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Mon, 29 Apr 1996 12:31:09 GMT |
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PES (Env), Univ of Nottingham |
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Thanks a lot for all who responded me regarding to wheat
phenology used in DSSAT3 models.
To correct some thoughts I found that I have to write a bit more
first of all I found the model simulation amazing regarding to
all experiment data I have I found a very good accurate agreement
between measured and simulated data.
To make my problem more clear:
As someone also adviced me to translate the Zadoks codes
to Ceres scale, actually I have no other way but it
is involved with some errors and will affect on my result and
maybe anything we publish as our work, so I thought that may
be some others faced such a thing as me and found a good way
Anyway, to forecast winter wheat yield through Mrkov Chain
method I used a multiple-run
of the model to find the stochastic transition probabilities, or
the rate of change of the system from one stage of life
( phenology ) to the next one, in this way at any phenology stage
we can have a stochastic estimation of different probabilities of
yield direction towards the next development stage. I finished that but
when I got back to see how this forecasting chart behave under
the real data, ( validating ) I found that the succeeding phenology
stages used in the model is different from what I have as measured
values, so to validate this forecasting method I have to find
that what are exact equal DSSAT Wheat phenology scales in terms
of Zadoks.
Anyway, thanks for all directions.
Best Regards
Mohammad Bannayan
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