Pine needle diseases NZ

Last updated: 2 September 2026

Blight in Radiata pine

Blight is a type of plant disease commonly caused by fungi. There are different sorts of fungi that can cause blight, including mildews, rusts and smuts.

If your pine trees look like they may be suffering from blight, check the table to narrow down the likely cause.

	Cyclaneusma needle cast	Physiological needle blight	Red needle cast	Dothistroma needle blight
When	September to November	June to November	April to October	All year
Tree age	6 to 20 years	15 years +	Usually 3 years +	Planting to 15 years
Spread	No pattern Very severe	Small area affected More than 50% of trees within the affected area	Small to medium-sized area affected Almost all trees within affected area	Widespread Almost all trees within affected area Wide variation between trees
Needles	Yellow Gold Brown	Brown Red-brown Grey Olive (with or without black bands)	Yellow Red Olive (with or without black bands)	Brown Grey Red bands with black spots
Wilt	None	Only at later stages	None	Slight
Retention	Needles detach easily	Needles are retained	Needles detach easily	Needles are retained but die
Cambium & bark	No damage No lesions No resin	No damage No lesions No resin	No damage No lesions Some resin blobs may appear at base of affected trees	No damage No lesions No resin

When

Cyclaneusma needle cast

September to November

Physiological needle blight

June to November

Red needle cast

April to October

Dothistroma needle blight

All year

Tree age

Cyclaneusma needle cast

6 to 20 years

Physiological needle blight

15 years +

Red needle cast

Usually 3 years +

Dothistroma needle blight

Planting to 15 years

Spread

Cyclaneusma needle cast

No pattern

Very severe

Physiological needle blight

Small area affected

More than 50% of trees within the affected area

Red needle cast

Small to medium-sized area affected

Almost all trees within affected area

Dothistroma needle blight

Widespread

Almost all trees within affected area

Wide variation between trees

Needles

Cyclaneusma needle cast

Yellow

Gold

Brown

Physiological needle blight

Brown

Red-brown

Grey

Olive (with or without black bands)

Red needle cast

Yellow

Red

Olive (with or without black bands)

Dothistroma needle blight

Brown

Grey

Red bands with black spots

Wilt

Cyclaneusma needle cast

None

Physiological needle blight

Only at later stages

Red needle cast

None

Dothistroma needle blight

Slight

Retention

Cyclaneusma needle cast

Needles detach easily

Physiological needle blight

Needles are retained

Red needle cast

Needles detach easily

Dothistroma needle blight

Needles are retained but die

Cambium & bark

Cyclaneusma needle cast

No damage

No lesions

No resin

Physiological needle blight

No damage

No lesions

No resin

Red needle cast

No damage

No lesions

Some resin blobs may appear at base of affected trees

Dothistroma needle blight

No damage

No lesions

No resin

Detailed disease descriptions

The 4 main diseases differ from each other in a number of small but important ways.

Symptoms

Needles:

turn mottled yellow then brown
often develop transverse (horizontal) bands during the later stages of disease development
remain rigid and are very easily removed from branches.

After the needles are cast, the tree crown appears very thin.

Other identifying factors

The entire tree crown may be affected.
Disease is not uniform in a stand unless the trees are genetically identical – affected trees are scattered amongst unaffected trees.
Symptoms start September or October, with a second (usually less severe) cast occurring around April.
Trees aged between 6 and 20 years are most affected.

Spread

CNC is abundant in the Waikato and Taranaki regions and very common in Northland and on the east coasts of both the North and South islands.

It is uncommon in Otago and the greater Wellington-Wairarapa region.

No areas in New Zealand are known to be free of CNC.

Treatment

No treatment is believed to be economically viable.

Farm Forestry New Zealand has more information on the diagnostic features, including pictures, and disease location.

Cyclaneusma needle cast – Farm Forestry New Zealand

Symptoms

Needle colouring:

In the initial stages, needles have distinct olive or olive-with-black resinous bands.
In later stages, needles turn red-brown.
After one year, needles turn grey.

Needles droop and wilt and are not easily removed from branches.

Other identifying factors

Symptoms develop on foliage that flushed in the previous year.
The entire tree crown may be affected.
On affected branches, nearly all foliage shows symptoms.
Symptoms start between May and November.
Trees older than 14 years are most affected.

Spread

PNB is abundant in parts of the Waikato region and very common in Northland and on the east coast of the North Island.

