2024 年 62 巻 2 号 p. 41-47
To control the harvest date of strawberries, we constructed a device that can control the local fruit temperature and investigate the effects of fruit cooling and heating on fruit maturation and quality. Fruits were sequentially placing into thermally insulated tubs to control the local temperature during fruit development. The average fruit temperature decreased by 4.1℃ during fruit cooling and increased by 3.8℃ during fruit heating when compared with fruit without local temperature control. The number of days from flowering to harvest (i.e., days to maturation) was strongly affected by fruit temperature, with fruit cooling prolonging and fruit heating shortening the days to maturation when compared to the control. Non-linear regression analysis revealed two regression formulas for predicting days to maturation from the average fruit temperature. When compared to the fruit without local temperature control, fruit size, soluble solids content and dry matter ratio decreased significantly with fruit heating, while in contrast, no differences were observed for these quality parameters with fruit cooling.
