Towards a 3D structural tomato model for calculating light interception

A number of physiological tomato models have been proposed the last decades, their main challenge being the correct simulation of fruit yield. For this, an accurate simulation of light interception, and thus photosynthesis, is of primary importance. Light interception is highly dependent of the canopy structure which is affected amongst others by distance between plant rows, distance of plants within the row, leaf pruning and crop variety. In order to simulate these processes, a functional structural tomato model for the simulation of light interception on an individual leaf basis is proposed. The 3D model was constructed using L-systems formalism. For the architectural part of the model, manual measurements of leaf length, width, angle of the leaf main stem to plant stem and leaf orientation were conducted. The diurnal pattern of leaf orientation was also tested. The architectural model was coupled with a nested radiosity model for light calculation. Area per individual leaflet served as input of the light module for calculation of reflection, absorption and transmission of light. The model was used to test different crop planting scenarios on their effect on light interception. Results were then compared with light simulation for a totally homogeneous canopy.