Phase 3 New Biocontrol Strains Against Fire Blight
Author: Sharon L. Doty
Published: 2025
Summary: By tapping into the natural bacterial interactions of the plant microbiome, this project sought to develop biocontrol strains from within plants near apple-growing areas in Washington State. Earlier phases of this project yielded dozens of endophytic bacterial strains with strong inhibitory activity against Erwinia amylovora, the causal agent of fire blight. Phases 2 and 3 of the project included genomic analysis of the strains to eliminate those with potential harmful effects and field trials to test a select few strains for biocontrol of fire blight. The small size of the field trials, variable weather conditions between the years of the trials, and large variations in the infection numbers made it difficult to achieve statistical significance in biocontrol. However, some of the strains did result in infection ranges lower than the untreated controls. With larger trials and earlier inoculation of the trees with the biocontrol strains, a clearer indication of the impact of these Washington State-sourced endophyte strains against fire blight will be achieved.
