Seeds saved in wake of threat
The native-tree harming fungus, myrtle rust, is still confined to Northland, but government agencies are banking seeds - just in case.
Myrtle rust is a serious fungal disease that attacks members of the myrtaceae plant family, which includes native pohutukawa, manuka, kanuka and rata trees.
The first case in New Zealand was discovered earlier in May at a nursery in Kerikeri. The second case, in a neighbouring garden.
Since then, the Department of Conservation had been working with Auckland Council on a seed bank, to ensure viable seeds were available, against any catastrophic event.
DOC’s Herb Christophers said the arrival of the disease had been expected since 2014.
While a nationwide, catastrophic outbreak was highly unlikely, the seed bank was just ‘‘health insurance’’.
It has been travelling on a ‘‘wispy wind belt’’ from South America, to South Africa to Australia to New Zealand, Christophers said.
‘‘It is difficult to manage wind-borne fungus,’’ Christophers said. ’’You can’t put a wall up.
‘‘A second infection is inevitable, and it will be too late to find seeds later on. We just want to be prepared and are taking precautions.’’
Symptoms include bright yellow powdery eruptions on the leaf or brown or grey rust pustules on older lesions. Leaves could buckle, twist and die off.
The fungus threatened native trees, but also common plants like feijoa, eucalypts and bottle brush.
Auckland Council’s biodiversity manager Rachel Kelleher said the contingency seed collection plan was purely a precautionary exercise.
DOC was collecting seed from DOC-administered conservation land and Auckland Council was picking up this work for councilowned land, Kelleher said.
Council staff from biosecurity, regional parks and botanic gardens teams were also assisting.
A false spotting of the disease in a nursery in south Auckland May 10, meant the cases were still restricted to the two sites in Kerikeri.
The myrtle rust incursion response was being led and managed by the Ministry for Primary Industries.
MPI said sightings should be immediately reported to 0800 80 99 66.