COMPOSIÇÃO ESPECTRAL E REGIME DA ILUMINAÇÃO ARTIFICIAL NA QUALIDADE E PRODUTIVIDADE DO MORANGUEIRO EM AMBIENTE CONTROLADO

Abstract

The food demand and population growth have required a set of actions that must be taken to guarantee food safety and nutritional quality. The use of more resilient food production systems to environmental and sustainable changes, such as aeroponic vertical farming, emerges as an alternative. However, it is important to know the modulation mechanisms of quality and quantity of light in this system, to optimize the energy use, growth, and metabolism of plants. In this study, strawberry plants were cultivated in aeroponic vertical farming, and the effects of the spectral quality of the LEDs light (selected in the blue and red region and combined) and the lighting regime (constant and sinusoidal) on the performance of the gases exchanges, chlorophyll a fluorescence, the activity of defense antioxidant enzymes, oxidative stress, and biometric and productivity parameters, as well as the production of secondary metabolites in the fruits were evaluated. It was observed that, regardless of the lighting regime and light quality of LEDs, during plant development stages, photosynthetic and chloroplast pigment regulation is necessary to improve energy absorption capacity, photochemical performance, plant establishment (flowering) and greater efficiency in water use during fruiting. However, the highest fruit production per plant was observed under blue LEDs and under constant lighting regime. Despite physiological adjustments, superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities were upregulated under plants grown under red LEDs. While, in fruits, the soluble solids content was higher under white LEDs, and the contents of phenolic compounds and flavonols were photomodulated by RBW and blue LEDs, respectively. The results indicate that, among the different light treatments evaluated, the use of blue light proved to be the most promising in terms of increasing productivity and antioxidant capacity of strawberry fruits grown in vertical farming systems.