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. 1. Tikhomirov, A.A., Ushakova, S.A., Shikhov, V.N. Features Choice of Light Sources for Bio-Technical Life Support Systems for Space Applications // Light & Engineering Journal, 2018, Vol. 26, # 4, pp. 117–121.
2. Tikhomirov, A.A., Lisovskiy, G.M., Sidko, F. Ya. Light Chromaticity and Plant Productivity [Spektralnyy sostav sveta i produktivnost rasteniy] / Novosibirsk: Nauka. Siberian branch, 1991, 168 p.
3. Prikupets, L.B., Boos, G.V., Terekhov, V.G., Tarakanov, I.G. Research into Influence from Different Ranges of PAR Radiation on Efficiency and Biochemical Composition of Green Salad Foliage Biomass // Light & Engineering Journal, 2018, Vol. 26, # 4, pp. 38–47.
4. Berkovich, Yu.A., Krivobok, N.M., Smolyanina, S.O., Erokhin, A.N. Space Greenhouses: the Present and the Future [Kosmicheskiye oranzherei: nastoyashcheye i budushcheye] / Moscow: Slovo, 2005, 368 p.
5. Lisovskiy, G.M., Sidko, F. Ya., Polonskiy, V.I., Tikhomirov, A.A., Zolotukhin, I.G. Light Intensity and Quality as Factors Defining Formation of Cenosis and Crop of Plants in a Photoculture [Intensivnost i kachestvo sveta kak faktory, opredelyayushchiye formirovaniye tsenoza i urozhay rasteniy v svetokulture] // Fiziologiya rasteniy, 1987, Vol. 34, # 4, pp. 636–643.
6. Tikhomirov, A., Ushakova, S., Tikhomirova, N., Velichko, V., Trifonov, S., Anishchenko, O. Establishing cycling processes in an experimental model of a closed ecosystem // Acta Astronautica, 2020, # 166, pp. 537–544.
7. Tikhomirov, A.A., Sharulich, V.P., Lisovskiy, G.M. Plant Photo-culture: Biophysical and Biotechnological Basics [Svetokultura rasteniy: biofizicheskiye i biotekhnologicheskiye osnovy] / A Study Guide, Novosibirsk: Siberian Branch of the Russian Academy of Sciences Press, 2000, 213 p.
8. Tikhomirov, A.A., Zolotukhin, I.G., Lisovskiy, G.M., Sidko, F. Ya. Specificity of Responses of Different Plant Species to PAR Chromaticity under Artificial Lighting [Spetsifika reaktsiy rasteniy raznykh vidov na spektralnyy sostav FAR pri iskusstvennom osveshchenii] // Fiziologiya rasteniy, 1987, Vol. 34, pp. 774–785.
9. Bergstrand K.-J., Asp H., Schüssler H.K. Development and Acclimatisation of Horticultural Plants Subjected to Narrow-Band Lighting // European journal of horticultural science, Vol. 79, # 2, pp. 45–51.
10. Cope, KR, Bugbee, B. Spectral effects of three types of white light-emitting diodes on plant growth and development: absolute versus relative amounts of blue light // Hort. Science, 2013, V. 48, pp. 504–509.
11. Craig, D.S, Runkle, E.S. An intermediate phytochrome photo-equilibria from night interruption lighting optimally promotes flowering of several long-day plants // Environ Exp. Bot., 2016, 121, pp. 132–138.
12. Craig, D.S, Runkle, E.S. A moderate to high red to far-red light ratio from light-emitting diodes controls flowering of short-day plants // J. Am. Soc. Hort. Sci., 2013, Vol. 138, pp. 167–172.
13. Trouwborst, G., Schapendonk, A., Rappoldt, K., Pot, S., Hogewoning, S.W, van Ieperen, W. The effect of intra-canopy lighting on cucumber fruit yield: Model analysis // Sci. Hort., 2011, Vol. 129, pp. 273–278.
14. Kuleshova, T.E. Blashenkov, M.N., Kuleshov, D.O., Gall, N.R. Development of a Laboratory Phytotron with Adjustable Radiation Spectre and Duration of Daily Exposure, and its Biological Testing [Razrabotka laboratornogo fitotrona s vozmozhnostyu varyirovaniya spektra izlucheniya i dlitelnosti sutochnoy ekspozitsii i ego biologicheskoye testirovaniye] // Nauchnoye priborostroyeniye, 2016, Vol. 26, # 3, pp. 35–43.
15. Aladov, A.V., Zakgeym, A.L., Mizerov, M.N., Chernyakov, A.E. Polychrome Spectrally Changeable Illumination Devices with Light Emitting Diodes: Experience of Development and Application // Light & Engineering Journal, 2014, Vol. 22, # 1, pp. 12–19.

• Previous article
• Next article

• photo-biological efficiency of radiation
• LEDs
• phytocenosis
• vegetation periods
• regulation of the spectrum and irradiance of PAR
• CES