Optimizing LED lighting for space plant growth unit: Joint effects of photon flux density, red to white ratios and intermittent light pulses. (November 2016)

• Record Type: Journal Article
• Authors: Avercheva, O.V.; Berkovich, Yu.A.; Konovalova, I.O.; Radchenko, S.G.; Lapach, S.N.; Bassarskaya, E.M.; Kochetova, G.V.; Zhigalova, T.V.; Yakovleva, O.S.; Tarakanov, I.G.
• Is Part Of: Life sciences in space research. Volume 11(2016)
• Page Start: 29
• Page End: 42
• Publication Date: 2016-11
• Subjects: Space greenhouse -- Light spectrum -- Pulsed light -- Optimality criterion -- Regression analysis -- A fractional multiple-factor experiment; LED light-emitting diode -- LSS life support systems -- PGU plant growth unit -- PPFD photosynthetic photon flux density; Space biology -- Periodicals; 571.0919
• DOI: 10.1016/j.lssr.2016.12.001
• Languages: English
• ISSNs: 2214-5524

Abstract

Highlights: A quantitative criterion for finding the optimal crop lighting regime was developed. Developed regression models can predict crop yield depending on lighting mode. The crop yield has nonlinear dependence on pulse light and spectral characteristics. Abstract: The aim of this work were to choose a quantitative optimality criterion for estimating the quality of plant LED lighting regimes inside space greenhouses and to construct regression models of crop productivity and the optimality criterion depending on the level of photosynthetic photon flux density (PPFD), the proportion of the red component in the light spectrum and the duration of the duty cycle (Chinese cabbage Brassica сhinensis L. as an example). The properties of the obtained models were described in the context of predicting crop dry weight and the optimality criterion behavior when varying plant lighting parameters. Results of the fractional 3-factor experiment demonstrated the share of the PPFD level participation in the crop dry weight accumulation was 84.4% at almost any combination of other lighting parameters, but when PPFD value increased up to 500 µmol m −2 s −1 the pulse light and supplemental light from red LEDs could additionally increase crop productivity. Analysis of the optimality criterion response to variation of lighting parameters showed that the maximum coordinates were the following: PPFD = 500 µmol m −2 s −1, about 70%-proportion of the red component of the light spectrum (PPFDLEDred /PPFDLEDwhite = 1.5) and the duty cycle with a period of 501 µs. Thus, LED crop lighting with these parameters was optimal for achieving high crop productivity and for efficient use of energy in the given range of lighting parameter values.