Effect of different times of exposure to LED treatment on microgreens of arugula (Eruca sativa) and radish (Raphanus sativus)

Microgreens are easy to produce due to their small space requirements, short growing period, low nutrient and growth medium requirements. For their production, light energy is considered one of the main factors in plant development. The aim of this study was to evaluate the development and quality of radish and arugula microgreens under different exposure times to light-emitting diode (LED) lighting. Pigment levels were determined: chlorophylls, carotenoids, flavonoids and anthocyanins. Chlorophylls a and b decreased with the increase in photoperiod and had higher levels over the days of growth. Total chlorophyll also increased as the microgreens grew. The carotenoid content was negatively affected by the increase in photoperiod in relation to the days. There was a tendency for flavonoids to accumulate as the days passed and the photoperiod increased. A reduction in anthocyanins was observed with increasing exposure time to LED light for radish microgreens, the opposite of what was observed for arugula. In general, the recommended exposure time to LED light for producing radish and arugula microgreens was 16 hours and harvesting on the 6th DAP.