During the French spring (April/May) Hayward orchards in the Tarn et Garonne area were expressing severe exudate, causing panic amongst some local growers. KVH Director Craig Thompson visited at this time to understand the situation and his report can be found in the July/August Kiwifruit Journal.
An update from Zespri’s Severine Brun in France, reports those growers who applied a consistent and robust protective spray programme over the past few years have reported little or no Psa-V symptoms; and unlike last spring in France, this spring has been kinder to French growers, with temperatures through June being warmer and drier than the 30-year average.
As a result, less Psa-V symptoms have been observed, flower loss is much lower than last year and growers are generally much more positive about the ability to continue growing kiwifruit in a Psa-V environment.
Hort16A continues to be a badly affected variety and those few growers who are still growing it are trying to achieve another harvest.
Gold3 is looking good, with very limited symptoms, mostly noticed in spring (dry canes and/or exudate on a few vines per block).
Zespri has removed Kasumin® from the Crop Protection Standard (CPS) for the 2015 season while further research is done to confirm the most effective use pattern. This research is expected to confirm the optimal pre-flowering withholding period for Kasumin® and the number of applications allowed in the pre-flowering period.
Zespri has taken a conservative approach to this Psa management tool in this case, as the suite of Psa-targeted products is considered sufficient to manage Psa this season.
Growers can use up to four applications of KeyStrepto™ on producing and non-producing vines for the 2015 season, though no more than two consecutive applications are allowed without using another Psa-targeted product – e.g. copper.
Refer to the KeyStrepto™ User Guide for detailed rules of use. Growers are responsible for ensuring all use conditions are complied with. KVH no longer conducts pre-use audits.
If you have any queries please contact Gordon Skipage at Zespri.
People working on orchards at this time of year can provide extra resource for carrying out monitoring duties. Growers should be alerting their orchard workers to be on the lookout for signs of Psa-V infection, particularly cane dieback and exudate.
Don’t forget hygiene measures should be in place to prevent introduction or spread of infection between plants, rows, blocks and orchards.
The Government Industry Agreement (GIA) Secretariat visited KVH staff today to give an update on the GIA, including where other primary industries were within the process. The GIA Secretariat facilitates implementation of the partnership described in the GIA Deed and acts in the interests of all Deed Signatories.
As reported in the KVH Bulletin (22 May) the kiwifruit industry was the first to sign the GIA Deed on 20 May.
On 22 July, New Zealand Pork will be the next industry to sign the GIA Deed, representing all New Zealand pork producers.
Like the kiwifruit industry, by signing the GIA Deed, NZ Pork is recognising that biosecurity is a major risk to New Zealand pork producers and that their industry is acting responsibly in taking all possible steps to mitigate this risk.
KVH Chief Executive, Barry O’Neil, spent two days in Wellington this week discussing financial arrangements for GIA as part of a joint working group; and the development of the Operational Agreement for Fruit Fly.
Click here for more information about GIA.
Winter is an opportune time for growers to remove visible signs of infection from their orchards, including cane dieback and exudate. Ideally, growers should do this before winter pruning. Cut back 40cm from signs of infection.
Removing infection allows pruners to structure vines accordingly and minimise later potential impacts on production.
Click here to read more about winter protection from Psa-V.
Right: The KVH Psa-V Risk Model forecasts further heavy rainfall in Opotiki
Continuing wet periods across the country are keeping Psa-V risk elevated. Growers should avoid pruning in wet conditions or when rain is imminent. Ensure all pruning cuts are protected prior to the next rainfall event and tools are sanitised between vines. Pruning staff should be asked to report signs of new Psa-V infection. Monitoring of males, especially in high risk blocks should be undertaken.
Consult the KVH Seasonal Management Guide—Autumn/Winter for best practice information and guidance. Growers unable to access their orchards because of wet ground conditions may consider aerial applications of copper. Address areas where soil drainage is an issue. Stressed vines are likely to be more susceptible to Psa-V.
KVH has developed a short one-page summary of key messages for orchard best practice during winter. This summary was distributed to attendees at the recent FON winter field days and is a useful tool to print out and place in staff areas and/or circulate to supervisors and orchard staff.
Growers in the process of removing Hort16A should ensure canopies are well protected with copper sprays to minimise the chances of infection and Psa-V spread. Ideally, remove any Psa-V infected material and dispose of it by on-site burial or burning. If removed canopy is remaining within the block, fine mulching and use of digesters to speed break-down of is highly recommended.
Psa-V can survive for at least 15 weeks on the orchard floor in prunings and infected plant debris, presenting an ongoing Psa-V risk. Removal of this material will benefit new grafts next spring.
This recommendation also applies to any canopies where infection may be present.
Traceability of plant material, whether it is budwood, nursery rootstock or pollen, is fundamental to a successful biosecurity response. It is only by having a complete and comprehensive database of ALL people that move plant material can effective traceability occur.
Budwood suppliers are reminded they must register with KVH annually, before their first budwood collection for the year, including male budwood. Registration is a quick and simple process. Please do your part to help the kiwifruit industry become better prepared for future biosecurity incursions by registering with KVH.
A reminder to all when travelling overseas: be vigilant with biosecurity measures particularly if you have been visiting kiwifruit orchards. Shoes must be free of soil material and clothes worn in an orchard environment must be washed before entering New Zealand orchards.
On arrival into New Zealand it is important you declare any visits to foreign orchards to MPI Border staff so they can ensure all necessary measures are taken to prevent the accidental introduction of unwanted pathogens that could be devastating to our industry (such as Ceratocystis fimbriata).
Ceratocystis fimbriata is a fungal pathogen causing widespread damage to the Brazilian kiwifruit industry (see KVH Bulletin, 20 Feb). The disease is of significant concern to the New Zealand kiwifruit industry and efforts are being made to increase our understanding of the disease—both to prevent it from entering our borders and to effectively manage it should it arrive.
Efforts that are being made to understand this pathogen include:
A full literature review on Ceratocystis fimbriata on kiwifruit and other crops by an international expert in this field. This report is due in early 2015 and will include;
Another research project being developed will use molecular techniques to determine the similarity of the Brazilian kiwifruit strain with the strain found in New Zealand kumara. This project would identify any underlying basis for differences in pathogenicity between the strains and would result in a DNA based detection test.
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.