Deae members,

I've got so many answers and distributions about my last mail, that the 
genetic coefficients in CERES have to be constant or not..
Whe tested this model in the collaborative project (Sonderforschungsbereich 
192) for 9 years (1991-1999) at the university in Kiel and we could not 
validate.
I think it is not right to calibrate these coefficients for each year, to 
make the model work correctly, only for one year. Because this is an adaption 
to the environment conditions in this special year.
Securely there are interactions between genetic coeffients and environment. 
And I think, these interactions have to be integrated in calculating 
predictions of CERES.
Every genetic factor has an interaction to his environment - more or less - 
we know from researching of behaviour of genes. If you calibrate the model 
directly about these genetic coefficients, you are overlayling the other real 
parameters of of influence. Or what do you think?

Best regards

Peter
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Schoop, Peter, Dr. sc. agr., Dipl. Ing.
Institut für Agri- und Environment Research 
Sonnenweg 1, 21647 Moisburg
Germany
Phone: +49-4165-224 700
Fax:     +49-4165- 224 701
E-Mail: [log in to unmask]
Internet: www.n-prog.de, also in english!
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