1.Member States shall ensure that pre-basic seed potatoes satisfy the following minimum conditions:
(a)they derive from mother plants which are free from the following harmful organisms: Pectobacterium spp., Dickeya spp., Potato leaf roll virus, Potato virus A, Potato virus M, Potato virus S, Potato virus X, and Potato virus Y;
(b)they are free from symptoms of blackleg;
(c)the number of growing plants not breeding true to the variety and the number of plants of a different variety together, shall not exceed 0,01 %;
(d)in the direct progeny, the number of plants showing symptoms of virus infection shall not exceed 0,5 %;
(e)the number of growing plants with mosaic symptoms or symptoms caused by leaf roll virus shall not exceed 0,1 %;
(f)the maximum number of field generations shall be four.
2.Member States shall provide that pre-basic seed potatoes may be marketed as ‘Union grades PBTC’ and ‘Union grade PB’, in accordance with the conditions set out in the Annex.
3.Compliance with the requirements of paragraph 1(b), (c) and (e) shall be established through official field inspections. In case of doubt, those inspections shall be supplemented by official tests on leaves.
Where methods of micro-propagation are used, compliance with point 1(a) shall be established by official testing, or testing under official supervision, of the mother plant.
Where methods of clonal selection are used, compliance with point 1(a) shall be established by official testing, or testing under official supervision, of the clonal stock.