Possibility of harvesting june-bearing strawberries in a plant factory with artificial light during summer and autumn by re-using plants cultivated by forcing culture

Abstract

The aim of this study was clarifying whether the strawberry plants used for forcing cultivation could be stored and continuously cultivated in a plant factory with artificial light (PFAL). Forced June-bearing strawberries were harvested from November to May in Japan. In this study, we transferred the forced June-bearing strawberries to a PFAL in late April, and examined the differences in flowering and yield, and the effects of lighting conditions on flowering, yield, and leaf photosynthesis. We observed continuous flowering and fruit development through August, in low-temperature (20℃ in light and 10℃ in dark) and short-day (8-hour day length) treatment, and medium-temperature (25℃ in light and 15℃ in dark) and medium-day (12-hour day length) treatment. The prolific “Benihoppe” and “Akihime” cultivars had high yields from May to October. Furthermore, “Benihoppe” showed significantly higher photosynthetic rate under strong light (Photosynthetic Photon Flux Density (PPFD) of 51012 mmol m2 s1) than under weak light (PPFD of 301.530.5 mmol m2 s1). The study suggests that the productive lives of June-bearing strawberry plants, which were usually discarded in commercial farms in mid-May, could be extended for up to 5 months (Jun. – Oct.) by transferring them to a PFAL.