Key Industries, the New Zealand supplier of KeyStrepto™ have advised there is currently no stock of KeyStrepto™ available for kiwifruit growers due to demand far exceeding supply. Zespri, KVH and retailers have been working with Key Industries to secure more supply as soon as possible. The shortage is due to offshore production constraints, not transportation.
As a result, it appears unlikely sufficient KeyStrepto™ supplies will be available to the kiwifruit industry before flowering this season.
Growers should re-consider their Psa-V control plan and ensure alternative control products are used.
Alternative Psa-V control products allowed pre-flowering include:
Growers should not consider using Kasumin® as a replacement for KeyStrepto™. Kasumin® has been removed from the Zespri Crop Protection Programme for the 2015 season while further research is done to confirm the most effective use pattern. This work is expected to confirm the optimal pre-flowering withholding period for Kasumin® and the number of applications allowed in the pre-flowering period.
Growers and those with stored pollen available for sale are reminded the movement of pollen between orchards and regions must be managed to minimise the risk of Psa-V spread.
Key requirements for providing pollen:
In a recent in-vitro study wound protectant Prunetec demonstrated absolute kill of Psa-V within an hour of incubation. Minimum inhibitory concentration, kill rate versus time and repeatability were tested by Verified Lab Services (VLS). VLS has previously conducted in vitro testing of other wound protectants commonly used in the industry.
Prunetec is listed in the Zespri Crop Protection Standard and is suitable for covering pruning wounds and for use when grafting.
Preparing for emerging pests and diseases that could affect New Zealand’s environment and economy is a key role for the Ministry for Primary Industries (MPI).
The Ministry has been keeping an eye on the brown marmorated stink bug (Halyomorpha halys or BMSB) for a number of years now and has stepped up its efforts to keep this pest out of New Zealand - or detect it early should it get here. This is in response to the insect emerging as a serious horticultural pest in the United States.
BMSB is native to Asia and has aggressively invaded the United States and has now been found in Canada, Switzerland, Germany, Italy and France. At present it is regarded by the New Zealand horticulture industry as one of the top six pests of concern.
Good phytosanitary measures are the best way to prevent introductions, and early detection through surveillance is the key to eradication before the pest can become established.
MPI is trialling 50 traps in high-risk areas to determine the feasibility of integrating pheromone lures for BMSB into its existing trapping programmes. Border and transitional facilities have also been put on alert for BMSB.
BMSB has not been detected in New Zealand – to report any suspect sightings phone MPI on 0800 80 99 66 or KVH on 0800 665 825. If you’ve been overseas or received parcels/shipments from overseas, check your luggage or parcels indoors for insects.
The Ministry for Primary Industries (MPI) has received laboratory results confirming insect larvae found in two separate consignments of citrus fruit (mandarins and oranges) from South Australia are NOT economically-significant fruit flies.
The fruit consignments were intercepted at the border last week as part of routine border inspection processes. They were found to contain suspected fruit fly larvae.
The insect larvae found in the consignments were the Island Fruit Fly (Dirioxa pornia) which is not regarded as economically significant as it predominantly affects damaged fallen fruit, and primarily not fruit for sale.
The consignments were from areas designated as pest-free for economically significant fruit flies in South Australia and imported to Auckland and Christchurch.
MPI immediately put a hold on fruit imported from Australia while it waited on laboratory identification to determine if the insects present were harmful species of fruit fly. This fruit was not to be distributed for sale.
None of the fruit from the consignments in question left containment until the larvae was identified and the fruit treated.
Interceptions at the border such as this incident are not infrequent and demonstrate the border system at work.
KVH was pleased to be notified quickly of the incident and supports the actions taken by MPI.
Strong winds over the last week have created high levels of wounding, particularly in more developed canopies. Combined with long periods of leaf wetness, the high-risk conditions for Psa-V also increase.
Recommendations are to apply additional protective copper cover to ensure wounds and expanding leaf surfaces are protected. Applications of KeyStrepto™ should also be considered in high-risk situations, including orchards which have suffered hail damage or where cankers are being actively managed.
