KVH staff visited Edgecumbe orchards this week to meet with growers and discuss Psa-V progression on orchards in the region this year.
Like other regions, spring has generally been cool, wet and windy in Edgecumbe. Two hail events have also occurred, with the most recent last Thursday coming just before pollination of Hayward. These conditions have been challenging.
Overall, more comprehensive spray programmes have been adopted by most growers in the region. Both KeyStrepto™ and Actigard™ have been widely used in conjunction with copper on a regular basis.
On Gold3 blocks visited, expression of Psa-V symptoms was still occurring with cane dieback and some whole cane collapse seen on more challenged sites. Older, apparently healed cankers were also active on some plants. One block which had young Gold3 plants with scions inadvertently girdled last February, was showing die-back and red exudate around the girdle site.
In contrast, girdles correctly applied to mature stumps remained clear of symptoms. This reinforced the message of care needed when girdling young plants and particularly in high Psa-V risk environments. As expected, levels of symptoms varied between blocks with disease expression appearing worse on cooler or stressed sites. All Gold3 growers in the area are advised to continue actively monitoring and cutting out symptoms to reduce the spread of the disease.
The extent of symptoms on Hayward blocks was quite variable. Growers commented that signs of leaf spotting and bud browning had begun to appear over the past month and in some blocks rapid acceleration of leaf-spot had been seen in the past week after a period of wet windy weather. For some growers there is concern about the potential impact of Psa-V on pollination and fruit set. Artificial pollination will be used as a tool to mitigate risk.
One Hayward site visited highlighted the value of a comprehensive spray programme. Control rows (with no sprays applied) showed severe leaf spotting and significant loss of female flower-buds, while adjacent rows were relatively symptom free and carried good cop loads. Three applications of KeyStrepto™ and four coppers had been applied since bud-break.
A G14 block visited showed increasing signs of bud rot despite an active protective spray programme.
Overall, Psa-V continues to make growing in this region a challenge. However, growers in general were quietly confident of a better fruit set than was achieved in 2013. Several Psa-V related trials continue within the Edgecumbe area.
An independent review by the Sapere Research Group on how the industry responded to the 2010 arrival of Psa-V into New Zealand has been released today. Click here.
The Sapere Research Group was commissioned by the KVH Board and selected following a tender process.
The aim of the review was to identify lessons learned from the response to the Psa-V incursion that could be used to support future responses to new pest and disease arrivals that could impact the New Zealand kiwifruit industry.
The review includes several recommendations for industry and KVH to consider going forward. Many of the recommendations have already been put in place by the industry and KVH, while others are under action and some will result in new work. Overall this confirms KVH is focussed in the right areas.
A document setting out the recommendations and how KVH proposes to address each of them has been prepared. Click here.
KVH is now seeking feedback from growers and the industry on this approach. Feedback can be sent to KVH by email firstname.lastname@example.org or by post: PO Box 4246, Mount Maunganui by Friday 28 November 2014.
Click here to read KVH’s Media Release.
The Ministry for Primary Industries (MPI) has initiated a biosecurity response following confirmation of a single, unmated female Yellow Spotted Stink Bug (YSSB) found last week in Temuka, South Canterbury.
KVH has notified ‘KiwiNet’ – a group of industry people selected by their organisations to form the kiwifruit industry capability network for biosecurity readiness and response.
MPI are asking the South Canterbury community to help by looking out for any further YSSB bugs and to call the Exotic Pest and Disease Hotline 0800 80 99 66 to report any suspect sightings.
MPI occasionally intercept live and dead specimens of YSSB. To date, these have all been single individual bugs - not breeding populations.
MPI investigators have carried out surveillance at the property and surrounding area where the bug was found to confirm there are no more present. Nearby transitional facilities have also been inspected and no further finds have been made.
Limited information is available on the potential impacts and host range of this species. However, the host range could include several species of economic importance to New Zealand. At this stage it is unknown whether kiwifruit would be significantly impacted if the YSSB was to establish in New Zealand.
YSSB isn’t considered as potentially damaging as Brown Marmorated Stink Bug (BMSB). Unlike BMSB, YSSB is not known to be an urban nuisance pest anywhere in the world.
YSSB is typically a hitchhiker pest, which means, for example, that they could arrive here from overseas in containers or used machinery and vehicles.
This is the first biosecurity response carried out under the Government Industry Agreement on biosecurity readiness and response (GIA). Kiwifruit Vine Health (KVH) is working in partnership with MPI and Pipfruit NZ.
For more details and a description, please see the Yellow Spotted Stink Bug fact sheet here.
Key Industries (manufacturers of KeyStrepto™) have advised KeyStrepto™ is now in stock. However, growers are reminded it cannot be used on kiwifruit vines within one week of the first flower appearing (male or female), and can only be used in the north island.
The KeyStrepto User Guide details the conditions of use.
Protection of wounds following hail is important to minimise Psa-V infection, particularly on blocks where Psa-V risk is high. With recent hail damage and the possibility of further hail bands sweeping across the country growers are reminded of their options.
Alternating sprayer travel up rows in alternate spray rounds will maximise coverage of hail wound sites. Do not spray blocks if bees are actively foraging.
Zespri has further information for growers with orchards affected by recent hail events, including information about insurance cover—click here to view on the Zespri Canopy.
