Hello Octavio,
 
   Aloha! I'm responding to your question about the genotype calculator.
 
   Let me preface my answer to your question by acknowledging that the
genotype calculator is a rough estimator.  It was designed to allow users
to easily find genotype coefficients for cultivars that have none.  The
data requirements are minimal (the user only needs to conduct a minimum
data set experiment), and the caculator will do the rest with a little
more information from the user such as which coefficients to estimate.
The premise is that simple is useful, but not particularly accurate.
 
   If you need precise, accurate genetic coefficients, then accept Jeff
White's help.  He can show the way.
 
   Otherwise, to estimate genotype coefficients with the calculator you
will need to have data files properly organized to run the maize model on
the experiment conducted with the cultivar in question. The genotype
calculator estimates the genetic coefficients by incrementally adjusting
the coefficients, running the model on these coefficients and comparing
the simulated results with the observed until an acceptable deviation is
reached.  For example, the genotype coefficients P1 and P2 are
incrementally adjusted until simulated silking date is close to the
observed.  Likewise, P5 is then adjusted until the maturity date is
approximate.  This process is automated so that you do not have to adjust
the genetic coefficients yourself.  But, you need to have the data files
that are used to  simulate maize growth. The data files include weather,
soil, fileX, and fileA. The required data for fileA can be found in
DSSATv3 volume 3 page 206.  Be sure to have the proper file names and
titles associated with the experiments in the file EXP.LST.
 
   Also, you will need to add a line into the *.CUL file for your new
variety.  The coefficients for this new variety doesn't matter too much
because it will be a starting point for the calculator. You may put the
coefficients from Pioneer Hybrid X304C into the new variety to start with.
 
   Once you've done this, you're ready to run the calculator as described
on pages 209 to 221 in DSSATv3 volume 3.
 
   If you have any other questions, would like to discuss the
limitations of the calculator, or thoughts on the model for tropical
cultivars, please feel free to contact me at [log in to unmask]  Good luck
with your work.
 
Sincerely,
Richard