Distribution of dry matter production in twenty families of Virginia pine (Pinus virginiana)
In the fall of 1963 seed was collected from 20 selected Virginia pine trees. The trees were selected in pairs of well- and poorly-pruned trees. Progeny (half-sib) derived from the 20 parent trees were sampled, at age nine, to determine if differences existed among the 20 families in the distribution of dry matter. Families differed in branch weight and cone weight but not in stem, stem bark, leaf, and total wood weight (stem + bark + branch weights).
Proportionate distributions of stem, branch and stem bark dry weights were significantly different among the 20 families. Differences in proportionate distributions were shown to be independent of tree size but there were significant differences in distributions between progeny from naturally well and poorly pruned parents. Heritability (h²) estimates were calculated for those values which showed significant among family differences.