The article presents the results of evaluation of photobiological efficiency of technological LED lighting in growing cucumber plants Svyatogor F1 variety under light culture conditions. In the experiment phyto-irradiators (FI) with high-pressure sodium lamps of DNAT type (control variant), as well as LED FI of combined spectrum were used. On the basis of photobiological experiments it was found that the emission of OP2 (where radiation with  = 730 nm was 3.1 times more and radiation with  = 660 nm 1.23 times less than in the emission spectrum of OP3) was more effective, providing not only better quality of cucumber seedlings but also higher productivity. The practical significance of the obtained results is shown.

Keywords: phyto-irradiator, LED light source, light-culture, photobiological research, radiation spectrum, photosynthetically active radiation, photosynthetic photon irradiation, cucumber plant