Psa Case Studies

This page has case study information from the field about Psa observations.

Lessons learned from Psa-V incursions to new regions in 2012: Waikato, Hawke Bay, Gisborne, Coromandel and Kerikeri.

It has been nearly two and a half years since the first case of Psa-V was detected in Te Puke in 2010. Over the last year, a number of new incursions have occurred in previously ‘clean’ regions. Observations and case studies have provided some information on the spread of the bacteria within these regions. We now understand more about the patterns of infection and expression of the disease.

Lessons learned from Psa-V incursions to new regions in 2012 (28.03.13)

Pathway assessment tracing Psa-V entry and spread in the Waikato: Te Awamutu, Karapiro and Paeroa

On 20 August 2012, KVH was notified of a positive Psa-V result in Te Awamutu in the South Waikato region. A second neighbouring orchard was confirmed positive on 21 August 2012.

At the first notification of a positive result, KVH senior technical staff visited the affected orchard to confirm symptoms. KVH initiated a pathway assessment into the Waikato region incursions.

Pathway assessment tracing Psa-V entry and spread in Waikato (28.03.13)

Psa-V in kiwifruit—bacterial disease comparison in stonefruit and citrus
To help the industry better understand management and cultural practices to control Psa-V, a comparison between Psa-V in kiwifruit and other bacterial diseases in the stonefruit and citrus industries has been prepared by KVH. Click on the link below to access the document.

Psa-V in kiwifruit—bacterial disease comparison in stonefruit and citrus (15.11.12)

KVH have created a video following up on the initial Kim Woolsey case study (28.11.12) Please click the link below to view the video.

Kim Woolsey—Opotiki grower (18.07.13) NEW

KVH has developed two videos, featuring two Bay of Plenty growers. Tim Torr from Tauranga and Kim Woolsey from Opotiki talk about their successful experiences growing Hort16A in a Psa-V environment. Click on the links below to view the videos.

Tim Torr—Tauranga grower (28.11.12)
Kim Woolsey—Opotiki grower (28.11.12)

Sixteen growers who grafted to Gold3 in 2011 recently participated in a KVH case study. Grower experience with grafting, hygiene, canopy management, the physical and environmental orchard conditions and grower approach to controlling Psa-V were identified and recorded in this case study.

Gold3 case study—available on the restricted area of the KVH webiste (27.11.12)

In September last year, KVH undertook a Gold3 Case Study to understand the impact of Psa-V on 2011-grafted Gold3 vines in the Bay of Plenty.

The case study considered grafting techniques, hygiene, management practices, symptom progression and control and what strategies, planning tools and coping mechanisms growers were using.

Eight growers that were successfully managing their young Gold3 were re-interviewed in March and April 2013. The purpose was to follow up these growers, six months after the initial assessment.

Follow up Gold3 case study

KVH recently conducted a field summary on the performance of two non-ZESPRI variety A19 Orchards (Enza Gold), in a Psa-V environment. The case study is available on the link below.

A19 (Enza Gold) case study (16.08.12)

KVH recently conducted a case study about 57 Hort16A Te Puke KPINS confirmed Psa-V positive this time last year. Only six of these KPINS made it to 2012 harvest, highlighting how few were able to achieve a crop.

The case study, and a video interview with Te Puke growers, Barry Roderick, Ken Edkins and Robbie Ellison (three of the growers featured in the case study) are available on the links below.

Hort16A case study (03.08.12)

Click here to view the video interview with the three growers (03.08.12) New

Following the first notification of a positive Psa-V result on an orchard in Franklin, South Auckland, in late November 2011, KVH initiated a routine ‘trace-back’ investigation. The investigation involves assessing known pathways for the wider-spread of Psa-V into new regions.

Click on the link below to read the Franklin trace-back investigation prepared by KVH from November 2011 to May 2012.

Franklin Psa-V trace-back report (10.05.12)

Routine orchard monitoring is essential for early Psa-V detection. This case study interview by KVH highlights the importance of orchard observation, preparedness and protectant programmes.

Click here to read the article published in Kiwifruit Journal, Psa Scientific Edition, March/April 2012.

In early August 2011 KVH investigated 35 orchards in the Te Puke region to determine why some orchards showed more severe levels of Psa-V infection than others. Strung canopies appeared to be a common factor amongst the most severely affected orchards.

Click here to see the Wild Fire Orchards report September 2011.

A case study from Colin Jenkins, General Manager Ngai Tukairangi Trust, Matapihi, Mount Maunganui.

Click here to read the article published in Kiwifruit Journal July/August 2011 (Issue no. 206).