# Commission Implementing Directive 2014/20/EU of 6 February 2014 determining Union grades of basic and certified seed potatoes, and the conditions and designations applicable to such grades (Text with EEA relevance), Division (2): The conditions for certified seed potatoes of ‘Union grade B’ shall be as follows:

Extent: E+W+S+N.I.

(a) conditions concerning seed potatoes:
(i) the number of plants not breeding true to the variety and the number of plants of a different variety shall, together, not exceed 0,5 %;
(ii) the number of growing plants affected by blackleg shall not exceed 4,0 %;
(iii) in the direct progeny the number of plants with symptoms of virus infection shall not exceed 10,0 %;
(iv) the number of growing plants with mosaic symptoms or symptoms caused by leaf roll virus shall not exceed 6,0 %;
(b) tolerances applicable to lots, as regards the following impurities, blemishes and diseases:
(i) seed potatoes affected by rots, other than ring rot or brown rot, shall not exceed 0,5 % by mass, of which seed potatoes affected by wet rot shall not exceed 0,2 % by mass;
(ii) seed potatoes affected by black scurf over more than 10 % of their surface shall not exceed 5,0 % by mass;
(iii) seed potatoes affected by common scab over more than one third of their surface shall not exceed 5,0 % by mass;
(iv) seed potatoes affected by powdery scab over more than 10 % of their surface shall not exceed 3,0 % by mass;
(v) shrivelled tubers due to excessive dehydration or dehydration caused by silver scurf shall not exceed 1,0 % by mass;
(vi) seed potatoes with external blemishes, including misshapen or damaged tubers, shall not exceed 3,0 % by mass;
(vii) presence of earth and extraneous matter shall not exceed 2,0 % by mass;
(viii) the total percentage of seed potatoes covered by tolerances, as referred to in points (i) to (vi), shall not exceed 8,0 % by mass.

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Source: https://www.legislation.gov.uk/eudr/2014/20/annex/II/division/2 (the official version)
Page: https://openlegislation.uk/eu-directive-2014-20/annex-II/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.