Document Type : Original Article
Authors
1 Agrotechnology Department, College of Aburaihan , University of Tehran, Tehran, IRAN. Postal Code: 3391653755
2 Department of Horticulture, Aburihan Faculty of Technology, Tehran University, Tehran, Iran
3 Agriotechnology, Aburihan Faculty of Technology, University of Tehran, Tehran, Iran
Abstract
Using controlled environments with stratified cultivation with artificial light is one of the alternative ways to produce agricultural products in controlled space. With the spectrum of different lights caused by LED lamps, the conditions of plant photosynthesis can be provided in the highest form along with other important parameters of plant growth in these greenhouses. In this research, the growth of lettuce was evaluated in different spectrums of artificial light using a stratified culture medium. In this greenhouse, three different combinations of light spectra are produced in this greenhouse: (100% red), (75% red + 25% blue), (50% red + 25% blue + 25% far red), with three exposure treatments of 12, 18 and 24 hours with light intensity of 250 μmol/m2/s was evaluated for lettuce cultivation with hydroponic feeding system. 216 lettuce plants were fully grown in this greenhouse and the red light spectrum had the highest performance. By carefully examining the efficiency of the photosynthesis device and the mutual effects of light quality and exposure time on the performance of Pertavosi variety lettuce, it was concluded that the precise combination of light spectrum and appropriate photoperiod increases the yield of lettuce. The far-red light spectrum played the greatest role in plant height. The highest fresh and dry weight of shoot was obtained in 24-hour exposure and in red and blue-red treatments. The fresh and dry weight of the root was recorded with the lowest amount of exposure of 12 hours. َAlso permanent exposure increases the vegetative growth of plants.
Keywords
)