Risk Management Proposal:   
New Import Health Standard (IHS) for Phase 3 
Mushroom Growing Medium  
MPI.STD.PHASE3  
 
 
 
 
14 December 2016  
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Plant  Imports  
Plants, Food & Environment  
Ministry for Primary Industries  
Pastoral House  
25 The Terrace  
PO Box 2526  
Wellington 6140  
New Zealand  
 
Tel: +64 4 894 0100  
Fax: +64 4 894 0662  
 
Email: plantimports@mpi.govt.nz   
Page 3 of 34 
  
 
Disclaimer  
This document does not constitute, and should not be regarded as, legal advice. While every effort has been 
made to ensure the information in this document is accurate, the Ministry for Primary Industries does not accept 
any responsibility or liability whatsoever for an y error of fact, omission, interpretation or opinion that may be 
present, however it may have occurred.  
Requests for further copies should be directed to:  
 
Plant Imports  
Plants, Food & Environment  
Ministry for Primary Industries  
PO Box 2526  
Wellington 6140  
New Zealand  
 
Email: plantimports@mpi.govt.nz  
 
© Crown Copyright – Ministry for Primary Industries.  
  Page 4 of 34 
 Submissions  
The Ministry for Primary Industries (MPI) invites comment from interested parties on the proposed issuance of a 
new import health standard (IHS) for Phase 3 mushroom growing medium, which is supported by this risk 
management proposal (RMP).  
The purpose of an IHS is defined as follows in section 22(1) of the Biosecurity Act 1993 (the Act): “An import 
health standard specifies requirements that must be met to effectively manage risks associated with importing 
risk goods, including risks arising because import ing the goods involves or might involve an incidentally imported 
new organism”.  
MPI must consult with interested parties in accordance with section 23 of the Act and MPI’s consultation policy 
before issuing or amending an import health standard under secti on 24A of the Act.  
MPI therefore seeks formal comment on the requirements (including phytosanitary measures) that are proposed 
for the import of phase 3 mushroom growing medium, that is mushroom growing medium inoculated with spawn 
of common mushroom ( Agar icus bisporus ). These requirements are set out in the draft IHS for Phase 3 
mushroom growing medium . 
MPI has developed this RMP based on the best available technical evidence and assessment of this evidence. If 
you disagree with the measures proposed to ma nage the risks, please provide either data or published 
references to support your comments. Similarly, if you support the proposed measures, or consider that additional 
measures are required to manage the risks, please provide appropriate evidence to supp ort your comments. This 
will enable MPI to consider additional evidence which may change how risks are proposed to be managed.  
The following points may be of assistance in preparing comments:  
 
 Wherever possible, comments should be specific to a particular section/requirement of the standard;  
 Where possible, reasons, data and supporting published references to support comments are 
requested;  
 The use of examples to illustrate particular points is encouraged.   
MPI encourages respondents to forward comments e lectronically. Please include the following in your 
submission:  
 
 The title of the consultation document in the subject line of your email;  
 Your name and title (if applicable);  
 Your organisation’s name (if applicable); and  
 Your address.  
Send submissions to: plantimports@mpi.govt.nz  . 
If you wish to forward submissions in writing, please send them to the following address:  
Plant Imports  
Plants, Food & Environment  
Ministry for Primary Industries  
PO Box 2526  
Wellington 6140  
New Zealand  
All submissions must arrive by close of business on 18 January 2017 . Submissions received by the closure date 
will be considered during the development of the final standard. Submissions received after the closure date may 
be held  on file for consideration when the issued standard is next revised/reviewed.   
Page 5 of 34 
 Official Information Act 1982  
Please note that your submission is public information and it is MPI policy to publish submissions and the review 
of submissions on the MPI website . Submissions may also be the subject of requests for information under the 
Official Information Act 1982 (OIA). The OIA specifies that information is to be made available to requesters 
unless there are sufficient grounds for withholding it, as set out in the OIA. Submitters may wish to indicate 
grounds for withholding specific information contained in their submission, such as the information is 
commercially sensitive or they wish personal information to be withheld.  
Any decision to withhold information re quested under the OIA is reviewable by the Ombudsman.  Page 6 of 34 
 Contents   
Objective and purpose  7 
Commodity description  7 
Backgrou nd 7 
Part 1: Context  9 
Domestic  9 
International  10 
Strength of measures  10 
Part 2: Approach  11 
Source information  11 
Assessment  11 
Description of mea sures  12 
Basic measures  12 
Targeted measures  12 
MPI-specified measures  13 
Post-clearance conditions  14 
Part 3: Risk assessment and management  16 
3.1 Viable seeds and pest or disease organisms of plants and A. bisporus  16 
3.2 Hitchhiker organisms  18 
3.3 Regulated organisms within mushroom spawn  19 
3.4 Regulated organisms within animal manure  19 
3.5 Trichoderma aggressivum  19 
Pest biology, impact and control  19 
Proposed measures  21 
3.6 Mushroom virus X  23 
Pest biology, impact and control  23 
Proposed measures  24 
Post clearance conditions  26 
Feasibility and practicality of measures  28 
Summary of proposed measures  29 
Part 4: References  33    
Page 7 of 34 
 Objective and purpose  
(1) MPI’s objective is to ensure that the known biosecurity  risks associated with phase 3 
mushroom growing medium are managed appropriately and in a way which is 
consistent with New Zealand’s domestic legislation and international obligations.  
(2) The purpose of this RMP is to:  
a) summarise the known phytosanitary risks that may be associated with the import of 
phase 3 mushroom growing medium into New Zealand;  
b) show how the measures proposed in the draft IHS schedule effectively manage 
known biosecurity risks and are consistent with New Zealand’s domestic 
legislation and international obligations.  
(3) The draft IHS is the subject of consultation under section 23(3) of the Act. Th e RMP 
provides information to support the consultation on the draft IHS, but is not itself the 
subject of consultation. However MPI will accept comments and suggestions on the 
RMP in order to improve future IHS consultations.  
Commodity description  
(4) Phase 3 mushroom growing medium described in this RMP is used to grow common 
mushroom ( Agaricus bisporus ). 
(5) The medium is produced using a mixture of horse manure, chicken manure, straw, 
gypsum and water. The raw ingredients are mixed and composted at high temperat ures 
(around 80°C) for several days; the temperature and duration of composting depends on 
the individual manufacturer. The composted product is known as ‘phase 1 medium’. 
Phase 1 medium is then pasteurised (for example at 57 -60°C for 8 -10 hours) and 
condi tioned at a lower temperature (for example 48°C for a further 2 -3 days). The 
conditioned product is called ‘phase 2 medium’.  
(6) Phase 2 medium is inoculated with mushroom spawn and incubated at around 25°C for 
approximately two weeks. During this time the mus hroom mycelium spreads 
throughout the growing medium. The colonised product is known as phase 3 growing 
medium.  
(7) Mushrooms can be grown directly from phase 3 medium after a peat -based casing is 
added to induce production of fruiting bodies (mushrooms). Alte rnatively, phase 3 
medium can be chilled to around -2°C and held until required; it is the chilled product 
that is being assessed under this RMP.  
Background  
(8) In 2015 MPI received an application to import into New Zealand phase 3 mushroom 
growing medium manu factured in the Netherlands. As part of the regular process for 
assessing import requests MPI reviewed the information provided in the import permit 
application. This included assessing the ingredients and processes used to manufacture 
the product. Based o n this review an import permit was issued under the IHS for 
Fertilisers and Growing Media of Plant Origin . The permit included specific conditions 
to manage known biosecurity risks associated with this product.  Page 8 of 34 
 (9) After the permit was issued MPI became aware that some of the raw ingredients used to 
manufacture the product were of animal origin. This had not been specified in the 
import permit application. These ingredients were horse and chicken manure.  
(10) Based on the new information MPI revoked the import permi t.  
(11) Since issuing the original import permit MPI has also become more aware of the risks 
posed by two serious diseases of mushroom that are not known to be present in New 
Zealand, namely Trichoderma aggressivum  and Mushroom virus X. Both of these 
diseases can be transmitted in phase 3 medium.  
(12) No further import permits for this product will be granted until after the biosecurity 
risks associated with the product are re -assessed and an IHS has been issued that 
specifically covers the ingredients of animal ori gin in the goods, and the two mushroom 
diseases of concern.  
(13) MPI officials visited the production facility in the Netherlands in June 2016 to review 
the pathway and to gather more information about the biosecurity risks that may be 
associated with the produ ct. 
(14) MPI has now completed its  assessment  and has prepared new import health standard s 
that set out risk management measures that are specific to phase 3 mushroom growing 
medium.  
(15) This RMP discusses the biosecurity risk associated with the plant -based compon ents of 
phase 3 mushroom growing medium and describes the measures that are proposed to 
manage this risk under  the new IHS for Phase 3 mushroom growing medium . 
(16) As part of this process, MPI has also released for consultation a draft generic IHS for 
Processed Animal Manure Products (ANMANURE.GEN ) which is available on  the 
MPI website  as part of this consultation . The generic IHS will include processed horse 
and chicken manure as a commodity type.  
(17) Because horse and chicken manure are components of the product, all phase 3 growing 
medium imported under the IHS for Phase 3 mushroom growing medium  must also 
meet all relevant requirements set out in the animal products IHS.  
   