This week KVH met with Gisborne growers to see first-hand the level of Psa-V progression on positive orchards within the region.
Gisborne did not suffer severe winter or spring frosts this year. However, spring growing conditions have been difficult with significantly higher than normal rainfall for both August (155% higher than 2013) and September (185% higher than 2013). Cooler temperatures and long periods of wet weather, particularly toward the end of September, have led to higher levels of cane die-back and leaf spot symptoms on already infected orchards.
The level of symptoms seen on Gold variety orchards was generally low. Males and vines in tougher growing conditions, such as those suffering from water-logging, had more die-back and leaf-spot. However, monitoring and cut-out rounds are continuing to minimise infection levels within the orchards. Removed material continues to be bagged and buried, or burnt.
Growers with vulnerable Gold varieties have clear plans for the removal of these blocks. With pollination now complete, the removal of the higher-risk male varieties from Hort16A blocks in their final production year is recognised as a means of reducing Psa-V risk for these orchards. Early removal also provides the opportunity for the earlier establishment of males suitable for Gold3.
Gold3 is performing well. Growers commented that signs of Psa-V are limited to a few canes with dieback, and on individual blocks some minor infection has been seen in a few M91 males. Again, male pruning provides an opportunity to remove this infection and to restructure vines to support good penetration of protective sprays for the balance of the season.
Some leaf spotting and sepal staining has appeared in the last three weeks in Hayward varieties on cold, wet sites and the impact of this is still to be seen.
The progression of bounty rootstock is being observed with interest. To date, some failed plants have been attributed to Psa-V infection. Overall however, this rootstock is showing promise in blocks with more difficult soil conditions where this new rootstock is being established.
Overall, as weather conditions start to improve, the rate of symptom progression is expected to slow across the region. However, robust protective spray programmes are still recommended to put vines in the best position as Hayward varieties move through to the higher-risk flowering period.
The Gisborne region now has 19 Psa-V positive KPINS. This represents 29% of orchards and 44% of kiwifruit hectares. Of these KPINS seven new finds were reported since 1 August 2014.
To minimise biosecurity risks across the supply chain, and to assist nurseries in meeting the Kiwifruit Plant Certification Scheme Core Standard, KVH has produced a series of factsheets on biosecurity best practice for kiwifruit nurseries. An independent nursery expert has assisted KVH in developing these factsheets which are aligned with key components of the Core Standard.
These factsheets will be added to over time and currently include:
KVH has amended its best practice guidelines for orchard hygiene to include a more practical approach in Recovery regions where infection is widespread.
The revised guidelines also recognise the lower risk of some vehicle movements onto orchards, such as harvest machinery, quad bikes used for maturity clearance, and fertiliser spreaders. These should be checked and have all visible plant material removed. However they no longer require sanitising between orchards in the same Recovery region. Higher-risk vehicles which come into direct contact with kiwifruit plant material (such as mulchers, root pruners etc) should continue to be cleaned and sanitised between orchards.
All vehicles should be cleaned and sanitised between Recovery regions. The requirements for Containment and Exclusion regions remain unaltered.
Growers in all regions are required to carry out a round of mandatory monitoring in November. Growers in Exclusion and Containment regions must submit their results to KVH by 10 December using the simple online tool.
Growers in Recovery regions must record their results and file with their GAP records and are also encouraged to submit them to KVH by 10 December.
Mandatory monitoring is an important tool for the industry, as it allows KVH to report a more accurate picture of Psa-V progression around New Zealand. Additionally, early detection and intervention is the most effective method to control and minimise the impact of Psa-V.
A severe hailstorm has destroyed apple and kiwifruit crops in Tasman district. The hail hammered the area around Lower Moutere, Motueka and Riwaka, west of Nelson, for 20 minutes from 9.30pm Tuesday night, collapsing hail nets and blanketing the ground with hailstones.
There are also reports of hail events in other growing regions, including the Bay of Plenty today.
All growers with orchards affected by hail are advised to apply a Psa-V copper protective spray. Wounds created by the hail create an entry point for Psa-V.
Those lodging a claim must contact the Zespri contact centre as soon as possible after the event (it needs to be done within 72 hours), and don’t cut or thin the orchard until the assessor has been out and you know the status of your orchard.
Males are difficult to identify and the flowering period provides the best opportunity to distinguish between cultivars. Male cultivars vary in susceptibility to Psa-V. Therefore, the ability to identify different male varieties can assist Psa-V management activities.
Diseased males can impact future pollination requirements. More-tolerant male varieties are more likely to provide an ongoing source of pollen within the orchard.
To help growers identify between males, KVH has developed a simple guide including photos, descriptions and leaf characteristics of each variety.
Also, growers wanting to test their males to confirm identify are can contact Tree Lab in Rotorua who process male samples and send them offshore for DNA analysis.
Three recent reports of symptoms appearing to be Psa-V (red exudate) have received ‘Not Detected’ results following testing.
The samples from three different varieties in three different regions have been sent to MPI for further analysis. Testing is in progress. While no other strains of Psa have been identified so far, a fungi commonly associated with wounding has been identified on one sample.
We know wounds are a pathway for Psa-V to enter, and this could also be the case for other diseases. Therefore growers are advised to remain vigilant with monitoring and applying protectant sprays and to continue to protect vines by sealing any wounds.