Regional update - Hawkes Bay and Gisborne
KVH staff recently visited Gisborne and Hawkes Bay orchards that were confirmed Psa-V positive for the first time through spring 2015.
Since 1 August 2015 an additional 14 orchards from Gisborne and five from Hawkes Bay have tested Psa-V positive.
Blocks showing symptoms last year were also revisited to understand the challenges growers had faced over the past six months.
Cold, wet spring conditions and in particular, damaging southerly winds, were considered the most likely drivers of new infections within the regions.
Growers converting from Hort16A to Gold3 with colder sites or more severely infected stumps, experienced difficulty achieving high winter graft success (pictured above). Re-grafting continued through summer and multiple grafts to the same stump and/or suckers have been completed.
Poor synchronisation of male and female flowers in some Gold3 blocks have been a concern, particularly for Gisborne growers. The need to stock pollen for artificial pollination and the importance of good male management was discussed. Male grafts on Bounty rootstock, autumn trunk-girdling of males to bring flowering forward and male management to provide a range of cane types to spread flowering timing, were all strategies thought worthy of trialling.
Two growers with young Gold3 blocks that suffered up to 20% canopy cut-out due to Psa-V through spring, identified the need to take care when managing strung cane through the autumn period. Both growers believed cane damage, and possibly poor tool hygiene during autumn work led to spring infection.
It was pleasing to see the level of proactive management in place and the high standard of hygiene being enforced by growers in general.
The KVH team also presented autumn Psa-V messages at the Zespri OPC field days, and reminded growers that a more proactive Psa-V management programme in autumn can lead to reduced symptoms in spring.
Click here for KVH’s field day notes on the KVH website.