A 3D architectural and process-based model of maize development

A 3D architectural and process-based model of maize development was implemented on the basis of the L-system software Graphtal, interfaced with physical models computing microclimate distributed on the 3D canopy structure. In a first step, we incorporated in the software Graphtal additional functions that enable bi-directional communication with external modules. A simple model for distributed photosynthetically active radiation and the model for apex temperature by Cellier et al. (Agricultural and Forest Meteorology 63: 35-54, 1993) were interfaced with Graphtal. In a second step we developed a L-system model for maize, where production rules for growth and development of organs are based on the current state of knowledge of maize development as a function of temperature. Visual representation of the plant is based on the geometrical model of leaf shape by Prevot, Aries and Monestiez (Agronomie 11: 491-503, 1991). Finally, various data sets were used to evaluate the physiological aspects and the geometrical representation. It is concluded that environmental L-systems are a convenient tool to integrate biophysical processes from organ to canopy level, and provide a framework to model growth of individual plants in relation to local conditions and ability to forage for resources. However, progress is needed to improve both the knowledge of physiological processes at the organ level and the calculation of physical environmental parameters; some directions for future research are proposed. (C) 1998 Annals of Botany Company.