Date of Award
Master of Science (MS)
Dr. Moustafa Amin Fadel
Dr. Mohammed Salem
The goal of this study was to investigate the influences of different light systems, on growth parameters (fresh and dry weight, height and width, number of leaves and leaf area) and accumulation of chlorophylls and carotenoids of the lettuce. The marketable sensory characteristics (shape, and color) of fresh plants were also evaluated.
(Lactuca sativa crispa. “Lollo bionda”) lettuce were cultured in three levels of vertical hydroponically for 45 days under different light sources of natural light in the upper level, 60% shade light in the middle level and red (R), green (G) blue (B), provided by light-emitting diodes (LEDs) was 12/12 (day/night) in the lower level. Three levels of vertical hydroponics were also prepared in the same levels of three treatments, while were exposed to natural light as a control group.
For treatments, lettuces exposed to natural light, with high light intensity, showed the highest values in all growth parameters as well as pigments, while lettuce under the 60% shade, the result showed all pigments and growth parameters were low, except the length was similar to the length of the natural light treatment. As for the lettuce exposed to the (RGB) LED, which recorded lowest light intensity, was a significantly lowest value at all growth parameters, while pigments not detectable.
As for the control group, all of which were exposed to natural light, where the light quality was equal, while the light intensity was decreased gradually from top to bottom. The values of the parameters were high at all levels. With noted that, the leaf area was the highest in the middle level, while the fresh and dry weight were highest at the upper level. As for the pigment values, where all were high and no significant difference.
Lettuce Plants under natural light looked large, vigorous, most compact morphology with dark green leaves, while those under 60% Shade and (RGB) LED treatments looked small, weak, sparse and fragile.
The overall results indicate that all levels of treatments and control group obtained the same qualities of light in terms of spectra radiation, which the required for plant growth, but the different quantities of light spectra radiation were the main parameter in the greenhouse in the experiment, which led to significantly different results.
These new strategies to exploit the quality and quantity of solar natural light in the vertical hydroponics system should be conveyed for vegetable production in the UAE.
Ali Hamuda, Ghada Mohammed, "Growth And Development of Lettuce (Lactuca sativa L.) In A Hydroponic System with Different Lighting Sources" (2018). Aridland Agriculture Theses. 1.