Functional-structural modelling of Chrysanthemum

The recently developed virtual plant modelling approach has strongly increased the potential of model applications in crop sciences. Virtual plants are based on a new modelling concept and are generated in a 3-dimensional (3D) virtual space. In this paper, a coupling of a structural and a physiological module is applied to incorporate 3D environmental effects in plant growth simulation. The methodology is used for cut Chrysanthemum. 3D data of digitised plants were used to calibrate the structural module, which was based on the L-systems algorithm. This L-system calculated temperature driven growth, branching pattern, and flower formation, and was able to visualise different flower qualities in terms of number and size of flowers per plant. This 3D model was coupled to an existing physiological growth model. Light interception based on the radiosity method was transferred from 3D model to physiological model to simulate photosynthesis and carbon dynamics. The effects on growth governed by environmental conditions were feed back to the structural module as actual growth rates. The effects of light limitation on growth and flower quality were demonstrated for a number of plant densities. The first results show that the combined strength of both models may help to understand and visualise plant growth and appearance.