An important element of the evaluation of alternatives is the comparison of the efficacy among different alternatives, as well as with the pesticide to be replaced. Deciding on what is “acceptable efficacy” depends on the aim of the use of a pesticide. If efficacy is acceptable, then the use of a plant protection product shows a satisfactory effect in relation to its aim.

The following criteria are often used in assessing acceptable efficacy:

• The alternative pesticide or pest management measure shows results that are significantly superior to those recorded in the untreated control, i.e. that the use of the pesticide or measure is better than no use. The measure should show a consistent, well-defined benefit to the user.
  
  
• If pesticides are compared, the performance of the alternative pesticide compares well with that of a reference product. The general intention is to prevent the use of products that have distinctly lower effectiveness than pesticides that are already available on the market for the same use.
  
  
• Other characteristics of the alternative can have advantages over the pesticide to be replaced. The following characteristics could influence the interpretation of acceptable efficacy:
  • Use over a wider range of growth stages of the crop or use in a wider range of crops, including minor crops
  • Effects against more pest stages
  • Lesser influence of climatic factors or soil type
  • Greater compatibility with cultural practices or other plant protection measures, such as IPM
  • Lower probability of resistance
  • Effects against other pests
  • Fewer undesirable effects (on beneficial organisms, other crops etc.)

Only using a fixed “minimum percentage control” to decide on acceptable efficacy is therefore not recommended. For instance, a biopesticide may result in lower direct mortality of the pest than a chemical pesticide but can have better overall efficacy, and therefore be more satisfactory with respect to the overall aim of the management of the pest.

Furthermore, many pest management measures are taken in combination, as part of an IPM or IVM approach, and should not (only) be assessed individually. It is the efficacy of the overall pest management approach taken that should be compared with the pesticide that needs to be replaced.

Further guidance on the evaluation of efficacy of pesticides in agriculture is available from FAO and from the European and Mediterranean Plant Protection Organization (EPPO)