Simulation of wheat ontogenesis. I. Appearance of main stem leaves in the field

Abstract

ABSTRACT: Rate of leaf appearance differs among wheat crops sown in the field at different dates. This can be interpreted either as a direct effect of the date of sowing on the rate of leaf appearance or as a n indirect effect of an ontogenetic decline in the rate of appearance. Analysis of data from both laboratory and field experiments led to the conclusion that the second hypothesis is more reliable. A simulation model of leaf appearance was formulated on the basis of this hypothesis, and tested using experimental results from the literature and 2 original experiments carried out in Italy There was a good agreement between experimental data and simulation results. The discussed model simplifies the problem of the sinlulation of leaf appearance. Other models are based on a complicated relation between the rate of change in daylength at crop emergence and the rate of leaf appearance, w h c h does not have a physiological base.