Keep What Works Working: NZ's New Resistance Campaign
New Zealand growers have always adapted to changing conditions, but one challenge is steadily gaining ground across the horticulture sector: resistance.
Gold3 was commercialised in 2010 by Zespri after 10 years of development.
It was selected from the extensive Zespri and Plant & Food Research new variety programme for its qualities of high orchard yields, handling characteristics, storage and positive appeal to consumers determined through in-market sensory work over consecutive seasons.
Subsequent to its commercial release, Gold3 has, to date, shown a greater level of tolerance to Psa than the original Zespri Gold variety, Hort16A.
Zespri chief executive, Lain Jager, said the wide-scale release of Gold3 was significant for the New Zealand kiwifruit industry for two reasons.
Firstly, of the 2068ha of Gold3 released, 1610ha will be to Hort16A growers, starting the process of all Hort16A growers eventually transitioning their orchards to a more Psa tolerant Gold cultivar.
Secondly, this will be the largest transition to a new variety in a year that has ever been undertaken by the industry and represents the transition of almost 15% of New Zealand's kiwifruit hectarage to a new variety. The previous largest transition to a new variety was in 2000, with the release of 1200ha of Hort16A to the industry.
"The impact of Psa on the New Zealand kiwifruit industry has been devastating. Almost half of all New Zealand kiwifruit hectares now have some level of infection. With this transition to Gold3 we can see that around 1600ha of Hort16A canopy will be cut out as a result of Psa since November 2010.
"The announcement is a significant turning point for our industry both in terms of beginning to emerge from Psa and in cementing the future growth of the industry," Jager says.
As well as the release of Gold3 to current Hort16A growers, a further 359 Gold3 hectares have been released to non-Hort16A growers, to give them an opportunity to diversify their orchard portfolio and have access to a higher-performing cultivar.
Jager cautioned while the release was a real positive for the industry, there still remained a high level of risk around the Gold3 recovery pathway.
"There are no Psa resistant varieties. This means even with the introduction of a variety with greater Psa tolerance, the learning curve for the industry as to how to best manage orchards in a Psa environment remains steep.
"Mitigating this risk will require the proactive management of orchards and an ongoing commitment to innovation. Managing the threat of Psa must now be considered as business-as-usual for all growers and the wider industry."
Jager says while the presence of Psa would mean a level of ongoing uncertainty for kiwifruit producers, the kiwifruit industry's unified structure coupled with the resilience and determination of New Zealand kiwifruit growers has allowed it to find a way forward in the face of the devastation caused by Psa.
