Abstract
The effect of combinational environment control, incorporating supplemental lighting and elevated CO2 concentration (maintained at 1,000 μmol mol−1) and air temperature (TA; maintained between 15 and 27°C in the day), on growth and fruit yield of June-bearing strawberry ‘Benihoppe’ was examined under forcing culture. Supplemental lighting significantly enhanced leaf photosynthesis, and this response was further increased by elevated CO2 and TA treatment. Flower opening on the first and second inflorescences was accelerated by supplemental lighting, and was further accelerated by elevated CO2 and TA, and resulted in a significant increase in fruit yield. Flower number per inflorescence was significantly increased under supplemental lighting and/or elevated CO2 and TA. Increase in flower number and shortening of the fruit maturation period caused by increasing the average air temperature under elevated CO2 and TA resulted in a significant increase in harvested fruit number and yield. By integration of combinational environment control and 1.5-fold increase in planting density (from 8 to 12 plants m−2) with a movable bed system, the fruit yield per unit land area achieved was 10.7 kg m−2 (10.7 t / 10 a), which represented a more than two-fold increase in yield compared with that attained in a conventional stationary bed system.
