The prediction reliability of the model for plants with larger leaf area was tested using data obtained on plants of the Rosalie group (C6) having a leaf area of 0.44 m* per plant,e.g.
twice the leaf area (0.22 m* per plant) of the largest plant used for the model parameter identification.
The model simulated fairly well the measured values until Z, reaches about 250 pmol photon m -2 s-’ .
For higher values of Z,, the model significantly overestimates the measured Pn rates, especially at the 600 and 900 Z~ll-’ levels (Fig. 7).
Finally, the model was checked against data obtained in situ (Fig. 8).
In this case, the predictions were less satisfactory, with a significant overestimation of Pn by the model:
u= 10.43& 1.40 Z.&g co, s-l per plant; b = 1.26 f 0.09 and R* = 0.40. Analysis of the residuals showed that the deviations (A Pn = Pnestimted - Pnmeasured) are important under conditions of high temperature (Fig. 9), which were associated with both elevated PPFD (more than 700 pm01 m-* s-’ ) and high VPD (over 1.5 kPa) levels.