Tree Improvement Cycle
Creating a Better Tree
Tree Improvement
• Application of knowledge to produce superior
trees
• Improvement can be made in:
-Trees’ growth rate
-Disease resistance
-Stem, wood and/or fiber
quality
Tree Selection
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Find “good” trees
Collect their seeds or take cuttings
Cross bred them
Test the offspring
Select the best of the offspring
Repeat
Easy?
What is a “good” tree?
Crown: Narrow; Short vs.
height of tree; healthy
Branches: small diameter
Stem: Straight; low taper;
high volume vs. neighbors;
disease and/or insect
resistant; high quality wood
Selection
• Select trees in natural stands based on
physical characteristics; superior growth,
form, reduce disease and/or insect damage.
Collect seeds or take grafts
• To preserve the genetic material, seeds of the
selected tree or twigs are collected to graft on
to root stock.
Test Offspring
• Testing involves growing seedlings of each
parent and comparing them to other selected
seedlings to determine the capability of the
parents to pass on their genetic superiority.
Breeding
• Breeders isolate young flowers of parent trees
so that unwanted pollen can not contaminate
the tree.
Seed Orchard
• Select the best of the offspring to establish a
seed orchard
• Repeat the process
Time
• It takes 6-8 years before one receives useful
results from testing
• About 10 years after a seed orchard is
establish it will produce seed for reforestation