Light fixture spectral composition and light regime influence the morphophysiological performance of strawberry plants in vertical farming

Indoor farming is a more resilient means to produce food, providing fresher, safer food with improved nutritional quality. Our aim was to investigate the effects of the spectral quality and regime of artificial lighting on the morphophysiology of strawberry plants (cv. Albion) in an indoor vertical farming environment. Strawberry seedlings were transplanted, after 2 weeks of growth in a greenhouse, into insulated cabins and grown on an aeroponic system. Selected LED light fixtures were: cool-white (peak at 450 nm and 557 nm), RBW (peak at 446 nm, 560 nm, 660 nm), blue (peak at 444 nm), and red (peak at 660 nm); with regimes defined as constant, or sinusoidal, with fluctuating intensity, both with a photoperiod of 12 h and a Daily Light Integral of 15.12 mol m − 2 day − 1 . After 90 days of growing, samples were collected for anatomical, photosynthetic pigment index, chlorophyll a fluorescence, and gas exchange analyses. Changes in light quality and intensity promoted significant variation in physiological performance and plant development. RBW light increased anatomical storage structures, photosynthetic pigment index, photosynthetic rate and carboxylation efficiency and improved water use efficiency. However, under constant light conditions, especially under RBW and red light, defense mechanisms were activated to dissipate excessive light energy. When comparing white light with the other spectra, we observed that the RBW spectrum consumes 40.45% less energy, the red spectrum 55.07% less, and the blue spectrum 10.56% more, highlighting the relevance of light quality and the need for further studies in controlled environments. Regardless of light quality, the fluctuating behavior of the sinusoidal light stimulated and signaled defense responses and yielded better morphophysiological performance indices in strawberry plant leaves.