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

• 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