Led modules in plant growing of protected soil

Irradiation installations in vegetable growing of protected soil are an effective tool for managing agrocenoses due to their specific characteristics. Rational management of irradi-ance, spectral composition and duration of exposure should be carried out according to certain regularities for obtaining the crop of required quality parameters. The development of rational for the energy and spectral characteristics irradiator for greenhouse technologies is the goal of the study. Four LED modules of different power are investigated: two - 60 W each and two - 43 W each. For the basic efficiency criterion, the effective return coefficient ηφ was adopted. The studies have shown that LED module based on full-spectrum LEDs has the lowest efficiency, because there is the maximum radiation density φ=120.6 mW/nm is at λ=450 nm, i.e. the blue part of the spectrum. Increasing the efficiency of such module while maintaining unchanged power is achieved by technical solution: replacing part of the LEDs with red and blue ones. Adding LEDs with short-wave red radiation (λ=635 nm) in the ratio of 1:3 to LEDs with long-wave red radiation (λ=660 nm) with equal number of white (λ=400...700 nm) and blue (λ=450 nm) gives the increase in photosynthetic photon flux by 8.5 % compared with the version where this ratio is 3:1. High efficiency of the red LED leads to the fact that the addition of red to white increases the energy efficiency of the irradiator to ηPF=1.92 μmol/W. On the basis of the LED mod-ule of LEDs from Cree, the H-Light FITO 43W LED Light irra-diator has been developed, which is recommended both for using in vegetation plant for experimental research and for industrial applications in rack installations.