As advised in the KVH Bulletin (5 June) Psa-V was recently identified in Japan. To date, the disease has been identified in six Japanese prefectures: Ehime, Fukuoka, Saga, Okayama, Wakayama and Shizuoka.

This week officials from Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF) visited KVH and Zespri to learn more about how to best manage the disease. The Japanese visit to KVH included an update on Psa-V in New Zealand; best practice orchard management; an overview of the NPMP; movement controls; the Kiwifruit Plant Certification Scheme; and communications to industry and growers.

Around one percent of the total kiwifruit acreage in the infected areas has been affected by Psa-V in Japan. Control measures include cutting out and disposing of infected material and proactive spray control.

A second Japanese MAFF visit also occurred during the week in Wellington with MPI to discuss future export conditions of New Zealand pollen and budwood.
 

It’s possible for Psa-V to change genetically in order to develop resistance to chemicals or compounds that are currently used by growers to manage the disease. In other words, they would no longer be effective against Psa-V.

As few products are currently known to have efficacy against Psa-V, the loss of one or more of these due to resistance would make Psa-V much more difficult to manage. This would be a significant issue for the kiwifruit industry.

To date, Psa-V resistance has not been identified in New Zealand kiwifruit. However, overseas experience has seen bacterial resistance develop against copper and antibiotics. It can happen as a result of products not being used properly, or being over-used.

Ongoing testing as part of the KVH/Zespri R&D programme is underway to identify early any strains of Psa-V showing potential resistance.

It’s essential the kiwifruit industry is aware of this potential issue, and carries out best-practice management to avoid resistance.

Preventing Psa-V developing compound resistance
Growers and the industry can help reduce the risk of Psa-V developing compound resistance by following these simple steps.

• Always read and follow label instructions, including the recommended label rates. Using products at lower rates can cause resistance to develop.
• Use a combination and/or alternate effective products. This avoids applying the same compound/chemical multiple times in a row—making resistance more difficult to develop.
• Reduce diseased material in the orchard by ongoing management and removal of infected material.
• Maintain best-practice orchard hygiene.

A coordinated approach incorporating the above strategies across the entire industry will reduce the risk of resistance developing.

Kiwifruit growers who believe spraying is providing no control, or suspect compound resistance on their orchard, should contact KVH on 0800 665 825 or email info@kvh.org.nz. 

KVH will then assess the situation and carry out additional testing for resistance as required.
 

Industry feedback from the KVH Communications Survey strongly suggested the search function on the KVH website, and in particular within the R&D section, needs improvement.

After investigating limited options it was decided implementing a dedicated ‘google custom search engine’ on the KVH website will be the most effective option. This option will effectively increase the ability of users to find KVH website content.

However, to use the google search to the best of its ability, and to avoid breaching Google’s Terms and Conditions, the ‘restricted’ documents on the website will need to be made available to all website users. Therefore:

• KVH plans to open the R&D section to all users so these documents will no longer be ‘restricted’.
• Other restricted documents, including Zespri variety information, monitoring results and variety-specific case studies, will be removed from the website and available on request.
• The KVH Psa-V Risk Model will remain a ‘restricted’ tool for New Zealand growers, and accessible to registered users only.

If growers have any concerns, please contact KVH on 0800 665 825 or info@kvh.org.nz.

Congratulations to Patrick Malley from Whangarei * who took out the 2014 BOP Young Grower of the Year title at an awards dinner in Mount Maunganui last night.

Patrick competed against four other young up-and-coming horticultural leaders for the title in a series of practical and theoretical activities during the day; and a speech competition and quiz during the evening gala dinner. KVH’s Chris Clement was runner up.

Minister for Primary Industries, Nathan Guy, was the Guest Speaker at the event attended by almost 200 industry supporters and presented Patrick with the award (pictured above).

Patrick will go on to represent the Bay of Plenty in the National competition against other regional winners for title of NZ Young Grower.

* Contestants from outside of the BOP can enter the competition if they do not have a competition in their own region.
 

This week Primary Industries Minister Nathan Guy announced 29 new biosecurity graduates will further strengthen New Zealand’s biosecurity system, and help safeguard New Zealand’s primary industries from pests and diseases. This includes 24 new quarantine inspectors and five new dog handlers to be based between Auckland, Wellington and Christchurch.

Click here to read The Minister’s media release.

Heavy rain over the last two weeks means Psa-V inoculum levels are likely to rise, increasing the potential for infection spread.

Growers need to be proactively monitoring their orchards to detect any signs of infection early. Three new orchards have been identified with Psa-V in the Kerikeri region in the last week. All had cane dieback symptoms on Gold3.

Pruners and grafters are working on orchards during this time of year, and if trained to identify Psa-V symptoms, can provide another opportunity for symptoms to be identified and removed.

Growers must be vigilant about who they allow onto their orchards—both where they have come from and what equipment/tools they are bringing onto the orchard.

KVH have protocols in place to restrict high-risk movements and growers need to be aware of these. Strict attention to orchard hygiene will minimise the risk of disease transferring between vines, orchards and regions.

With pruning and grafting activities taking place, all growers should be familiar with the KVH Protocol—Budwood regarding movement controls.

If considering planting rootstock growers need to be sourcing plants from either KVH Accredited or KVH Registered Nurseries and ensuring that the movement protocols are adhered to.
 

As advised in last week’s KVH Bulletin, the Agricultural Compounds and Veterinary Medicines (ACVM) group within the Ministry for Primary Industries has approved a limited-label claim for KeyStrepto™ for use as a Psa-V protectant on producing and non-producing kiwifruit vines.
 

• Between 13 June and 31 July 2014, KeyStrepto™ use is permitted with a Justified Approval (JA).
• A JA is not required from 31 July 2014 until seven days before the first kiwifruit flowers opening (male or female).
• KeyStrepto™ must not be used during flowering.
• Post-flowering until 28 February 2015 – KeyStrepto use is permitted on non-producing vines only and a JA is required.

The conditions of use for KeyStrepto™ include:

• KeyStrepto™ is permitted for use in the North Island only.
• Must be applied at the label rate. For concentrate spraying adjust rates accordingly.
• AI nozzles must be used until the canopy develops. Apply with a suitable adjuvant.
• A maximum of four applications of KeyStrepto may be made per season.
• No more than six antibiotic applications (Kasumin® and KeyStrepto) in total per season can be made.
• Do not apply more than two consecutive sprays of KeyStrepto™ before applying a different Psa-V control product.

Growers must refer to the KeyStrepto™ User Guide for detailed rules of use, including sward management, notification, signage, record keeping etc.

Growers are now responsible for ensuring the conditions of use are complied with. KVH will no longer be conducting pre-use audits.

Zespri will once again test 100 percent of supplying orchards for more than 300 residues – including antibiotics – in the 2015 season.