Thermal Time

Daily thermal time for wheat based on SubDailyInterpolation with three cardinal temperature and ThreeHourAirTemperature interpolation method.

Overview

The Thermal Time function in wheat model calculates the daily thermal time. This is crucial for crop development and organ growth. The model uses a sub-daily interpolation method to estimate air temperatures at three hourly interpolation method (ThreeHourAirTemperature), then applies a three cardinal temperature function to each interpolated temperature. These values are averaged to give a daily thermal time used in phenological and growth calculations.

  • InterpolationMethod: ThreeHourAirTemperature is used for sub-daily interpolation, i.e. 3-hourly temperature estimates.
  • Response: Three cardinal temperature using XYPairs to define the temperature response function. This function determines how effective the temperature is for thermal time accumulation.
Cardinal Point Description Value (°C)
Base Minimum for growth 0
Optimum Maximum rate of growth 26
Maximum Growth ceases above this 37

Thermal Time Function with Three Cardinal Temperatures

Cultivar-Specific Parameters

In general, we do not modify the thermal time function for different cultivars.

Practical Example

No practical example is provided for the thermal time function.