
  
8  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock For diseases of unknown aetiology, the causal organism is unknown, so there are no specific 
laboratory testing methods available for thei r detection. Woody indexing onto suitable woody 
indicators (susceptible Malus cultivars) provides the be st chance of detection. 
 
With prior approval from MAF, internationally accepted testing methods will be accepted as equivalent to the requirements of the import health standard.  The MAF Post Entry Quaran tine Testing Manual for Malus  (Apple) describes appropriate 
testing protocols for each of the proposed tests. 
3.6 Non-compliance 
Nursery sto
ck that is not compliant with the import requirements will not be eligible for 
biosecurity clearance. Where the inspector iden tifies that the nursery stock is not compliant, 
the importer will be given the option to make the consignment compliant (where appropriate) 
or to reship or destroy the material. 
3.7 Equivalence 
If the nursery stock will not m
eet the conditi ons of the import health  standard, the importer 
may submit to MAF an application for assessme nt of equivalent phytosanitary status. Where 
MAF determines that alternative measures will provide an equivalent phy tosanitary status, the 
details of the equivalence will be recorded on the permit to import. 
3.8 Biosecurity clearance 
Biosecurity clearance sh
all only  be given for imported material where the inspector is 
satisfied that the following has occurred: 
 The nursery stock complies with the require ments of the import health standard 
 There are no discrepancies in accompanying documentation 
 The goods display no signs of harbouri ng organisms that may be unwanted 
organisms 
 There has been no recent change in circumstances or knowledge that makes it unwise 
to give biosecurity clearance. 
4. MAF PROPOSAL 
This section outlines the proposed requirements for each regulated organism associated with 
Malus spp. nursery stock. A summary of the pro posed inspection, treatment, and testing 
requirements are included in Appendix 1. 
4.1 Insects and mites 
MAF considers tha
t the pesticide treatments re quired as part of the Basic Conditions for 
nursery stock (section 2.2.1.6 of the import health standard), and the period of growing season 
inspection in post entry quarantine, will be suffi cient to mitigate the presence of insects and 
mites on imported material. 
4.2 Fungi 
MAF-appro
ved offshore facilities in the USA and Canada are due to be audited by MAF in 
2011. As part of the audit process, MAF will ensure  that these offshore facilities have suitable 
procedures in place for the inspection of symptoms caused by Sphaeropsis pyriputrescens. 
For nursery stock from non- approved facilities, growing season inspection during the 
minimum 36 months post entry quarantine period will be sufficient to observe symptoms of S. 
pyriputrescens.  
 
 
9  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock  
The June 1998 Malus  nursery stock import health standa rd required generic measures (i.e. 
growing season inspection) for all regulated f ungi. It is proposed that growing season 
inspection still provides an appropr iate level of protection for re gulated fungi. It is proposed 
that material from non-approved f acilities is held in a Level 3 pos t entry quarantine facility, as 
a Level 2 facility is not suitable to contain fungi.  
4.3 Bacteria 
4.3.1 Pseudomonas syringae pv. papulans   
Pseudomonas syringae pv. papulans  can be spread to leaves, blossoms, and fruit surfaces by 
the rain in spring and summer, where bacteria can multiply. Insects are also implicated in the spread of inoculum. The host range for Pseudomonas syringae pv. papulans  is wider than 
Malus , and includes other economically  important crops such as Pyrus and Prunus . As such, 
this bacterium is included on the list of regulat ed pests, for which MAF will take action if 
identified in post entry quarantine.  Trees of cultivar ‘Mutsu’ infected with Pseudomonas syringae pv. papulans  display 
symptoms on both leaves and fruit; blemis hes on fruit make it unsuitable for sale. The Malus  
cultivars ‘Braeburn’, ‘Fuji’, ‘Golden Delicious’,  ‘Gala’, and ‘Delbarestivale’ are also known 
to display symptoms when infected with Pseudomonas syringae pv. papulans.  
 MAF considers that specific testing for this bacterium is required. PCR, using specific 
primers, is appropriate to detect Pseudomonas syringae pv. papulans . 
 
