Treatment | Clam shell area (cm2)a |
| ||||||
1 yr-old | 2 yr-old | 3 yr-old | 4 yr-old | 5 yr-old | ||||
Z. japonica | 0.38 | 1.13 | 1.95 | 3.33 | 3.81 | |||
No Z. japonica | 0.47 | 1.69 | 2.62 | 3.57 | 4.15 | |||
T test significance | 0.001 | 0.04 | 0.006 | 0.1 | 0.1 | |||