Insured against myrtle rust
‘‘It is difficult to manage wind-borne fungus. You can't put a wall up.’’
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 has been working with Auckland Council on a seed bank, to ensure viable seeds are available, against any catastrophic event.
DOC’s Herb Christophers said the arrival of the disease has been expected since 2014.
While a nationwide, catastrophic out- break was highly unlikely, the seed bank was just ‘‘health insurance’’.
It had 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.
Auckland Council’s biodiversity manager Rachel Kelleher said the contingency seed collection plan was purely a precautionary exercise.
DOC was collecting seed from DOCadministered conservation land and Auckland Council was picking up this work for council-owned 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 on May 9, meant the cases were still restricted to two sites in Kerikeri.
The myrtle rust incursion response was being led and managed by the Ministry for Primary Industries.
MPI said the rust should not be touched and sightings should be immediately reported to 0800 80 99 66.
Myrtle rust has so far been found at two Northland sites.