Evaluation of Biorational and Conventional Spray Applications for the Management of Fire Blight on ‘Gala’ Apple in North Carolina, 2023

Fire blight, caused by the pathogen Erwinia amylovora, is a significant bacterial disease affecting pome fruit production globally. Symptoms include water soaking of floral tissue, blackening of leaf midribs, shoot wilt resembling a shepherd's crook, and at later stages may include lesions and wide-spread necrosis, potentially resulting in tree death. This report evaluates 11 different treatments consisting of individual or combined biorational and conventional treatments in addition to an untreated control group. The trial was conducted on 3-year-old Malus × domestica ‘Gala’ trees on G890 rootstock. Results from this trial provide will inform growers of potential antibiotic alternatives for the management of the blossom blight stage of fire blight disease in apple.