AN ADEQUATE MODEL OF PHOTOSYNTHESIS .1. PARAMETERIZATION, VALIDATION AND COMPARISON OF MODELS

Many models of leaf photosynthesis have been proposed but there have b een few attempts to compare them and determine their adequacy for vari ous purposes. Three of the most popular models of leaf photosynthesis were compared quantitatively and qualitatively. The models were the re ctangular hyperbola, Farquhar's model, and Harley's interpretation of Farquhar's model. The methodology for statistical assessment and compa rison is described. The models were fitted to experimental data for to mato plants (Lycopersicon esculentum Mill., cv. Rutgers Large Red) by an optimization procedure. The data set consisted of leaf light respon se curves measured at temperatures of 18, 25 and 32 degrees C and CO2 concentrations of 100, 350, 700 and 1000 vpm. The hyperbolic model of leaf photosynthesis proved to be adequate quantitatively, and it can b e used in models of productivity for predictive calculations, It is no t necessary to introduce a more complicated model with a greater numbe r of parameters. The two interpretations of Farquhar's model (his own and Harley's) were quantitatively and qualitatively adequate, and can be used for research purposes.