The efficacy of plant protection products will be thoroughly evaluated in the authorization process, in addition to the other assessment areas (e.g. ecotoxicology, environmental behavior, residual behavior, and toxicology).
As a matter of principle, plant protection products can only be authorized if an appropriate effect has been demonstrated for the intended use. The level of control should typically achieve the level of already approved products for the same use. However, under certain conditions, also lower levels of effectiveness may be accepted:
- Extended application window compared to other plant protection products
- Effectiveness against further developmental stages of the target
- Decreased dependence of effectiveness on climatic factors
- Better compatibility with other phytosanitary measures
- Additional effects on other pathogens
- Reduced adverse effects on beneficial organisms or subsequent crops
- Advantageous features regarding resistance and anti-resistance strategy
Consequently, the term ‘moderate control’ has already been used as a label claim. To encounter current developments – in particular concerning plant protection products based on low-risk active substances – a new category of effectiveness is now being introduced: ‘Some control only’.
The following table depicts guidance for the appropriate label classification. The values may vary depending on the mode of action, the crop and the respective target.
Critical levels of effectiveness:
| Recommended value Efficiency | Restriction of the indication |
| above 80 % | None |
| 60 % | moderate control |
| below 60 % | some control only |
With the label claim ‘some control only’, the following warning will be displayed: The instructions for use is to include comprehensive information about the conditions necessary to achieve an appropriate level of effectiveness.
If required, certain application restraints resp. conditions will be pointed out below “Further conditions of authorization”.
If an approval lacks an efficacy assessment, as it is common for minor uses (Art. 51) and emergency authorizations (Art. 53), the subsequent warning has to be noted: The user is wholly responsible for any damage due to the lack of efficacy or damage to crops. For such uses, it is up to the user to assess selectivity and efficacy under their specific conditions of use.