2026 年 20 巻 p. 32-44
Local cooling of the root zone or crown was assessed as a strategy to mitigate heat stress in ever-bearing strawberry during summer-autumn production. Two local cooling treatments: root zone cooling, crown cooling, and an untreated control were compared. Root zone cooling reduced temperature around root at night, increased root and total dry weight, promoted dry matter allocation to roots during the mid-growth period, and considerably increased fruit dry weight and total yield compared to the control. Crown cooling decreased crown temperature, increased leaf dry weight, leaf area, projected leaf area, cumulative light interception, and bleeding rate in the early stage. Notably, crown cooling decreased the incidence of self-topping plants, suggesting a suppressive effect on this high temperature-associated growth disorder. No clear differences were noted among the treatments in fruit soluble solids, acidity, or chlorophyll fluorescence. Days to flower bud emergence and flowering were not markedly affected, although crown cooling did not strongly promote early reproductive development under the present conditions. Thus, local cooling enhanced plant performance under high temperature conditions by modifying dry matter production and partitioning. Root zone cooling was especially effective for increasing yield via greater dry matter accumulation in roots and fruits. In contrast, crown cooling primarily supported vegetative growth and canopy maintenance. Therefore, local cooling may be an effective approach for stabilizing summer-autumn production of ever-bearing strawberry under increasing temperature conditions.
