Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** fire blight, caused by the…

Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** fire blight, caused by the bacterium erwinia amylovora, is top on the list of the most concerned diseases of apple and pear by organic growers. Among all organic approved control measures of fire blight, blossom protect, a biological control with a yeast-like fungus aureobasidium pullulans as the active ingredient, is the most effective and widely used material. Integrated disease management protocols centered around blossom protect have been developed and widely adopted by organic growers in the pacific northwest. However, applying blossom protect under humid conditions can cause of fruit russeting, a disorder of fruit skin that reduce the value of fresh market crops, therefore cannot be adopted by growers in the east. We hypothesize that there are other yeasts from apple and pear flowers that can effectively suppress fire blight similar to a. Pullulans in blossom protect, without causing significant russeting. Prior to this research, we determined that a. Pullulans in blossom protectinduces plant defense response which is the mechanism for its disease suppression. In this project, we aim to perform an extensive search of flower/fruit colonizing yeasts for their ability to 1. Induce plant defense, 2. Suppress fire blight, and 3. Cause russeting. Isolates with desirable fire blight suppression efficacy with minimal russeting will be selected for a multi-year, multi-location field trial. Extension and education activities include disseminating research findings to growers, educating fruit consumers about the cause of fruit russeting and other skin disorders, and training the next generation organic growers in the northeast through undergraduate education.