Table 7.
Log-logistic model parameter estimates, standard errors, dose to 90% biomass reduction (GR90), and resistance ratios (R/S) for each P2 population of waterhempa.
| Population | Herbicide | Progeny | b | e | GR90 | R/S |
|---|---|---|---|---|---|---|
| Stanton | Glyphosate | Unselected | −1.8 ± 0.3 | 101.4 ± 17.8 | 349.0 ± 109.2 | — |
| Air inclusion | −1.1 ± 0.1 | 56.1 ± 7.7 | 412.2 ± 129.1 | 1.2 | ||
| Flat Fan | −0.8 ± 0.1 | 46.6 ± 7.0 | 684.5 ± 262.3 | 2.0 | ||
| 2,4-D | Unselected | −1.2 ± 0.1 | 71.9 ± 6.8 | 468.7 ± 83.5 | — | |
| Air inclusion | −1.1 ± 0.1 | 78.4 ± 7.3 | 578.1 ± 114.4 | 1.2 | ||
| Flat Fan | −1.1 ± 0.1 | 85.5 ± 8.0 | 614.0 ± 116.1 | 1.3 | ||
| Dicamba | Unselected | −1.0 ± 0.1 | 29.9 ± 4.5 | 286.7 ± 63.0 | — | |
| Air inclusion | −1.2 ± 0.2 | 37.4 ± 4.0 | 235.3 ± 46.5 | 0.8 | ||
| Flat Fan | −0.7 ± 0.1 | 33.8 ± 6.0 | 696.4 ± 181.5 | 2.4 | ||
| Thayer | Glyphosate | Unselected | −1.4 ± 0.2 | 81.7 ± 12.5 | 402.8 ± 133.9 | — |
| Air inclusion | −0.8 ± 0.1 | 56.4 ± 9.1 | 984.6 ± 359.4 | 2.4 | ||
| Flat Fan | −1.0 ± 0.1 | 133.3 ± 22.5 | 1326.8 ± 374.3 | 3.3 | ||
| 2,4-D | Unselected | −1.5 ± 0.2 | 78.3 ± 6.4 | 344.4 ± 56.2 | — | |
| Air inclusion | −1.4 ± 0.2 | 156.0 ± 12.0 | 759.8 ± 131.4 | 2.2 | ||
| Flat Fan | −1.3 ± 0.1 | 101.3 ± 8.8 | 584.6 ± 106.2 | 1.7 | ||
| Dicamba | Unselected | −0.8 ± 0.2 | 19.7 ± 5.5 | 294.3 ± 93.2 | — | |
| Air inclusion | −0.8 ± 0.1 | 27.8 ± 5.8 | 432.7 ± 121.5 | 1.5 | ||
| Flat Fan | −0.9 ± 0.1 | 62.6 ± 7.3 | 648.1 ± 147.5 | 2.2 |
ab parameter corresponds to the slope at the inflection point; e parameter corresponds to the inflection point; GR90 corresponds to the effective dose to reduce plant biomass by 90%; resistance ratios (R/S) were calculated as the ratio of the GR90 for each P2 population to the respective P2 unselected population.