Table 3.
Toxicity threshold summary. Derived effect concentrations (EC10 and EC50 from Fig. 1) and no effect concentrations (NECs from Fig. 2) with 95% confidence intervals for each herbicide, and relative equivalent potencies (ReP). NA indicates values could not be calculated. Concentrations are reported in µg L−1.
| Herbicide | Endpoint | SGR | ΔF/Fm′ | SGR (EC50): ΔF/Fm′ (EC50) |
|---|---|---|---|---|
| Diuron | EC50 | 6.27 (6.02–6.54) | 1.71 (1.63–1.80) | 3.7 |
| EC10 | 1.94 (1.75–2.14) | 0.43 (0.38–0.48) | ||
| NEC | 1.68 (1.53–1.90) | |||
| ReP | 1 | 1 | ||
| Metribuzin | EC50 | 13.4 (12.3–14.5) | 2.95 (2.72–3.18) | 4.6 |
| EC10 | 2.66 (2.21–3.18) | 0.60 (0.50–0.71) | ||
| NEC | 2.21 (1.97–2.82) | |||
| ReP | 0.47 | 0.59 | ||
| Hexazinone | EC50 | 8.50 (7.99–9.06) | 5.85 (5.61–6.09) | 1.5 |
| EC10 | 3.96 (3.40–4.57) | 1.81 (1.63 – 1.99) | ||
| NEC | 4.58 (4.34 – 4.78) | |||
| ReP | 0.71 | 0.29 | ||
| Bromacil | EC50 | 19.3 (17.7–21.0) | 3.56 (3.19 – 3.98) | 5.4 |
| EC10 | 4.89 (4.01–5.91) | 0.59 (0.45–0.75) | ||
| NEC | 5.53 (4.33 – 6.44) | |||
| ReP | 0.33 | 0.47 | ||
| Tebuthiuron | EC50 | 112 (106–119) | 16.0 (15.1–17.0) | 7.0 |
| EC10 | 27.5 (24.2–31.2) | 2.66 (2.31–3.06) | ||
| NEC | 22.7 (20.3–25.2) | |||
| ReP | 0.056 | 0.11 | ||
| Simazine | EC50 | 184 (173–195) | 59.2 (56.7–61.8) | 3.1 |
| EC10 | 38.4 (33.0–44.2) | 9.28 (8.41–10.2) | ||
| NEC | 48.0 (44.0–51.0) | |||
| ReP | 0.034 | 0.029 | ||
| Propazine | EC50 | 188 (177–201) | 39.5 (37.1–42.1) | 4.8 |
| EC10 | 42.0 (37.1–47.3) | 5.85 (4.90–6.91) | ||
| NEC | 27.8 (24.2 – 31.1) | |||
| ReP | 0.033 | 0.043 | ||
| Imazapic | EC50 | 790,000 (760,000–825,000) | >790,000 | NA |
| EC10 | 410,000 (362,000–462,000) | >790,000 | ||
| NEC | 363,000 (341,000–386,000) | |||
| ReP | NA | NA | ||
| Haloxyfop | EC50 | >3,700 | >3,700 | NA |
| EC10 | >3,700 | >3,700 | ||
| NEC | >3,700 | |||
| ReP | NA | NA | ||
| 2,4-D | EC50 | >279,000 | >279,000 | NA |
| EC10 | >279,000 | >279,000 | ||
| NEC | >279,000 | |||
| ReP | NA | NA |