Kerikeri Psa-V progression

Those who observe KVH’s weekly statistics will have noticed Psa-V has progressed in Kerikeri recently, with Psa-V identified on seven new orchards in June.

Last week Zespri’s Shane Max, KVH Operations Manager, Peter Mourits and Te Puke grower, Robbie Ellison visited growers on newly infected Kerikeri orchards to discuss the situation and options going forward. The team also held a grower meeting which was attended by more than 50 local growers.

Key points from the Kerikeri visit

• In most cases, the recently infected orchards received fewer copper sprays over the wet autumn weather than other local orchards; and infection was found in less sheltered parts of the orchard.
• Psa-V has been found in a number of young Gold3 orchards, while disease was not present in neighbouring Hort16A orchards where more regular copper has been applied. This highlights that while Gold3 is more tolerant to Psa-V it still requires regular protective sprays, particularly in wet, cool conditions.
• Growers were reminded of the importance of continuous removal of all infected material, regular protective sprays and the need for orchard hygiene.
• Psa-V progression in Hort16A has been slower than expected. This is partly attributed to the warm, dry weather earlier in the year, regular copper sprays over the wet weather and early removal of any Psa-V symptoms.
• Spray diary analysis shows Hort16A blocks in Kerikeri have had an average of nine copper applications over the last season, compared to six applications on Gold3 blocks.
• Overall, the management of low vigour males on some orchards was excellent; and its obvious Kerikeri growers are learning from experience in other regions.
• Growers have been asked to be vigilant and carefully monitor orchards with the expectation that more orchards will express red exudate when sap starts to flow in spring.