2021 Volume 37 Issue 3 Pages 215-
June-bearing strawberry plants (Fragaria × ananassa Duch. cv. Benihoppe) were grown in a growth chamber with florescent lamps as light source at the light periods of 12 h and the temperature of 22 / 10°C (light / dark periods). The diurnal change of diameters of a fruit and a fruit stalk were measured with a digital displacement sensor. The sugar flux through the cut section of fruit stalk was attempted to estimate by EDTA method. A fruit grew faster in light periods than dark periods. The fruit growth rate was the highest at the start of light periods. Short-time shrinkage of the fruit was observed at the start of dark periods. The change of fruit diameter and the change of diameter of the fruit stalk were closely associated. When vapor pressure deficit changed greatly in a short time because of the operation of the air conditioner, these changes were closely associated with the change of vapor pressure deficit. Water flux through the cut section of fruit stalk took negative value in light periods and positive value in dark periods. It might be estimated that the contribution to the water flux was higher through phloem (56.9%, 59.4%) than xylem (43.1%, 40.6%) in both of light and dark periods. Sugar flux through the cut section of fruit stalk was much higher in dark periods than in light periods. The sugar flux through the cut section of fruit stalk in light periods and dark periods were estimated as 20.2% and 79.8% of total flux, respectively.
