Dear listers, we are comparing observed and simulated leaf area index (LAI)
in wheat and barley. At flowering some of the low leaves are already dry, so
we measured LAI and green-LAI. When comparing with CERES simulated LAI,
which one should we use?
Thanks in advance,
Miguel Quemada

----- Original Message -----
From: "Matthias Langensiepen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, May 16, 2002 10:46 AM
Subject: Re : CERES-Barley dry matter accumulation slope


> Hello Jans,
>
> the only choice you have is to fiddle around with
> the genetic coefficients and see what happens
> with seasonal model outputs. Keep in mind,
> that PHINT also influences the simulation of
> biomass accumulation.
>
> A pre-condition will be a sound experimental
> basis, preferably gathered during an extended
> period. Choose those treatments which are certainly
> known not to be affected by any kind of stresses
> (which means not only checking management
> conditions, but also Bavarian weather conditions).
> Use GENCALC then, to determine the genetic
> coefficients for your specific variety under
> these optimum conditions.
>
> A sound determination of genetic coefficients
> is a prerequisite to proceed with further
> analysises, including stress events.
> The water routines of CERES strongly influence
> the simulation of actual biomass growth
> and I would recommend to keep an eye
> on that.
>
> Since potential biomass is estimated
> on the basis of the concept of radiation
> use efficiency, it is strongly recommendable
> to also check outputs from your radiation
> sensor.
>
> Wish you good luck in solving your problem.
>
> Matthias
>
>
>
> --
> Matthias Langensiepen, PhD
> Hannover, Germany
>
> Home : www.langensiepen.net
> Email : [log in to unmask]
>