KVH has recently received a number of reports of red exudate appearing, particularly in male vines. Best practice advice is to determine the level of infection in each block by monitoring and recording the number of plants infected and the severity of infection.
If cankers are isolated, such as at the ends of canes or leaders, consider removing them. For cankers that cannot be easily removed, excision or cauterisation may be an option. Note—research has shown cauterisation is less successful at slowing canker spread than total removal.
Growers with more susceptible male varieties should consider their options now to graft some, or all, of their male vines over to another variety in the upcoming November grafting window. It is also important to consider the potential impact on pollination, and plan now to ensure artificial pollen can be procured. Above all else, it is important to have a plan in place to determine how cankers will be managed, and the process that will be followed moving forward.
A focus on spraying at regular intervals from budbreak onwards will provide ongoing protection of expanding leaves and shoots. Leaves in the first week of emergence and up to three weeks old are most vulnerable to Psa-V infection.
‘Pulses’ of leaf infection observed in previous years may have been due to high numbers of leaves at this vulnerable stage not being suitably protected through significant infection events.
Psa-V inoculum on the edges of leaf spots can reactivate in suitable weather conditions and add to the inoculum load within the canopy. This increases the risk of flower bud infection across the spring period. Hayward and Green14 can be particularly vulnerable to this infection.
A full winter rate copper with a spreader applied immediately prior to budburst is highly recommended to protect breaking buds on all varieties.
A following regular programme of coppers, Actigard™ and, in high-risk situations, KeyStrepto™, should be applied through to flowering.
Ambitious may also help reduce leaf spot and may be applied once there is sufficient leaf in the canopy (see photo). Similarly, Actigard™ also requires sufficient leaf cover at time of application to ensure uptake is sufficient to fully activate the vine. Manufacturer recommendation is to apply Actigard™ two to three weeks after bud burst, when leaf diameter is approximately 25mm.
Many Hort16A canopies will already have sufficient leaf for application of these products. AI nozzles and drift-reducing adjuvants must be used until canopy closure to minimise spray drift. Excellent spray coverage will optimise product efficiency. Use of wetter papers is recommended to check applications.
Plant Health Australia (PHA), the industry body that coordinates the government-industry partnership for plant biosecurity in Australia, visited KVH yesterday to learn about our Psa-V management approach, and to share information about future biosecurity priorities.
The full Board of Directors participated in the visit and were extremely impressed with what the NZ kiwifruit industry has accomplished in just under four years since Psa-V arrived, in terms of managing and reducing the risks using the NPMP, and also the major R&D efforts that have been achieved.
Discussions on future biosecurity priorities included understanding the Australian approach to cost sharing for fruit fly, where the arrangement in place has government funding 80 percent and industry 20 percent of the costs associated with responses.
As advised in the KVH Bulletin (15 May) Lincoln University is manufacturing a prototype trichoderma product called Trimix 1. Trichoderma are fungi present in soils, and some strains are able to colonise the root system of plants resulting in beneficial effects to the plant.
Trimix 1 is available once again to growers for use as a plant health enhancer (bio-fertiliser) from Lincoln University.They also recently received BioGro approval for TriMix-1 so it can now be used without restriction by organic growers.
While there is experimental evidence that the TriMix 1 can improve plant growth, Lincoln and/or KVH and Zespri cannot promote the product for Psa-V control as it does not have ACVM label claim from the Ministry for Primary Industries (MPI).
Growers interested in using the product as a plant health enhancer (bio-fertiliser) can click here to email Lincoln University.
KVH have an exciting development opportunity for a future leader within the Kiwifruit Industry.
We are seeking an upcoming leader to join the Kiwifruit Vine Health Incorporated & The KVH Foundation Incorporated Board of Directors as an Associate Director.
This opportunity arose at the Young Grower of the Year national competition in August where contestants debated the benefits of this approach as part of the competition programme. It was strongly supported by all competitors who encouraged organisations like KVH to develop such an opportunity for future horticultural leaders.
This opportunity will expose the successful applicant to gain experience in governance, leadership and strategy while bringing his/her own industry knowledge and experience to the KVH Board table.
The Associate Director will also have the opportunity to be mentored by an Industry Leader and receive a contribution from KVH towards their governance training.
This is a non-voting role however the Board seeks full participation in meetings and will welcome constructive contributions from the Associate Director in the workings of the Board.
Click here for a copy of the position description.
Please email your current CV and application letter to email@example.com
Applications close 5pm Monday 20 October 2014.
A KVH meeting in Coromandel on Tuesday was well-attended by local growers. Psa-V expression in the region has increased significantly over the last month.
The region has experienced a cooler and wetter winter than previous years which is seen as a major contributor to the increased levels of Psa-V.
Some orchards that suffered frost shortly after harvest did not have an opportunity to apply an autumn Actigard™. These orchards are showing considerably more Psa-V than those in the same area who did manage to apply Actigard™.
A number of Hort16A orchards showing increased symptoms are being actively monitored with regular cut-out to remove Psa-V and growers have applied KeyStrepto™. All but one remaining Hort16A orchard are now notch-grafted and growers are looking to remove susceptible male vines following flowering.
Hayward and Green14 in the region are showing few symptoms at this early stage. The Gold3 grafted in 2012 is generally looking good. However, 2013-grafted Gold3 is showing increasing symptoms with a number of orchards cutting out infected areas.
While in the region KVH also visited a Psa-V positive Hort16A Coromandel orchard.
Over the last two weeks KVH has monitored four orchards with Chieftan males as part of an ongoing monitoring programme that has been running for the past two years. Two of the orchards are located in high altitude Te Puke, and the other two in Waihi.
All four orchards showed more secondary Psa-V symptoms during this monitoring round than observed at the same time last year. This is consistent with reports received from growers and postharvest over the last two weeks.
Levels of symptoms were higher in Waihi than Te Puke. After reviewing weather data it appears temperatures went below 0°C during nine days in Waihi; and on one day in Te Puke. This occurred between 1 June and 31 August. Both regions had a heavy rainfall event on 19-20August (30mm in Waihi and 19mm Te Puke).
Click here for information about male management in a Psa-V environment
New Zealand is tightening its borders by increasing scrutiny of yachts arriving in Northland this summer as a result of the two Queensland fruit fly detections in Whangarei early this year. This follows a review of how the fruit flies could have arrived in New Zealand which KVH participated in.
Eight extra quarantine inspectors will be working in Northland in ‘rummaging teams’, from October to mid-December when the bulk of yachts arrive.
MPI is also training detector dogs, working with locals, the navy and air force and contact yachties before they come to New Zealand.
Click here to read MPI's media release.
Click here to read the full article on the 3 News website.
The KeyStrepto™ User Guide has been updated with the new ACVM conditions of use. The updated User Guide and accompanying grower letter to be distributed through retailers is available on the KVH website here.
The key change is from 1 October growers must register their intent to spray KeyStrepto™ on the Zespri Canopy or KVH website and orchards may be subject to random audits. The online function will be available from 1 October. Before 1 October, you do not have to register intent online but all requirements and best practices must be followed. Refer to the KeyStrepto™ User Guide, including a Site Inspection Record.
While some of the conditions of use have changed, the responsibility to minimise nectar-bearing flowers such as buttercup and clover is unchanged from previous years.
Other conditions of use
Refer to the KeyStrepto™ User Guide for detailed rules of use. Growers are responsible for ensuring all use conditions are complied with.