4.—(1) No growing crop certificate may be issued containing a statement that seed potatoes are capable of being marketed as pre-basic seed potatoes of any grade unless the authorised officer is satisfied that the land on which the seed potatoes are growing or were grown—
(a)is land which, as a result of a soil test carried out by the Welsh Ministers prior to the planting of the crop, has been found not to be contaminated with Potato Cyst Nematode (Globodera species infesting potatoes);
(b)is not demarcated under Schedule 15 to the Plant Health (Wales) Order 2006 as infested with a European population of Potato Cyst Nematode; and
(c)has not been used for growing potatoes at any time during the seven years immediately preceding the planting of the crop.
(2) But sub-paragraph (1)(a) does not apply in the case of seed potatoes grown in a soil-free medium.