Proposal 
That Pseudomonas syringae pv. papulans is included as a regulated pest, and that one of the following measures is met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production (assessed by MAF) 
 PCR
 
4.4 Viruses 
4.4.1  Cherry rasp leaf virus 
Cherry rasp leaf virus  can be vectored by the nematode Xiphinema americanum  (present in 
NZ), as well as natural spread from root grafting. The host range for CRLV is wider than 
Malus , and includes other economically  important crops, such as Rubus  and Prunus . CRLV is 
included in the nursery stock schedule for Prunus  (requiring woody indexing and herbaceous 
indexing and TEM) and Rubus  (requiring herbaceous indexi ng and ELISA or PCR). As 
CRLV is not known to be present in New Zeala nd, this virus is included on the list of 
regulated pests, for which MAF will take ac tion if identified in post entry quarantine. 
 Trees of cultivars ‘Delicious’,  ‘Golden Delicious’, ‘Jonagold’ and ‘Gala’ infected with CRLV 
will display symptoms on both leaves and fr uit; fruit take on a flat appearance.  
 MAF considers that specific testing for this vi rus is required. A biol ogical indexing test, in 
conjunction with a molecular test, is consid ered as appropriate to detect CRLV.  
 
Proposal  
10  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock That Cherry rasp leaf virus is included as a regulated pest, and that one of the following 
measures is met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Woody indexing  or herbaceous indexing  (Chenopodium quinoa  and Chenopodium 
amaranticolor ) AND PCR  
 
4.4.2  Clover yellow mosaic virus 
Clover yellow mosaic virus is an addition to the pest li st, and replaces Apple leaf pucker 
which was included in the 1998 Malus  IHS. Clover yellow mosaic virus  is recorded as causing 
a leaf pucker disease of Malus sylvestris  cultivar ‘McIntosh’ (Welsh et al. , 1973).Clover 
yellow mosaic virus  can be spread by mechanical inoc ulation (contaminated tools), and by 
animals walking through fields. The host range for ClYMV is wider than Malus , and includes 
other economically important crops, such as Trifolium . As ClYMV is not known to be present 
in New Zealand, this virus is included on the list  of regulated pests, for which MAF will take 
action if identified in post entry quarantine. 
 Welsh et al .,1973 found that ClYMV was associated with 10 trees of  Malus sylvestris cultivar  
‘McIntosh’, which were displaying leaf pucker symptoms. The same trees were also found to 
be infected with Apple chlorotic leafspot virus  (non-regulated), as indicated by woody hosts. 
ClYMV could not be isolated from a further 44 trees displaying the same leaf pucker 
symptoms, or 200 trees that we re not displaying symptoms. 
 At the time of publishing the 1973 paper, further trials were underway to return ClYMV to its 
apple host to produce leaf pucker symptoms. No  further literature could be found on this 
topic. At this time it is not known if ClYMV is the causal agent of th e leaf pucker symptoms 
in Malus sylvestris cultivar ‘ McIntosh’. As ClYMV is not k nown to cause the leaf pucker 
symptoms MAF considers that specific testing for this organism is not justified, and that growing season inspection provides an  appropriate level of mitigation. 
 It should be noted that ClYMV can be mechanically transmitted to Chenopodium quinoa , and 
diagnostic symptoms will devel op. If ClYMV was detected in a consignment of imported 
Malus  budwood, MAF would take action for this organism. 
 
