The coupling effect of nutrient solution EC （electrical conductivity） levels and CR （circulation rate） on the morphology and quality, in hydroponically grown lettuce was assessed. Lettuce was grown at 5 treatments...The coupling effect of nutrient solution EC （electrical conductivity） levels and CR （circulation rate） on the morphology and quality, in hydroponically grown lettuce was assessed. Lettuce was grown at 5 treatments fi＇om High EC ＆ Low CR to Low EC ＆ High CR. The environmental parameters were controlled in a 20 m^2 plant factory during the hydroponic cultivation with the following values： irradiated by blue and red light-emitting diode lighting with PPFD （photosynthetic photon flux density） value of 150 mol·m^-2·s^-1 for 16 hours per day; Temperature was maintained at 22.0 ℃ during the photoperiod and 16.0 ℃ in dark cycle. The results demonstrate that growing lettuce can be adopted using nutrient solution with lower EC levels and higher CR. The results also indicate that the effect of bi-directional coupled EC and CR resulted in expansion of root length but reducing the root biomass. Nitrate content was significantly reduced.展开更多
文摘The coupling effect of nutrient solution EC （electrical conductivity） levels and CR （circulation rate） on the morphology and quality, in hydroponically grown lettuce was assessed. Lettuce was grown at 5 treatments fi＇om High EC ＆ Low CR to Low EC ＆ High CR. The environmental parameters were controlled in a 20 m^2 plant factory during the hydroponic cultivation with the following values： irradiated by blue and red light-emitting diode lighting with PPFD （photosynthetic photon flux density） value of 150 mol·m^-2·s^-1 for 16 hours per day; Temperature was maintained at 22.0 ℃ during the photoperiod and 16.0 ℃ in dark cycle. The results demonstrate that growing lettuce can be adopted using nutrient solution with lower EC levels and higher CR. The results also indicate that the effect of bi-directional coupled EC and CR resulted in expansion of root length but reducing the root biomass. Nitrate content was significantly reduced.
