Division 1 F1
United Kingdom
The previous cropping of the field shall not have been incompatible with the production of seed of the species and variety of the crop, and the field shall be sufficiently free from such plants which are volunteers from previous cropping.
In the case of hybrids of Brassica napus , the crop shall be raised in a production ground where five years have elapsed since plants of Brassicaceae ( Cruciferae ) were last grown.