Plant & Food Research initiative develops safe pathway south for new cultivar mitigating Psa risk

Image: Plant & Food Research

Dr Falk Kalamorz is one of the scientists monitoring the vines in the Plant & Food Research quarantine glasshouse on New Zealand’s South Island

A new biosecurity initiative from Plant & Food Research has given South Island kiwifruit growers access to new cultivars, including Zespri RubyRed, for the first time.

When the vine killing disease Pseudomonas syringae pv. actinidae (Psa) arrived in New Zealand in 2010, the movement of kiwifruit plant material was restricted between the North Island, where the outbreak occurred, and the South Island.

While these regulations helped the South Island avoid Psa, they also prevented South Island growers from accessing the new kiwifruit cultivars that have been developed and released to North Island growers, including Zespri’s RubyRed kiwifruit variety - the latest release from the Zespri-Plant & Food Research breeding programme.

In response to this challenge, scientists from Plant & Food Research have worked with industry to develop a safe pathway for kiwifruit plant material to cross the Cook Strait.

This process involves three stages: laboratory-based tissue culture, a quarantine glasshouse facility, and an outdoor containment facility. Over two years the plants are closely monitored, with an expert team at Plant & Food Research’s Lincoln site stress testing the plants in a contained environment to ensure there’s no infection risk.

As a result of this programme, plants from Zespri’s most recently commercialised variety are now in the hands of South Island growers. Plant & Food Research business manager, Yvette Jones, said around 11ha hectares of propagated ‘Zes008’ RubyRed had already been established in the Nelson Tasman region, with growers picking their first crop of the new variety this year.

“It’s so exciting to know these orchardists at the top of the South Island can now be a part of this journey with this new cultivar, it’s an important milestone for the industry. We anticipate this pathway will also be used for other cultivars in the future, such as our pipeline of future green kiwifruit varieties,” said Jones.

As well as unlocking equal opportunity for growers, the pathway for Psa-free material is also supporting science that’s being undertaken at the Kiwifruit Breeding Centre’s South Island facilities in Motueka and Clyde. This work is of particular importance with likely changes in suitable production regions due to climate change.

“We’re thinking a step ahead when it comes to what the future of kiwifruit production could look like in a changing climate. That’s why our kiwifruit breeding programme spans from Kerikeri in the North and Clyde in Central Otago – allowing us to see how crops perform in contrasting environmental conditions,” said Jones.