ASHS 2025 Conference

Pre-harvest fruit drop (PFD) causes significant yield losses in commercially valuable apple cultivars like 'Honeycrisp'. Ethylene, the master regulator of various fruit ripening traits in climacteric fruits, accelerates pre-harvest fruit drop. While ethylene inhibitors such as aminoethoxyvinylglycine (AVG) effectively reduces PFD, it can negatively impact fruit color development, a process also regulated by the plant hormone ethylene. To address this trade-off, we evaluated various plant growth regulators (PGRs), such as Accede (1-aminocyclopropane-1-carboxylic acid (ACC)-10%), Motivate (ethephon-21.7%), ReTain (AVG-15%) and their combinations, in ‘Honeycrisp’ apples over two consecutive years (2023