Growers should monitor their male vines for Psa-V infection and work to remove or reduce cankers where they occur. Cankers are Psa-V inoculum sources and create infection risk for male and female flower-buds. Infected male flowers can result in insufficient male pollen supply within the orchard and severely impact on orchard productivity. Where male plants are showing infection, assess pollen needs and make arrangements with your pollen provider now. Indications are that pollen availability is low this season.
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.
In early October, KVH staff completed a round of monitoring on six Whangarei orchards to confirm the region’s ‘Exclusion’ status.
The orchards were chosen to represent the region with the focus on Hort16A plantings due to their higher susceptibility to Psa-V.
Samples taken from two CK3 males showing Psa-V like symptoms on one orchard were tested and confirmed ‘Not Detected’. There were no other visible signs of Psa-V symptoms on the other orchards.
A review of the 2014 season spray diaries showed four of the six orchards had good protective spray programmes in place and all orchards had good hygiene protocols in place. The growers had plans to convert their Hort16A blocks to less susceptible varieties; and some had begun this process by stump or notch grafting some of their Hort16A blocks to Gold3.
Due to Whangarei’s close proximity to Kerikeri (a containment region where Psa-V has spread this season) it’s essential Whangarei growers remain proactive with their protective spray programmes and hygiene practices to continue to keep Psa-V out of their region.
A report of the Whangarei monitoring will be available on the KVH website shortly.
France is one of the largest kiwifruit production countries in Europe, and like most kiwifruit production regions is infected with the global outbreak strain of Psa-V (r Biovar 3).
As at autumn 2013, France had about 4400 hectares planted in the following cultivars:
Estimates of total Psa-V infection rates are difficult to obtain. The French Ministry of Agriculture provides official data at the annual Psa meeting each February for the previous year. Therefore, 2013 data is the latest official data available.
In 2013, 2344 hectares of kiwifruit were officially inspected for Psa with 123 samples returning positive results (out of 400 taken from orchards with symptoms). This represents 386 canopy hectares or 8.9 percent of the total industry.
However reports based on visual inspections since 2011 suggest the cumulated infection rate is much higher—around 50 percent. Since 2011, four percent of the orchards have been cut back or removed.
Data from 2014 survey will be released in February 2015 and KVH will report these when they become available.
MPI have established a working group to improve and clarify the requirements for managing the risk of fruit fly entering through the commercial fresh produce pathway.
Although the commercial produce pathway is considered to be well managed and relatively low risk, MPI has identified several pieces of work necessary to maintain a high level of biosecurity risk management.
The group will review work being undertaken and communicate progress back to respective industries on an on-going basis. KVH is participating in this group along with representatives from other New Zealand horticultural industries.
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.
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.
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.
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.
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.