Articles
Finding optimal supplemental lighting strategy for greenhouse tomato (Solanum lycopersicum) by using 3D-scanned plant models and optical simulation
Article number
1337_36
Pages
271 – 276
Language
English
Abstract
In greenhouse cultivation, seasonal and temporal low light intensity can limit the plant growth due to insufficient light amount reaching the canopy.
Supplemental lighting has been attempted as a countermeasure, but adequate lighting strategies are required for minimizing electrical costs.
This study aimed to construct weekly-scanned tomato 3D plant models and analyse the light interception, photosynthesis, and light use efficiency under supplemental HPS and LED light sources with growth stage.
Photosynthetic rate was calculated using the FvCB biochemical photosynthesis model with obtained light distributions from optical simulation.
We placed light sources at the top and middle of the tomato canopy in CAD software and evaluated light interception, photosynthesis, and light use efficiency (LUE) of top lighting HPS and inter-lighting LED sources.
Light deficiencies were also analysed for 1.4, 2.0 m height tomato models with light extinction factor k to dispose HPS and LED light module at the top and inside the canopy.
In solely HPS, the absorbed PAR of the tomato canopy from the HPS sources steadily increased with growth stage.
In contrast, the photosynthetic rate of the canopy was maintained at a low value of 0.5 µmol m‑2 s‑1 after five weeks of growth.
With adding two layers of inter-lighting from top-lighting, photosynthetic rates improved to 1.1 and 1.5 µmol m‑2 s‑1 in 1.4 and 2.0 m height of tomato models, respectively.
In particular, LUE was much higher at inter-lighting cases than HPS, with higher spectral photosynthetic efficiency.
We could quantify the light interception and photosynthetic efficiency of the plants under different supplemental lighting conditions using 3D plant models and optical simulation.
This method can contribute to optimization of supplemental lighting in greenhouses.
Supplemental lighting has been attempted as a countermeasure, but adequate lighting strategies are required for minimizing electrical costs.
This study aimed to construct weekly-scanned tomato 3D plant models and analyse the light interception, photosynthesis, and light use efficiency under supplemental HPS and LED light sources with growth stage.
Photosynthetic rate was calculated using the FvCB biochemical photosynthesis model with obtained light distributions from optical simulation.
We placed light sources at the top and middle of the tomato canopy in CAD software and evaluated light interception, photosynthesis, and light use efficiency (LUE) of top lighting HPS and inter-lighting LED sources.
Light deficiencies were also analysed for 1.4, 2.0 m height tomato models with light extinction factor k to dispose HPS and LED light module at the top and inside the canopy.
In solely HPS, the absorbed PAR of the tomato canopy from the HPS sources steadily increased with growth stage.
In contrast, the photosynthetic rate of the canopy was maintained at a low value of 0.5 µmol m‑2 s‑1 after five weeks of growth.
With adding two layers of inter-lighting from top-lighting, photosynthetic rates improved to 1.1 and 1.5 µmol m‑2 s‑1 in 1.4 and 2.0 m height of tomato models, respectively.
In particular, LUE was much higher at inter-lighting cases than HPS, with higher spectral photosynthetic efficiency.
We could quantify the light interception and photosynthetic efficiency of the plants under different supplemental lighting conditions using 3D plant models and optical simulation.
This method can contribute to optimization of supplemental lighting in greenhouses.
Authors
D.P. Kim, J.E. Son
Keywords
light use efficiency, optical simulation, supplemental lighting, 3D plant model
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