How is it measured
- Straightness is assessed visually on a 1 (good) to 6 (poor) subjective score and treatment means are compared to the mean for the QCI control
What does it mean
- This means a low score is better and infers more straight trees. If the QCI control scores 3.5 and a selected family scores 2.75, the selected family is said to be 22% better than the QCI control; a family with a mean score of 4.00 has a straightness -14% compared to QCI.
- Published data are weighted by genetic repeatability and across-site performance.
- Stem straightness has a neutral correlation with most other traits so fast growing straight trees with fine branches are relatively easy to find.