Page 9 of 34 
 Part 1: Context  
Domestic  
(18) New Zealand operates a biosecurity system for which the phytosanitary aspect 
(covering plant health) is a key part.  
(19) The biosecurity system is regulated through the Biosecurity Act 1993. Section 22 of the 
Act describes an import health standard (IHS) and outlines the types of matters for risk 
goods that an IHS c an cover.  
(20) MPI is the government authority responsible for maintaining biosecurity standards for 
the effective management of risks associated with the importation of risk goods into 
New Zealand (Part 3, Biosecurity Act 1993).  
(21) The biosecurity system in New Z ealand operates a series of components or layers (pre -
border, border and post border) that together provide a high level of assurance that pests 
are unlikely to establish in New Zealand. No one part of the system is able to achieve 
the necessary assurance on its own.  
(22) No biosecurity system is capable of reducing risk to zero. The objective of the system is 
to reduce to an acceptable level the likelihood of entry and establishment of regulated 
organisms (including pests, diseases and weeds).  
(23) An organism is ‘r egulated’ by MPI if it could cause unacceptable consequences (i.e. 
likely to cause unacceptable economic, environmental, socio -cultural or human health 
impacts in New Zealand) if it were to enter and establish in New Zealand, provided the 
organism is:  
a) not present in New Zealand, or if present in New Zealand is under official control;  
b) able to establish and spread in New Zealand.  
For plant -based organisms, entry and establishment is defined as ‘introduction’ by the 
International Plant Protection Convention  (IPPC).  
(24) The New Zealand phytosanitary system focuses on ensuring that the most significant 
pests, for example economically important fruit flies, are unlikely to ever establish in 
New Zealand. The system also manages risk associated with all other regulat ed pests.  
(25) The focus of an IHS for plant -based goods is to manage unacceptable phytosanitary 
risks identified as being associated with the goods before they arrive at the New 
Zealand border. The expectation is that, to the greatest extent possible, commerc ial 
consignments of plants and plant products meet New Zealand’s phytosanitary import 
requirements on arrival (risk is managed off -shore).  
(26) MPI monitors the pathway performance related to each IHS to ensure it provides the 
expected level of protection. This  is achieved through verification and inspection 
activities at the border and, where necessary, audits of offshore production systems  
through MPI’s ‘Pathway Assurance’ programme . Page 10 of 34 
 (27) MPI is committed to the principles of transparency and evidence -based technic al 
justification for all phytosanitary measures, new and amended, imposed on importing 
pathways.  
International  
(28) Where possible, phytosanitary import requirements are aligned with international 
standards, guidelines, and recommendations as per New Zealand’s obligations under 
Article 3.1 of the World Trade Organisation (WTO) Agreement on the Application of 
Sanitary and Phytosanitary Measures; WTO, 1995 (SPS Agreement).  
(29) The SPS Agreement sets in place rules that protect each country’s sovereign right to 
take th e measures necessary to protect the life or health of its people, animals, and 
plants while at the same time facilitating trade. It embodies and promotes the use of 
science -based risk assessments to manage the risks associated with the international 
moveme nt of goods.  
(30) In keeping with New Zealand‘s obligations under the SPS Agreement and the IPPC, 
phytosanitary measures must:  
a) be justified and can only be for regulated pests. The strength of any phytosanitary 
measure will depend on the assessment of risk, wi th an emphasis on the 
consequences of the pest establishing in New Zealand;  
b) not discriminate unfairly between countries or between imported and domestically 
produced goods;  
c) be based on international standards wherever possible, but WTO members can 
adopt a measure that is more stringent than an international standard, provided the 
measure is scientifically justified.  
(31) Note that international standards, guidelines or recommendations referred to in the 
WTO agreement are those of Codex, OIE (World Organisation f or Animal Health) and 
the IPPC, including regional standards developed by Asia Pacific Plant Protection 
Commission.  
Strength of measures  
(32) Measures are required for regulated pests where the ‘probability of introduction and 
spread’ on a pathway is unacceptable (i.e. if a regulated organism is able to enter 
through the pathway, find a suitable host, and establish and spread in New Zealand).   
(33) The required strength of a measure depends on the risk posed by a particular regulated 
organism on the pathway. This risk is determined by a combination of the consequences 
the pest may cause if it was introduced into New Zealand and the likelihood that th e 
pest will enter and establish from a pathway.  
(34) The greater the risk or consequence a pest can cause, the greater the level of assurance 
MPI requires that the pest is not present in a consignment.   
Page 11 of 34 
 (35) The strength of the measure required should be no more than  necessary to manage the 
risk the organism poses. MPI has classified measures into three categories of increasing 
strength: Basic Measures , Targeted Measures  or MPI-Specified Measures . 
(36) The proposed requirements for phase 3 growing medium include all measur es accepted 
for regulated pests assessed as being possibly associated with the commodity.  
Part 2: Approach  
Source information  
(37) In developing this RMP the following information was used to identify risk organisms 
and to develop appropriate measures to preven t their entry and establishment in New 
Zealand:  
a) MPI Import Risk Analysis: Phytosanitary risks of importing phase III Agaricus 
bisporus mushroom compost from northern Europe ( available on the MPI website 
as part of this consultation) ; 
b) MPI Discussion Documen t for the Importation of Fertilisers and Growing Media 
containing Plant Material (available on the MPI website as part of this 
consultation) ; 
c) relevant literature (scientific journals, webpages, books, databases etc.);  
d) information provided by stakeholders a nd manufacturers of phase 3 mushroom 
growing medium.  
e) information obtained during the MPI visit to a phase 3 production facility in the 
Netherlands  and during discussions with the NPPO of the Netherlands . 
Assessment  
(38) The above information sources were used t o assess the potential for an organism to 
enter New Zealand in association with phase 3 growing medium, and to establish and 
spread in New Zealand.  
(39) Factors considered as part of the assessment were:  
a) presence or absence of an organism in the exporting count ry; 
b) presence or absence of an organism in New Zealand (or under official control if 
present in New Zealand);  
c) regulatory status of an organism in New Zealand;  
d) association of an organism with the commodity and pathway;  
e) potential for an organism to establish and spread in New Zealand;  
f) potential for an organism to cause economic, environmental and/or human health 
consequences in New Zealand.  Page 12 of 34 
 (40) All organisms identified as ‘pests of concern’ were assessed by MPI to determine the 
‘probability of introduction and spr ead’ (entry, exposure to suitable hosts, establishment 
and spread) in New Zealand (following part 2.2 of ISPM 11).  
Description of measures   
(41) In the context of developing requirements for the import into New Zealand of phase 3 
growing medium, the categories of measure described below were considered.  
Basic measures  
(42) Basic measures are required to manage all organisms that could enter or establish in 
New Zealand, and consist of the following components:  
Commercial production  
(43) Standard commercial production measu res will act to reduce or eliminate some of the 
biosecurity risk associated with the product.  
