The Rate of Growth and Partitioning of Assimilates in Young Grass Plants: A Mathematical Model

Abstract

A model describing the increase in weight with time of young grass plants is formulated. The parameters are the relative growth rates of the root and shoot systems; k, the ratio of the relative growth rate of the root system relative to that of the shoot system; b, the weight of the root system when that of the shoot system is unity, and u the rate of increase in weight of the whole plant per unit of shoot system per unit of time, k and b are the constants in the allometric formula, r = bs^k where r and are the weights of the root and shoot systems. The model enables the effect of changes in the distribution of assimilates between the root and shoot systems upon the rate of growth of the plant to be assessed. Data from a number of experiments are analysed in this manner and the significance of the results discussed.