Kauri dieback
Peronosporaceae - Phytophthora agathidicida
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What does it look like?

Kauri dieback is a deadly, fungus-like disease that can kill kauri trees of any age.  Spores in the soil infect kauri roots and damage the tissues that carry nutrients within the tree. 

Infected trees show a range of symptoms including yellowing of foliage, loss of leaves, canopy thinning, dead branches and lesions that bleed gum at the base of the trunk.  However, some trees can show symptoms of dieback and even be killed without any gum showing on the trunks.  Nearly all infected kauri die and in the past 10 years, it has killed thousands of kauri in New Zealand.

Kauri dieback disease can infect any kauri tree. Kauri forest grows only in northern New Zealand north of 38°S, which is roughly from Kawhia Harbour in the west (Waikato Region) to the Kaimai Range in the east (Bay of plenty Region).  Kauri forests are scattered throughout Northland with the most well-known locations including Puketi, Waipoua, Trounson, Whangarei Heads and Russell Forest.

Why is it a problem?

Nearly all trees that are infected with kauri dieback disease will die. In a laboratory study on two-year-old seedlings the disease spread through the plants quickly and they all died within about 6 weeks (Horner and Hough 2014).  It produces millions of spores that can be spread in soil or water.

Kauri dieback disease produces millions of spores. Resting spores (oospores) can be found in soil around infected trees and can survive for at least three years, and possibly much longer. Waterborne spores (zoospores) are produced in wet conditions and can move through water films in soil, freshwater streams and ponds.  They do not survive in seawater and have a short life span.

Control Methods

Please contact the Northland Regional Council if you suspect that you may have kauri dieback on your property.

More Information

The Annual Operating Report for the 2015/16 Financial Year from the Kauri Dieback Management Programme highlights the extent of work carried out in 2015/16. To read this report go to:

www.nrc.govt.nz/kauridiebackAR

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