Comparison of Two Shoot—Root Partitioning Models with Respect to Substrate Utilization and Functional Balance

Abstract

A transport resistance model for shoot—root partitioning by Thornley and a more aggregated partitioning model by Reynolds and Thornley are compared. Three functional forms of substrate utilization are applied, corresponding to different assumptions on the ability of carbon and nitrogen to compensate one another in promoting structural growth. On the basis of simulations at balanced exponential growth, it is shown that the Reynolds and Thornley model (in optimal form) is embedded in the Thornley model. Davidson's functional balance is studied as a function of the degree of carbon-nitrogen compensation. The applicability of the models and the utilization functions is discussed.

Model, shoot-root partitioning, substrate utilization, functional balance