New Zealand Kiwifruit Industry – Psa Information Update
New Zealand Kiwifruit Industry – Psa Information Update
• With strong support by growers across the industry, the kiwifruit Industry Advisory Council on Friday 19 November supported the aggressive management of Psa in New Zealand and authorised $25 million of industry funding to support the management strategy.
• The Government will also contribute $25 million to the strategy which aims to reduce the level of Psa bacteria across the industry, thereby greatly slowing the spread of the disease.
• Strong grower endorsement of this strategy reflects everyone’s awareness of the destructive potential of this bacteria and the robust rationale of the risk management plan.
• We recognise we will need to adjust the plan as more information becomes available over the coming weeks, but the main focus right now is to remove infected plant material from vines on a timely basis to stop the advancement of the infection. This is particularly the case where symptoms have progressed beyond the initial stage of leaf spotting.
• Given the latest announcement regarding historic samples of NZ pollen testing positive, it is looking increasingly likely that Psa has been present in NZ for some time.
• The existence of Psa in NZ kiwifruit orchards may have been undetected due to low expression of the bacteria. Environmental or other factors may have contributed to an outbreak this year which has had a significant effect on a number of vines.
• Regardless of how long Psa may have been in NZ, what we are experiencing now is an outbreak of the disease and a potentially virulent spread of the bacteria.
• It is important that affected growers take aggressive action to minimise the potential spread of the disease across their orchard and to neighbouring properties through cutting back severely affected vines (vines with wilting, dieback and exudates). Details of the Industry Advisory Council-agreed On-orchard management plan are available to growers on The Canopy (www.zespricanopy.com).
• All growers are encouraged to remain vigilant; monitoring their orchard on a regular basis and taking the recommended actions in order to control innoculum levels.
• MAF are continuing to research a number of potential vectors of Psa – of which pollen is one. It may be some time before we have a definitive cause of infection or spread and it is possible that this may never be fully identified.
• MAF has confirmed that testing of historical samples of kiwifruit leaf material, going back to 1980, has not found any prior evidence of Psa in NZ, but testing of pollen from the last few years has come back positive, indicating that Psa may have been in NZ for some time.
• Psa is a bacterial vine disease that carries no risks associated with human or animal health, and does not affect plants other than kiwifruit vines. Psa has been present in Italy, Korea and Japan for many years but has not previously been detected in New Zealand.
• Because Psa is not transmitted on kiwifruit, there has been no change to market access for New Zealand kiwifruit.
• The New Zealand kiwifruit industry is a strong and coordinated industry, working well together, and we’re confident that this issue will be overcome to ensure a prosperous future for the industry.
• Of the total orchards inspected by trained assessors (n=470), 12% have been put on a Restricted Place Notice (n=58).
• Of the total test results received to date (n=234), approximately 76% have come back as negative.
• Positive tests for Psa have increased from 51 to 55 orchards – the new Psa-positive orchards are in Te Puke (1) and Motueka (3).
• The majority of the Psa-positive orchards are within a 23km area south of Te Puke township, with Psa-positive tests also coming back from orchards based in Hawke’s Bay, Tauranga, Whakatane, Edgecumbe, Waikato, Golden Bay and Motueka.
• 18 orchards out of the 55 confirmed are GREEN orchards (33%).
• Some growers under a Restricted Place Notice are taking action on their own orchards to cut back affected vines, and they’re doing this in conjunction with MAF to follow correct hygiene and disposal procedures.
• ZESPRI has received 1,300 emails through its Grower Contact Centre – approximately 43% are reporting suspected symptoms (which are immediately being followed up) and 57% are emailing to report that their orchard is clear of Psa symptoms.
Key information for growers
• Adopt recommended orchard hygiene practices, regularly monitor your orchard for Psa symptoms and keep updated on the latest information via The Canopy (www.zespricanopy.com) and your ZESPRI/packhouse grower representatives.
• If you see Stage 1 symptoms (leaf spotting) on your orchard, go to The Canopy and refer to the ‘Overview of Monitoring Process’ Guide. You will need to complete the ‘Symptom Monitoring Sheet’ and take digital photos of the infected leaves and email these to email@example.com. You may choose to spray copper over the block where the symptoms are found (at own cost) while you await further advice from ZESPRI or AsureQuality. If a trained assessor takes leaf samples from your orchard and the test comes back positive, then you should apply copper spray (at own cost) to reduce bacteria advancement.
• If you see Stage 2 symptoms
(leaf wilting, dieback and/or exudate), go to The Canopy,
complete the ‘Symptom Monitoring Sheet’ and email the
completed sheet and digital photos to firstname.lastname@example.org
. Spray copper over affected blocks, prepare to cutback vines by tagging affected areas and await further advice from an independent assessor. The cutback decision will depend on the independent assessment. These growers can then apply for funding (through a process yet to be determined).