Proposal 
That Clover yellow mosaic virus  is included as a regulated pest , and that one of the following 
measures is met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Growing season inspection 
 
4.4.3  Tomato bushy stunt virus 
Tomato bushy stunt virus  can be released from the roots of infected plants into the soil where 
is can remain infective for up to 12 weeks, or spread by other natural methods of dispersal (e.g. seed, and pollen to seed). The ho st range for TBSV is wider than Malus , and includes 
other economically important crops, e.g. Pyrus, Lycopersicon esculentum , and Capsicum . As 
TBSV is not known to be present in New Zeal and, this virus is included on the list of 
regulated pests, for which MAF will take acti on if identified in post entry quarantine.  
 As TBSV latently infects Malus (i.e. does not cause symptoms), MAF considers that specific 
testing for this virus is require d. As TBSV is unlikely to have a direct impact on the apple  
 
 
11  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock industry, MAF considers that specific serolo gical/molecular testing is not justified. 
Herbaceous indexing on to the indicator species Chenopodium quinoa  and Chenopodium 
amaranticolor  provides an appropriate level of mitigation for this virus on Malus  spp. nursery 
stock. 
 
Proposal 
That Tomato bushy stunt virus is included as a regulated pest , and that one of the following 
measures must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Herbaceous indexing ( Chenopodium quinoa  and Chenopodium amaranticolor ) 
 
4.4.4  Tomato ringspot virus 
Tomato ringspot virus  can be vectored by nematodes in the genus Xiphinema (six species are 
present in New Zealand), as well as spread th rough infected seed. The host range for ToRSV 
is wider than Malus , and includes other economi cally important crops, e.g. Fragaria , Prunus , 
Rubus , Vaccinium , and Lycopersicum esculentum.  
 
Some strains of ToRSV are present in New Zealand. However, the strain infecting Malus  has 
not been detected in New Zealand. ToRSV has a host range wider than Malus , and is included 
in the nursery stock schedule for Fragaria  (herbaceous indexing and ELISA/PCR), Lilium  
(‘Pest free area’/‘Pest free place of production’), Prunus  (Woody indicators, herbaceous 
indicators, ELISA/PCR and TEM), Rubus  (herbaceous indexing and ELISA/PCR), Tulipa  
(‘Pest free area’/‘Pest free place of production’), and Vaccinium  (herbaceous indexing, 
ELISA/PCR, and TEM).  As ToRSV can be dispersed naturally, and the introduction of this viru s would have impacts 
outside the apple industry, MAF c onsiders that specific testing for this virus is required. 
Recognising that ToRSV has been associated with Apple union necrosis and decline, MAF 
considers that herbaceous indexing on to the indicator species Chenopodium quinoa  and 
Chenopodium amaranticolor , in conjunction with a serological or molecular test, is 
appropriate to detect ToRSV.  
 
Proposal 
That Tomato ringspot virus  is included as a regulated pest, and that one of the following 
measures must be met prior to bi osecurity clearance being given: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Herbaceous indexing ( Chenopodium quinoa  and Chenopodium amaranticolor ) 
AND ELISA or PCR 
4.5 Viroids 
4.5.1 Apple dimple fruit viroid 
Apple dimple fruit viroid  is an addition to the pest list (Saerio et al., 2003). This viroid is not 
known to be spread by a biological vector; however, ADFVd can be transmitted through 
flowers, leaves, roots and stems. As ADFVd is  not known to be present in New Zealand, this 
viroid is included on the list of regulated pests, for which MAF will take action if identified in 
post entry quarantine.   
12  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock Plant material infected with ADFVd may remain asymptomatic (latent infection), with some 
symptomatic cultivars not displaying symptoms  for 2-3 years. ADFVd is known to infect 
cultivars that are economica lly important to New Zealand industry, with symptoms 
developing on fruit.  
 As the establishment of ADFVd would have an  effect on fruit production/quality for some 
economically important cultivars, MAF consider s that specific testing for this viroid is 
required. A molecular test followed by woody indexi ng in the field on to the indicator cultivar 
‘Red Delicious’ is appropriate to detect ADFVd.  
 
