Effects and Adjustments of Competition Bias in Progeny Trials with Single-Tree Plots

Washington D.C.

1989

S. 532-547

7 Abb., 1 Tab., 46 Lit. Ang.

Bandaufführung

16236

A competition model based on the height difference between a subject tree and its neighbours was used to adjust annual growth data (age 1-5) in a close-spaced single tree plot of 25 open-pollinated Pinus banksiana progenies. Competition effects in tree height, basal area, and volume growth were estimated within each of eight classes of dominant suppression. This procedure allowed a differential adjustment of family performances in their large plot expectations. It is limited to the absence of competition effects on height growth. Response to competition was the same in all families. Variance components and heritability estimates of basal area and stem volume were inordinately inflated by competition.