The present Directive sets out the measures to be taken within the Member States against the organism which is the cause of potato ring rot, in order to: (a) locate it and determine its distribution; (b) prevent its occurrence and spread; and(c) if found, prevent its spread and control it with the aim of eradication. Member States are required to conduct systematic official surveys for the organism on tubers and, where appropriate, on plants of potato (Solanum tuberosum L.) originating in their