Epidemiology and Management of Fire Blight ( Erwinia amylovora ) in Apple and Pear Orchards

Fire blight, caused by the Gram-negative bacterium Erwinia amylovora , is a destructive disease of economically important crops in the Rosaceae family, particularly commercial apple ( Malus X domestica ) and pear ( Pyrus communis ) cultivars. The pathogen overwinters in cankers and is disseminated to blossoms during bloom by rain, wind, or insects. Blossoms are the primary site of infection, where the pathogen can rapidly multiply and invade host tissues, making blossom protection a critical target for control strategies. Although antibiotics such as streptomycin have been highly effective, their extensive use has led to the emergence of resistant bacteria and raised One Health concerns, leading to bans or severe restrictions in many global regions. As a result, current research has shifted toward developing sustainable management strategies. This case study outlines the distribution, symptoms, and life cycle of E. amylovora and reviews management practices, with particular emphasis on sustainable management practices. Information © His Majesty the King in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada, 2026