| Cephalosporin concentration (mg/L) | Agrobacterium re-infection days (d) | Induction rate (%) |
| 0 | 4 | 100% |
| 150 | 9 | 100 |
| 250 | 16 | 100 |
| 350 | 39 | 100 |
| 500 | 50 | 80 |