Proposal 
That Apple dimple fruit viroid  is included as a regulated pest , and that one of the following 
measures must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Woody indexing  (‘Red Delicious’)  AND PCR  
 
4.5.2 Apple fruit crinkle viroid 
Apple fruit crinkle viroid is not known to be spread by a bi ological vector; however, AFCVd 
can be transmitted through propagative plant material (i.e. grafting). The host range for AFCVd is wider than Malus , and includes other economically important crops, e.g. Pyrus , 
Humulus , and possibly persimmons. As AFCVd is not known to be present in New Zealand, 
this viroid is included on the list of regulated pests, for which MAF will take action if identified in post entry quarantine. 
AFCVd is known to infect cultivars that are economically important to New Zealand industry, 
with symptoms developing on fruit. The estab lishment of AFCVd woul d have an effect on 
fruit production and quality in some cultivars. The establishment on this  viroid could also 
have an impact on other industries. MAF consid ers that specific testing for this viroid is 
required. A molecular test followed by woody indexi ng in the field on to the indicator cultivar 
‘Golden Delicious’ is appr opriate to detect AFCVd. 
 
Proposal 
Apple fruit crinkle viroid  is included as a regulated pest, and that one of the following 
measures must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Woody indexing  (‘Golden Delicious’)  AND PCR  
 
4.5.3 Apple scar ski n viroid  
Natural spread of Apple scar skin viroid  has been observed, which is thought to be by root 
grafting; ASSVd is also reported to be seed  transmitted. The host range for ASSVd is wider 
than Malus , and includes other economi cally important crops, e.g. Pyrus. As ASSVd is not 
known to be present in New Zeala nd, this viroid is included on the list of regulated pests, for 
which MAF will take action if identified in post entry quarantine. 
 Trees infected with ASSVd of the cultivars ‘Jonathan’, ‘Red Gold’, ‘Ralls Janet’, ‘Indo’, ‘Ohrin’, ‘Starking Delicious’, and ‘Red  Delicious’ display symptoms on fruit.  
 The establishment of ASSVd w ould have an effect on fruit production and quality in some 
cultivars. The establishment of this viroid could also have an  impact on other industries. MAF  
 
 
13  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock considers that specific testing for this viroid is required. A molecular test followed by woody 
indexing in the field on to the indicator cultiv ar ‘Golden Delicious’ or ‘Red Delicious’ is 
appropriate to detect ASSVd. 
 
Proposal 
That Apple scar skin viroid  is included as a regulated pest , and that one of the following 
measures must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Woody indexing  (‘Golden Delicious’ or ‘Red Delicious’) AND PCR  
4.6 Phytoplasmas  
4.6.1 ‘ Candidatus  Phytoplasma asteris’ (Apple sessile leaf phytoplasma) 
‘Candidatus  Phytoplasma asteris’ is an addition to the pest list (Jomantiene & Davis, 2005). 
This phytoplasma causes disease in  a wide range of hosts. In Malus  it causes a disease called 
Apple sessile leaf phytoplasma which was first id entified infecting apple trees in 2005, and is 
considered as an emerging pest. Phytoplasmas are generally transmitted by phloem-feeding 
insects (i.e. leaf-hoppers, plant-hoppers, or psy llids); however, at this time the method of 
transmission has not been identified. As ApSL  is not known to be present in New Zealand, 
this phytoplasma should be included on the list of regulated pests, for which MAF will take action if identified in post entry quarantine.  Symptoms are known to express on the leaves and shoots of infected trees, and have not yet 
been shown to exhibit on the fruit. Ho wever, the initial report comments that ‘ Candidatus  
Phytoplasma asteris’ has considerab le significance for fruit production.  
 As the method of transmission of ApSL is unknow n, it is possible that a vector present in 
New Zealand could be able to transmit th is phytoplasma. The establishment of this 
phytoplasma could also have an impact on other i ndustries. A molecular test is appropriate to 
detect ApSL. It should be noted that nested PCR with uni versal phytoplasma primers is 
suitable to detect all regulated phytoplasmas. 
 
