The clones surviving the first three years of selection are planted at three trial fields. In this way the performance of the clones at different locations can be measured. The next year the clones will be tested at 5 trial fields in the Netherlands and on trial fields in Germany. Besides those trial fields, the clones are also tested at disease trial fields where the clones are tested for resistance to phytophthora, viruses, wartdisease, common scab and other diseases.