Recent spread and potential pathways for fire blight in South Korea

Abstract In 2020, 744 orchards in South Korea were reported to be infected by fire blight ( Erwinia amylovora (Burrill) Winslow et al.). The Animal and Plant Quarantine Agency, South Korea, immediately conducted a surveillance study involving 350 orchards to determine the source of the outbreaks, and the extent of its spread and pathway(s). A delimiting survey and sampling surveys were carried out to gather and analyse data during 2020. The attempts to trace the source of the diseased plants revealed a possible pathway. Infected apple trees could have been transported to previously pest‐free regions such as Gwangju and Yangju of Gyeonggido via the purchase of infected materials, e.g. from a domestic nursery. Once established, the disease could readily spread by natural means such as insects and wind into flowers, shoots and growing tips on adjacent trees. This is the likely pathway for entry of fire blight in the new region. Contaminated pruning tools may be another pathway for long‐distance dispersal of this pathogen within South Korea based on data collected through this survey.