DOSE EXPRESSION FOR VERTICAL CROPS – Leaf Wall Area (LWA) in EPPO Central Zone

From 01/01/2020, it is compulsory for the Central Registration Zone that applications for new products or new uses in vertical crops, such as orchards, grapevine, high growing vegetables, are supported by GEP trials carried out based on LWA as a unit of dose expression. 

For any category of upwards or sideways directed spray application, the applicant needs to propose a dose/10 000m² LWA. The application dossiers for new products (under Article 33) will only be accepted when trials were planned and carried out based on LWA.

The LWA dose rate shall be included in the GAP table.

Why change dose expression from rate/ha to the rate/10000m² LWA ?

The main reason is to harmonize the application rates in high growing crops to achieve the actual needs and make trials comparable even if different cropping systems are used in different trials/countries. A secondary advantage is the reduction of unnecessary emissions of plant protection products to the environment and residues in feed and food.

The best way to achieve this is to adapt the dose to the area where the treatment is needed (e.g. crop canopy) and its structure. (See example)

Example:

If a fixed rate e.g. 2.0 L/ha is applied in all orchards independent of the cropping system, the efficacy of the product will most likely differ between these orchards.

If a fixed rate e.g. 2.0 L/ha is applied in all orchards independent of the cropping system, overdosing might occur in some orchards.

We can expect this to be extended to other zones to harmonize and to better support the exchange of data between countries. Today, the dose expression for vertical crops can differ in different EU Member States as for example, FR: L,kg/ha ground surface,  DE, AT: L,kg/m crown height, dose rate dependant on crop developmental stages (e.g. grapevine), NL: kg/hl and maximum l water/ha ground surface, …

However, for the product application the maximum rate per unit of ground area will still be needed as this is required for other specialist areas to complete their risk assessments.

Our agronomists can provide advice to define the right rate per 10000 m² LWA for each category of crops concerned. Do not hesitate to contact us for further information.

EU Central Zone (according to Regulation (EC) No 1107/2009)