Table II. Parameter estimates of the nonlinear regression analysis (the logistic 3-parameter model) of herbicide rates causing 50% plant mortality (LD50) or growth reduction (GR50) for glyphosate-susceptible (S), EPSPS wild-type, and homozygous P106S and TIPS EPSPS E. indica mutants.
se is in parentheses.
| Genotype | a | b | X0 g ha−1 | P Value for X0 | Ratio to S of X0 |
|---|---|---|---|---|---|
| LD50 | |||||
| S | 99.7 (0.22) | 8.71 (1.61) | 142 (1.3) | <0.0001 | 1 |
| Wild type | 99.7 (0.22) | 8.71 (1.61) | 142 (1.3) | <0.0001 | 1 |
| P106S | 101 (1.78) | 3.14 (0.78) | 798 (29) | <0.0001 | 5.6 |
| TIPS | >25,900 | >182 | |||
| GR50 | |||||
| S | 98.3 (8.42) | 1.65 (0.43) | 65 (8.0) | 0.0013 | 1 |
| Wild type | 97.8 (6.12) | 1.98 (0.37) | 57 (10.8) | 0.0063 | 0.88 |
| P106S | 100 (1.96) | 1.76 (0.12) | 173 (7.3) | <0.0001 | 2.67 |
| TIPS | 99.8 (3.87) | 0.85 (0.08) | 2,023 (299) | 0.0005 | 31.1 |