Plant Growth Analysis: A 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 meanrelative growth and net assimilation rates, and their variances,over an interval of time, from replicated plant weight and leafarea data at each end of the time interval. The advantage ofthe method is that it avoids the necessity of pairing replicateplants at each of the two harvests, and gives exact resultsfor relative growth rate. The results for net assimilation rateare approximate, but the method proposed still avoids the pairingprocess which is regarded as an artificial necessity inherentin the conventional method. net assimilation rate, relative growth rate, mathematical analysis, Helianthus annuusL, sunflower, Triticum aestiuumL, wheat