**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** POOR RED SKIN COLORATION AND CONTAMINATION FROM LISTERIA MONOCYTOGENES ARE MAJOR STAKEHOLDER-IDENTIFIED FACTORS LIMITING PRODUCTION AND MARKETABILITY OF HIGHLY PROFITABLE APPLE VARIETY, 'HONEYCRISP' IN THE MID-ATLANTIC. TO INCREASE SKIN COLORATION, GROWERS DELAY HARVEST UNTIL THE COLOR REQUIREMENT IS MET. HENCE, FRUIT IS HARVESTED OVERRIPE RESULTING IN DRAMATIC YIELD AND ECONOMIC LOSSES. POSTHARVEST ULTRAVIOLET (UV) IRRADIATION IS A PROMISING TECHNOLOGY FOR PROMOTING RED SKIN COLORATION AND MAINTAINING FRUIT SAFETY. OUR GOAL IS TO DEVELOP AND ESTABLISH A POSTHARVEST UV IRRADIATION TREATMENT FOR IMPROVING 'HONEYCRISP' RED SKIN COLORATION, PHENOLIC CONTENT, FRUIT QUALITY AND SAFETY. SPECIFIC OBJECTIVES ARE TO: 1) DETERMINE THE EFFECT OF POSTHARVEST UV TREATMENTS ON ENHANCING RED SKIN COLORATION AND ON FRUIT RIPENING PATTERNS IN 'HONEYCRISP' APPLES, BY CONDUCTING A LARGE SCREENING STUDY OF UV TREATMENTS; 2) EVALUATE THE IMPACT OF THE THREE MOST EFFECTIVE TREATMENTS ON FRUIT QUALITY, POSTHARVEST PHYSIOLOGICAL DISORDERS, PHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY; 3) ASSESS THE IMPACT OF THE OPTIMUM SELECTED UV TREATMENT ON L. MONOCYTOGENES INACTIVATION AND ITS SURVIVAL ON THE SKIN OF 'HONEYCRISP' APPLES; AND 4) EDUCATE STAKEHOLDERS, THROUGH DIVERSE EXTENSION VENUES, ON (A) APPLICABILITY OF THE TECHNOLOGY, (B) TOOLS FOR DETERMINING OPTIMUM HARVEST, (C) HARVEST AND POSTHARVEST PRACTICES FOR IMPROVING FRUIT QUALITY AND SAFETY. WE ANTICIPATE THIS PROJECT WILL INCREASE APPLE PRODUCTION EFFICIENCY BY DECREASING FRUIT LOSSES, WHILE IMPROVING ITS MARKETABILITY AND SAFETY. THIS PROJECT SEEKS TO DEVELOP SOLUTIONS TO CRITICAL STAKEHOLDER PROBLEMS ASSOCIATED WITH TWO AFRI PRIORITIES: (A) PLANT HEALTH AND PRODUCTION AND PLANT PRODUCTS AND (C) FOOD SAFETY, NUTRITION AND HEALTH.