NOVEL FIRE BLIGHT BIOPESTICIDE FIELD TESTING AND EVALUATION

Fire blight disease is one of the most important bacterial diseases affecting apple and pear production in the United States and worldwide. The disease costs US fruit growers about $160 million annually in crop losses and expenditures on management tools, and the disease limits commercial pear production to mainly the western part of the US. Fire blight can be managed quite effectively using antibiotic sprays such as streptomycin or oxytetracycline at bloom time to prevent infection through the flowers. However, this practice is leading to antibiotic resistance development in Erwinia amylovora, the fire blight causal bacterium. There is a need for fire blight management tools that do not rely on antibiotics. This project will help to validate a novel fire blight biopesticide. Previously, we discovered that certain non-pathogenic, auxotrophic strains of E. amylovora can effectively reduce fire blight disease incidence in both apples and pears in Washington and Pennsylvania during two years of orchard tests. In this proposed study, the novel biopesticide will be tested in New York and Michigan using commercial research service provider facilities to allow a larger number of tests to be performed than could be done at academic test sites. These tests will reveal the concentrations of active ingredient and amino acid inactive ingredient needed for optimal activity under natural infection and inoculated plant conditions over two seasons. These results will position the novel biopesticide for development into a commercial product that will provide an effective new fire blight management tool to apple and pear growers.