Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Pitch canker disease
Scion is the leading provider of forest-related knowledge in New Zealand
Formerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. The information presented below arises from these research activities.
From Forest Health News No. 37, December 1994.
There has been a lot of interest in (and a good deal of uninformed comment on) pitch canker recently. This brief note provides information on what is known about the disease and what we are and have been doing to prevent its introduction in to New Zealand.
The Disease
Pitch canker is considered to be endemic in south-eastern United States and has caused damage in plantations of Pinus elliottii and P. taeda in that region. It was first recorded on P. radiata in California in 1986. The disease is now widespread in the Ano Nuevo - Monterey area south of San Francisco and isolated occurrences have been recorded as far south as San Diego. The disease is characterised by copious resin exudation from shoots, branches and stems of infected trees. Needles on infected branches are killed and crown dieback occurs when the disease is well advanced.
The Causal Organism
Originally, the fungus that causes pitch canker was known as Fusarium lateritium . It was later reduced in rank to a mere variety and was called Fusarium moniliforme var. subglutinans . In 1983, its specific rank was restored and it became Fusarium subglutinans . Recently, in 1991, it was proposed that as not all isolates of F. subglutinans are pathogenic to pines, the pine pathogens should be regarded as a distinct sub-population within the species and be called F. subglutinans f. sp. pini (f. sp. = forma specialis). In the literature on pitch canker, both names, F. subglutinans and F. subglutinans f. sp. pini, are to be found. Both refer to the same organism.
Hosts
Many species of Pinus, including P. contorta, P. ponderosa and P. radiata; Pseudotsuga menziesii.
Disease Transmission
F. subglutinans is known to be seed-bome. It may also be transmitted by insects, principally bark beetles and beetles which feed in cones.
Quarantine Implications and Action
Pitch canker could reach New Zealand either on live plants or in seed. No imports of live plants of Pinus spp. or of Douglas fir from North America are permitted. Since 1986 seed of Pinus spp. cannot be imported from Canada, USA or Mexico without a prior permit to import from MAF and one of the conditions for entry is that the seed must be sent directly to FRI to be tested for the presence of Fusarium . We asked MAF in 1986 for this condition to be imposed (and they agreed) when pitch canker was detected in California and there was good evidence that the disease could be transmitted by seed.
(Peter Gadgil)
This information is intended for general interest only. It is not intended to be a substitute for specific specialist advice on any matter and should not be relied on for that purpose. Scion will not be liable for any direct, indirect, incidental, special, consequential or exemplary damages, loss of profits, or any other intangible losses that result from using the information provided on this site.
(Scion is the trading name of the New Zealand Forest Research Institute Limited.)
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