Respiration, Growth and Maintenance in Plants

Abstract

THE dependence of plant respiration on photosynthesis and dry weight interests the crop scientist, and recently McCree¹, in order to account for his data on white clover, put forward the following simple equation to describe whole plant behaviour where R_d is the dark respiration rate, W is the plant dry weight, and k and c are constants. P_g ′ is a gross photosynthetic rate which is calculated by using where P_n is the net photosynthetic rate. In this communication equation (1) is derived theoretically using a straightforward extension of Pirt's discussion of yield and maintenance in bacterial cultures². The derivation gives a better understanding of the role of the constants k and c in McCree's equation. The relevance of dark and light respiration to the following analysis (where this distinction is at first ignored) and to McCree's equation is discussed later.