Evaluation of growth and nutritional profile of microgreens of different crops under various LEDs light spectrums.

Carefully selecting the appropriate lighting is vital for indoor farming systems to ensure sustainable agriculture and the production of microgreens rich in health-beneficial phytochemicals. This study aimed to investigate the impact of various light spectrums on the growth and nutritional composition of microgreens. The experiment focused on a single factor: five different concentrations of LED lights, specifically White light (L1) at 100%, Red light (L2) at 100%, Blue light (L3) at 100%, Red and Blue light (L4) at a 70:30 ratio, and Red, Green, and Blue light (L5) at a 70:10:20 ratio. Four microgreen crops were used: Mustard (C1), Lettuce (C2), Radish (C3), and Broccoli (C4). The results showed that the hypocotyl lengths of C1, C2, C3, and C4 were higher under the L4 light treatment (70:30 Red and Blue), measuring 10.53 cm, 8.47 cm, 15.23 cm, and 11.43 cm, respectively. The shorter hypocotyl lengths of 7.67, 5.53, 11.2 and 7.73 cm were observed under the L1 (White light) condition. The greater fresh weights for C1, C2, C3, and C4 (0.1 kg each) and yields (0.115 kg, 0.110 kg, 0.135 kg, and 0.125 kg, respectively) were also obtained under the L4 light condition. The higher SPAD values for C1 (38.2 nm), C2 (16.9 nm), C3 (55.3 nm), and C4 (49.9 nm) were recorded with the L4 light treatment. Additional findings included potassium content for C1 (0.19%), C2 (0.19%), C3 (0.22%), and C4 (0.16%), and antioxidant capacity for C1 (0.22%), C2 (0.23%), C3 (0.19%), and C4 (0.18%). The higher gross income was achieved with the L4C1, L4C2, L4C3, and L4C4 treatments, while the lower was with the L1C1, L1C2, L1C3, and L1C4 treatments. The benefit-cost ratios were higher (4.1, 3.9, 4.9, and 4.5) for the L4C1, L4C2, L4C3, and L4C4 treatments, respectively. Therefore, a 70:30 Red and Blue light combination (L4) can be used profitably in indoor farming to maximize growth, yield, and nutritional content of microgreens.