Increasing the energy efficiency of microgreen production by using shortened light/dark cycles

Borage, fenugreek and sunflower microgreens were grown under light-dark cycle of 7/4/9/4 h (7 h light (10 a.m. - 5 p.m.) /4 h darkness (5 p.m. - 9 p.m.) /9 h light (9 p.m. -6 a.m.) /4 h darkness (6. a.m.-10 a.m.)), selected taking into account electricity tariffs during periods of peak, semi-peak loads and the night zone. The results show that this lighting strategy can reduce the cost of electricity by 14-32% compared to a conventional photoperiod of 16/8 h and increase the efficiency of energy use by increasing yield (for fenugreek and sunflower, yield exceeded the control by 10 and 14%) and plant quality. In terms of a number of parameters (activity of antioxidant enzymes, content of carotenoids, flavonoids, ascorbic acid and proline), the experimental plants were superior to the control ones, which increases the nutritional value of microgreens used as a functional product for healthy nutrition.