Minor and major uses in efficacy context

In the GAP table all uses intended for registration of a plant protection product are listed. A use is generally defined by the relationship between crops and pests, e.g. the use against scab (Venturia inaequalis) in apples.

The multitude of uses is divided in two groups, namely major and minor uses. According to the European and Mediterranean Plant Protection Organization (EPPO) “Minor uses are those uses of plant protection products in which either the crop is considered to be of low economic importance at a national level (minor crop), or the pest is of limited importance on a major crop (minor pest).”
The economic importance (e.g. area harvested, production quantity) of a crop, as well as the occurrence and severity of a pest, differs between EU countries, which is why the definition of a use as major or minor is made on national level.

The availability of plant protection products for each single minor use can have a high economic value for farmers, e.g. growing speciality crops, and can be essential for survival of an agricultural holding. However, the availability of plan protection products authorised for application in minor uses is limited, as their marketing is often not of primary economic importance for plant protection product manufacturers. This is due to the fact that registration costs (including e.g. study and dossier generation, registration fees) for each use are quite high, and for a minor use with low economic potential the authorisation is not profitable given the low quantity of expected sales.

To unburden the decision for registration of a minor use by a plant protection product manufacturer, several actions were taken in the EU, such as the definition of EPPO standards on efficacy for minor uses, e.g. reflecting the reduced number of trials needed to justify the safe and effective application of a plant production product in a minor use. Furthermore, for efficacy and crop safety, EPPO standards allow for extrapolation, offering a multitude of possibilities to extrapolate from data generated in some use to a minor use, either supported by a low number of data generated for the minor use itself or even without minor crop-related data.

The number of fully supportive trials required for a use, as well as the extent of extrapolation possibilities is further depending on the plant protection product in question. In the general EPPO standard on the number of efficacy trials and in the standard for low-risk plant protection products the requirements are defined as follows:

 The number of trials for low-risk plant protection products is generally reduced, especially for major uses, and extrapolation possibilities are extended, due to the fact that even extrapolation from pest and/or crop groups (defined in the extrapolation tables) is accepted.

To compile a comprehensive GAP table, broadening the intended uses with the lowest possible efforts by extrapolation to minor uses and complementing the list of efficacy trials by few studies to support the minor use registration, should therefore be considered at an early stage of the registration planning.