Do changes in the azimuthal distribution of maize leaves over time affect canopy light absorption?

In maize canopies, when modelling the architecture and light regime one usually assumes leaf azimuths are distributed uniformly. Once we had demonstrated azimuthal re-orientation of maize leaves during the vegetative phase, we tested the weight of this hypothesis on the light absorbed daily by the canopy. We thus modelled the three-dimensional (3D) geometry of maize canopies with various plant densities and at different developmental stages using plant digitizing under field conditions. We simulated radiative transfer using a volume-based approach within actual and hypothetical canopies, obtained by simply rearranging leaf azimuths. Simulations indicated that changes to horizontal heterogeneity have little effect on daily light absorption efficiency. It is concluded that changes in leaf azimuths do not have to be taken into account in crop-functioning models. ((C) Inra/Elsevier, Paris.).