(44) For the purposes of this RMP, commercial production of phase 3 growing medium is 
considered to include:  
a) phase 1 composting and phase 2 pasteurising and conditioni ng completed in 
enclosed bunkers  at a temperature appropriate to manage biosecurity risk . 
b) Stringent hygiene measures throughout the production process including:  
i) using dedicated equipment and machinery for different stages of production ; 
ii) preventing contami nation between different areas of a production facility;  
iii) rigorous cleaning of all equipment between each batch;  
iv) using heat treatment and /or disinfectants between each batch;  
v) packaging phase 3 medium in impermeable material after spawning.  
Quality system pr oduction  
(45) A quality production system aims to provide a consistent quality of product by setting 
standards for each stage of manufacturing or processing. This is particularly suitable for 
managing the risk of hitchhiker organisms associated with contaminati on during 
processing and storage, and can have a general focus where the exact pests likely to be 
associated with a product are uncertain.  
(46) An awareness of the necessity for cleanliness and regular monitoring and product 
checks is required. Importers and su ppliers will need to provide suitable evidence that 
measures are in place to avoid contamination and monitor sites in the production 
process.  
(47) Manufacturers of phase 3 medium are expected to be subjected to regular audits by an 
official accreditation body t o ensure all relevant procedures continue to be followed.  
Targeted measures  
(48) Targeted measures are used in addition to basic measures to manage the risk of entry 
and establishment of regulated organisms that pose a higher level of risk and may not be  
Page 13 of 34 
 sufficiently managed by basic measures, or where a greater level of assurance is needed 
that appropriate risk management actions have been taken.  
(49) Targeted measures may have a more general mode of action and are often not fully 
prescribed in the IHS, allowing th e exporting NPPO to select an appropriate method, 
based on availability in the exporting country, expert judgement and experience.  
(50) MPI will assess whether the proposed targeted measures are appropriate for the 
management of a particular regulated organism before imports are allowed.  
(51) The Export Plan will document the means by which all Targeted Measures set out in the 
IHS will be achieved.  
(52) The application of a targeted measure may also be effective against non -target 
organisms.  
(53) Targeted measures include a wide range of options and provide MPI with the assurance 
that regulated organisms that may be associated with a product are eliminated or 
reduced to a level that will not enable the organism to establish in New Zealand.  
(54) The following measures are some that  may be considered for managing pests requiring 
targeted measures:  
a) pest free area; requirements for pest free areas are described in the International 
Standard for Phytosanitary Measures (ISPM) 4: Requirements for the establishment 
of pest free areas. A pe st free area may include an entire country (‘country 
freedom’), or uninfested parts of a country. Additional measures are not required 
for pests where pest free area status is recognised for the exporting country for that 
pest;  
b) systems approaches; a system s approach is composed of two or more independent 
measures and will be assessed by MPI before imports are allowed.  
(55) Targeted measures are subject to pathway assurance audit by MPI.  
MPI-specified measures  
(56) MPI-specified measures are used in addition to basic measures when the likelihood of 
entry and establishment or consequence of a regulated organism is very high. MPI -
specified measures are reserved for regulated organisms that will have a very high 
consequence to New Zealand (for example Queensland fruit fly ). 
(57) MPI specified measures include end -point treatments such as temperature treatments, 
irradiation or fumigation, and laboratory testing where the test method is specified.  
(58) Requiring a  permit to  import also allow s MPI to check  that an importer will be able  to 
comply with any post clearance conditions that are imposed on the imported goods  
before imports commence.  
Certification and verification  
Permit to import  
(59) A permit to import allows MPI to verify that an Export Plan is in place for production 
facility (s) before imports can commence.  Page 14 of 34 
 (60) Where an Export Plan is not required, a permit to import allows MPI to verify that 
appropriate Basic Measures are being used and that appropriate phytosanitary 
certification (e.g. pest free area declarations ) can be provided by the NPPO of the 
exporting country prior to export.  
Pre-export inspection and phytosanitary certification  
(61) Pre-export inspection and phytosanitary certification of the product by the National 
Plant Protection Organisation (NPPO) of the e xporting country ensure s that the 
requirements of the relevant IHS have been met by the exporting country.  
(62) A phytosanitary certificate can provide verification that a consignment is free from 
visually detectable contaminants such as viable seed, soil, cont aminant animal or plant 
material or other extraneous matter.  
(63) The certificate can also be used to provide additional verification for other steps of the 
production process if the NPPO has sufficient oversight over the process. For example, 
a manufacturer ma y apply targeted measures (see below) to manage the risk associated 
with a particular disease organism. In such cases, the NPPO could provide verification 
that the targeted measures notified to MPI have been undertaken as stated by the 
manufacturer.  
Verifi cation on arrival in New Zealand  
(64) MPI will inspect documentation prior to each consignment arriving in New Zealand. 
Upon arrival, a consignment will normally have a representative sample taken and 
inspected for the absence of regulated pests. Any reduction  in the level of inspection 
from current on -arrival levels is based on sound evidence of the compliance of a 
pathway. In a few cases where a pathway is highly compliant inspections will be 
conducted on an audit basis to ensure ongoing compliance.  
(65) When a co nsignment is found to be infested with live regulated pests on arrival in New 
Zealand, one of the following risk management activities will be applied:  
a) reshipment of the consignment;  
b) destruction of the consignment; or  
c) treatment of the consignment.  
Post -clearance conditions  
(66) Post clearance conditions may be applied under either section 22 or 27 of the Act .  
(67) Under section 22 of the Act, post clearance conditions may specify the following:  
a) the class or description of persons to whom the requirements apply;  
b) the use to which the goods must be put;  
c) the restrictions or conditions on the use of the goods;  
d) the duration of the requirements;  
e) any other matters reasonably necessary for the effective implementation of the 
requirements.   
Page 15 of 34 
 (68) Under  section 27A of the Act, an inspector who gives a biosecurity clearance under 
section 26 of the Act may impose post -clearance conditions on the goods if the post 
clearance conditions are approved by a Chief Technical Officer.  The conditions may : 
a) specify the use to which the goods mus t be put:  
b) specify the restrictions or conditions on the use of the goods:  
c) specify how long a restriction or condition lasts by reference to a period of time, a 
date, or an event:  
d) specify how the goods must be managed or disposed of:  
e) specify the place or a rea within which the goods must be kept, managed, or used:  
f) require notification of a change in circumstances that affects the goods:  
g) require reporting to an inspector or another specified person in specified 
circumstances on specified matters:  
h) deal with an y other matters reasonably necessary for the effective management of 
the risks associated with the goods.  
(69) Post clearance conditions can be included as a requirement of an applicable IHS.  
 
