Analysis of Growth, Photosynthesis and Light Interception for Single Plants and Stands

Abstract

The two traditionally distinct treatments of growth analysis, using either relative growth rate (RGR) or crop growth rate (CGR), can be integrated in a single treatment in which RGR is a component of CGR. CGR can alternatively be analysed as the product of incident light receipt, efficiency of light interception (as determined by leaf area index and extinction coefficient) and efficiency of use of intercepted light in dry-matter production or in canopy net photosynthesis. Further, the net assimilation rate or net photosynthetic rate can be resolved into two components which quantify the dependence of light interception on leaf area and of CO2 assimilation on intercepted light. These relations provide increased flexibility in the analysis of assimilation and growth in terms of light interception and the structure of plants and stands. The usefulness of growth analysis in elucidating physiological mechanisms is discussed in relation to the use of more complex mechanistic models.