Results for all possible pairwise comparisons (Tukey) between all treatment means and for all treatments against the control (Dunnett) were the same, showing significant differences in dry weights and diameter for the extension casing treatment only. Depths of roots from ground surface were measured at 2 distances (33 and 66 cm) from the tree bole center. Compared to control, barrier and extension casing treatment roots were growing at a deeper level.
| Treatment | Root dry weight inside barrier (kg) | Root dry weight outside barrier (kg) | Root diameter outside barrier (cm) | Root depth at 33-cm radius (cm) | Root depth at 66-cm radius (cm) |
|---|---|---|---|---|---|
| Control | 0.308 a* | 0.684 a | 1.87 a | 18.54 a | 18.82 a |
| DeepRoot | 0.389 a | 0.616 a | 1.61 a | 27.15 b | 23.74 b |
| Tree Root Planter | 0.376 a | 0.633 a | 1.69 a | 28.74 b | 23.25 b |
| Extension cabling | 0.067 b | 0.345 b | 1.04 b | 24.46 b | 22.39 b |
| Standard error | 0.047 | 0.065 | 0.121 | 0.796 | 1.012 |
↵* Treatments followed by the same letter are not significant at α = 0.05.