Optimisation of Lighting Parameters of Irradiation in Light Culture of Lettuce Plants Using LED Emitters

Abstract

The results of the ending phase of photo biological studies of capacity of lettuce and basil grown in conditions of a phytotron with irradiation by radiation of different ratio of fractions in the red-blue and blue-green-red regions of photosynthetic active radiation (PAR) are presented. The spectral variants of PAR providing the maximum or near to maximum capacity of the specified cultures are found. The complex and multiple-valued nature of effect of main PAR spectral regions on photo energetic and photo regulatory processes in plants providing their capacity is highlighted, which makes it impossible to determine common unified requirements to optimal parameters of artificial irradiation for growing of plants. These requirements shall be defined on the basis of direct photo biological experiments with main species of agricultural plants and be the most important element of the general photo culture macro technology. The general principles of fulfilment of the specified requirements to PAR spectra of phytoemitters are reviewed, including with consideration of setting of normal vision conditions for personnel of greenhouses and other protected ground structures.

Effects of Light Spectral Quality on Photosynthetic Activity, Biomass Production, and Carbon Isotope Fractionation in Lettuce, Lactuca sativa L., Plants

“…Most of the negative monochromatic red-light effects can be avoided by the addition of blue light [ 22 , 23 , 24 ]. Furthermore, a combination of red and blue light in certain cases can result in synergetic effects in biomass accumulation [ 25 , 26 ] Plant photosynthesis and growth, directly or indirectly, can also be mediated by the photoreceptor response. Additionally, chloroplasts play an important role in photoreceptor-mediated control of photomorphogenic responses [ 27 ].…”

Effect of Photoconversion Coatings for Greenhouses on Electrical Signal-Induced Resistance to Heat Stress of Tomato Plants

“…The coatings used in this work have photoluminescence maxima at 450 and nm, which quite well correspond to the absorption maxima of tomato plants, locate the region of 440 and 675 nm [29]. Stimulating photosynthesis by increasing the pro tion of light in the blue and red regions of the spectrum has been shown in a large num of works [1][2][3][4][5][6]10,11,14]. Such stimulation can be caused both by a direct increase in amount of energy available for photosynthesis and by the adjustment of physiolo processes due to signaling pathways starting from photoreceptors.…”

“…In temperate and polar latitudes, one of the most serious problems is insufficient illumination, in particular at wavelengths used in the course of photosynthetic reactions. This problem can be solved by active backlighting using LEDs or other light sources [1][2][3][4][5][6]. However, this approach requires high economic and energy costs, which leads to an increase in carbon footprint [7].…”

Control of phyto-radiator energy flows in artificial lighting of sustainable agriculture

“…Known irradiation technologies are aimed at studying the characteristics of the response of plants of different species to the quantity, quality and duration of irradiation, which makes it possible to develop a set of basic artificial lighting algorithms, optimized for different groups of plants, united by a set of certain characteristics, which will lead to an increase in yield and product quality, as well as to reduce its cost [8][9][10][11].…”