Evaluation and estimation of light interception and photosynthetic rate of lettuce plants grown under LEDs using 3D-scanned plant modelling
Light interception is one of the important factors required to estimate canopy photosynthesis and crop growth. Several approaches have been tried to estimate canopy light interception and photosynthetic rates under solar radiation, but rarely applied to plant factories using artificial lights. The objectives of this study were to evaluate and estimate the light interception and photosynthetic rate of lettuce plants grown under LED lighting conditions in plant factories. At 21 days after transplanting, high-resolution 3D plant models were constructed by using an optical scanner. For optical simulation, models of a growth chamber and LEDs were described and optical properties of the leaves were reflected in the 3D models. The photosynthetic rate was estimated by intercepted light distribution and FvCB model. The estimated light intensity and canopy photosynthetic rate were evaluated using measured ones in the growth chamber with LEDs. Estimated values were compared according to the resolution of the plant model. The 3D-scanned model showed detailed morphological features which can affect light interception. The spatial distributions of the light interception could be accurately estimated by the optical simulation and showed good agreements with the measured ones. The light interception and photosynthetic rate of the low-resolution models were overestimated compared to those of the 3D-scanned models. This method is thought to be effective in designing light environments and estimating light interception and photosynthetic rate in plant factories.
Kim, J., Kang, W.H., Kim, D., Hwang, I., Lee, H.J. and Son, J.E. (2020). Evaluation and estimation of light interception and photosynthetic rate of lettuce plants grown under LEDs using 3D-scanned plant modelling. Acta Hortic. 1296, 411-416
canopy light interception, light emitting diode, optical simulation, photosynthesis, ray-tracing