Dear Misael,

numerous variants on the subject of temperature sums based on linear
functions are published.
MCMASTER & WILHELM (1997) point at the need for clear definitions
regarding the concept of growing degree-days.
Different methods of calculating growing degree-days implemented in crop
models can easily
cause errors when relying on parameters from literature.
Maybe you would like to look at this article:
MCMASTER, G.S. & W.W. WILHELM (1997): Growing degree-days: one equation,
two interpretations. Agricultural and Forest Meteorology 87, 291-300.

Greetings from Germany,
Victoria



Misael Rodriguez Arvizu schrieb:
> DEAR ALL:
>
>
> FOR CALCULATE GROWING DEGREE DAYS (GDD) IS USED,    /Tmean -Tbase/ BUT
> I HAVE A DUDE, WHAT IS THE BEST USEFULL MEANS OF DATA IN 24 HOURS OR
> ONLY TO USE  /(Tmax+ Tmin)/2/
>
>
>
> ANYBODY HELP ME
>
>
>
>
>
>
> MISAEL RODRIGUEZ ARVIZU
>
> UNIVERSIDAD AUTONOMA AGRARIA ANTONIO NARRO,
>
> BUENAVISTA, SALTILLO, COAHUILA, MEXICO.
>

--
Dipl.-Geogr. Victoria Lenz

Universität zu Köln
Geographisches Institut
Albertus-Magnus-Platz
50923 Koeln
Tel.: +49-(0)221-470-6823
Fax:  +49-(0)221-470-5124