dear Aston

the best way to calibrate a model is to understand what the model is
trying to do and the processes it is trying to describe.

best wishes

John R Porter

John R Porter DSc
Professor of Agroecology
Environment, Resources and Technology,
Faculty of Life Sciences
The University of Copenhagen
Hoejbakkegaard Alle 9
2630 Taastrup DENMARK

email: [log in to unmask]
vox: +45 3528 3377/3375
fax: +45 3528 3384
mobil: +45 2652 1484

.....Credeamus vita non ioca est...

>>> "Chipanshi, Aston" <[log in to unmask]> 14/02/2007 17:32 >>>




Hi,

Could someone assist with how to go about tinkering with genetic
coefficients when calibrating the CERES models (in particular barley
and
wheat)? We tried to follow the changes suggested in DSSAT v4.2 but we
are getting extremely low yield values. We have  a very good dataset
on
phenology and grain yield from experimental plots over a period of
about
3 years. The yield values that we are getting don't make sense at
all!!

Thank you,



ASTON