Functional-structural modelling of chrysanthemum

An integration of structural and physiological models is used to simulate 3D plant growth and visual appearance of cut chrysanthemum, reacting to environmental factors. Measurements to calibrate the model include 3D data of digitized plants as well as a number of measurements and observations on harvested plants, including biomass per organ. The structural module is based on the L-systems algorithm. This L-system calculates temperature- and light-driven development, branching pattern and flower formation. In this 3D-structural model existing rules for physiological processes are incorporated, enabling calculation of carbon dynamics. A 3D radiosity method is used to calculate light absorption of every organ (leaf) at an hourly basis. Hourly photosynthesis per leaf is calculated according to the biochemical model of Farquhar taking into account absorbed light, CO2 and temperature at hourly intervals. A relative sink-strength approach is used to distribute the available assimilates among organs at a daily basis. Simulation of plant-to-plant competition for light is enabled. The modelling of temperature and light-level effects on growth and flower quality is based on trial data at different temperatures and plant density levels. The model is able to visualize different flower qualities in terms of flower number and branching patterns per plant. The results show the integrative effects of local sinks, specific in time and 3D position, on structure and ornamental quality at plant level