SHORTENING OF NON-HARVEST PERIOD IN HIGH-BENCH STRAWBERRY FORCING CULTURE BY A SIMPLE CONTROL METHOD OF MEDIUM TEMPERATURE

High temperature of the culture medium in a high-bench culture system of strawberries is apt to induce delay and lack of uniformity in flower bud emergence. These phenomena promote the non-harvest period. We devised an experimental system of heat control using the latent heat of evaporation for the culture medium (a medium-cooling system). We observed that the temperature of the culture medium affects continuous flower bud emergence in high-bench forcing culture. During the post-planting high-temperature period in the beginning of September, the medium-cooling system lowered the temperature of the culture medium by 2.5-3.0°C, compared with the temperature of the control medium. The medium-cooling system increased the duration of an optimum temperature of the medium. In addition, this system accelerated flower bud emergence in cv. ‘Benihoppe’ by almost 5 days on primary axillary branches and caused more uniform flower bud emergence compared with controls.