| Siberian elm | Silver maple | ||
| Stem height | Stem diameter | Stem height | Stem diameter |
SAP | 0.000*** | 0.883 | 0.000*** | 0.778 |
Watering frequency | 0.004** | 0.848 | 0.000*** | 0.001** |
SAP × watering frequency | 0.000*** | 0.818 | 0.006** | 0.279 |