Foliar applications of Actigard™ are also recommended once the majority of leaves within the canopy have reached 25mm. This provides an additional systemic mode of protection helping to reduce infection levels and protect against leaf spot.
Additional applications of Actigard™ can be made at 21 day intervals. Avoid applications in marginal areas where vines are stressed due to water-logging or other factors such as root diseases.
In regions where varieties are approaching flowering, foliar applications of Actigard™ can help provide protection through the flowering period. However, care must be taken to avoid applying once flowers begin to open.
Actigard™ can be tank mixed with commonly used coppers, and with KeyStrepto™ and DuWett. A three way mix of copper, Actigard™ and KeyStrepto™ is not recommended as some precipitation of product may be observed. Actigard™ may be tank mixed with pre-flowering Movento, Luna Privilege or Prodigy sprays.
Agenda includes an update on Psa-V status in the Wanganui region, best practise tips for spring and managing bud-rot in Hayward.
All growers welcome.
KVH will hold its Annual General Meeting (AGM) at 2pm on Wednesday 26 November 2014 at Classic Flyers (Boeing Room), 9 Jean Batten Drive, Mount Maunganui—Google maps.
During bud-rot trials in Hayward and Green14 orchards last year, Actigard™ and copper spray programmes had the biggest impact in reducing Psa-V leaf spot. Applications of KeyStrepto™ also reduced leaf spot.
As Psa-V is associated with bud-rot, a protective programme that includes these products is highly recommended for all sites vulnerable to bud-rot. This will minimise leaf spot, which once established, can provide ongoing sources of inoculum.
Girdling provided the best bud-rot control. Recommended timing for girdling is 16-30 days pre-flowering. Further trials will run this year to better understand optimal girdle timing.
Growers intending to apply a pre-flower girdle should plan for this now. All growers are urged to measure impacts of this treatment on their site and share this information with the industry to build knowledge quickly about the value of this tool.
By leaving some control vines amongst girdled areas or alternatively, girdling only a few vines within high-risk blocks and measuring flower-to-fruit retention, assessment of the success of this tool across multiple sites can be gained. A methodology to assist growers has been developed by the Zespri OPC team – click here.
As of 1 October growers must register their intent to spray KeyStrepto™ through an online form available on the Zespri Canopy or KVH website. Click here to access the online form. After registering your intention to spray, application must occur within three days.
Orchards may be subject to random audits; and strict conditions apply to the use of KeyStrepto™. All requirements must be followed, including the completion of a Site Inspection Record, and compliance with the KeyStrepto™ User Guide.
Click here for more information about KeyStrepto™ and its use conditions.
This season’s rules for KeyStrepto™ use are different to previous seasons. However, as in previous seasons, the key focus continues to be ensuring open flowers in the orchard (e.g. sward, shelter, and canopy) are minimised and neighbours must be notified before use.
From 1 October, all growers must register their ‘Intent to Spray’ via the Canopy or KVH websites. Growers may be selected for random audit to ensure they are adhering to the rules set by the ACVM. Audits are conducted in a similar manner to the KVH audits of previous years and will target the same areas of concern. Failure to meet the ACVM conditions of use can have significant impact on:
Orchards which fail the audit are subject to automatic future audits and the normal penalties imposed under GLOBALG.A.P and the Zespri Crop Protection Standard. These penalties can include:
Maintaining a responsible attitude towards KeyStrepto™ use will ensure continuing use of this tool while making sure risks to all industry stakeholders are mitigated.
If you have any queries, please contact Zespri Crop Protection Development Manager, Gordon Skipage on 07 572 7633 or by email.
A further observation report on infected male vines shows how the effects of a colder site, Psa-V infection history, lower input Psa-V strategies (cultural management and protective spray programmes) and less-tolerant varieties can result in very compromised pollination potential.
Ongoing Psa-V management is necessary on all orchards and more challenging spring conditions clearly illustrate the re-emergence of Psa-V on vulnerable sites.
Monitoring and removal of infected material through spring remains a primary tool in reducing risk of Psa-V inoculum building and compromising orchard productivity.
Click here for the observation report.