Proposal 
That ‘ Candidatus  Phytoplasma asteris’ (Apple sessile leaf phytoplasma) is included as a 
regulated pest and that one of the following measures must be met prior to biosecurity 
clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production de claration (assessed by MAF) 
 Nested PCR using universal phytoplasma primers 
 
4.6.2 ‘ Candi datus  Phytoplasma mali’ (Apple proliferation phytoplasma) 
‘Candidatus  phytoplasma mali’ causes a disease in a wide range of hosts such as Corylus , 
Pyrus, Prunus , Rosa , and Vitis . In Malus  it causes a disease calle d Apple proliferation 
phytoplasma, and can be vectored by psyllids and leafhoppers (a leafhopper which has been found to experimentally vector AP is present in  New Zealand), as well as spread naturally by 
root fusion. As such, this phytoplasma is include d in the list of regulated pests, for which 
MAF will take action if identified in post entry quarantine.   
14  Ministry of Agriculture & Forestry   Risk Management Proposal:  
  Malus  spp. Nursery Stock A number of cultivars develop symptoms wh en infected with AP, including ‘Golden 
Delicious’, ‘Granny Smith’, and ‘McIntosh’. Sy mptoms develop on leaves, shoots, flowers, 
and fruit; the size, weight, and quality (i.e. sugar and acid content) of fruit significantly 
effected. Symptoms exhibited in infected trees are unevenly dist ributed, and are most 
pronounced under favourable temperatures of 21-24°C,  so would be expected  to be significant 
in most parts of New Zealand. Infected trees ma y also be more susceptible to other diseases 
(i.e. powdery mildew). Apple pr oliferation is one of the most  economically important plant 
diseases caused by phytoplasmas (Seemuller and Schneider 2004).   AP could be spread by a vector present in  New Zealand, and the introduction of this 
phytoplasma could have a signifi cant impact on fruit production. The establishment of this 
phytoplasma could also have an impact on ot her industries. MAF considers that specific 
testing for this phytoplasma should be require d. A molecular test followed by woody indexing 
in the field on to the indicator  cultivar ‘Golden Delicious’ is  appropriate to detect AP.  
 
Proposal 
That ‘ Candidatus  Phytoplasma mali’ (Apple prolifera tion phytoplasma) is included as a 
regulated pest and that one of the following measures must be met prior to biosecurity 
clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production (assessed by MAF) 
 Woody indexing (‘Golden Delicious’)  AND nested PCR using universal 
phytoplasma primers  
4.7 Diseases of unknown aetiology 
For diseases of unknown aetio logy, the causal organism
 is unknown, so there are no 
laboratory testing methods availa ble for their detection. Where a disease is likely to exhibit 
symptoms on the fruit of susceptible cultivar s, or reduce productivity MAF considers that 
specific testing measures are required. Woody indexing on to susceptible Malus  cultivars is 
appropriate to detect the followi ng diseases of unknown aetiology:  
 Apple dead spur agent  
 Apple rough skin agent 
 Apple russet wart agent 
 Apple star crack agent 
 
Proposal 
Diseases of unknown aetiology of significant bios ecurity concern are included as regulated 
diseases, and that one of the following measures  must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production (assessed by MAF) 
 Woody indexing (‘Golden Delicious’ a nd ‘Red Delicious’) 
 
MAF have identified that the generic measur e of growing season inspection provides an 
appropriate level of protecti on for the following diseases: 
 Apple blister bark agent  
 Apple brown ringspot agent 
 Apple bumpy fruit agent 
 Apple decline agent 
 Apple freckle scurf agent 
 Apple green dimple and ring blotch agent 
 Apple junction necrotic pitting agent  
 
 
15  Ministry of Agriculture & Forestry  Risk Management Proposal:  
  Malus  spp. Nursery Stock  Apple McIntosh depression agent 
 Apple narrow leaf agent 
 Apple Newton wrinkle agent 
 Apple pustule canker agent 
 Apple red ring agent 
 Apple rosette agent 
 Apple transmissible intern al bark necrosis agent  
 
