Evaluation of the light profile and carbon assimilation of tomato plants in greenhouses with respect to film diffuseness and regional solar radiation using ray-tracing simulation

The benefits of informed management of sunlight in production greenhouses and polytunnels

“…Likewise, the height of the structure and of the plants grown within production environments will create vertical gradients in total irradiance and spectral quality (Ting & Giacomelli, 1987). In fruit crops, like tomatoes ( Solanum lycopersicum ), foliage in the canopy causes a large reduction in UV radiation and PAR reaching close to the ground, potentially detrimental to plant health and ripening of fruits (Shin et al, 2021). Mapping or modelling vertical gradients in spectral irradiance provides the information required to plan countermeasures that can be implemented to diminish their effect (Cossu et al, 2018).…”

“…Diffusive glass, plastic and spray‐on coatings scatter the sunlight incident on cladding materials. Under a clear cloudless sky, where irradiance is high and the proportion of diffuse radiation low, they enable a more even vertical and horizontal distribution of radiation through the day in the crop canopy (at least 10% more light in the lower canopy; Shin et al, 2021), while retaining a similar overall absorption of radiation by leaves in the canopy (Li et al, 2014; Timmermans et al, 2020). A more uniform light distribution across leaves is typically beneficial to those crop canopies with high leaf area index, which implies more self‐shading (Li & Yang, 2015), and helps curtail photoinhibition and responses to high temperatures associated with strong direct radiation (Burgess et al, 2015).…”

“…A more uniform light distribution across leaves is typically beneficial to those crop canopies with high leaf area index, which implies more self‐shading (Li & Yang, 2015), and helps curtail photoinhibition and responses to high temperatures associated with strong direct radiation (Burgess et al, 2015). This results in better canopy light use efficiency by enhancing whole‐canopy photosynthesis without altering the amount of absorbed radiation (Li et al, 2014; Shao et al, 2019; Shin et al, 2021), which may benefit overall productivity, evident as increased fresh weight of harvested fruits (up to 10% for tomato and cucumber) and through enhanced produce quality due to more even ripening (Hemming et al, 2014; Li et al, 2014; Li & Yang, 2015). Improvements in light and heat distribution can also be made by considering the optical properties of the ground surface or mulches over the growing medium.…”

Determination of the Optimal Orientation of Chinese Solar Greenhouses Using 3D Light Environment Simulations

“…The radiance of the lighting roof and the transparency of the plastic film are the dominant factors that determine the performance of greenhouse light absorption and resulting energy performance. Previous studies on the optical properties of the lighting roof have achieved remarkable outcomes and recommended that the diffuse light plastic films can improve the homogeneity of the canopy light distribution and increase crop production [14,36]. However, only a few studies have investigated the effect of greenhouse orientation on light interception [16].…”

“…Compared with other greenhouse types, the CSG type requires unique maintenance structures such as the back wall, roof, and quilt to guarantee the winter production of vegetables without any additional heating [9,10]. Previous studies on light optimization of CSG have mainly focused on greenhouse structures [11][12][13] and optical properties of plastic films [14,15], while the orientation of the CSGs has not been considered. Due to the lack of theoretical information for greenhouse construction, the orientation of the CSGs is usually determined by either experience or simply following the local topography [16].…”