sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ ORMAN FAKÜLTESİ DERGİSİ
were rain splashed and disseminated on lower shoots, killing the residual trees the
following year.
Planting stock for this plantation was produced in the Wooddale provincial tree
nursery in central Newfoundland. This plantation and several others in the forest
management district were established in 1989 using the same red pine planting
stock. An inspection in the fall of 2007 of the other plantations showed no other
signs of infection, ruling out infected planting stock as the source of the disease.
Geographic isolation of this plantation, surrounded primarily by bog and scrub
forest with no pine content, has all but ruled out natural spread of the disease from
the Avalon Peninsula. Forestry personnel from the Bay D'Espoir office commented
that locations along the road through the plantation were common camp sites for
moose hunters from the Avalon Peninsula in the late 1980's early 1990's. Two tall
communication towers along the road to the plantation were easy landmarks for
hunters to locate the campsites. It is suspected that hunting groups from the Avalon
Peninsula brought their own kindling and firewood with them, which would have
been readily available from recently killed red pine in the infected Conception Bay
plantations.
5. DISCUSSION
After 15 years of observations on the development of a Scleroderris canker
epidemic, EU race, in 50 red pine plantations located in Quebec, we can sum up the
results into three steps:
1- There is a build up of inoculum in a centre of infection.
2- Followed by a spread of infection on lower branches in the snow over a large
area.
3- Finally, under conducive climatic conditions, conidia of G. abietina produced
on lower branches will spread the disease higher in the crown of trees.
In south-central Newfoundland, we observed a different pattern. The epidemic
started in a centre of infection and killed the trees in that centre relatively rapidly.
The large number of infected shoots in the crown of dead and dying trees produced
a large amount of inoculum in the upper part of trees. The strong wind prevailing in
that region, with rain and snow had spread the disease to the top of surrounding
trees, causing their death in less than 2 to 3 years. The disease became so
widespread that nothing could be done to save the plantation. Because of the
climatic conditions favourable to the disease in that region, the other red pine
plantations should be pruned to prevent any build up of inoculum in the eventuality
of an introduction of G. abietina.
From the historical reports, seedlings of pine were imported into the Island of
Newfoundland from Ontario, Canada. It is difficult to conclude that the
introduction of the disease came with this nursery stock: the European race was not
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