2015 Volume 53 Issue 3 Pages 135-143
The effect of supplemental lighting with high irradiance LED on growth and fruit yield of various cultivars was examined in forcing culture of strawberry. Four cultivars of strawberry plants, having the different flowering timing and the flower number per inflorescence were illuminated 12 h daily from October to May. Supplemental lighting significantly accelerated leaf photosynthesis in all cultivars, which supported the translocation of additional carbohydrate to fruits, and improved fruit quality compared with non-lighting treatments. The flower opening of 2nd inflorescences in ‘Sagahonoka’ and ‘Benihoppe’ were accelerated by supplemental lighting, and this brought a remarkable increase in fruit yield. In ‘Akihime’, flower number per inflorescence was remarkably increased through an acceleration of leaf photosynthesis resulting in a significant increase in fruit yield. In ‘Ookimi’, supplemental lighting inhibited flower bud differentiation, and the positive effect of supplemental lighting was not observed on fruit yield. An acceleration of anthesis and an increase in flower number under supplemental lighting varied in each cultivar. These results suggest that supplemental lighting provided based on the hereditary characteristics (e.g., flowering timing, flower number) of each cultivar is appropriate for high-yield production based on the stabilizing effect of supplemental lighting in forcing culture of strawberry.