sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ ORMAN FAKÜLTESİ DERGİSİ
branch stubs on each whorl were treated as controls and were not inoculated. After
6 months, eight of the trial trees were showing very slight canker development
from inoculated sites. Following 12 months stem depressions were recorded above
17 of the 123 inoculated branch collars. This trial is ongoing and isolations will be
made from trees felled after 18-24 months to determine whether N. fuckeliana had
infected the stem and how far it has spread.
5. DISCUSSION AND FUTHER RESEARCH
The inoculation experiments described in this paper have given some insight
into the potential infection mechanisms for N. fuckeliana in P. radiata in New
Zealand. In the first trial, infection and symptom development was clearly
demonstrated using both ascospores and conidia from the Acremonium stage. This
indicates that spores from both these lifestages could potentially play a role in
infection of this pathogen. In New Zealand however, although the Acremonium
stage is produced in culture, it is rarely observed in the field. In contrast, perithecia
producing ascospores of the teleomorph are frequently observed in the field and,
due to their abundance, are much more likely to play a role in dispersal and
infection of the pathogen.
While both deep and shallow stem wounds in the first trial resulted in successful
infection of N. fuckeliana and development of some stem depressions, it is unlikely
that these infection mechanisms play an important role in infection in the field.
Few wounds are found on P. radiata in plantations. Thus wounding is unlikely to
play a role as a primary infection court for N. fuckeliana.
Although no N. fuckeliana was isolated from inside the stems in the branch
crotch trial this does not rule out branch crotches as an infection court for this
pathogen. During the experiment, it was very difficult to simulate the effect of
snow weight on branches, particularly any repetitive opening and closing of the
branch crotch associated with branch movement. As a result, the experimental
conditions may not have been sufficient to allow penetration of spores into the
stem. Further trials of this nature are planned.
6. REFERENCES
Bulman, L.S., 2007. Nectria pruning trial. Forest Health News 179,1-2. Available from
http://www.ensisjv.com/NewsEventsandPublications/Newsletters/ForestHealthNews/Fore
stHealthNewsArchive/tabid/179/Default.aspx [accessed 6 March 2009].
Dick, M.A. and Crane, P.E., 2009. Neonectria fuckeliana is pathogenic to Pinus radiata in New
Zealand. Australasian Plant Disease Notes 4, 12-14.
Gadgil, P.D., Dick, M.A. and Dobbie, K., 2003. Fungi Silvicolae Novazelandiae: 4. New Zealand
Journal of Forestry Science 33, 265-272.
NZFOA (New Zealand Forest Owners Association). 2009. New Zealand Forest Industry Facts and
Figures 2008/2009 booklet. Available from www.nzfoa.org.nz. [accessed 5 June 2009].
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