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14 | April/May - 2017 | 15
R&D | NEW ZEALAND RESPONSE |
New Zealand has been battling the destructive tomato-potato psyllid for over 10 years. Potatoes Australia
spoke to Plant & Food Research New Zealand scientist Dr Jessica Dohmen-Vereijssen about our Trans-
Tasman neighbour’s experience in dealing with the initial incursion and current management strategies.
NE IGHBOURS ACROSS THE DI TCH REFLECT ON
TOMATO-POTATO PSYLL ID
The tomato-potato psyllid (TPP) and the plant pathogen it transmits,
Candidatus Liberibacter solanacearum (CLso), were first recorded in
New Zealand in 2006 and 2008 respectively.
Crop & Food Research (CFR) initially undertook the main research
on TPP and CLso at the time of the incursion, and this continued
after CFR became part of the New Zealand Institute for Plant & Food
Research Limited (PFR) in late 2008.
The researchers worked in parallel with industry to coordinate,
prioritise, identify funding sources and implement a research
program to underpin the ongoing management of the TPP/CLso
complex in a range of solanaceous crops, after it became clear that
eradication was not feasible.
LACK OF KNOWLEDGE
In hindsight, and taking into account the limited prior knowledge
of TPP/CLso risk and the lack of a recent high impact incursion in
the vegetable industry, organisations and industry in New Zealand
could have been better prepared for TPP/CLso.
In 2006, CFR had no policy for assessing the risk for new pest
or disease incursions, no systematic way of listing potential risks,
and no plan for responding to incursions or allocating resources
to deal with new incursions, including those that could not be
eradicated and so required long-term management. Neither did
the vegetable industries.
The relative fragmentation of the industries affected (capsicums,
fresh tomatoes, processing tomatoes, seed potatoes, processing
potatoes, fresh potatoes and tamarillos) compounded the
challenge of mounting a cohesive and coordinated response.
“Truly collaborative research between growers and science
organisations are essential for uptake by industry of useful
strategies and learnings,” PFR scientist Dr Jessica Dohmen-
Vereijssen said.
“Besides learnings in terms of management strategies, a lot of
knowledge was and had to be generated through fundamental
research projects, to elucidate insect and bacterium genetics,
biology and ecology.”
PEST MANAGEMENT
Over the past 10 years, PFR and other agencies have developed the
following psyllid management strategies in New Zealand:
• Defining action thresholds based on multiple decision-aiding
tools, including regular scouting of crops, yellow sticky trap
monitoring (potato) and degree day accumulation to aid start of
spray programs.
• How to conduct plant assessments in potato crops.
• Identifying where and how to trap for TPP in potato crops.
• Presence and seasonality of natural enemies/beneficial insects
naturally occurring in potato crops.
• Companion plantings to sustain natural enemies around crops.
• Development of spray programs (insecticides and agricultural
oils) to manage TPP in potato – going from no sprays to weekly
sprays was the big shift in potato crops.
• Focusing on the importance of insecticide resistance
management. While TPP is a focus, management for other pests
and diseases still needs to be taken into account.
• Effect of selected insecticides and agricultural oils on CLso
transmission, as well as natural enemies/beneficial insects.
• Identifying botanicals and biorational insecticides to manage TPP
in potato crops.
• Post-harvest disinfestation of fruit, particularly capsicums.
ASSISTING NEIGHBOURS
PFR is actively assisting Western Australian agencies, including the
Department of Agriculture and Food, Western Australia (DAFWA),
with TPP surveillance, management options, post-harvest
disinfestation options and molecular diagnostics.
Dr Dohmen-Vereijssen travelled to Western Australia where she
provided expertise based on her experiences and trained surveillance
personnel with a focus on plant assessments, insect identification
and plant symptoms related to TPP and CLso. She will continue to
work with DAFWA and other agencies from New Zealand.
Her PFR colleagues Dr Grant Smith, Dr Rebekah Frampton and
Sarah Thompson have also been providing expertise in TPP and
CLso molecular diagnostics from New Zealand.
Dr Dohmen-Vereijssen said it is always desirable to eradicate new
pest incursions if this is possible.
“If eradication is not possible, an effective pest management plan
needs to be developed as quickly as possible to enable growers
to continue to produce high quality crops in the presence of TPP
and/or CLso. This is likely to require considerable changes to pest
management practices in affected crops.”
For more information, please visit .
