Known issues regarding current version (or previous ones) of WDC.

WDC 2.61:
Regarding ‘fodder grassland’ (DTG crop 2.1), the default setting for the last nozzle position is 0.0 in WDC 2.61. This should be changed manually to -0.25 m. It will be adjusted to a default setting in an update of the WDC.

The justification for this change is as follows. A last nozzle position of 0.0 appeared to be different from what was used in the registration procedure so far. In general, for crops that are not specifically mentioned in the EAD (Environmental Activities Decree) a crop-free zone of 0.50 m is required. However, with grassland which is grown all up to the field edge it is not clear how to define a crop-free zone. In fact, in the EAD a crop-free zone is not defined for fodder grassland. Then, it appears reasonable for grassland to replace the crop-free zone of 0.50 m by a spray-free (untreated) zone of that same width. According to ISO22866 the sprayed (treated) area ranges to half the nozzle distance outside the last nozzle at a sprayer boom. Thus, for conventional boom sprayers with a nozzle distance of 0.50 m, the edge of the treated area is 0.25 m outside the position of the last nozzle. This is the position where the crop-free (or rather spray-free) zone starts. In effect the last nozzle is 0.75 m from the field edge (= top of the bank). This can be achieved in WDC 2.61 by setting the last nozzle position to -0.25 m.