Proposed changes to the requirements for importing hop plants for planting

Change to the risk management

We've added the option to test for Fusarium luffae, F. meridionale, and Verticillium nonalfalfae [hop strain] by plating on suitable isolation medium.

Why this change?

Testing by PCR is faster and less resource-intensive than other testing methods. This makes it our preferred method. MPI's Plant Health and Environment Laboratory is currently validating PCR tests for Fusarium luffae, F. meridionale, and Verticillium nonalfalfae [hop strain]. These tests are not ready yet, so we are offering plating as an option while the PCR tests are being validated.

Plating is a diagnostic tool that involves taking samples from imported plants and inoculating a surface designed to help fungi grow. The plating test is a suitable alternative to PCR here.

• The test has a proven track record and is used for other nursery stock such as Actinidia, Citrus, Persea americana and Prunus.
• The test provides an appropriate level of risk management to detect Fusarium luffae, meridionale, and Verticillium nonalfalfae [hop strain] if they are present in imported plants.

Change to the risk management

We've added a specific value for the relative humidity needed during spring in post-entry quarantine. A minimum relative humidity of 75% (±5%), with two 48-hour periods of continuous misting during spring.

Why this change?

Humidity control during spring in post-entry quarantine is needed to give extra confidence that growing conditions promote detection of downy mildew of hops (Pseudoperonospora humuli) if present in imported plants.

This was mentioned in the risk management proposal as an option we were considering because periods of high humidity and moisture are ideal conditions for downy mildew. Industry feedback has confirmed our understanding that mildew is a high-risk pest, and that humidity control is needed to increase the assurance for detecting downy mildew (and coincidentally other fungi) if it is present in imported plants.

Change to the risk management

We've removed the requirement to sample root material for testing downy mildew (Pseudoperonospora humuli). The PCR test for downy mildew will be completed using samples taken from the stem/shoot.

Why this change?

Plant material sampled from the shoot/stem is likely to detect the mildew if present in the plant because plants in vitro will be made from aerial plant parts only. So, if mildew is present in imported plant material, it is likely to be present in the sample. Also, root sampling will be too risky as it will likely compromise the plant's growth too much.

Comments from consultation

There was confusion around whether mildews would be managed by the proposed requirements.

Response

Hop mildews are managed by the requirements we’re proposing. In the first consultation we listed powdery mildew of hops and downy mildew of hops using their scientific names as Podosphaera macularis and Pseudoperonospora humuli respectively. Common names are not always available or clear-cut for some pests, but we will try to be clearer about what the scientific names mean in the future.

Comments from consultation

Some people were concerned that the risk of downy mildew (Pseudoperonospora humuli) will not be mitigated by 6 months in Level 3B post-entry quarantine.

Response

Our assessment shows that downy mildew can develop symptoms on hop plants within 6 months, and exposing the plant to ideal environmental conditions increases this likelihood. Spring temperatures with high humidity and extended periods of moisture are ideal conditions for downy mildew of hops. Therefore, we proposed requiring humid conditions and misting during spring-like conditions in post-entry quarantine to increase the likelihood of detecting downy mildew if it is present in imported hop plants.

Our assessment also showed some cultivars of hops may be resistant and infected without showing symptoms. We proposed additional PCR testing for all plants to make sure we find this pest even if there are no disease symptoms. PCR testing is highly sensitive. Testing the plants means that we will find the mildew even if an imported plant takes more than 6 months to show symptoms.

We are confident that 6 months in Level 3B post-entry quarantine together with PCR testing, humidity and misting controls will adequately manage the risk from this pest, and will ensure that, if it is present, it will be found before imported plants are released from quarantine.

If downy mildew (or any other regulated pest) is found on plants in post-entry quarantine, the plants will not be released into New Zealand. The plants will be either treated to remove pests or destroyed to prevent the pest entering New Zealand.

Level 2 post-entry quarantine would only be allowed if offshore activities have managed the risk of downy mildew before the hop plants are exported to New Zealand.

Comments from consultation

Some people were concerned that the risk of powdery mildew (Podosphaera macularis) will not be mitigated by 6 months in Level 3B post-entry quarantine.

