The genus prunus contains economically important species such as cherry and peach, all of which are vulnerable to pseudomonas infection

The Department of Agriculture National Institute of Food and Agriculture awarded Washington State University $5.853 million on August 1, 2026, under the Specialty Crop Research Initiative (Assistance Listing 10.309) to develop management strategies for bacterial canker disease and blossom blast disease in stone fruits, which have caused severe economic losses to growers worldwide since the 1900s and for which copper-resistant pathogens now render traditional control methods ineffective.

The project, which runs through July 31, 2030, assembles a multidisciplinary team from six states to execute six interconnected objectives: identifying the pathogen complex and developing machine-learning tools for pathogen prediction while establishing isolate panels for resistance screening; determining molecular mechanisms of pathogenesis; understanding host genetics of resistance and susceptibility; evaluating chemical and biocontrol agent efficacy and tree physiology; measuring economic costs and benefits of best management practices; and developing a comprehensive nationwide extension and outreach program to disseminate science-based management deliverables. The work is performed in Pullman, Washington. The Specialty Crop Research Initiative supports research and extension addressing key challenges of national, regional, and multi-state importance in sustaining specialty crop industries, with project periods not to exceed five years.

Bacterial canker disease (BCD) has remained one of the most important diseases of stone fruit trees since 1900S and outbreaks of the disease lead to severe economic losses to growers worldwide. BCD and blossom blast disease (BBD) of stone fruits are two main phases of the disease. However, the exact taxonomic identity of the pathogens, which is a species complex, remain unclear. Due to widespread copper resistance in the pathogens, no viable management tools are currently available. The long-term goal of this project is to comprehensively understand the pathogen/disease/host interactions to minimize the impact of BCD/BBD on stone fruit production and to provide viable management strategies for growers to improve productivity and increase profitability. Specifically, a multidisciplinary team from six states will work together in a transdisciplinary way on six interconnected objectives, to 1) unveil the pathogen complex, develop a machine-learning tool for pathogen prediction, and establish a panel of isolates for resistance screening; 2) determine the molecular mechanism of pathogenesis; 3) understand the genetics of resistance and susceptibility of hosts; 4) evaluate the efficacy of chemicals and biocontrol agents as well as tree physiology and make recommendations; 5) measure the economic costs and benefits of the best management practices; and 6) develop a comprehensive nationwide program to disseminate practical science-based extension and outreach deliverables. Ultimately, this will lead to novel control strategies and minimize the impact of the disease.