Photobiological Efficiency of Radiation of LED Radiators for Cenoses of Different Age Plants in Relation to Conditions of Closed Ecosystems

Abstract

The paper presents experimental data on the photo-biological efficiency of the emission of white light LED irradiators and phyto-spectrum with an intensity of 460 μmol/(m2s) and 800 μmol/(m2s) at the intermediate (18 days) and final (27 days) stages of the growing season of growing Chinese cabbage (Brassica rapa), chard (Beta vulgaris), and radish (Raphanus sativus) in relation to the conditions of closed ecosystems (CES). The presence of different specifics of the reaction of plants to the spectral composition of radiation, both at the intermediate and final stages of vegetation, has been established. It has been suggested that in some plant species (Chinese cabbage) it may be physiologically justified at the intermediate stage of vegetation to change the spectral regime of irradiation from the phytospectrum to white light in order to achieve higher productivity values. Using the example of chard, it has been established that the phyto-spectrum can be more effective than white light when growing leaf biomass, regardless of the growing season. Using the example of radishes, it was shown that the phytospectrum stimulates the accumulation of high values of above-ground biomass in comparison with white light, however, for the accumulation of root biomass in relation to the conditions of the CES, it is more expedient to use white light, since with a biomass of root crops comparable to the phytospectrum, plants with an increased coefficient of economic efficiency are formed in white light, which reduces the share of waste in the CES (inedible leafy biomass). On the basis of the data obtained, possible tasks of scientific research on evaluating the spectral efficiency of radiation at certain stages of plant vegetation, as well as the prospects for creating LED irradiators with a physiologically based program for regulating the spectral composition and radiation intensity, are discussed.