  Page 16 of 34 
 Part 3: Risk assessment and management  
(70) The purpose of this section  is to:  
a) identify known hazards associated with phase 3 mushroom growing medium that 
have been identified as being a potential biosecurity risk to New Zealand;  
b) identify ways in which each type of hazard can be managed.  
(71) The following have been identified as potential biosecurity risks that may be associated 
with phase 3 growing medium:  
a) viable seeds;  
b) plant pest and disease organisms in raw ingredients;  
c) pests or disease organisms of  A. bisporus  excluding Trichoderma aggressivum and 
Mushroom virus X  disease  (which are considered separately below);  
d) hitchhiker organisms;  
e) regulated organisms that may be present within mushroom spawn;  
f) regulated organisms that may be present in animal manure ;  
g) Trichoderma aggressivum ; 
h) Mushroom virus X (MVX) disease.  
3.1 Viable seeds  and pest or disease organisms of plant s and A. 
bisporus   
(72) Basic measures  as described in this section are justified and sufficient to manage the 
following hazards that may be associated with the raw ingredients  (plant mat erial and 
animal manure) : 
a) viable seeds ; 
b) plant pest or disease organisms  (for example insects or microorganisms) ; 
c) pest or disease  organism s of A. bisporus , as identified in the MPI import risk 
analysis, apart from  T. aggressivum and MVX , which are considere d separately 
below .  
(73) The following attributes of commercial mushroom cultivation and growing medium 
production reduce  the biosecurity risk associated with  hazard organisms considered in 
this section of the RMP : 
a) common mushroom ( A. bisporus ) is a secondary decomposer. This means that it 
will only grow on a substrate that is already partially decomposed. The primary 
decomposition that occurs during phase 1 composting and phase 2 pasteurising and 
conditioning will devitalise the types of hazard organism consid ered in this section 
of the RMP.   
Page 17 of 34 
 b) to produce phase 3 growing medium, all raw ingredients are composted at high 
temperatures (a maximum of around 80°C) for a minimum of 48 hours at high 
humidity (around 70%). Product is then pasteurised (for example at 57 -60°C for 8 -
10 hours) to eradicate any disease organisms that may remain, and then conditioned 
at a lower temperature (for example 46 -49°C for 48 -72 hours) to remove free 
ammonia . This processing will reduce  biosecurity  risk associated with viable seeds, 
insects or plant disease organisms that may be present in the raw ingredients, 
especially when high temperatures are taken in combination with the primary 
decomposition that occurs during phase 1 and phase 2 production, and microbial 
antagonism or release of t oxic products, as described in the MPI import risk 
analysis.  
(74) The recommended temperatures to manage T. aggressivum  and MVX ( either 60°C for 
at least 12 hours,  or 65  °C for at least 8 hours ) are also considered sufficient to manage 
risk associated with hazard organisms considered in this section of the RMP.  
(75) Paragraphs (76) to (78) identify Basic measures  (commercial production, quality 
systems production and visual inspection)  which , in combination  with post clearance 
condi tions  and factors summarised in paragraph (73), will reduce to an acceptable level, 
or eliminate the biosecurity risk, associated with hazards identified in section  2.1 of this 
RMP:  
(76) The following attributes of commercial production  are considered relevant to managing  
the biosecurity risk associated with hazards identified in section 2.1 of this RMP:  
a) A requirement to use  enclo sed bunkers  for phase 1 composting allows  better 
moderation of  temperatures  than if composting is done in windrows or partially 
enclosed bunkers . This means that even temperatures are achieved more effectively 
across the compost heap, and helps to ensure that the minimum required 
temperature  is attained  throughout the heap . 
b) A requirement to use  the following  hygiene measures will reduce the likelihood of 
hazard organisms contaminating phase 1 compost  after processing : 
i) removing compost debris from areas used to hold raw ingredients, and from 
phase 1 tunnels  after composting, will prevent  hazard organisms accumulating 
in phase 1 production areas;  
ii) segregating equipment and machinery used t o process raw ingredients from 
other parts of the production process, and cleaning this equipment between 
each batch will prevent phase 1 compost from being contaminated  with 
hazard organisms from unprocessed material ; 
iii) thoroughly cleaning  winches and conve yors used to transport phase 1 medium 
to phase 2 tunnels will prevent hazard  organism s accumulating on this 
equipment  and/or being dispersed to other parts of a production facility ; 
iv) transporting phase 1 medium in closed conveyors will prevent contamination  
between composting and  pasteurisation.  
(77) Quality system production , including independent auditing by an official accreditation 
body , will to ensure that processes and procedures (such as hygiene  procedures  listed 
above ) continue to be followed as described in standard operating procedures.  Page 18 of 34 
 (78) Visual inspection  is expected to identify any insects or  viable seeds present in the 
composted product.  
a) phytosanitary i nspections in the country of origin will verify that the product is free 
of contaminant plant material, or organisms such as insects;  
b) MPI inspections of previously imported consignments did not detect any insects or 
viable seeds. When seeds were recognisab le within the product these were 
decomposed and non -viable . 
(79) It is considered that the likelihood of viable seeds and plant pests and diseases being 
introduced (entering and establishing) in  New Zealand , is negligible because:   
a) The measures described above,  including commercial production and visual 
inspections, will reduce the risk of viable seeds and other plant material being 
present in the growing medium.  
b) Growing medium when imported into New Zealand is unlikely to contain viable 
seeds and plant pests & diseases after production which will lead to establishment 
of these organisms in the New Zealand environment.  
Export eligibility:  
(80) If MPI considers that the proposed composting parameters , operating procedures , and/or 
quality production system  at a particular facility will not  manage the risk, material from 
that facility will not be eligible for import.  
(81) If viable seeds are detected during a product inspection (pre -export or on -arrival in New 
Zealand) material from that batch will not be eligible  for import . This is because 
presence of viable seeds will be seen as evidence of a systems failure  indicating that the 
composting conditions for that batch were not sufficient to manage all biosecurity risk.  
3.2 Hitchhiker organisms  
(82) Hitchhiker organisms a re organisms such as insects  that may  contaminate a 
consignment  during processing, handling or storage , but do not infest the product . 
(83) Basic measures are justified and sufficient to manage any biosecurity risk associated 
with hitchhiker organisms  that may contaminate  the product during processing . 
(84) The hygiene measures used in commercial production  as described in paragraph (44)b)  
of this RMP,  will reduce to an acceptable level, or eliminate the biosecurity risk, 
associated with hitchhiker organisms.  
(85) Quality system production , including independent auditing by an official accreditation 
body, will ensure that processes and procedures (such as hygiene procedures listed 
above) continue to be followed as described in standard operating procedures.  
(86) Visual inspection  is expected to detect viable hitchhiker organisms that were introduced 
during or after processing.  
Export eligibility:   
Page 19 of 34 
 (87) If regulated hitchhiker organisms are detected during a product inspection (pre -export or 
on-arrival in New Zealand) material from that batch will not be eligible for import, or 
will require treatment before being given a biosecurity clearance.  
3.3 Regulated organisms within mushroom spawn  
(88) Basic measures are considered justified and sufficient to manage any biosecurity risk 
associated with  disease organisms that may be present within mushroom spawn.  
(89) Phase 3 mushroom growing medium is inoculated with common mushroom ( Agaricus 
bisporus ) spawn  prior to export . 
(90) Spawn is produced by a specialist third party producer. Spawn consists of mushroom 
mycelium that is usually inoculated onto a sterile grain -based substrate , although other 
substrates may be used . 
(91) It is known that mushroom viruses could potentially be present within spawn and that a 
small number of  benign viruses are present in modern hyb rid strains, Spawn production 
companies have strict processes to ensure freedom from pathogenic viruses, including 
hygienic preparation of the substrate and testing of starter cultures for diseases . 
3.4 Regulated organisms within animal manure  
(92) As noted in the background to this document, an integral component of phase 3 medium 
is horse and chicken manure . 
(93) MPI’s Animal Imports team has recently developed a draft IHS for processed animal 
manure products for import into New Zealand. The draft IHS and RMP  for this type of 
