Table 4 European Weed Research Council (EWRC) rating scale is used to score the level of plant injury following herbicide application.
From: Investigating the impacts of airborne dust on herbicide performance on Amaranthus retroflexus
EWRC score | Crop tolerance | Efficacy (weed kill) | Weed control (%) |
|---|---|---|---|
1 | No effect | Complete kill | 100 |
2 | Very slight effects; some stunting and yellowing just visible | Excellent | 99.9–98 |
3 | Slight effects; stunting and yellowing; effects reversible | Very good | 97.9–95 |
4 | Substantial chlorosis and or stunting; most effects probably reversible | Good–acceptable | 94.9–90 |
5 | Strong chlorosis/stunting; thinning of stand | Moderate but not generally acceptable | 89.9–82 |
6 | Increasing severity of damage | Fair | 81.9–70 |
7 | Increasing severity of damage | Poor | 69.9–55 |
8 | Increasing severity of damage | Very poor | 54.9–30 |
9 | Total loss of plants and yield | None | 29.9–0 |
