Jagannathan,

I looked at your PTX.  I'm going to guess at a few things and let you try them out.

First, your EM is set to 11000, but your start of simulation date is 11314.  There is a strong probability that the model never comes to your "modification" date, and therefore does not change the CO2.  Either set your EM to be 11314, or your start of simulate to 11000 in Simulation Controls.

A less likely possibility is that the CO2 is set to "D" in Simulation Controls, giving you 380 ppm, and EM does not change it (But I don't believe this is the problem).  You could set CO2 in Simulation Controls to Mauna Loa (M), and see what that does.

A last possibility is that the potato model is not sensitive to CO2 (I hope that is not the case).

Ken Boote

From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On Behalf Of jagan TNAU
Sent: Thursday, April 28, 2011 2:57 PM
To: [log in to unmask]
Subject: CO2 environment modification

Dear all,

I am trying to predict the yield of potato for future climate projections. Using the downscaled weather data (TMAX, TMIN, SRAD & RAIN) for 2011 t0 2020 I modified the CO2 in the Environment modifications menu and made simulation for all the 10 years. Unfortunately with CO2 addition and without it fresh tuber yields are same. Please see in attachment the PTX file and Evaluate.out for verification. Where I am doing wrong?

--
With regards

Dr.R.Jagannathan
Professor of Agronomy,
Department of Agronomy
Tamil Nadu Agricultural University,
Coimbatore - 641 003 India

PHONE:  Mob: +91 94438 89891

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