Potential Gains from Genetically Improved Sitka Spruce

Wrecclesham

1990

5 S.

8 Abb., 2 Tab.

Bandaufführung

4035

55146

End of rotation genetic gains can only be measured when a stand of improved material is felled and compared with an unimproved control. In the absence of such comparative stands, potential gains must be estimated using data from the oldest progeny tests available. Such data suggest that genetic gains obtainable from planting vegetatively propagated improved bulked family mixtures or stock from approved clonal seed orchards should be a minimum of 15% for height at 10 years and also for volume at 27 years. Genetic gains for form should be around 7% at age 10. Gain estimates for timer density are not yet available.