sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 65-70
THE EFFECTS OF SIROCOCCUS SHOOT BLIGHT AND VITALITY
FERTILIZATION ON GROWTH OF MATURE NORWAY SPRUCE
Markus HUBER 1 , Erhard HALMSCHLAGER 2* , Hubert STERBA 1
Department of Forest and Soil Science, University of Natural Resources and Applied Life Sciences,
Vienna (BOKU),
1 Institute of Forest Growth and Yield Research, Peter Jordanstraße 82,
A-1190 Vienna, Austria, 2 Institute of Forest Entomology, Forest Pathology and Forest Protection
(IFFF), Hasenauerstraße 38, A-1190 Vienna, Austria
ABSTRACT
* erhard.halmschlager@boku.ac.at
The impact of Sirococcus shoot blight and vitality fertilization on the growth of mature
Norway spruce (Picea abies (L.) Karst.) was studied in a single tree fertilization
experiment, established in autumn 2000. A total of 144 sample trees were selected among
the dominant and co-dominant trees of the 90-year-old Norway spruce stand. Half of the
trees exhibited severe symptoms of Sirococcus shoot blight whereas the other half were
apparently healthy and vigorous. A randomised block design with the factors “slope
section” (lower slope versus upper slope) and “Sirococcus shoot blight” (severely affected
versus healthy trees) was used. Within these blocks sample trees were randomly assigned to
one of the three treatments (dolomitic liming, application of gypsum and kieserite,
unfertilized control). Due to tree mortality caused by bark beetle infestation the
experimental design became unbalanced and therefore final analyses were performed with
the volume growth data of 125 sample trees only. The effects of Sirococcus shoot blight
and fertilization treatments on current annual volume increment were investigated by
analysis of covariance, using the average volume increment of the period 1977–1980 as a
covariate attribute (assuming that tree growth was not yet affected by Sirococcus shoot
blight during this period). Indeed results indicated that Sirococcus shoot blight started in
1981 in the experimental stand and trees with shoot blight symptoms had a significantly
lower increment over the whole period 1981–2006. Sirococcus induced increment reduction
of the nonfertilized trees continuously increased from 7,5 ± 2,9% in 1981 to 37 ± 3,8% by
the year 2000. A significant positive effect of vitality fertilization was only achieved with
the gypsum and kieserite variant from 2002 to 2006. The highest surplus increment was
found in 2004 with 31,6 ± 15,2%, calculated as average over the diseased and healthy
group. However, a mitigation of increment loss caused by Sirococcus shoot blight was
statistically significant only for the year 2003.
Keywords: Sirococcus conigenus, Norway spruce, increment reduction, vitality
fertilization
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