Effect of Light Quality on Flowering in Everbearing Strawberry Cultivars

Abstract

The effect of light quality on flowering in everbearing strawberry (Fragaria × ananassa Duch.), a long-day plant, was investigated under night illumination conditions. Two everbearing strawberry cultivars, ‘Natsuakari’ and ‘Suzuakane,’ were tested. Flowering was promoted under far-red light, but it was almost inhibited under red light at 30/25°C (day/night temperature) in a natural light type phytotron. In another treatment, plants were grown under night illumination in a glass house from September. In this case, flowering was reduced under red light conditions compared with under an incandescent lamp. In everbearing strawberry cultivation, flowering is markedly promoted and plants may die due to self-topping under high temperature and long-day conditions. However, the mortality rate due to self-topping was lower under red light in this study. These results reveal the flowering response of everbearing strawberry cultivars to red and far-red light under relatively high temperatures, and the possibility of using red light to maintain vegetative growth by regulating flowering.