product have been made available as part of this consultation process and can be viewed 
on the MPI consultations page . 
(94) All phase 3 growing medium will be expect ed to meet all relevant  requirements set out 
in the animal products IHS to ensure that any risk associated with  disease organisms of  
animal s is appropriately managed.  
3.5 Trichoderma aggressivum  
Pest biology, impact and control  
(95) Trichoderma aggressivum is a fungal competitor of mushroom that causes a disease 
commonly known as green mould disease. T. aggressivum  was originally detected in 
Ireland in the 1980s (at that stage it was known as ‘ Trichoderma harzianum Th 2’).  
(96) T. aggressivum  has been recorded as be ing present in Australia, Canada, China, 
England, mainland Europe (including Croatia, France, Hungary, the Netherlands, 
Poland and Spain), Scotland , South Africa  and the USA (O'Brien, 2012; Kredics, 201 0; 
Baars, 2013; Anon, 2010) . The disease is not known to be present in New Zealand , and 
is a regulated organism . 
(97) Although T. aggressivum has been recorded as being present  in Australia (Anon, 2010; 
Baars, 2013) and China  (Baars, 2013), there are no re cords of the organism causing Page 20 of 34 
 major losses in these countries . It is not clear why the disease is not recorded as having 
an impact in these countries. However, MPI are aware of anecdotal evidence that only a 
single isolate of T. aggressivum  was found in Australia, and that whilst it caused 
significant problems at the site where it was collected, it seems that it may have been 
confined to that site, and/or eradicated.  
(98)  T. aggressivum is primarily transmitted by  mechanical means (for example o n 
contaminated equipment  and machinery , or on people and clothing), via contaminated 
airborne dust and debris, and by mixing operations associated with handling phase 3 
compost (O’Brien et al. 2015) . Transport of contaminated p hase 3 growing medium is 
one means by which the disease organism  has been spread in  Europe  (Lemmers, 2010) . 
(99) T. aggressivum  has a much higher impact on the mushroom industry than other  species 
of Trichoderma  (Krupke et al., 2003) . If present, T. aggressivum  aggressively colonises 
the growing medium, usually early in the growing cycle during spawn run. Small 
pockets of T. aggressivum  in a phase 3 batch can be further spread throughout clean 
phase 3 during emptying of tunnels at production facilities and empty ing of 
transportation containers at grower facilities. Symptoms initially become visible as large 
green patches on the compost and/or the casing (due to production of spores by T. 
aggressivum ). Mushrooms generally do not develop in medium that is colonised  by T. 
aggressivum . In areas where mushrooms do develop there will often be spotting and 
deformation of the fruiting bodies.  
(100)  There  are two distinct biotypes of T. aggressivum.   
a) T. aggressivum f. europaeum (formerly T harzianum Th 2) is the cause of green 
mould disease in Europe;  
b) T. aggressivum f. aggressivum  (formerly T harzianum Th 4) is the cause of the 
disease in North America.  
(101)  The disease has caused serious losses, costing millions of euro, to the European 
mushroom industry (Kredics, 2010)  and can result in complete crop loss.  Similar losses 
have been recorded in the USA (Castle, 1998) .  
(102)  Disease outbreaks are sporadic , but when they do occur they tend to be  severe. The 
presence of the pathogen incurs additional costs and changes to facilities and production 
processes.  
(103)  T. aggressivum  spores are heat tolerant up to temperatures of around 60°C. It is 
recommended that c ompost pasteurisation conditions of 60°C for 12 hours are needed to 
eradicate Trichoderma aggressivum  (Anon 201 1). 
(104)  Stringent hygiene measures are known to be effective at decontaminating equipment 
and facilities ( Kilpatrick, 2015) . If T. aggressivum  is present in a growing facility, it is 
recommended that at crop termination spent mushroom compost should be heated to at 
least 65°C for a minimum of 8 hours to eradicate the disease organism. The same heat 
treatment should be applied again once the spent mediu m has been removed from the 
growing room (Kilpatrick, 2015).  
(105)  T. aggressivum  has never been found in the natural environment (Kredics, 2010). This 
means that the likelihood of the disease organism being present in raw ingredients is 
negligible .  
Page 21 of 34 
 (106)  Growing  medi um can be contaminated with T. aggressivum  if spores or mycelium are 
present in the production facility (for example on machinery used to process the 
composted product).  
(107)  Spores are not readily airborne  (Kilpatrick, 2015) , however studies have shown that 
handling contaminated phase 3 medium can spread spores and/or infected compost 
fragments throughout a facility . If T. aggressivum  is present in a production facility, 
product could be contaminated during the following stages of production:  
a) before  composting. In this case the disease organism may not be killed if the phase 
1 compost heap (or parts of it) do not reach the minimum temperature for the time 
period necessary to kill spores;  
b) between phase 1 composting and pasteurisation. In this case the  disease organism 
may not be killed during pasteurisation if:  
i) there are zones in the pasteurisation tunnel which do not reach the required 
temperature ;  
ii) the time/temperature combination used for pasteurisation is insufficient to kill 
all spores (for exampl e if pasteurisation temperatures are less than 60°C or the 
pasteurisation period is too short).   
c) after pasteurisation, during inoculation with mushroom spawn (spawning);  
d) during processing of phase 3 medium after spawning (for example during tunnel 
emptying , mixing, loading of trucks or packing for export).  
Proposed measures  
(108)  Targeted measures are required in addition to basic measures to manage T. 
aggressivum . 
(109)  Targeted measures will effectively manage risk from T. aggressivum  by ensuring that 
production faci lities and the end product are free from the disease organism.  
(110)  Targeted measures considered to manage the risk associated with T. aggressivum 
include any of the following : 
a) country freedom ; 
b) pest free area;  
c) systems approaches, composed of  two or more indepen dent measures . 
Country freedom and p est free areas  
(111)  If the NPPO of an exporting country can provide a ‘country freedom’ declaration 
according to requirements set out in ISPM 4, specific phytosanitary measures will not 
be required for T. aggressivum . 
(112)  If the NPPO of an exporting country can verify that growing medium is produced in an 
uninfested part of a country in which a limited infested area is present , specific 
phytosanitary measures will not be required for T. aggressivum . In this case, an official 
contr ol programme must be being undertaken to manage T. aggressivum  according to Page 22 of 34 
 requirements set out in ISPM 4. Other relevant requirements of ISPM 4 must also be 
met. 
(113)  In both of the above cases, the NPPO of the exporting country will be required to 
endorse th e phytosanitary certificate with an additional declaration verifying that the 
growing medium was produced either in a country free from T. aggressivum, or in a 
pest free area.  
Systems approaches  
(114)  The likelihood of T. aggressivum being present in phase 3 med ium can be minimised 
using an effective systems approach. A systems approach consists of two or more 
independent measures. The following are considered suitable options as independent 
measures:  
a) stringent  hygiene measures to ensure production facilities remain free of the 
disease organism. This may include the following (Fleming -Archibald, 2015a; 
Kilpatrick, 2015):  
i) heat treatment of phase 3 incubation tunnels between batches, or alternate use 
of tunnels fo r phase 2 (pasteurising) and phase 3 (incubation), assuming that 
pasteurisation conditions are of sufficient temperature and/or duration to 
manage risk associated with T. aggressivum1. Minimum temperature 
requirements are either 60°C for at least 12 hours,  or 65°C for at least 8 hours ; 
ii) maintaining positive air pressure during spawning;  
iii) HEPA filtration of spawning areas;  
iv) isolating spawning from other stages of production;  
v) restricting entry to production tunnels;  
vi) rigorous cleaning procedures for tunnels, winc hes, conveyors and equipment 
to remove all traces of compost debris;  
vii) using heat treatment and disinfectants;  
viii) using clean clothing and footwear when entering production areas;  
ix) using dedicated equipment for different stages of production.  
b) testing to ensure f reedom from T. aggressivum , with confirmation of species 
identity using PCR or DNA sequencing if any species of Trichoderma  are detected : 
i) testing samples of phase 3 medium for T. aggressivum  when tunnels are being 
emptied;  
ii) testing debris on production equipment (conveyors, winches, mixers, ground, 
trucks, dispatch area etc.)  for the presence of T. aggressivum ; 
iii) testing air plates positioned throughout the facility (for example beneath 
tunnels that are being emptied, on winches, in dispatch halls etc.) fo r T. 
aggressivum . 
                                                
