Myrtle rust disease and kiwifruit

The Ministry for Primary Industries (MPI) has confirmed the presence of the myrtle rust plant disease on mainland New Zealand for the first time, in Kerikeri and Taranaki.

Both finds were reported to MPI by nurseries who we congratulate for being aware of what to look for and calling immediately something unusual was spotted.

This is an example of how important it is to be on the lookout – the sooner unwanted pests and diseases that make their way here are found, the more can be done to manage spread and take appropriate action.

Myrtle rust is a fungal infection that can travel long distances in the wind and attacks plants of the myrtaceae family. It doesn’t affect kiwifruit but could affect iconic New Zealand plants like pohutukawa, kanuka, manuka and rata, as well as commercially-grown species such as eucalyptus, guava and feijoa.

Although myrtle rust doesn’t affect kiwifruit vines this is an important and timely reminder for all growers to look out for symptoms on orchard myrtaceae trees. Look for:

• bright yellow powdery eruptions appearing on the underside of the leaf (young infection)
• bright yellow powdery eruptions on both sides of the leaf (mature infection)
• brown/grey rust pustules (older spores) can appear on older lesions
• leaves may become buckled or twisted and die off.

If you see any of these symptoms call MPI immediately on 0800 80 99 66. Take a photo but don’t touch or take samples as this might increase spread of the disease.

A myrtle rust fact sheet is available on the MPI website and there is also a lot of guidance available on the New Zealand Plant Producers site.