Immediately following harvest, growers should be getting copper spray programmes underway to help prevent Psa entering their vines through harvest wounds and leaf scars.
Incorporation of Actigard into a post-harvest programme will reduce the likelihood of disease symptoms appearing the following spring. Actigard can be tank mixed with copper and is most effective when applied to leaves that are still in good condition. Extreme care must be taken to avoid spray drift onto unharvested blocks.
Following the discovery of copper-tolerant and streptomycin-resistant Psa developing on some orchards, a robust spray programme and cutting out infected material is particulary important through autumn and winter to reduce the spread of these new Psa strains.
Best practice advice for post-harvest protection and managing tolerance and resistance:
Autumn and winter are high-risk periods for Psa-V. While vines are dormant the disease can still be active and enter through pruning wounds, new grafts and frost-damaged tissue.
For more information, refer to KVH’s Psa-V Best Practice Guide at www.kvh.org.nz/seasonal_advice.
Any growers concerned they may not be achieving the expected levels of Psa control from copper applications at label rates should contact KVH on 0800 665 825 or email email@example.com.
Young plants, or vines newly grafted this season should be protected through the autumn period—particularly those located in frost-prone sites or close to Psa-V affected locations.
New leaf spot symptoms are being seen on a number of sites indicating a lift in Psa-V activity as we begin to experience colder wetter weather periods.
A protective spray programme re-establishing copper cover is now high priority to protect young tissue and plants.
The KVH Psa-V Risk Model has predicted high risk periods for Psa-V over the last few weeks with these periods matching periods of rainfall.
Actigard manufacturer Syngenta, will not be renewing the limited label claim on soil-applied Actigard from May 2016. Therefore, from May onwards soil-applied Actigard will be considered off-label use. However, it may still be approved by Zespri under Justified Approval (JA).
Foliar-applied Actigard is not affected by this change.
Please contact Sylvia Warren, Crop Protection Advisor on firstname.lastname@example.org for more information on a JA.
Record numbers of arriving passengers into NZ over the 2015/16 summer have kept border biosecurity defences busy over the season.
However, strengthened biosecurity measures have stopped hitchhiking pests and diseases from entering New Zealand without affecting passenger processing time. In fact, processing time is down on last year, and compliance rates (the amount of times MPI correctly detects risk goods carried by passengers) are up at 99%.
Significantly, these detections included 14 fruit fly found on passengers—reflecting the biosecurity risk pressure at our borders.
Strengthened biosecurity measures include:
Click here to read more on MPI’s website.
MPI’s latest summer statistics are a good indication of the pressure New Zealand’s borders are facing. Here’s a snapshot of some interesting stats:
Click here for full details.