Physiological Changes in Yellow Summer Squash at Chilling and Nonchilling Temperatures

Abstract

Abstract Summer squash (Cucurbita pepo L.) fruit were harvested 8 ± 1 day after anthesis and held at 2 or 15C. Samples were transferred from 2 to 15C after 3, 6, 9, or 12 days of storage. Respiration and ethylene production were measured 24 and 48 hr after fruit had been transferred to 15C. Electrolyte leakage from pericarp disks was determined 48 hr after transfer to 15C. Weight loss during storage was greater at 15 than at 2C; however, chilled fruit had a greater rate of weight loss after transfer to 15C than did nonchilled fruit. Surface pitting became obvious after 6 days at 2C and was progressively more severe with increased duration of chilling. Respiration rates of nonchilled fruit decreased with increased storage duration, whereas respiration rates of chilled fruit increased with increased storage duration. Ethylene production was <0.1 nl g-1hr-1 in nonchilled fruit. Ethylene production was enhanced in chilled fruit and increased with increased duration of chilling to a peak of 1.5 nl-g-1-hr-1 after 9 days at 2C, then decreased. Electrolyte leakage was not influenced by chilling.