7.—(1) No person may market any seed potatoes other than pre-basic seed potatoes of grade PBTC unless the tubers have a minimum size such that they do not pass through a square mesh of 25 millimetres x 25 millimetres.
(2) No person may market any seed potatoes in a lot in which the maximum variation in size between tubers is such that the difference between the lower size limit and the upper size limit exceeds 25 millimetres.
(3) The requirements of paragraph (2) are to be treated as being met provided that no more than 3% of the total weight of tubers in the lot consist of—
(a)tubers which are smaller than the lower size limit; or
(b)tubers which are larger than the upper size limit.
(4) Where the size of seed potatoes is required to be stated in accordance with these Regulations, the following must be stated—
(a)where the lower size limit and the upper size limit are the same, the dimensions of the square mesh through which the tubers do not pass;
(b)where they are not the same, the lower size limit and the upper size limit.
(5) For the purposes of paragraph (4), dimensions of more than 35 millimetres must be stated to the nearest 5 millimetres.
(6) For the purposes of this regulation—
(a)“the lower size limit” means the dimensions of the largest square mesh through which the smallest tuber does not pass;
(b)“the upper size limit” means the dimensions of the largest square mesh through which the largest tuber does not pass.