Proposal 
Diseases of unknown aetiology of biosecurity concern, but that do not pose a significant risk 
to the New Zealand environment or economy, are to be included as regulated diseases and 
that one of the following measures must be met prior to biosecurity clearance: 
 Pest free area declaration (assessed by MAF) 
 Pest free place of production (assessed by MAF) 
 Growing season inspection 
REFERENCES 
 Jomantiene, R; Davis, R E (2005) Apple sess ile leaf: a new diseas e associated with a 
'Candidatus Phytoplasma asteris' subgroup 16SrI-B phytoplasma in Lithuania. Plant 
Pathology 54(2): 237. 
 Seemuller, E and Schneider, B.  2004.  “ Candidatus Phytoplasma mali”, “ Candidatus 
phytoplasma pyri” and “ Candidatus  Phytoplasma prunorum” the causal agents of apple 
proliferation, pear decline and Europ ean stone fruit yellows, respectively.  International 
Journal of Systematic and Evolutionary Microbiology : 54 (4), pp 1217-1226 
 Serio F di, Malfitano M, Alioto D, Ragozzino A,  Flores R (2003) Apple dimple fruit viroid. 
In Hadidi A, Flores R, Randles J W, Semancik J S (Eds) Viroids. CSIRO Publishing; 
pgs 146-149. 
 Sholberg, P. L., Stokes, S. C., and O’Gorman, D.T. 2009. First Report of a New Postharvest 
Disease of Pear Fruit Caused by S phaeropsis pyriputrescens in Canada. Plant Disease . 
August 2009, Volume 93, Number 8. 
 Welsh. M.F., Stace-Smith, R., and Brennan, E. 1973. Clover yellow mosaic virus from apple 
trees with leaf pucker disease. Phytopathology. 1973. 63(1):50-57. 
 Xiao, C. L., Rogers, J. D., and Boal, R. J. 2004. First Report of a New Postharvest Fruit Rot 
on Apple Caused by Sphaeropsis pyriputrescens. Plant Disease . February 2004, 
Volume 88, Number 2.  
 Xiao, C. L. and Rogers, J. D. 2005.
 A Postharvest Fruit Rot in d'Anjou Pears Caused by 
Sphaeropsis pyriputrescens sp. nov.  Plant Disease . February 2004, Volume 88, Number 
2. 
 Xiao, C. L. and Boal, R. J. 2005. A New Canke r and Twig Dieback Disease of Apple and 
Crabapple Trees Caused by Sphaeropsis pyriputrescens in Washington State. Plant 
Disease. October 2005, Volume 89, Number 10.  
APPENDIX 1 
The table below identifies the current testing requirements for Malus  spp. nursery stock sourced from MAF- approved offshore facilities. Tests 
highlighted in blue bold  are undertaken at the offshore facility prior to  export to New Zealand. 
 
MAF-approved offshore faciliti es, testing undertaken offshore Regulated organism 
 Proposed MAF requirement   
Central Attivita Vivaistiche 
(CAV), Italy Centre Technique 
Interprofessionnel des 
Fruits et Légumes (CTIFL), 
France Saanichton, Center for Plant 
Health, Canada Washington State 
University, Prosser, USA 
Insects Pesticide treatment in 
accordance with section 
2.2.1.6 of import health 
standard Pesticide treatment  Pesticide treatment  Pesticide treatment  Pesticide treatment  
Mites Pesticide treatment in 
accordance with section 
2.2.1.6 of import health 
standard Pesticide treatment  Pesticide treatment  Pesticide treatment  Pesticide treatment  
Fungi Growing season inspection     
Bacteria 
Pseudomonas syringae  pv. 
papulans  PCR PCR completed in New 
Zealand PCR completed in New 
Zealand PCR completed in New 
Zealand PCR completed in New 
Zealand 
Viruses 
Cherry rasp leaf virus Woody indexing or 
herbaceous indexing  
AND  PCR Woody indexing 
PCR completed in New 
Zealand Woody indexing Agreement to be updated Woody indexing 
Clover yellow mosaic virus Growing season inspection     
Tomato bushy stunt virus Herbaceous indexing Herbaceous indexing 
completed in New Zealand Agreement to be updated  Herbaceous indexing Herbaceous indexing 
Tomato ringspot virus Herbaceous indexing AND  
ELISA or PCR Herbaceous indexing and 
ELISA or PCR completed in 
New Zealand Woody indexing 
ELISA or PCR completed in 
New Zealand Herbaceous indexing and 
ELISA Woody indexing and 
herbaceous indexing and 
ELISA 
Viroids 
Apple dimple fruit viroid Woody indexing AND  PCR Woody indexing and PCR Woody indexing 
PCR completed in New 
Zealand Pest free area declaration 
endorsed on Phytosanitary 
certificate Pest free area declaration 
endorsed on Phytosanitary 
certificate and woody 
indexing 
 
