Identifying myrtle rust

by Ann van Engelen

Biosecurity New Zealand and the Department of Conservation have launched an online training programme to help New Zealanders identify suspected myrtle rust infections in their backyards.

The plant fungus can be hard to identify without training and can look different during seasonal changes. The new online training modules provide resources to understand the fungus and its symptoms better.

“The courses are available to everyone and cover how it spreads, what to do if you find it and climatic factors that influence myrtle rust,” says Biosecurity New Zealand’s manager for recovery and pest management, John Sanson.

“We are trying to understand the spread of the disease so are asking staff and the public to keep an eye out for myrtle rust over the autumn months.”

New Zealand’s precious native myrtle plants including pohutukawa, rata, manuka, kanuka and ramarama are vulnerable to the disease. The fungus, which is mainly spread by wind, generally infects shoots, buds and young leaves of myrtle plants. Infected plants show typical symptoms including bright yellow powdery spots on the underside of leaves but can also show other symptoms such as grey powdery spots during the cooler months.

DOC and Biosecurity New Zealand have developed a new website as a central place to house resources and information — myrtlerust.org.nz.

If you think you see symptoms of myrtle rust, especially in areas where it has not yet been found, remember to not touch the plant or collect samples, but take pictures and report it to Biosecurity New Zealand’s Exotic Pest and Disease Hotline on 0800 80 99 66.