A Shoot:Root Partitioning Model

Abstract

A model for partitioning newly-synthesized structural dry matter between shoot and root is developed. It is based on a postulated partitioning function, which depends upon the relative levels of carbon and nitrogen substrates, with parameters determining the control point and also the degree of control. The model is used to investigate the relationships between plant specific growth rate, shoot:root ratio, and the specific activities of shoot and root (which depend upon environment), during steady-state exponential growth; the transient behaviour of the model is also explored and oscillations in these quantities are obtained.