Response

Our assessment shows that Podosphaera macularis causes powdery mildew symptoms on hop plants within days, even at low temperatures.

We are confident 6 months in Level 3B post-entry quarantine will adequately manage the risk from this pest. This is because our risk assessment showed:

• disease symptoms will be noticeable on infected plants as soon as the shoots start to emerge, with dormant periods not exceeding 21 days.
• environmental conditions affect symptom expression. Powdery mildew of hops develops symptoms from 5°C. Above 30°C, symptoms are reduced. The optimal temperature is between 18°C and 25°C, and so the proposed standard will have temperature requirements to reflect this.
• if the imported plants have mildew and the mildew releases spores, the spores will not escape into the New Zealand environment. All air that leaves Level 3B post-entry quarantine is HEPA-filtered to capture spores if they are present.

We are not proposing specific testing for powdery mildew. We did not find any evidence that powdery mildew can be asymptomatic on hop plants. We have a high level of certainty that we will see symptoms before plants are released from post-entry quarantine if powdery mildew is present in imported plants.

If powdery mildew (or any other regulated pest) is found on plants in post-entry quarantine, the plants will not be released into New Zealand. The plants will be either treated to remove pests or destroyed to prevent the pest entering New Zealand.

Level 2 post-entry quarantine will only be allowed if offshore activities have managed the risk of powdery mildew before hop plants are exported to New Zealand.

Comments from consultation

Biosecurity New Zealand needs to be aware that New Zealand is nearly free from all major pests that affect hops. This provides the industry with significant benefits and advantages and allows the industry to remain generally spray-free.

Response

We are aware of the unique situation that the hop industry is in and the benefit they receive from it. We took this into account while we analysed the risks and developed the risk management proposal to make sure the measures provide New Zealand with the protection it needs, while enabling access to import new varieties and genetics to help with breeding programmes.

Comments from consultation

Why has this work been done? Why do you want to re-enable imports of hop plants?

Response

We prioritised and completed this work because the breeders who supply the hop industry with plants need new varieties and genetics to improve their breeding programmes. See below for more on the benefits of importing hops.

These interested parties submitted requests for the pathway to be opened by following the process for requesting a new import health standard

Comments from consultation

What are the benefits to this proposal, how do they outweigh the risks?

Response

Biosecurity New Zealand's role is to enable safe trade while reducing risk to an acceptable level for wider New Zealand. Our work involves both protection and trade. As such, we hear from different parts of the industry who sometimes have differing opinions and interests (for example, importing new varieties versus growing what we already have).

We know that some parts of the hop industry are very keen for us to allow imports to help the industry stay prepared and resilient for adverse events, such as an incursion of a hop pest we don’t have here or changing climate conditions. Biosecurity New Zealand wants to help industries stay prepared for the future and be able to recover well after adversity.

Hop breeders also want to continue developing unique cultivars for growers and require new genetic material to do so. Developing new varieties will ensure a steady stream of new novel cultivars in the future. New genetics will support innovation in New Zealand's hop industry and help the industry maintain and grow its international competitiveness.

Breeders and growers depend on each other for the wellbeing of their businesses. The work that breeders do provides benefits to growers, and both need each other for mutual success.

We believe New Zealand's well-established import system can effectively manage the risks associated with imported hop plants. We have confidence in our import system. We have used measures such as post-entry quarantine, testing and importing plants in vitro to manage the risks of many other key food and fibre crops over the years, helping importers safely obtain new plants without introducing new pests. We are confident that the proposed import requirements for hop plants will manage risk appropriately while enabling trade.

Comments from consultation

The information about the risk analysis in the risk management proposal was sparse.

Response

We have tried a new way of presenting the information to provide you with clear summaries of the risk for each pest that give you only the necessary information. However, we understand this is something we need to adapt over time to reach a good balance between too much information and not enough. Below is some more information about the risk assessment process.

For this proposal for hops, we followed our usual import risk analysis process, in line with guidelines in the International Standard for Phytosanitary Measures 11: Pest risk analysis for quarantine pests – IPPC  

Find out more about our import risk analysis process

Our risk assessment includes looking at the published information on pests associated with hops throughout the world. This gives us information on pest symptoms, impacts, and mitigation. We use this information to help us identify how we can manage the risks from potential pests so that we can have confidence that all imported plants are free from regulated pests before they are released into New Zealand.