1 The heating in phase 1 composting and phase 2 pasteurising and conditioning is achieved through biological activity, rather than through 
direct heating. As such, even though temperatures are controlled by forcing air through spigots in tunnel floors, there may b e variation in 
temperatures within production tunnels during phase 1 and phase 2 p rocessing.   
Page 23 of 34 
 c) post production monitoring in the country of export to verify freedom from T. 
aggressivum  (at mushroom production facilities who receive material for the same 
batch of compost as will be exported to New Zealand). This monitoring will be 
done whilst growing medium is in transit to New Zealand, so signs or symptoms of 
T. aggressivum would be expected to become evident before product arrives in 
New Zealand;  
d) routine audit of production facilities by an independent accreditation body to verify 
that all processes and procedures are being carried out as described.  
(115)  In addition to the measures identified above, post clearance conditions will be imposed 
on any imported phase 3 medium to manage any residual risk that could be associated 
with the produ ct. This will include managing residual risk that could be associated with 
T. aggressivum . Proposed post clearance conditions are described in paragraphs (146) to 
(149)  of this RMP.  
Export eligibility:  
(116)  If an additional declaration is provided on a phytosanitary certificate verifying that 
growi ng medium was produced in a country recognised by MPI as being free from T. 
aggressivum, no additional measures will be required for T. aggressivum . 
(117)  If an additional declaration is provided on a phytosanitary certificate verifying that 
growing medium was p roduced in a pest free area free from T. aggressivum , MPI will 
audit the management of the pest free area for compliance with ISPM 4. Imports will 
not be allowed unless all relevant requirements of ISPM 4 are met.  
(118)  A systems approach  will be evaluated when an Export Plan is negotiated. If MPI 
consider that the proposed independent measures used in a systems approach  (i.e. the 
Export Plan)  will not manage the risk, or if an independent audit of a production facility 
shows system failures, material from that facility will not be eligible for import.   
(119)  If T. aggressivum is detected  either during routine testing of a phase 3 growing medium 
production facility, or within a batch of phase 3 medium  for export to New Zealand, 
material from that facility will no longer be eligible for import . Exports will not be able 
to resume until any weaknesses in the production system have been identified and 
repeat testing has demonstrated that the facility is free from T. aggressivum . 
(120)  MPI will require evidence that an importer can comply with all post clearance 
conditions before an import permit is issued.  
3.6 Mushroom virus X  
Pest biology, impact and control  
(121)  Mushroom virus X disease (MVX) was first detected in the United Kingdom in the 
1990s. MVX disease causes a range of symptoms affecting yield and/or quality.  
(122)  A number of viruses are believed to make up the MVX complex  (Burton, 2011) . Brown 
mushroom sy mptoms and poor mushroom quality are believed to be caused by Agaricus 
bisporus  Virus 16 (AbV16). AbV16 is usually found in association with other viruses, 
however it is not c lear what effect (if any) other viruses in the MVX complex  have on 
mushroom quality, or if these viruses interact with AbV16 (H Grogan, pers. comm.).  Page 24 of 34 
 However, Fleming -Archibald et al. (2016) note that two other viruses, Agaricus 
bisporus  Virus 6 (AbV6) and Mushroom bacilliform virus (MBV) may also contribute 
to symptoms.  
(123)  MVX has been reported from Belgium,  Ireland, Italy, the Netherlands, New Zealand, 
Poland and South Africa (Eastwood, 2015; Kaur, 2002; Pudelko, 2010;) . 
(124)  The report of the disease being present in New Zealand (Kaur, 2002)  stated that MVX 
symptoms had been seen in New Zealand mushrooms, and that testing of symptomatic 
samples detected virus sequences associated with the disease. However this unpublished 
report is not considered sufficient evidence to verify the presence of  the disease in New 
Zealand, and there are no records of MVX being detected subsequently, or of symptoms 
of MVX being observed in New Zealand. As such, MVX is a regulated organism that is 
considered to be absent from New Zealand.  
(125)  MVX only occurs in associa tion with infected mushroom spores or mycelium fragments 
(Grogan, 2003) and is known to be associated with phase 3 medium (Fleming -
Archibald, 2015a).  
(126)  The disease causes yield losses, delayed croppi ng and reduced mushroom quality. 
Disease symptoms may be transient and variable (for example Fleming -Archibald, 
2015a,b).  
(127)  When MVX first emerged in the UK it had a large impact on the industry, and affected 
around 80% of growers. By 2003 losses had amounte d to around £50 million (Anon, 
2003) . 
(128)  Grogan (2007)  noted that UK growers have now been able to significantly reduce or 
eliminate the effects of MVX, and that disease is decreasing in terms of its significance 
to the British mushroom industry . Similarly, G rogan (2011)  noted that r eviewing the 
hygiene procedures and weaknesses on sites where MVX is present has resulted in most 
affected farms in Britain becoming clear of the problem.  However, it is still 
recommended that producers of phase 3 medium should rou tinely test for the presence 
of viruses ( Fleming -Archibald et al., 2016).  
(129)  MVX is only transmitted in association with mushroom mycelium, usually within 
infected growing medium. This means that the virus can be controlled if all material 
containing mushroom  mycelium is removed or destroyed.  
(130)  The likelihood of the disease organism being present in the raw ingredients is 
negligible.  
(131)  It is recommended that host material should be heated to a minimum of 65°C for at least 
8 hours to eradicate the virus (Fleming -Archibald, 2015a) . 
Proposed measures  
(132)  Targeted measures are required in addition to basic measures to manage MVX.  
(133)  Targeted measures will effectively manage risk from MVX by ensuring that production 
facilities and the end product are free from the disease org anism.  
(134)  Targeted measures considered to manage the risk associated with MVX  include the 
following :  
Page 25 of 34 
 a) country freedom;  
b) pest free area;  
c) systems approaches, composed of  two or more independent measures.  
Country freedom and pest free areas  
(135)  If the NPPO of an expor ting country can provide a ‘country freedom’ declaration 
according to requirements set out in ISPM 4, specific phytosanitary measures will not 
be required for MVX.  
(136)  If the NPPO of an exporting country can verify that growing medium is produced in an 
uninfes ted part of a country in which a limited infested area is present  specific 
phytosanitary measures will not be required for MVX. In this case, an official control 
programme must be being undertaken to manage MVX  according to requirements set 
out in ISPM 4.  Other relevant requirements of ISPM 4 must also be met.  
(137)  In both of the above cases, the NPPO of the exporting country will be required to 
endorse the phytosanitary certificate with an additional declaration verifying that the 
growing medium was produced e ither in a country free from MVX , or in a pest free 
area.  
Systems approaches  
(138)  The likelihood of MVX  being present in phase 3 medium can be minimised using an 
effective systems approach. A systems approach consists of two or more independent 
measures. The following are considered suitable  options as independent measures:  
a) stringent hygiene measures to ensu re production facilities remain free of the 
disease organism. This may include the following (Fleming -Archibald, 2015a; 
Kilpatrick, 2015):  
i) heat treatment of phase 3 incubation tunnels between batches, or alternate use 
of tunnels for phase 2 (pasteurising) and phase 3 (incubation), assuming that 
pasteurisation conditions are of sufficient temperature and/or duration to 
manage risk associated with MVX2. Minimum temperature requirements are 
either 60°C for at least 12 hours, or 65°C for at least 8 hours ; 
ii) maint aining positive air pressure during spawning;  
iii) HEPA filtration of spawning areas ; 
iv) isolating spawning from other stages of production;  
v) restricting entry to production tunnels;  
vi) rigorous cleaning procedures for tunnels, winches, conveyors and equipment 
to remove all traces of compost debris;  
vii) using heat treatment and disinfectants;  
viii) using clean clothing and footwear when entering production areas;  
                                                
