Abstract
ABSTRACT The artificial light source is one of the most important factors in a controlled environment for vegetable production. It could provide new opportunities to improve growth and increase phytochemicals content in vegetables. Therefore, this study focused on the effects of artificial light sources on growth and phytochemicals in green oak lettuce (Lactuca sativa). The plants were grown under growth chamber with three artificial light sources, namely bar-LED (the 1:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), bulb-LED (the 2:1:1 ratio of blue 460 nm : red 630 nm : red 660 nm), and fluorescent lamp (FL) (the wavelength range 380-700 nm) for 4 weeks. The quality of bar-LED light was better than either bulb-LED or FL, when assessed by the parameters of photosynthetically active radiation (PAR), photosynthetic photon flux density (PPFD, 400-700 nm), PPFD-B (blue, 400-500 nm), PPFD-R (red, 600-700 nm), the yield photon flux density (YPFD), and the color of red. However, shoot and root (fresh and dry mass), leaf area, leaf number, and shoot/root ratio did not significantly differ between plants grown under bar-LED and bulb-LED, but they were significantly higher than plants grown under FL. Bulb-LED and bar-LED induced larger dry mass of the plants than FL. The dry mass per mole of artificial lighting was highest in plants grown under bar-LED. On the other hand, the fresh mass per mole of artificial lighting was highest in plants grown under bulb-LED. As regards power consumption, bar-LED provided the lowest consumption with 44.4% energy saving over the FL. Total phenolic content, 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenylpicrylhydrazyl (DPPH) activities were highest in plants grown under bar-LED. FL lighting gave the least contents of chlorophyll a and chlorophyll a + b. However, chlorophyll b and carotenoid contents did not significantly differ among the treatments. Thus, the results suggested that bar-LED has the potential to improve energy saving, and both growth and phytochemicals content of green oak lettuce grown in a controlled environment of vegetable production.
Highlights
Efeitos de fontes de luz artificiais no crescimento e no conteúdo de fitoquímicos de alface green oak
Controlled environment cultures can produce higher quantity and quality of vegetables per unit and reduce the losses or costs incurred by weeds, fungi, bacteria, insects, water and nutrition management, labor, and land area used
Incandescent Lamp (IL) converts only 15% of the electric power used to light for plant photosynthesis, while the remaining 85% is converted to heat that is not useful and can be harmful to the plants (Massa et al, 2008)
Summary
Efeitos de fontes de luz artificiais no crescimento e no conteúdo de fitoquímicos de alface green oak. A massa seca por mole de iluminação artificial foi maior nas plantas cultivadas sob bar-LED. A massa fresca por mole de iluminação artificial foi maior nas plantas cultivadas sob bulb-LED. Os resultados sugeriram que o bar-LED tem potencial para maior economia de energia e o conteúdo de fitoquímicos e crescimento de alface green oak cultivada em ambiente controlado de produção vegetal. Plant production in the controlled environment system mainly uses artificial light source. There is no compared information how the different spectrum ratio of LED promotes the growth and phytochemicals content on green oak lettuce under controlled environment. This research aimed to study the effects of the artificial light sources of bar-LED, bulb-LED and FL on plant growth and phytochemicals content in green oak lettuce
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
