AbstractThe gram-negative bacterium ‘Candidatus Liberibacter solanacearum’ (Lso) causes potato zebra chip disease and carrot Lso disease, which resembles a physiological disorder, and has raised concern on its impact on carrot production and whether the pathogen can be transmitted via carrot seeds. Here, we evaluated the possibility of carrot seed transmission of the bacterium using grow-out tests and probability analyses. On the basis of the tests, we concluded that transmission is unlikely in practice. Therefore, this finding will help to promote the international trade of carrot seeds.