Juan and DSSAT users:  



For wheat (and barley) only for the CROPSIM-CERES model, you are correct, that the genetic coefficients were changed considerably by Tony Hunt and need to be re-computed following the guidelines that Tony inserted into the wheat and barley cultivar file:  See header in *.CUL that advises users on how to re-compute those coefficients:

	

	 Coefficients used in the Cropsim-Ceres model differ from those used 

	in DSSAT Version 3.5 AND 4.0.



But for the maize/corn and soybean models, the cultivar coefficients have the same meaning in V3.5 and V4.5, and model performance should be relatively similar.   You should recognize that minor model improvements have occurred over the past 15 years and the given genetic coefficients may have been re-calibrated very slightly since then.  So you should not expect to have exactly the same model prediction as V3.5.  If the phenology is off a day or so, or grain size or yield are not as close to observed as you want for your given cultivar, you should feel free to slightly modify genetic coefficients for your cultivar (but not the ones for which we in DSSAT already have experiments backing up a cultivar).



Best regards,

Ken







-----Original Message-----

From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On Behalf Of [log in to unmask]

Sent: Thursday, September 11, 2014 11:45 AM

To: [log in to unmask]

Subject: Maize and soybean genetic coefficients from older versions into DSSAT v4.5



Dear DSSAT users,

We would like to conduct simulations for maize/corn and soybean in DSSAT v4.5. We got calibrated genetic coefficients of two genotypes for each crop from a collaborator. However these calibrations were obtained with DSSAT v3.5. When we run DSSAT v4.5, our yields are around 50% under average and we have seen in the mailing list that someone suggested to multiply wheat genetic coefficients in DSSAT v3.5 to use them in DSSAT v4.5. Should we also convert the genetic coefficients of maize and soybean?



Best regards,

Juan Herrera

P.S. Sorry if the information is available somewhere, I checked the manual and mailing list and couldn't find it.