2 The heating in phase 1 composting and phase 2 pasteurising and conditioning is achieved through biological activity, rather t han through 
direct heating. As such, even though temperatures are controlled by forcing air through spigots in tunnel floors, there may be variation in 
temperatures within production tunnels during phase 1 and phase 2 processing.  Page 26 of 34 
 ix) using dedicated equipment for different stages of production . 
b) testing phase 3 growing medium for MVX , or post pr oduction monitoring (for 
example at mushroom production facilities) in the country of export to verify 
freedom from symptoms of MVX;  
c) routine audit of production facilities by an independent accreditation body to verify 
that all processes and procedures are  being carried out as described.  
(139)  In addition to the measures identified above, post clearance conditions will be imposed 
on any imported phase 3 medium to manage any residual risk that could be associated 
with the product. This will include managing residu al risk that could be associated with 
MVX . Proposed post clearance conditions are described in paragraphs (146)  to (149)  of 
this RM P.  
Export eligibility:  
(140)  If an additional declaration is provided on a phytosanitary certificate verifying that 
growing medium was produced in a country recognised by MPI as being free from 
MVX, no additional measures will be required for MVX.  
(141)  If an additional declaration is provided on a phytosanitary certificate verifying that 
growing medium was produced in a pest free area free from MVX, MPI will audit the 
managem ent of the pest free area for compliance with ISPM 4. Imports will not be 
allowed unless all relevant requirements of ISPM 4 are met.  
(142)  Independent measures will be evaluated when an Export Plan is negotiated. If MPI 
considers that the proposed independent m easures used in a systems approach will not 
manage the risk, or if an independent audit of a production facility shows system 
failures, material from that facility will not be eligible for import.   
(143)  If MVX  is detected at a production facility during product ion of a particular batch of 
growing medium, material from that production run will not be eligible for import.  
(144)  If MVX  is detected in a batch of phase 3 medium produced at a particular facility, 
material from that batch will not be eligible for import.  
(145)  MPI will require evidence that an importer can comply with all post clearance 
conditions before an import permit is issued.  
Post clearance conditions  
(146)  As noted in part 2 of this RMP, post-clearance conditions  can be included as part of an 
applicable IHS.  
(147)  In this case, it is proposed to include post clearance conditions as a requirement of th is 
IHS for the following reasons:  
a) new evidence (O’Brien et al., 2016) indicates  that very low levels of infection with 
T. aggressivum may be below the detection threshold of current diagnostic tests. In 
addition, the same researchers illustrated that it is possible that  the characteristic 
symptoms of infection may not be readily apparent during the first two flushes of 
mushr oom production if there are  very low levels T. aggressivum .  
Page 27 of 34 
 As noted in this RMP, MPI will require specific testing of offshore production 
facilities for the presence of T. aggressivum , along with  testing of samples from 
each batch of compost , and post-production monitoring at mushroom producing 
facilities in the country of export (who receive growing medium from the same 
batch as will be exported to New Zealand). However, based on the findings of 
O’Brien et al (2016), a very low level of residual risk may remain ; 
b) Mushroom virus X disease is believed to be caused by a number of different 
viruses, of which one (AbV16) is known to cause brown mushroom symptoms and 
poor quality mushrooms. It is not yet known what effect, if any, the other viruses 
within the dis ease complex have, or if they interact with AbV16. However, g iven 
that not all of these viruses have been fully characterised, and possible interactions 
between viruses are not yet fully understood, a very low level of residual risk may 
remain.  
(148)  Based on th e above, post clearance conditions are proposed to manage any residual risk 
that could be associated with the following  hazards : 
a) Trichoderma aggressivum ; 
b) Mushroom virus X disease  (MVX) . 
(149)  Proposed post clearance conditions are summarised as follows:  
a) after it  has received a biosecurity clearance, all phase 3 mushroom growing 
medium must be held in a transitional facility approved to the MPI facility standard 
for Transitional Facilities for General Uncleared Risk Goods (MPI -STD -TFGEN).  
Transitional facilities are approved by MPI, and will be used to ensure the post -
clearance conditions are met.  
b) all spent growing medium  will be required to undergo heat treatment at a minimum 
temperature of 65°C for at least 8 hours prior to removal from growing rooms . This 
is considered sufficient to manage residual risk associated with all hazards listed 
above ; 
c) specific measures will be  required to manage any residual risk  associated with T. 
aggressivum and/or  MVX as follows : 
i) specific hygiene measures must be implemented to minimise the likelihood of 
either disease organism spreading beyond an importing facility ; 
ii) daily crop inspections will be required  to verify freedom from both disease 
organisms ; 
iii) representative samples of any Trichoderma infections  observed in imported 
growing medium  must be sent for diagnostic testing to confirm that T. 
aggressivum is not present within an imported consignment ; 
iv) contingency plans are identified which  must be followed in the event that 
either disease organism is identifie d within an imported consignment . 
d) the location at which imported medium must be retained is specified in order to 
ensure traceability of all product until it is disposed of following heat treatment ; Page 28 of 34 
 e) MPI must be informed if an importer becomes aware of a change in circumstances 
associated with imported growing medium . Example s of when this may apply 
include:  
i) if T. aggressivum  or MVX is detected at an offshore mushroom growing 
facility using growing medium from a batch that is in transit to New Zealand ; 
ii) if T. aggressivum  or MVX is detected within a phase 3 growing medium 
production facility  that is eligible to export medium to New Zealand;  
iii) if T. aggressivum  or MVX is detected in a pest free area that is considered 
free from these organisms . 
Feasibility and practicality of measures  
(150)  Most of the proposed requirements reflect good management practices that must be 
followed  to produce a high quality product. As such, reputable manufacturers producing 
growing medium using a quality production system should be able  to meet these 
requirements.  
(151)  Before an import permit is issued, MPI will require assurance that critical control 
points , including those required as part of either Basic Measures or Targeted Measures, 
are being appropriately managed.  This assurance will either be achieved : 
a) during negotiation of an Export Plan  (at which time Basic and Targeted Measures 
will be assessed against the requirements set out in the IHS);  
b) as part of the import permit application process . This will only apply when an 
Export Plan is  not required (i.e. in cases where product is obtained from a pest free 
area, or country free from organisms for which targeted measures are required ). In 
this case, Basic Measures will be assessed against the requirements set out in the 
IHS. 
In either of the above cases, MPI may need to conduct audits (either on -site or desktop) 
of production facilities. The type of audit  will depend on existing audit regimes already 
in use at the facility and on the level of oversight provided by the NPPO of the 
exporting  country.  
