19b.,Tubers of Solanum tuberosum L. which originate in Poland, other than those mentioned in column 2 of items 16 to 18,Without prejudice to the requirements of items 19 and 19a, the tubers shall be accompanied by a certificate issued by the responsible official body in Poland confirming that they have been found to be free from Clavibacter michiganensis ssp. sepedonicus (Spieckerman and Kotthoff) Davis et al. in official laboratory tests.,