Effects from the application of LED lighting in a vertical planting model for lettuce cultivation

Abstract

This work aimed to analyze the application of artificial lighting on crispy lettuce cultivars, through the use of LEDs, applied to a new planting methodology known as Vertical Farms. For this purpose, a prototype vertical planting model was built, consisting of 21 isolated production units, equipped with sensors to collect environmental data and actuators for controlling RGB intermittent lighting and hydroponic irrigation. With the built model, two experimental tests were carried out: evaluation of the application of different light treatments (red, blue, purple, white) and application of different white light intensities (36 LEDs, 54 LEDs and 72 LEDs). In both experiments, lasting 30 days, the analyzes of the total fresh mass weight, dry mass weight, leaf area and number of leaves were carried out. of the white spectrum (combination between red, blue and green), presented the best results in all analyzed variables, followed by the purple spectrum (combination between red and blue), in contrast, the red treatment presented the worst results, considering that the referring samples at the same they perished after 15 DAT. In the second experiment, after a linear regression analysis, it was observed that the light intensity had an influence on all the morphological parameters analyzed, with the exception of the number of leaves (indiscriminate length).