(152)   An important critical control point is  the initial composting process reach ing the 
temperatures required to devitalise all seeds and disease organisms. To ensure that this 
does happen, MPI will assess the processes and procedures used during com posting at 
each facility before an import permit is issued. As part of this assessment, MPI may 
require the manufacturer to provide additional information to verify that the composting 
process is sufficient to manage all biosecurity risk  and that robust systems are in place 
to verify that the processing temperatures and times described to MPI are attained 
during each production run . 
(153)  Managing imports by means of a negotiated Export Plan, is considered the best way to 
ensure that all biosecurity risk is being  appropriately managed  because:  
a) production processes and procedures vary between manufacturers. This means that 
the risk profile of phase 3 compost may differ between facilities ;  
Page 29 of 34 
 b) the risk management measures use d at each production facility will be assesse d on 
a case -by-case basis . This will enable MPI to  verify that the desired biosecurity 
outcome can be  achieved  by each manufacturer of phase 3 medium ; 
c) each production facility can be re -assessed on an annual basis (at the time of import 
permit renewal)  to ensure that risk continues to be managed appropriately ; 
d) the import permit will identify specific risk management measures that must be 
used at each production facility , based on the MPI assessment of that facility;  
e) the importer and manufacturer will have a clear understanding of all requirements 
that must be met prior to the product being imported  because:   
i) requirements identified in the import permit will be based on production 
protocols used at each individual facility ; 
ii) MPI will notify the manu facturer  and importer once a facility has been 
approved ; 
iii) the notification from MPI will describe  any risk management measures 
additional to those identified in the production protocol that must be met in 
order for product to be eligible for import into New  Zealand ; 
iv) any additional measures will be agreed upon by both MPI and the 
manufacturer  before exports can commenc e. 
f) MPI will be able to audit each production facility against set criteria agreed upon 
by all parties.  
(154)  Where an Export Plan is not required, Ba sic Measures will still be assessed before  
imports commence as part of the import permit application process.  
(155)  The proposed post clearance conditions are consistent with good industry practice, and 
MPI anticipate that commercial mushroom producers in New Zealand should be able to 
meet these requirements . 
Summary of proposed measures  
(156)  MPI considers that the risk asso ciated with the import of phase 3 growing medium will 
be effectively managed by applying a combinati on of risk management measures . These 
measures are  summarised in Table 1 . 
(157)  Activities undertaken to meet the requirements of the IHS  at each individual phase  3 
production facility  will be assessed by MPI before an import permit is issued.  This 
assessment will occur when an Export Plan is negotiated between MPI and either the 
NPPO of the exporting country, or  between MPI and a particular production facility.  
Where an Export Plan is not required, Basic Measures will be assessed before an import 
permit is issued.  
(158)  Once MPI has verified that a particular  country or  facility can comply with all 
requirements set out in the IHS,  as described in a negotiated Export Plan, details  will be 
included on a list of recognised production facilities . This list will be made available on 
the MPI website ; the link to the website will be included as guidance information in the 
IHS. Page 30 of 34 
 (159)  The product ion system, as documented in the Export Plan, will form the basis for any 
audits of phase 3 growing medium production facilities that are undertaken by MPI.  
(160)  Where an Export Plan is not required, MPI will include a particular facility on a list of 
recognise d production facilities once Basic Measures have been assessed and an import 
permit has been issued.  
(161)  The measures contained in the IHS will be subject to review based on pathway 
compliance, emerging risk assessment, and any new information/intelligence rec eived 
by MPI.  
(162)  MPI will monitor any interceptions of regulated organisms (and hitchhiker  organism s) 
and the appropriateness/effectiveness of phytosanitary measures during trade.   
Page 31 of 34 
 Table 1. Measures required to manage the risk associated with phase 3 growing medium  
Type of measure  Hazard * Notes  
Basic  Viable seeds  
Plant pest or disease organisms 
in raw ingredients  
Pest or disease organisms of A. 
bisporus  
Hitchhiker organisms  
Mushroom spawn  
Trichoderma aggressivum  
Mushroom virus X disease  
 Commercial production procedures  will effectively manage these hazards  (with the exception of T. 
aggressivum and MVX, which also require targeted measures as described below) . 
All raw ingredients must be subjected to a minimum temperature of either 60°C for at least 12 hours, or 
65°C for at least 8 hours.  
Only facilities that are subject to a  negotiated  Export Plan will be eligible to export material to New 
Zealand. If an Export Plan is not required, Basic Measures will be assessed as part of the permit 
application process. Production facilities  and/or countries  eligible to export to New Zealand will be listed on 
the MPI website.  
An import permit will be required.  
A manufacturer’s declaration along with phytosanitary certification by the NPPO of the exporting country 
will be required for each consignment. This will provide a means of verifying that the production process 
has been comp leted as described to MPI . 
Product inspections (pre -export and on -arrival) will be used as a verification step.  
Targeted 
measures  Trichoderma aggressivum  
Mushroom virus X disease  
 As well as the basic measures noted above, targeted measures will be required to effectively manage risk 
from T. aggressivum and MVX . These measures will ensure that production facilities and the end product 
are free from these disease organisms.  
Targeted measures may consist either of country freedom, production in a pest free area, or a systems 
approach consisting of two or more independent measures.  An Export Plan will not be required where 
‘country freedom’ status is recognised for the exporting country , or where growing medium is produced in a 
pest free area . 
All targeted measures used in a systems approach will be  agreed upon as part of a  negotiated  Export Plan  
before a facility is recognis ed as eligible for export by MPI . 
As a minimum, the targeted me asures identified in paragraphs (114)  and (138)  of this RMP will be required 
to manage risk associated with T. aggressivum and MVX, respectively, as part of a systems approach.  Page 32 of 34 
 Post clearance 
conditions  
 Trichoderma aggressivum  
Mushroom virus X disease  All phase 3 mushroom growing medium must be held in a transitional facility approved to the MPI facility 
standard MPI-STD-TFGEN.  
Heat treatment (65°C for a minimum of 8 hours) will be required prior to disposal of growing medium t o 
manage any residual risk.  
Specific hygiene measures must be implemented at all importing facilities.  
Daily crop inspections as a verification step.  
All Trichoderma  infections on imported medium must be sent for testing to confirm absence of T. 
aggressivu m. 
Contingency plans must be followed if either disease organism is detected.  
Growing medium must be used at a specified location.  
MPI must be informed of any change in circumstances related to imported growing medium.  
 
*Risk management measures for the animal -based ingredients of phase 3 growing medium are identified in the IHS for Processed Animal Manure 
Product s. 
Page 33 of 34 
 Part 4: References  
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