You can also read more about all the pests we considered during the risk analysis on the hazard identification list [PDF, 364 KB]

Comments from consultation

Post-entry quarantine facilities should not be located in areas where hops are grown commercially (for example, Nelson/Tasman).

Response

Level 2 post-entry quarantine facilities are found throughout New Zealand. However, if a plant is imported without any offshore pest risk management, it will need to go into Level 3B. There is currently only one Level 3B facility in the country, and this is in Auckland.

We don't place any restrictions on where post-entry quarantine facilities can be located or where in New Zealand plants must be quarantined. When deciding what level of quarantine is needed for any given plant, we evaluate what pests may be present on imported plants and assign a level of quarantine that will give us a high level of assurance that if pests are present, they will be very unlikely to escape from quarantine, no matter where the facility is located. Based on this, there is no need to place restrictions on where post-entry quarantine facilities can be located.

Comments from consultation

Some people were concerned about whether post-entry quarantine facilities in New Zealand can handle hop plants appropriately.

Response

Biosecurity New Zealand has very well-established systems in place that work for managing biosecurity risk on any imported plants regardless of the species.

Quarantine facility operators must show Biosecurity New Zealand that they can meet all requirements of the post-entry quarantine standard , and must complete an operator training programme, before a quarantine facility is approved. Once a quarantine greenhouse is approved, it is regularly audited by Biosecurity New Zealand to ensure that facility operators continue to meet all requirements.

Post-entry quarantine standard [PDF, 545 KB]

While plants are in quarantine, they are regularly inspected for pests and diseases by Biosecurity New Zealand inspectors, and by the greenhouse operator. When disease symptoms are seen, samples are sent to MPI's diagnostic laboratory so that we can identify what pests are present. Plants are also tested for key regulated pests, even if they are not showing symptoms of disease. These measures help give us a high degree of confidence that any plants that are released into New Zealand are free from regulated pests.

Comments from consultation

How does Biosecurity New Zealand approve offshore export sources for plants being sent to New Zealand?

Response

There are different levels of approval depending on the export source.

• No approval: plants from any country can be exported to New Zealand if the plants meet all the requirements of the proposed standard.
• MPI-approved offshore facility: some facilities are approved for holding and testing plant material before exporting to New Zealand. Facilities are approved after MPI confirms they can manage the risk from plant pests. To confirm this, MPI audits the facilities documents, processes, testing regimes, physical containment and the like. There is also a regular audit cycle to ensure approved facilities continue to meet our requirements. More information on facility approval 
• Export plans: export plans are agreements between MPI and the exporting country's equivalent of MPI (a national plant protection organisation (NPPO)). They describe how the risk from particular pests will be managed before plants are exported. These plans are usually approved after audits and negotiations between MPI and the exporting NPPO.

Comments from consultation

Some people were concerned about whether the hop industry would be prepared if a pest infected hop plants. What happens? Would information be shared?

Response 

Biosecurity New Zealand has systems in place that help us identify potential pests in New Zealand early. We also have good processes for dealing with pests if they do arrive. This includes sharing information with those who are impacted by the pests or are at risk of being impacted.

Find out more

What is a biosecurity response?

Surveillance programmes for pests and diseases

Comments from consultation

Someone suggested including arabis mosaic virus in this import health standard.

Response

Biosecurity New Zealand does not regulate or manage arabis mosaic virus. Arabis mosaic virus is already in New Zealand. It has been isolated from hop plants in New Zealand, and it is not under official control or eradication. Biosecurity New Zealand is only allowed to regulate pests that are not in New Zealand or under official control. We cannot regulate this virus or impose measures for it.

