Table 2.
Injury to corn roots for Bt corn and non-Bt corn (refuge plants) in fields where refuge plants were collected as part of the sampling transect
| Year | Fielda | Bt root injuryb ± SEM (N) | Non-Bt root injuryb ± SEM (N) |
|---|---|---|---|
| 2015 | PC-2 | 0.046 ± 0.008 (9) | 0.02 ± N/A (1) |
| 2016 | NPC-7 | 0.15 ± 0.05 (7) | 0.08 ± 0.01 (3) |
| PC-7 | 0.05 ± 0.01 (8) | 1.88 ± 0.44 (2) | |
| PC-9 | 0.01 ± 0.003 (9) | 0.1 ± N/A (1) | |
| PC-10 | 0.45 ± 0.13 (9) | 1.7 ± N/A (1) | |
| 2017 | NPC-12 | 0.03 ± 0.009 (8) | 0.02 ± 0.0 (2) |
| NPC-14 | 0.27 ± 0.10 (9) | 1.00 ± N/A (1) | |
| NPC-16 | 0.18 ± 0.14 (8) | 1.03 ± 0.69 (2) | |
| NPC-17 | 0.03 ± 0.005 (8) | 0.04 ± 0.01 (2) | |
| PC-20 | 0.20 ± 0.11 (9) | 0.90 ± N/A (1) | |
| Mean | 0.14 ± 0.04 (84) | 0.68 ± 0.23 (16) |
aPC = problem county field, NPC = non-problem county field. Bt traits present in fields were: Cry3Bb1 single-trait (NPC-7), Cry34/35Ab1 single-trait (NPC-12), Cry34/35Ab1 + Cry3Bb1 (PC-2, PC-7, NPC-14, NPC-16, NPC-17, PC-20), and Cry34/35Ab1 + mCry3A (PC-9, PC-10).
bMean injury was significantly higher for non-Bt plants compared to Bt plants T = 2.59, df = 9, P = 0.03.