A LED-based smart illumination system for studying plant growth

Abstract

A smart illumination system for greenhouses and growing rooms capable of controlling the quantity and quality of light emitted by a number of LEDs is described. The system uses lamps containing blue and red LEDs programmed to emit various spectra at sixteen different frequencies and ten different pulse widths. The performance of the system is evaluated by determining the effect of pulsed light emission at different frequencies with a pulse width of 50% on tomato plants (Lycopersicon esculentum). The results show that low frequencies (0.1, 1, 10 Hz) have higher quantum efficiency in photosystem II compared to higher frequencies (50 and 100 kHz) and continuous light. They also show that the electron transport rate decreases when the frequency of pulses increases.