The first of a KVH-produced bi-monthly R&D update is available through the KVH Bulletin. The report has previously been published through the Zespri Kiwiflier. This report provides information about the progress over December 2014 and January 2015 for the Psa R&D programme.
KVH spent two days in February in the Kerikeri region visiting kiwifruit orchards worst-affected by Psa-V.
Psa-V has established a significant presence in the Kerikeri region over the last six months, with 60 orchards or 68% of the region hectares now confirmed as Psa-V positive. A number of Hort16A orchards in the cross roads area (the Psa-V ‘hotspot’) have seen significant progression of the disease with up to 25-30% of canopy removed at the time of visiting.
As expected the warm, dry weather over January and early February, with average mean temperatures in the mid-20s, has significantly slowed progression of the disease.
It was encouraging to observe most growers with infected orchards have a proactive monitoring and removal programmes in place. These programmes, supported by proactive spray plans targeting high-risk periods, has clearly assisted in slowing the progression of the disease and minimising the risk to neighbouring properties.
However, with a significant Hort16A presence in the region, there is high degree of uncertainty as to what level of progression we may see once autumn starts and the climatic conditions are more suited to the bacteria.
There was a good level of participation at a recent KVH grower meeting held in Kerikeri, with more than 50 growers attending.
Discussion at the meeting confirmed the majority of growers who still have Hort16A are looking to remove this variety following harvest. However, a number of growers also indicated they will be looking to grow another Hort16A crop next season. KVH will be monitoring disease progression on these orchards and working with growers to ensure risks to neighbouring orchards are kept to a minimum.
Overall, Gold3 has been performing well in Kerikeri with limited signs of Psa-V. Last spring a number of orchards showed symptoms in young canes that had been bought down the previous autumn, these symptoms have not progressed.
Some Gold3 orchards have experienced an increase in Psa-V in M33 males which is causing some concern.
Going into harvest and then the cooler, wetter months of autumn and winter, growers need to continue with their Psa-V best practice management activities. Orchard hygiene, monitoring and proactive spray programmes are all essential to ensure symptoms are kept to a minimum next spring.
Peter Mourits, KVH Operations
The biosecurity levy of 0.6 cents per tray for all varieties comes into effect from 6 March 2015. The levy was agreed at the KVH Annual General Meeting held on November 2014.
AgResearch has been carrying out a long-term project investigating the use of bio-herbicide product Sclerotinia sclerotiorum (Sclerotinia) to control pasture weeds including thistles and giant buttercup. But what are the risks to the kiwifruit industry?
Concerns were raised regarding this project to understand what, if any, would be the risks imposed to the kiwifruit industry. Therefore a risk assessment was commissioned to provide background to the Sclerotinia bio-herbicide research programme to date, an understanding of the programme activities and the risks and management of these with respect to disease caused by the fungus in kiwifruit.
The final report concludes the risk of Sclerotinia as a bio-herbicide, creating off-target increased risk of Sclerotinia infection in nearby kiwifruit orchards, is very low.