The growth of spruces in Songa seed orchard
1992
Etverk, I. | Kurm, M. (Estonian Scientific Research Institute of Forestry and Nature Conservation, Tartu (Estonia))
In the autumn of 1988 the height, diameter at breast height and crown diameter of 1940 trees belonging to 79 clones at the spruce seed orchard of Viljandi forestry enterprise were measured. The majority of clones (57) is the progeny of the Estonian plus trees. The spruces measured were planted in 1965...1972. So far the height growth of spruces has corresponded td II quality class, but it remarkably differs by the clones. On the basis of variance analysis the influence of the mother tree on the height on an average makes up 17% of the sum of all of the effects. The same is the influence on the crown diameter and that on the diameter at breast height is a little higher (19%). It results in increasing of the influence of mother trees (heredity) with the age of clones, which can reach even more than 50% in 20 years after the planting in the seed orchard. This enables us to evaluate the genetic characteristics of plus trees on the ground of the measurements of ramets. An effect of geographical origin also became apparent
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