It is uncommon in the greater Auckland region, Taranaki, the greater Wellington-Wairarapa region and all but the west coast of the South Island.

PNB is known to be absent in the areas surrounding the Abel Tasman National Park.

Treatment

Phosphite spray may be effective in treating PNB. Research is still being done to work out how much phosphite should be used and how frequently it should be applied.

Scion does not recommend spraying affected trees until at least 35% of the tree's leaves show signs of infection. This percentage can vary – more valuable trees should, in general, be treated more promptly.

Farm Forestry New Zealand has more information on the diagnostic features, including pictures, and disease location.

Physiological needle blight – Farm Forestry New Zealand

Symptoms

Needle colouring:

In initial stages, needles have distinct olive or olive-with-black resinous bands.
In later stages, needles turn yellow then red-brown.

Needles remain rigid but are easily removed from branches.

Other identifying factors

The entire tree crown may be affected.
Symptoms may start anytime between March and September but are rare during summer.
Peak disease occurs from July to September, depending on the region.
Needles are cast or blown off the branch within a few months of symptoms. After the needles are cast, the tree crown appears very thin.
Affects trees of all ages.

Spread

Red needle cast is abundant in parts of the Waikato, Central Plateau and Gisborne regions and is very common in Northland, the upper South Island and the Bay of Plenty.

It is uncommon in the greater Auckland region, Taranaki, the greater Wellington-Wairarapa region, Hawke's Bay and the area surrounding Abel Tasman National Park.

Treatment

Research by Scion shows copper fungicides may be effective in treating RNC. These fungicides are also used to control Dothistroma needle blight (DNB). The research is based on applying copper fungicide at the DNB rate.

Research is underway to find out the best timing and efficacy of copper against severe disease. Aligned research is also underway to find ways to forecast and measure how much disease affects tree growth. This will help with analysing the costs and benefits of disease control operations.

The Dothistroma Control Committee can help with options to treat DNB or RNC.

Dothistroma Control Committee – Farm Forestry New Zealand

Symptoms

Needles:

turn red-brown – there is a clear distinction between the red zone and the remainder of the needle
remain rigid, and are not easily removed from branch
remain on the tree after they have died.

The lower half of the crown is usually affected. In severe cases, the entire crown can turn red-brown.

Other identifying factors

Symptoms start on the flush of needles around December or January.
Disease development continues through to winter – when it slows but does not stop.
Peak disease occurs about September.
Affects pines from planting age up to about 15 years.

Spread

Dothistroma needle blight is abundant in parts of the Waikato and Central Plateau regions and is very common in the Bay of Plenty and upper South Island.

It is uncommon the greater Auckland region, Taranaki, the greater Wellington-Wairarapa region, Hawke's Bay and the area surrounding Abel Tasman National Park.

No areas in New Zealand are known to be free of DNB.

Treatment

Copper fungicides are effective at treating DNB.

Plan your copper fungicides spraying for early summer for any trees with less than 15% of the crown affected (at the time of assessment during winter).

The Dothistroma Control Committee can help with options to treat DNB or red needle cast.

Dothistroma Control Committee – Farm Forestry New Zealand

Farm Forestry New Zealand has further information on DNB, including pictures and links to the latest research.

Dothistroma needle-blight – Farm Forestry New Zealand

Identifying diseases

If you're unsure what may be affecting your forest, Farm Forestry New Zealand has a step-by-step identification guide that may help.

Key to identifying needle diseases in radiata pine – Farm Forestry New Zealand

Scion's field guide has more information including identification, how to estimate the amount of current infection in a tree crown and the number of trees that should be assessed in a stand during inspections.

Field assessment, control and identification of common foliage diseases of pine in New Zealand – Scion

Top

Te mārama ki te ahungahere Understanding forestry

Whakamaheretia tō ngahere Plan your forest

Whakatōngia, whakatipuria Plant and grow

Te tiaki me te tope Care and harvest

Te mārama ki te ahungahere Understanding forestry

Whakamaheretia tō ngahere Plan your forest

Whakatōngia, whakatipuria Plant and grow

Te tiaki me te tope Care and harvest

Ngā rauemi me ngā māramatanga Resources and insights

Blight in Radiata pine

Detailed disease descriptions

Symptoms

Other identifying factors

Spread

Treatment

Symptoms

Other identifying factors

Spread

Treatment

Symptoms

Other identifying factors

Spread

Treatment

Symptoms

Other identifying factors

Spread

Treatment

Identifying diseases