Net photosynthetic rate of cos lettuce under pulsed light generated with full-wave rectification of 50 Hz sine-wave alternating-current power

Abstract

　The net photosynthetic rate (NPR) of cos lettuce plants at an average photosynthetic (wavelength range: 400-700 nm) photon flux density of 100 µmol m^-2 s^-1 under pulsed light generated with full-wave rectification of 50 Hz sine-wave alternating-current power (FWR pulsed light) was compared with those under square-wave (SW) pulsed light at a frequency of 100 Hz and duty ratio of 50%, and under constant continuous light. The NPR under FWR pulsed light was significantly greater than that under SW pulsed light and not significantly different from that under continuous light. Considering that FWR pulsed light is producible using a simple driving circuit, and therefore low cost and low energy loss are expected compared with continuous light, FWR pulsed light is an option for plant cultivation by artificial lighting with light-emitting diodes.