Hello,
I was wondering if anyone can point me to any literature that gives
specific instructions on calibrating CERES-Wheat.  I have read the section
in the DSSAT manual on calibration and the specific instructions seems to
apply to legumes.  Also, I do not understand how you access the parameters
described in the manual (ex: specific leaf area, time to cessation of leaf
area expansion, etc...).  Unfortunately the only data I have to calibrate
the model is final yield, soil water content, and some limited phenological
observations, but it does appear that the model is predicting the
antithesis data too early and I was trying to figure out how to correct
this.  It might be a problem with the genetic coefficients since I do not
have the data to calculate the genetic coefficients for the cultivar used
(McNeal) and I used the coefficents provided in the model for spring high
latitude wheat.  It might also be a problem with the water deficit
factors.  I am also finding similar results to those who posted a message
on the list server about unreasonable estimates of grain yield for dry
conditions.  It also appears to me that the models relationship between
water and biomass production (i.e., the model estimates water deficit
factors that are too high) is not correct, at least for my study
sites.  Has anyone found any solutions to this problem?  I would be glad to
share results with anyone interested.  Any comments or suggestions related
to this are appreciated.  Thank you for any help in advance.

Derek McNamara

Derek McNamara
Graduate Research Assistant
Mountain Research Center, Montana State University
P.O. Box 173490, 106 AJM Johnson Hall
Bozeman, MT 59717-3490, USA
406-994-5073
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