Light quality and photoperiod influence crop growth, productivity and produce quality in hydroponic vegetable production
The plant factory system, enabling continuous, enhanced and rapid crop production under precise environmental control and automation, regardless of natural environmental conditions is gaining significant global attention and popularity. Under the arid agro-climatic conditions of Kuwait, the plant factory system is a prudent choice to improve indigenous vegetable production round the year, and ensure food security. Therefore, a study was conducted during 2015-2016 using a modular agricultural production system (MAPS) to investigate the effect of three light qualities and three photoperiods on growth, productivity and produce quality of hydroponic lettuce. MAPS, which is a prototype closed-plant factory system; consists of a closed, multilayer hydroponic plant growing system with advanced light emitting diode (LED) lighting, nutrient management, and Argus control, that enables food production in extreme environments. The experimental crop was grown under three light qualities (white, blue and red) and three photoperiods (8/16 light/dark (L/D), 16/8 L/D and 24/0 L/D). The growing conditions during the study were uniformly maintained at 200±10 µmol m‑2 s‑1 photosynthetic photon flux, 21±2°C ambient temperature and 65±10% relative humidity. The study revealed that the vegetative growth, yield and quality of hydroponic lettuce was significantly influenced by light quality and photoperiod. Plants grown under red lighting at 24/0 L/D photoperiod significantly excelled those exposed to blue and white light at 24/0 L/D photoperiod by 40.7% fresh biomass accumulation and 26.6% dry matter partitioning. Lettuce grown under red light at 16/8 L/D photoperiod produced comparable fresh biomass and dry matter with those grown under blue and white light at 24/0 L/D photoperiod. However, the majority of the vegetative growth parameters observed were significantly higher in plants grown under blue light at 24/0 L/D photoperiod. The study revealed the influence of light quality and photoperiod on crop growth, productivity and produce quality in hydroponic vegetable production.
Thomas, B.M. and Awadh, D.G. (2020). Light quality and photoperiod influence crop growth, productivity and produce quality in hydroponic vegetable production. Acta Hortic. 1273, 271-280
artificial lighting, closed production system, nutrient film technique, Lactuca sativa L. 'New Red Fire'