Analysis of Growth Parameters for Crop Vegetables Under Broad and Narrow LED Spectra and Fluorescent Light Tubes at Different PPFs

• Autor(a) principal: Peixe, Augusto
• Data de Publicação: 2018
• Outros Autores: Ribeiro, Hugo, Ribeiro, Augusto, Soares, Marco, Machado, Rui, Rato, Ana Elisa, Coelho, Renato
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10174/23611; https://doi.org/Peixe, A., Ribeiro, H., Ribeiro, A., Soares, M., Machado, R., Rato, A. E., & Coelho, R. (2018). Analysis of Growth Parameters for Crop Vegetables under Broad and Narrow LED Spectra and Fluorescent Light Tubes at Different PPFs. Journal of Plant Studies, 7(1), 47. https://doi.org/10.5539/jps.v7n1p47; https://doi.org/10.5539/jps.v7n1p47
• topic: controlled environment; light intensity; light spectra; photosynthesis; plant growth; yield parameters

Several physiological and yield parameters were evaluated in lettuce plants, cv. ‘Trocadero’, while growing at four different photosynthetic photon flux (PPF) (70, 120, 250 and 400 ± 10 µmol m-2 s-1), under four light spectra, white (W), red (R) and blue (B) Light-Emitting Diode (LED) lamps and cool white fluorescent tubes (FL). Yield parameters were also evaluated on spinach, turnip and radish, growing under identical light spectra but using a single PPF (340 ± 10 µmol m-2 s-1). Lettuce development was impaired at PPFs below 250 µmol m-2 s-1 for all tested spectra. At higher PPFs (250 and 400 ± 10 µmol m-2 s-1), for the two broad spectra tested (W LEDs and FL light), no significant differences were registered on all physiological and yield parameters evaluated. On all situations W LEDs performed, at least, as good as the FL light, indicating that actual W LEDs can efficiently replace traditional light sources, with all the inherent benefits, which include significant lower power consumption. For all species, narrow light spectra (R and B LEDs) proved not being able to provide normal plant development. Plants under R LEDs, although presenting, in some situations, a fresh weight higher than those achieved with the broad light spectra, always led to abnormal plant morphology, characterized by expanded petioles and leaf curling. B LEDs, in spite of promoting plant growth with normal morphology, frequently led to a lower number of leaves and consequently to a lower fresh weight.