Prunetec - Invitro study of Psa survival in PruneTec (Wound protectant)
The purpose of this trial was to carry out an invitro study of Psa survival in wound protectant (PruneTec).
Wound protectants are used to protect wounds following pruning and grafting. Kiwifruit vines are pruned to remove excess wood in summer and to structure the vine in winter. Pruning wound dressings generally contain a bactericide that aimed at providing protection from bacterial infections. This report presents the evaluation of PruneTec 20001948 wound protectant tested against Psa-V to determine efficacy under laboratory conditions.
Click here to view the full report
Impact of covered structures on the progression of Psa-V, Phase Two
Trials were set up in the kiwifruit growing season of 2012–13 on three orchards to test whether plastic, breathable covers erected over existing kiwifruit vines could reduce the incidence, progression and severity of Pseudomonas syringae pv actinidiae (Psa-V) infections. These structures had been erected in an attempt to slow the progression of Psa-V. Vines were already infected with Psa-V, with varying levels of symptoms expressed. Across the three sites the varieties Actinidia chinensis ‘Zesy002’ (Gold3), A. chinensis ‘Zesy003’ (Gold9), A. deliciosa ‘Zesh004’ (Green14) and A. chinensis ‘Hort16A’ were assessed, along with Gold3 scions that had been notch grafted onto existing rootstocks. Grafted seedlings were planted out at each site and used as trap plants that would indicate infection from Psa.
Click here to view the full report
The KVH AGM is scheduled for 26 November 2014 starting at 2pm in Classic Flyers, Jean Batten Drive, Mount Maunganui. AGM papers and proposed resolutions have been sent to KVH members and are now available on the KVH website here.
In addition to the AGM matters, Zespri’s Dave Tanner, GM Science & Innovation, will give an overview on the Psa-V research programme, what it has achieved and its future direction. This will be the last opportunity for Dave to present on the Psa-V R&D programme, as he leaves employment with Zespri at the end of the year.
All growers and industry participants are encouraged to attend.
Please RSVP to firstname.lastname@example.org
KVH has revised its best practice guidelines for orchard hygiene. The main changes include a more practical approach to orchard hygiene in Recovery regions where infection is widespread.
More focus is placed on removing any visible signs of plant material rather than sanitisation of footwear and hands between orchards in Recovery regions. The revised best practice guidelines also recognise the lower risk of vehicle movements onto orchards, such as quad bikes and fertiliser spreaders, and doesn’t require cleaning and sanitisation between orchards in Recovery regions.
However, the risk of transferring disease through movement of infected plant material remains. Therefore growers who require additional measures to reduce the risk, including sanitisation of footwear and hands, are encouraged to do so.
If you have any feedback about the changes, please email email@example.com.
As a result of the increasing number of confirmed Psa-V positive orchards in the wider Coromandel region, the KVH Board has made the decision to reclassify the region from Containment to Recovery.
Psa-V was first identified in the Coromandel region in September 2012.
The NPMP defines a Recovery region as a region with widespread Psa-V infection. The Coromandel region currently has more than 65% of kiwifruit hectares on orchards with Psa-V identified.
The KVH Board, while having empathy with Coromandel growers who did not support this change, had to consider the rules of the NPMP and the need to move pollen into the region for the upcoming pollination season.
MPI have released a new fact sheet for BMSB which includes comparison to other stink bugs already present in New Zealand. Click here to view the fact sheet.
This fact sheet is part of a larger public awareness campaign that KVH is supporting. Growers who have travelled internationally recently will have noticed the increased publicity at the airport.
KVH has also participated in the development of a research strategy to minimise and manage the risks posed by BMSB to New Zealand.
What is Brown Marmorated Stink Bug?
BMSB is a significant pest to many horticultural industries. It is native to parts of Asia but is currently undergoing rapid range expansion in the United States, Canada and Europe—which previously did not have established populations.
BMSB is considered a high priority pest as;
Growers are encouraged to look out for this organism. Any suspected sightings should be caught, photographed and reported to MPI on 0800 80 99 66.
The cancellation of trans-Tasman international flights in and out of Rotorua Airport means there is one less biosecurity risk pathway into New Zealand.
Since the trans-Tasman flights started in 2009, Rotorua Airport has been a potential entry pathway for biosecurity risks into New Zealand. Of particular concern was the risk of importing Queensland Fruit Fly from Australia directly into the Bay of Plenty.
Last year KVH completed a preliminary review of border interventions at Rotorua Airport to ensure potential biosecurity risks to the kiwifruit industry were being managed appropriately. While KVH was satisfied with the level of biosecurity intervention on this pathway, the cancellation of the flights eliminates this risk altogether and enables MPI resources to be applied to managing other pathways.
Rotorua Airport will cancel its international air service from the end of April 2015.
Chilean growers have been dealt another significant blow after frosts last week devastated crops for the second year in a row. One large producer estimates between 80-100% crop loss on some kiwifruit orchards.
The frosts, which were “completely unexpected” came roughly one year after severe frost wreaked havoc on almost the entire Chilean agricultural industry last year. Many growers did not have their frost protection systems turned on as the weather had been so mild.
This week KVH visited twelve orchards in the Whanganui region and also held a meeting with local growers to discuss best practice Psa-V management strategies and to provide latest research information.
All growers in the region had good monitoring programmes in place. Results from these show some spring progression within previously affected orchards. Levels of infected male vines remain below 10 percent with cane dieback and exudate being the symptoms observed. Minimal numbers of female vines are showing any infection.
Severe spring wind, and for some, recent hail events, have provided challenging growing conditions and proactive spray programmes, cut out of infection as it is found and good orchard hygiene procedures is likely to have minimised infection spread to date.
No leaf spot was evident. However, some bud browning was seen on one Psa-V positive site.
Shelter and adequate pollination are seen as challenges in this region. Notch-grafting of older male varieties has begun. Successful results from December 2013-grafted males, has resulted in growth which will contribute to pollination this year.
This region previously had two unmanaged sites recorded, and each of these sites were visited. One of these blocks has now been removed and the other has been returned to management.
Using products at lower than the recommended label rates can increase the risk of resistance developing, and has been implicated as a factor in cases of resistance to disease in other crops.
Given the limited control options available, it is important the kiwifruit industry use the tools that are available appropriately. This will maximise the useful life of the products. To reduce the risk of resistance, it is very important that the label instructions, including label rates are followed.
On-going use of products outside label recommendations risks ACVM reviewing copper label approvals.
The use of KeyStrepto™ at less than label rates is illegal, and must not occur in any circumstances.
Growers who are concentrate spraying need to adjust product rates to ensure correct rates are applied.
Low levels of leaf spotting within some orchards in the Bay of Plenty region have been reported over the last week. Sepal browning is being reported for some blocks historically vulnerable to bud infection. Leaf spot symptoms are traditionally seen this time of year—often appearing after periods of wet weather and particularly if these are also associated with wind and cold conditions.
Research has shown that a good protective spray programme helps minimise leaf spot symptoms, reducing inoculum build-up within orchards. Maintain copper cover, and in high-risk situations the use of KeyStrepto™, is highly recommended at this time to avoid build-up of orchard inoculum levels. Actigard™ provides further support by eliciting the vine’s defence system through this critical pre-flowering period.
Growers intending to trunk girdle as an additional tool against flower bud and flower infection are recommended to leave some un-girdled vines, to allow measurement of the value of this tool on their individual site. Click here for Zespri’s methodology on the Canopy.
Copper protectant products Tri-Base Blue® and Champ™ DP have been removed from KVH’s recommended product list (below) as their use period from post-harvest to leaf-fall and then through dormancy has ended.