Hello Alex,

First you can look in to library of the University of Kiel, Germany.
(www.uni-kiel.de). The theme of my dissertation was the kernel weight in
wheat.

I think, the genetic coefficients have to be constant. DNA! (It is a long way
of discussion). Only their interactions, as a part of genetic coefficients
and DNA, are variable with environment, weather cycle conditions, soil
quality, production techniques and others. And these interactions are fixed
in a wide range.
In our researching time, there is no model available to work on every
specific site.
So you have to calibrate and try to validate your experimental data with your
observed data in field experiments of your region,  just as Matthias
Langensiepen recommended.

Don't  hesitate to contact me.

Peter Schoop
------------------------------------------------------------------
Institute of Agriculture and Environment Research
Dr. sc. agr. Peter Schoop
Sonnenweg 1
21647 Moisburg
Germany

Tel.: +49-4165-224 700
Fax: +49-4165-224 701
Mobil: 0173-31 85 118

E-Mail: [log in to unmask], [log in to unmask]
Internet: www.n-prog.de
---------------------------------------------------------------------