Hi all,

I am calibrating the wheat model of DSSAT v4 using measured data.  The measured maximum leaf area index was about 7.0, but the simulated was only 4.5.  The model seems to overestimate stem weight but underestimate the leaf weight for the most part of the growing season.  However, the simulated specific leaf weight was similar to measured values.  My question is: Which parameters should be tapped in order to increase LAID while decreasing stem weight?  I have tried a few leaf area related paramters in the ECO file, but had no luck.  Anyone out there has a magic bullet for this?  BTW, the biomass at harvest was underpredicted by some 20% by the model.

Any advice or suggestion will be greatly appreciated.

Thanks and Regards,

John Zhang
Hydrologist
USDA-ARS Grazinglands Research Lab
El Reno, OK