Relation between Changes in Photosynthetic Rate and Changes in Canopy Level Chlorophyll Fluorescence Generated by Light Excitation of Different Led Colours in Various Background Light
Artikel i vetenskaplig tidskrift, 2019

Using light emitting diodes (LEDs) for greenhouse illumination enables the use of automatic control, since both light quality and quantity can be tuned. Potential candidate signals when using biological feedback for light optimisation are steady-state chlorophyll a fluorescence gains at 740 nm, defined as the difference in steady-state fluorescence at 740 nm divided by the difference in incident light quanta caused by (a small) excitation of different LED colours. In this study, experiments were conducted under various background light (quality and quantity) to evaluate if these fluorescence gains change relative to each other. The light regimes investigated were intensities in the range 160-1000 molm-2s-1, and a spectral distribution ranging from 50% to 100% red light. No significant changes in the mutual relation of the fluorescence gains for the investigated LED colours (400, 420, 450, 530, 630 and 660 nm), could be observed when the background light quality was changed. However, changes were noticed as function of light quantity. When passing the photosynthesis saturate intensity level, no further changes in the mutual fluorescence gains could be observed.

optimal light spectrum

fluorescence gain

light emitting diode

chlorophyll fluorescence

photosynthesis

greenhouse illumination

Författare

Linnéa Ahlman

Chalmers, Elektroteknik, System- och reglerteknik, Reglerteknik

Daniel Bankestad

Heliospectra AB

Torsten Wik

Chalmers, Elektroteknik, System- och reglerteknik, Reglerteknik

Remote Sensing

2072-4292 (ISSN)

Vol. 11 4 434

Ämneskategorier

Etologi

Atom- och molekylfysik och optik

Zoologi

DOI

10.3390/rs11040434

Mer information

Senast uppdaterat

2019-04-08