** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** BERRY PRODUCTION AND CONSUMPTION IS INCREASING RAPIDLY IN THE U.S., LEADING TO OPPORTUNITIES AND STRAINS ON THE INDUSTRY. THE PILLARS OF BERRY QUALITY ARE COLOR, SIZE, FIRMNESS, SWEETNESS, AND FLAVOR. OF THESE, FLAVOR AND SWEETNESS DRIVE CONSUMER ACCEPTANCE. FLAVOR IS A CHALLENGING PHENOTYPE TO OPTIMIZE BECAUSE OF ITS CHEMICAL COMPLEXITY AND MANY INFLUENCING FACTORS, INCLUDING CROP GENETICS AND HORTICULTURAL PRACTICES. PLANT GROWTH REGULATORS (PGRS) ARE A PROMISING TOOL FOR OPTIMIZING FLAVOR BECAUSE THEY ARE RELATIVELY INEXPENSIVE AND ALREADY ROUTINELY USED BY GROWERS. THE OBJECTIVES OF THIS PROJECT ARE TO 1) MEASURE THE EFFECTS OF 3 PGR TREATMENTS ON STRAWBERRY AND BLUEBERRY VOLATILE CHEMISTRY AND SUGAR AND ANTHOCYANIN CONTENT, 2) ELUCIDATE MECHANISM BY MEASURING THE EFFECT OF PGR TREATMENTS ON FLAVOR VOLATILE GENE EXPRESSION, AND 3) VALIDATE TREATMENT EFFICACY BY MEASURING PGR TREATMENT EFFECTS ON SENSORY ATTRIBUTES AND CONSUMER LIKING. BY TESTING TREATMENTS IN NEW AND LEGACY CULTIVARS IN FLORIDA (SOUTHERN HIGHBUSH) AND MICHIGAN (NORTHERN HIGHBUSH; STRAWBERRY), WE CAN PROVIDE SPECIFIC GUIDANCE TO INFORM PGR TREATMENT SELECTION FOR MOST GROWERS AND BREEDING TARGETS FOR NORTHERN AND SOUTHERN HIGHBUSH. THROUGH EXISTING EXTENSION PROGRAMS, RESEARCH RESULTS WILL BE COMMUNICATED TO BLUEBERRY AND STRAWBERRY STAKEHOLDERS. THE RESULTS OF THIS WORK MAY EXTEND TO OTHER BERRY CROPS, SUCH AS RASPBERRY, BLACKBERRY, AND GRAPE, AND POSITIVE RESULTS WILL LAY THE GROUNDWORK FOR FUTURE PROPOSALS. THIS PROJECT SUPPORTS FOUNDATIONAL KNOWLEDGE OF PLANT PRODUCTS PROGRAM GOALS OF REGULATING THE BIOSYNTHESIS OF PLANT METABOLITES THAT IMPROVE THE QUALITY OF FOOD AND MICRONUTRIENT BIOSYNTHESIS BENEFICIAL TO HUMAN HEALTH.