Articles
THE EFFECT OF THE CYCLOPHYSIS AND THE TOPOPHYSIS ON THE TOORING AND BEHAVIOR OF NORWAY SPRUCE CUTTINGS
Nevertheless the position on the tree and the age of the tree has great influence as well on the root formation as on the later behavior of the cuttings.
With the aim of mass propagating forest trees we were faced with the problem, that we wanted to select old trees, because it might give a better basis for selection, but from a propagation point of view we had to select young trees to get good enough rooting.
The litterature discribing this problem was limited.
So it was decided to investigate the effect of topophysis and cyclophysis on the rooting and of the later development of Norway Spruce cuttings in the ages in which we would think about selection for mass propagation.
The material consisted of 80 trees from 6 to 21 years.
The total number of cuttings was 12 160. An average increase of 2.5% per whorl from the top to the lower parts, and an average decrease per year of 4% from 7–9 years, 6.3% from 9–13 years and 1.3% from 13 to 21 years was found.
However, a big variation around this general trend was characteristic, and is mainly due to individual variation.
In a nursery experiment the same clones were scored for orthotropic growth.
After 4 years all the cuttings from ortets 6–13 years had changed to orthotropic growth, while the cuttings from ortets 16–20 years still had plagiotropic growth.