PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Radiata Pine needle blight in Chile
NEEDLE BLIGHT IN CHILE
Field Identification Guide for Daño Foliar del Pino (DFP) PDF, Lindsay Bulman and Rebecca Ganley
Forest Biosecurity and Protection, Scion, December 2007
Report on visit to Chile to examine Daño Foliar del Pino (DFP) PDF- October 2007
Lindsay Bulman and Rebecca Ganley (June 2009)
From Forest Health News 179, December 2007
(For more photos of DFP click here)
In mid-October 2007, Lindsay Bulman and Rebecca Ganley
visited Chile to look at unusual symptoms on Pinus radiata foliage.
The visit was funded by the Forest Biosecurity Research Council
and the Foundation for Research, Science and Technology. The
symptoms were first noted in 2003 when fewer than 100 ha were
affected. By 2006 symptoms were recorded over approximately
60 000 ha. The problem is named Daño Foliar del Pino (DFP),
meaning damage to pine foliage. Since early 2006 Scion
pathologists have been in contact with Chilean researchers, who
have carried out many studies on possible causes including looking
for abiotic factors such as poor nutrition, solar radiation, ozone,
and soil type, as well as pests and fungal pathogens. In early
October 2007, Mike Wingfield from the Forestry and Agricultural
Biotechnology Institute in South Africa announced that an
undescribed species of Phytophthora had been isolated from
symptomatic material growing in Chile; however, the association
between the disease and Phytophthora or any fungal pathogen has
not been proved. It is likely that DFP is has a complex aetiology,
although interactions between DFP, pathogens, environment, and
host are not yet well understood.
From a distance, affected trees appear similar to those affected
by Cyclaneusma needle-cast. Foliage turns yellow, gold, and then
brown and 1-year-old foliage is affected (Fig. 1). However, the
resemblance ends there. Needles do not detach from branches as
readily as those affected by Cyclaneusma and symptoms often
start with a pale area at the base of the needle, accompanied by
a black band.
Fig. 1–A young stand affected by DFP. Note similarities with Cyclaneusma needle-cast, and the moist conditions
typical of the location. Photo taken October 2007.
Fig. 2- A lesion on a young shoot
Another distinctive feature of DFP is the formation of resin at the
point of connection between the needle fascicle and the branch.
Lesions may form on young succulent tissue (Fig. 2), but tend not
to form on old tissue or on branches of older trees. Sometimes a
brown discoloration can be found in the cambium at the trace of
a symptomatic needle.
In Chile, DFP is most severe on sites prone to prolonged periods
of moisture through low cloud, mist, fog, or rain.
In New Zealand inspectors should be especially vigilant on sites
with similar environments. DFP could well be a problem on such
sites. The Forest Health Reference Laboratory at Scion is routinely
testing all Pinus foliage with suspicious symptoms for Phytophthora
spp. Protocols for testing have been developed and documented.
Molecular diagnostic tests specific for this species of Phytophthora
are unavailable but are currently being developed overseas. Total
DNA extracted from needles displaying DFP symptoms in Chile,
collected during this latest visit and stored at Scion, will be used
to test the reliability of any diagnostic tests developed. We have
also written a field identification guide that has been sent out to forest
health surveillance providers. Copies of this can be accessed at:
http://www.ensisjv.com/NewsEventsandPublications/ Publications/ResearchPublications/ ForestHealthandProtectionBulletins/tabid/314/Default. aspx
Through the visit, not only has our understanding of DFP increased,
but communication with Chilean officials has been enhanced.
Scion and Servicio Agricola y Ganadero (SAG), the Government
Department responsible for protecting Chile’s primary sector, are
developing a Memorandum of Understanding. Scion pathologists
are maintaining close contact with SAG officials and keeping
up-to-date with results of surveys and other research activities
currently under way in Chile.
Lindsay Bulman and Rebecca Ganley
