Hello Ben,
 
   Aloha!  If no one is able to supply you with the specific genetic
coefficients requested, you may want to consider using the genetic
coefficient calculator, GENCALC, in DSSAT v3.  This will give you a rough
estimate of the genetic coefficients.
 
   To use GENCALC, you will need to be able to simulate maize growth and
development of the cultivars you list below.  The plant data is minimal and
is common for breeders to collect during variety trials.  You can try and
ask a breeder for this data.  You will also need the soil data and weather
data for the trials.
 
   The plant data you need is the silking date, maturity date, grain number
per m^2, and the dry grain weight.  Put this data into the File A.  Create
the File X and format the weather and soil data according to the trials.
Then access the menu item DATA-GENOTYPE-OTHER-CALCULATE in DSSAT v3.  The
details to running the program can be found starting on page 201 of the
DSSAT version 3 volume 3 user guide.
 
   Good luck with your work.
 
Sincerely,
Richard
 
 
 
At 01:57 PM 8/25/97 -1000, you wrote:
>List members,
>
>My company, Abt Associates, is working as a contractor for the U.S. EPA on a
>project to analyze potential effects of climate change on the U.S. corn crop.
>We are using CERES-Maize in DSSAT v3 to model corn yield.  As part of this
work,
>we are looking for DSSAT genetic coefficients for the following varieties of
>corn, which are commonly used in Nebraska:
>
>        DEKALB 591
>        PIO 3162
>        Cargill 7777
>        Fontanelle 5325
>        NC+ 5037
>
>If anyone has developed coefficients for these cultivars, or can refer me to
>someone who can help me, I would greatly appreciate hearing from you.
>
>
>Best regards,
>Ben Strauss
>
>
>P.S.  The genetic coefficients required for maize by CERES-Maize are as
follows:
>
>P1      Thermal time from seedling emergence to the end of the juvenile phase
>        (expressed in degree days above a base temperature of 8 deg C) during
>        which the plant is not responsive to changes in photoperiod.
>
>P2      Extent to which development (expressed as days) is delayed for
each hour
>        increase in photoperiod above the longest photoperiod at which
>        development proceeds at a maximum rate (which is considered to be
12.5
>        hours).
>
>P5      Thermal time from silking to physiological maturity (expressed in
degree
>        days abobe a base temperature of 8 deg C).
>
>G2      Maximum possible number of kernels per plant.
>
>G3      Kernel filling rate during the linear grain filling stage and under
>        optimum conditions (mg/day).
>
>PHINT   Phylochron interval; the interval in thermal time (degree days)
between
>        successive leaf tip appearances.
>
>
>****************************************************************
>Ben Strauss                     Tel:    301.913.0509
>Abt Associates, Inc.            Fax:    301.652.7530
>4800 Montgomery Lane            Email:  [log in to unmask]
>Suite 600
>Bethesda, MD 20814
>