Diameter of pruning cuts, length of barrier zone, and decay column length in longitudinal section behind heading cuts made through 2- to 3-year-old and 4- to 5-year-old wood 4 years after original heading cut. (Means are based on three stems on three trees in each treatment.)
| Pruning treatment | Mean diameter of original heading cut (mm) | Mean length of barrier zone (mm) | Mean decay/discoloration column length (mm) |
|---|---|---|---|
| Headed 2- to 3-year-old wood (pollard) | 18 (0.7 in.) by | 18 (0.7 in.) b | 8 (0.3 in.) b |
| Headed 4- to 5-year-old wood (topped) | 27 (1.1 in.) c | 736 (29.0 in.) c | 58 (2.3 in.) c |
| Not pruned | 0 a | 0 a | 0 a |
z Distance in longitudinal section from heading cut to end of decay or discoloration, whichever is longer.
↵y Means in a column are statistically different at P < 0.01.