However, we propose regulating and managing a virus with a very similar name: arabis mosaic virus small satellite RNA. This is a different virus that does not cause harm on its own. If a plant is infected with both arabis mosaic virus and the small satellite RNA, the plant can develop nettlehead disease. We are proposing to manage this small satellite RNA virus because we already have arabis mosaic virus on hops in New Zealand, which means the small satellite RNA could cause nettlehead disease if it got into the country. We propose managing this through growing season inspection in post-entry quarantine. However, we are not proposing any specific measures (for example, PCR) for arabis mosaic virus small satellite RNA because our risk assessment concludes the risk of impact from this virus is still quite low. The virus has not been reported since 1983, and there are no recent reports of this pest impacting hop production, which suggests it is not a significant pest of hops.

Comments from consultation

Someone asked Biosecurity New Zealand to include PCR tests for the redefined genus Verticillium sensu stricto in the required testing regimen for hop plants.

Response

We are not going to test for other species of Verticillium because a recent taxonomic revision of Verticillium divided V. albo-atrum sensu lato into 3 different species: V. albo-atrum sensu stricto, V. nonalfalfae and V. alfalfae (Inderbitzin et al. 2011).

Following this revision, V. albo-atrum sensu lato isolates that are pathogenic to hop plants are now recognised as V. nonalfalfae (EPPO 2020).

We expect to find out about any new information about pathogenic Verticillium on hops through our Emerging Risks System. If this happens, we will review the import requirements and amend them if needed.

While all of the mentioned Verticillium species are present in New Zealand, our analysis showed that there is an increased risk from V. nonalfalfae since this species has not been isolated from hop plants in New Zealand and has several different pathotypes that are currently not present in New Zealand. We propose measures only for these pathotypes of V. nonalfalfae. These pathotypes are the only ones not present in New Zealand, and they are known to infect hop plants, so pose an increased risk to New Zealand.

Comments from consultation

Differences between requirements for different commodity types, for example, plants in vitro and cuttings.

Response

All the requirements in this proposal apply to plants in vitro. This means that these plants must be deflasked into a post-entry quarantine greenhouse where they will be grown and tested before they can be cleared for entry into New Zealand.

We only assessed plants in vitro as they have fewer pests associated with them compared with whole plants and cuttings.

Whole plants and cuttings could be imported into an approved lab in New Zealand without clearing them into the country. These whole plants and cuttings can be used to make in vitro plants, which must then complete post-entry quarantine and testing. The originally imported whole plants and cuttings would not receive biosecurity clearance and would be destroyed.

Comments from consultation

Could hop seeds be added to this review of import requirements?

Response

We couldn’t work on seeds this time, if you still want the seed import pathway reviewed, you can make a request

Your request will go through a prioritisation process, where Biosecurity New Zealand decides what requests will provide the most benefit to New Zealand's primary industries and New Zealanders before committing to work on the requests.

Comments from consultation

Could cannabis nursery stock be added to this review of import requirements?

Response

Biosecurity New Zealand has prioritised developing a new import health standard for cannabis tissue culture, which will enable these plants to be imported in the future.

Hop plants were already eligible for import, but the requirements were out of date. Cannabis nursery stock is not yet eligible for import, so writing requirements for cannabis is a bigger project than updating existing requirements.

While cannabis nursery stock is not part of this project, you can still contact us to discuss the cannabis project at PlantImports@mpi.govt.nz 

Comments from consultation

If a comprehensive economic risk analysis (regarding potential impacts and benefits of importing) has not been conducted, one should be commissioned.

Response

Economic risk analysis is not something that Biosecurity New Zealand does for import pathways.

The benefits of trade are not part of the proposed risk management requirements. We prioritise work that benefits New Zealand. Biosecurity New Zealand does not conduct its own benefit analysis. Instead, we listen to members of the horticulture industry. Industry members evaluate the possible benefits of new commodities and share these expected benefits with us when they request a review of import requirements.

Our role is to evaluate biosecurity risks and make sure plants can be imported safely.

Comments from consultation

There were some comments on the taxonomy of H. neomexicanus, and this being a variety of H. lupulus rather than being its own species.

Response

Some sources call it H. lupulus var. neomexicanus, and other sources call it H. neomexicanus. Biosecurity New Zealand recognises both names. We have listed these as different species, but this does not make any difference to the import requirements. You can still import these plants under either name, as long as you follow the import requirements.