PLANT-GROWTH ANALYSIS - RE-EXAMINATION OF THE METHODS OF CALCULATION OF RELATIVE GROWTH AND NET ASSIMILATION RATES WITHOUT USING FITTED FUNCTIONS

A method is proposed for estimating expected values of mean relative growth and net assimilation rates, and their variances, over an interval of time, from replicated plant weight and leaf area data at each end of the time interval. The advantage of the method is that it avoids the necessity of pairing replicate plants at each of the two harvests, and gives exact results for relative growth rate. The results for net assimilation rate are approximate, but the method proposed still avoids the pairing process which is regarded as an artificial necessity inherent in the conventional method. © 1979, Annals of Botany Company.