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How are GeoPEARL assessments carried out?

• GeoPEARL is run for 250-6405 plots, depending on spatial detail wanted;

• The model is run for the area of potential usage only. This area is assumed equivalent to the area of the crop(s) for which a registration is requested;

• For each plot and crop-type, the model is run for 26, 46 or 66 years (FOCUS procedure);

• For each plot the median leaching concentration in time is extracted and put into a map.

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To be specified by the user:

•Substance properties (start withstandard dossier)

•Application schedule

•Number of plots (i.e. spatial detail wanted)

•One or more crops for which a registration is requested

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Effect of area of use on pesticide authorisation (1)

Maize is grown on slightly acidic sandy soils

Potatoes are grownon light sandy claysoils and in ‘the Veenkolonien’

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Effect of area of use on pesticide authorisation (2)

Substance with pH-dependent sorption behaviour

Light sandy claysoils and ‘the Veenkolonien’

Slightly acidic sandy soils

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The target variable produced by the model:

•The 90th percentile in space and the 50th percentile in time of the leaching concentration at 1 m depth at the area of (potential) usage

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Effect of area of usage on authorisation (cntd.)

Unsafe in potatoes

Safe in maize

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Some conclusions from previous section:

• GeoPEARL explicitly considers the variation of the leaching process, so that it is now possible to evaluate the leaching for different crop types

• Consideration of the area of usage can have a strong effect on the authorisation decision