Angela,

The phenology in the DSSAT model for soybean does not translate into GDD
for two reasons:  1) our temperature function is more complex, having a
flat topped Topt, and a temperature (Topt2) above which the rate of
development slows down.  So you can not translate into GDD;  2) the
reproductive stages are also mostly daylength sensitive, plus having the
complex temperature function, so even more reason you can not translate
to GDD.  So what you want, does not exist.  You will need to use it the
DSSAT soybean model the way we use it.  V stages predict very well, and
there is no need to adjust anything.  If you have a soybean cultivar for
which the R stages are not predicted accurately, you need to adjust to
the correct maturity group type (or changing the CSDL) in the cultivar file.

Good luck with it.
Ken Boote



Angela Gessleman wrote:

>Hello. I am a new user of the DSSAT program. Does anyone know of a
>reference which corresponds GDD with the Vegetative (V) and Reproductive
>(R) stages in soybean? Additionally, is there an area in the DSSAT
>software that lists the phenological scales that are used for barley,
>chickpea, potato, soybean and wheat. If anyone knows of someone doing
>work in DSSAT for canola, that would be appreciated as well.
>
>
>
>Regards...
>
>Angela Gessleman
>
>