Architectural and Geometrical Representations of Cotton Plants to Simulate Their Light Interception at Low Density

The purpose of this investigation was to develop a method for building simplified geometrical representations (GM) of cotton plants that could be used to simulate plant light interception at low planting densities. Individual plants were observed infield trials throughout their growing period and their 3D architecture (AM) was reproduced at all growth stages. The crown envelope of the GM was represented by an ellipsoid. The ellipsoid content consisted of foliage elements randomly dispersed in a planophile distribution. The radiative transfers of both plant representations were simulated in the PAR range using the ARCHIMED simulation platform. Different ellipsoid envelope and foliage element sizes were investigated. With an appropriate set of sizes, light interception calculated using GMs tallied well with that obtained using AMs. It can be concluded that a simple turbid medium model is sufficient for modelling GM content without needing to introduce a clumping factor.