Xiong Wei and others,

The cultivar coefficients for the wheat model have indeed been revised for DSSAT v4.0. However, I highly recommend that you check and evaluate the values of your DSSAT v3.5 coefficients in DSSAT v4.0 prior to any application of the models. In many cases they will need to be adjusted due to improvements and changes in the models.

The definition of the cultivar coefficients for most crops are clearly defined in the book "Understanding options for agricultural production," as well as in each cultivar file (*.CUL). The definitions for many cultivar coefficients do not apply across species, especially the cereal crops.

Regards,

Gerrit



In DSSAT4, the coefficiencts used in the CSM-Cropsim-Ceres model differ from those used in DSSAT version 3.5, is the change occured for all cereal crops or just for some given crops, e.g. wheat.  I used the version 3.5 rice coefficients in DSSAT 4, but there is no problem.