Crop development
After emergence, the effective increase in temperature sum depends on the daily air average temperature. This relation is specified in an AFGEN table, which allows for non-linearity (lower and upper threshold values and optimum ranges). Average temperature is the independent variable in this table. Development rate can be obtained by:
where DVRn is development rate of the phenological stage n (unitless), Tcf is the temperature correction factor (°C), dependent to the daily average air temperature(°C) and GDDn are growing degree days from the stage n-1 to the stage n (°C-days).
Tcf and GDDn are crop dependent and should be provided by the user. Development stage at time step t is the integral of development rate over time (i.e. time span from emergence to current time step).
Listed below are decimal codes for the main stages, according to WOFOST:
For homogeneity with the other models currently implemented in CropML component, a further version of the decimal code-scale is provided also for WOFOST, that is:
The response to photo-period is approximated by a linear relation of day length (Dl, h, see topic Astronomic equations), which fluctuates from 0 and 1, multiplicative of growing degree days accumulated in the course of crop development. (see topic Crop development of WARM section for further details)
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