The Direction of Far-red Light Is Crucial in Strawberry Cultivation

In this study, strawberry ‘Keepsake’ plants were exposed to supplemental far-red (FR) light from above or the sides at a level of 40.2 μmol·m −2 ·s −1 and a peak wavelength of 730 nm. A control was also included, in which plants received only natural light (FR−). Leaf number and leaf area increased under top lighting vs. side or FR−. FR lights elongated the petiole vs. FR−. Crown diameter and shoot fresh and dry biomass were lower in side FR lighting, particularly vs. top FR lighting. Far-red lights accelerated flowering and increased total soluble solids (Brix) regardless of direction vs. FR−. Fruit diameter was marginally smaller when using side FR lighting compared with top lighting and FR−. However, fruit number, fruit weight, and titratable acidity were unaffected. Therefore, supplemental FR lighting applied from the top appears more effective for enhancing growth and fruit production in some June-bearing strawberry cultivars.