scholarly journals Evaluation of Light Quality Variation through Supplement of Far-Red Light and the Difference in the Effects on Growth of a Pole-Type and a Bush-Type Kidney Bean, Phaseolus vulgaris L.

1996 ◽  
Vol 34 (4) ◽  
pp. 267-275 ◽  
Author(s):  
Hiromichi HANYU ◽  
Kazuhiro SHOJI ◽  
S-Bao JI
Crop Science ◽  
1977 ◽  
Vol 17 (5) ◽  
pp. 797-799 ◽  
Author(s):  
Paul J. Kretchmer ◽  
J. L. Ozbun ◽  
Stuart L. Kaplan ◽  
D. R. Laing ◽  
D. H. Wallace

2019 ◽  
Vol 11 (4) ◽  
pp. 434 ◽  
Author(s):  
Linnéa Ahlman ◽  
Daniel Bånkestad ◽  
Torsten Wik

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 μ mol   m − 2   s − 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.


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