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
• 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.
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