This communication has been funded by Horticulture Innovation Australia Limited
using the research and development Fresh Potato Levy and funds from the
Australian Government.
Project Number: PT15007
INFO
AUSVEG has been heavily involved in dealing with one of the most potentially damaging
pests to arrive in Western Australia – tomato-potato psyllid (TPP). AUSVEG Biosecurity
Adviser Dr Kevin Clayton-Greene explains what happens behind the scenes in response
to a potato and vegetable pest incursion, such as TPP.
RESPONDING TO AN EXOTIC PEST INCURSION
AUSVEG is a signatory to the Plant Pest Deed, which is a contract
between all states, territories, the Federal Government and
industry parties who have elected to sign.
The Deed sets out what happens when an exotic pest arrives
in Australia, how it is managed and the obligations of parties who
have signed up to the Deed. The Deed only covers eradication
responses and does not cover issues such as trade and
management of the pest if it can’t be eradicated.
The Deed is managed by Plant Health Australia, which is jointly
funded by all signatories to the Deed – funding is one-third
Federal, one-third states and territories and one-third industry
parties. AUSVEG is a signatory and has a levy set currently at zero.
WHAT HAPPENS WHEN A SUSPECT PEST IS IDENTIFIED?
After receiving information that an unusual and suspect exotic
pest has been found, plant health officers are legally required to
inform the Federal Government’s Australian Chief Plant Health
Officer (ACPHO).
Shortly after, the ACPHO calls a meeting of all states and
territories and those industry parties that the pest could
impact. This group is known as the Consultative Committee
on Emergency Plant Pests (CCEPP). In the case of tomato-
potato psyllid (TPP), the industry parties include AUSVEG,
Nursery and Garden Industry Australia (NGIA) and processing
tomatoes. The fresh tomato industry is not part of the process
as it does not have a national body and is not a signatory to
the Plant Health Deed.
The function of the CCEPP is essentially to determine if the
incursion is an exotic plant pest; if it can be eradicated; and
produce a response if eradication is deemed feasible.
The response plan is the responsibility of the state or territory
in which the incursion occurred. In the current case involving
TPP, the host state is Western Australia.
AUSVEG’s role on the CCEPP is to provide an industry
perspective and assist where it can with the preparation of a
response plan and incursion control. This can take many forms
but in serious cases such as TPP, it usually involves an AUSVEG
staff member working directly with grower organisations in the
host state.
Decisions of the CCEPP are by consensus, but in some cases
consensus cannot be achieved. In this case, matters are referred
to the board of Plant Health Australia.
After determining that a pest can be eradicated and an
agreeance on a response plan has been reached (which must
contain a budget), CCEPP provides this advice to the National
Management Group (NMG), which is comprised of the Senior
Executives of all organisations involved in the incursion. NMG
is responsible for making the decision about an incursion and
eradication, and relies on the advice from CCEPP. However, it
is not bound by the CCEPP. In agreeing to a response plan, all
parties must agree on the budget.
AUSVEG must then consult with the Federal Government about
financial obligations and how it can repay any debts for which it is
obligated. This will, in some cases, require a positive levy to be struck.
With respect to other areas such as trade and market
access, AUSVEG can only provide advice and hope to achieve
harmonisation of responses by jurisdictions and seek to be
informed so it can advise relevant industry bodies. Decisions
around these aspects are solely the provenance of governments
through the Sub-Committee on Domestic Quarantine and
Market Access (SDQMA).
With respect to the current TPP outbreak, the NMG considers
that responding to the current incursion is in the national interest
given the potential economic impacts, should TPP be established
in Australia. Accordingly, a 30-day response plan has been
approved to allow critical information to be collected on the
nature and spread of the complex. This process will be led by
DAFWA. After 30 days, a re-evaluation of the situation will occur.
For more information, contact AUSVEG on 03 9882 0277 or email info@ausveg.
. A more detailed statement on the 30-day response plan can be seen at
This communication has been funded by Horticulture Innovation Australia
Limited using the research and development Fresh Potato Levy and funds from
the Australian Government.
Project Number: PT15007
INFO
R&D | RULES AND REGULATIONS | TPP FEATURE TPP FEATURE
Black nightshade Solanum nigrum, a non-
crop host plant of tomato-potato psyllid.
Bactericera cockerelli nymph. Image courtesy
of Plant & Food Research New Zealand.