Functional-structural plant models (FSPM) provide a framework that can advance our understanding of how aspects of plant structure and function interact. By abstracting from reality, they provide a way to test our hypotheses of the behaviour of real plants and offer simple explanations of observed phenomenon. To investigate and develop mathematical and computational methods for use in FSPMs, an L-system based kiwifruit vine model was constructed that integrates architectural development, carbon transport and allocation, and environmental and orchard management effects on vine growth.

In my talk, I will present the methods used in the kiwifruit vine model, which include a discrete-time Markov chain for capturing axillary shoot development, an extension to a carbon transport-resistance allocation model for modelling several source/sink components of individual plant elements, and a quasi-Monte Carlo path tracing algorithm for estimating the absorbed irradiance of each leaf. To illustrate the model's potential to reproduce features of the vine's behaviour, I will show several simulations that were qualitatively similar to growth responses observed in experiments. In particular, simulations that show the effect of carbon limitation and topological distance on fruit size and the complex behaviour of sink competition for carbon.

This work was part of my PhD at The University of Queensland in Brisbane, Australia, and was supported by The New Zealand Institute for Plant & Food Research Limited.