Title : Effects Of Artificial Coelux Light On Plants Growth
Abstract:
The visible light is an important environmental factor for promoting plants growth and development. Plant pigment molecules, such as chlorophyll and carotenoids, absorb light mainly in the wavelength range of 650-700 nm (red light) and 460-480 nm (blue light) of the electromagnetic spectrum. There are many technologies able to reproduce artificially light for both space lighting and indoor plants production. CoeLux® is a brand new interesting and innovative “green technology” that reproduces the natural light and visual appearance of the sun and the sky through nanostructured materials, LED lighting and optical systems, which create a distance sensation between sky and sun. Unlike other artificial lighting systems, CoeLux® is able to reproduce the effect of Rayleigh scattering, which occurs when light cross earth’s atmosphere and interact with gaseous substances. Although the lighting effects on ornamental and/or agronomic plants are widely studied, the influence of CoeLux® lighting system on plants growth is still unknown. Therefore, the present work aims to assess the short-term effects of this new lighting system on plant morpho-physiological aspects. The experiment was performed at the CoeLux® showroom, located in ComoNExT science and technology park (Lomazzo, CO - Italy) in a room characterized by 45 HC CoeLux® light type. Two common ornamental plants species, Anthurium and Spathiphyllum, were placed in different position points characterized by a different PAR (Photosynthetically Active Radiation) value. For each position point, plants were grown for 16 days (16/8 hours light/dark) and successively moved to the next position point, which was characterized by a higher PAR value. Photosynthetic efficiency in dark-adapted (Fv/Fm), photosystem II yield in light reaction (ΦPSII) and stomatal conductance (gs) were measured every 24 hours, 48 hours, 4 days, 8 days and 16 days. Moreover, an image of the plants was acquired at the beginning and at the end of the growth period. Later, the image analysis (Image J open access software) allowed measuring the leaf area index. For each position point similar photosynthetic activity and stomatal conductance were detected between Anthurium and Spathiphyllum. In particular, for both first and second position points, plants showed a compensation point characterized by corresponding rate of respiration and photosynthetic activity. Thus, from the visual analysis, there was not leaf area increment. From the third to the fifth position point, although a decrease of leaf area index was detected, both biomass and flowers were produced. The expansion of leaves was not detected by the image analysis due to a phototropic response of leaves. Indeed, while stalks extended leaves moved orienting downwards to the wall light reflection. In conclusion, further analysis with different plant species are in progress. In particular, ornamental (Anthurium and Spathiphyllum), aromatic (Malva sylvestris, Ocimum basilicum, Coriandrum sativum), agronomic (Olea europaea, Solanum lycopersicum) and forestry (Quercus ilex) plant species are under investigation.