16  MAF Biosecurity New Zealand   Risk Management Proposal:  
  Malus  spp. Nursery Stock  
 
 
17  MAF Biosecurity New Zealand   Risk Management Proposal:  
  Malus  spp. Nursery Stock 
 
 MAF-approved offshore faciliti es, testing undertaken offshore Regulated organism 
 Proposed MAF requirement   
Central Attivita Vivaistiche 
(CAV), Italy Centre Technique 
Interprofessionnel des 
Fruits et Légumes (CTIFL), 
France Saanichton, Center for Plant 
Health, Canada Washington State 
University, Prosser, USA 
Apple fruit crinkle viroid Woody indexing AND  PCR Woody indexing 
PCR completed in New 
Zealand Woody indexing 
PCR completed in New 
Zealand  Pest free area declaration 
endorsed on Phytosanitary 
certificate  Pest free area declaration 
endorsed on Phytosanitary 
certificate and woody 
indexing 
Apple scar skin viroid Woody indexing AND  PCR Woody indexing and PCR Woody indexing 
PCR completed in New 
Zealand  Woody indexing and PCR PCR 
Phytoplasmas 
‘Candidatus Phytoplasma 
asteris’  Nested PCR using universal 
phytoplasma primers Woody indexing and PCR Woody indexing and PCR Pest free area declaration 
endorsed on Phytosanitary 
certificate PCR 
‘Candidatus Phytoplasma mali’  Woody indexing AND  nested 
PCR using universal 
phytoplasma primers Woody indexing and PCR Woody indexing and PCR Pest free area declaration 
endorsed on Phytosanitary 
certificate and Woody 
indexing Woody indexing and PCR 
Diseases of unknown aetiology 
Apple blister bark agent Growing season inspection    Woody indexing 
Apple brown ringspot agent Growing season inspection     
Apple bumpy fruit agent Growing season inspection     
Apple bunchy top agent Growing season inspection     
Apple dead spur agent Woody indexing Woody indexing Woody indexing Woody indexing Woody indexing 
Apple decline Growing season inspection    Woody indexing 
Apple freckle scurf agent Growing season inspection    Woody indexing 
Apple green dimple and ring 
blotch agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary 
certificate  
Apple junction necrotic pitting agent Growing season inspection     
Apple McIntosh depression 
agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary   
 
18  MAF Biosecurity New Zealand   Risk Management Proposal:  
  Malus  spp. Nursery Stock MAF-approved offshore faciliti es, testing undertaken offshore Regulated organism 
 Proposed MAF requirement   
Central Attivita Vivaistiche 
(CAV), Italy Centre Technique 
Interprofessionnel des 
Fruits et Légumes (CTIFL), 
France Saanichton, Center for Plant 
Health, Canada Washington State 
University, Prosser, USA 
certificate 
Apple narrow leaf agent Growing season inspection     
Apple Newton wrinkle agent Growing season inspection   Growing season inspection 
of mother plants  
Apple pustule canker agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary 
certificate Woody indexing 
Apple red ring agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary 
certificate Woody indexing 
Apple rosette agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary 
certificate  
Apple rough skin agent Woody indexing  Woody indexing Woody indexing Woody indexing Woody indexing 
Apple russet wart agent Woody indexing  Woody indexing Woody indexing Woody indexing Woody indexing 
Apple star crack agent Woody indexing  Woody indexing Woody indexing Woody indexing Woody indexing 
Apple transmissible internal 
bark necrosis agent Growing season inspection   Pest free area declaration 
endorsed on Phytosanitary 
certificate