Effect of mulch application over the root ball on bending stress to tilt elm and maple trunks five yearsz after planting in the landscape.
| Elm | |||
|---|---|---|---|
| Mulch 7 cm deep over root ball | Bending stress to 5 degrees trunk tilt 5 years after planting (MN/m2) | Bending stress to 10 degrees trunk tilt 5 years after planting (MN/m2) | Bending stress to 15 degrees trunk tilt 5 years after planting (MN/m2) |
| Yes | 25.9 ay | 31.6 a | 33.4 a |
| No | 23.3 b | 27.9 b | 29.5 b |
| Maple | |||
| Mulch 7 cm deep over root ball | Bending stress to 5 degrees trunk tilt 5 years after planting (MN/m2) | ||
| Yes | 15.5 a | ||
| No | 13.4 b | ||
↵z Bending stress not affected (P > 0.05) years 3 and 4.
↵y Means followed by a different letter within columns are statistically different at P < 0.03; n = 20, averaged over nursery planting depth and root pruning due to insignificant interactions of these two factors with mulch (P > 0.07, elm; and P > 0.22, maple).