SITKA SPRUCE CLONAL PERFORMANCE WITH SPECIAL REFERENCE TO BASIC DENSITY - 23 YEARS RESULTS OF A CLONAL TRIAL

The results from a 23 year-old Sitka spruce clonal trial are presented . Seven clones and a standard provenance were tested at one site. Sign ificant differences between clones were found for the following charac ters at different ages from setting: height (age 3, 11, 23), diameter (age 11, 23), volume production (age 23), basic density (age 22), pilo dyn (age 22), stem straightness (age 3, 23), form quotient (age 11) an d volume level (age 23). In order to compare the performance of the di fferent clones in basic density, this trait was adjusted for differenc es in ring width using the latter as a covariate. It was shown that it is possible to select clones with both high basic density values and good growth. The coefficient of clonal variation varied within a range from 5 % to 18 % for growth characters and 3 % to 14 % for quality tr aits at age 23 years. Phenotypic correlations were calculated. At age 11, diameter seems to be a better indicator than height for volume pro duction at later stages.