Which of the following formulas is used to calculate GDDs for cotton?

The formula used to calculate Growing Degree Days (GDDs) for cotton is critical for understanding the development stages of the plant in relation to temperature. The correct formula, which is based on the average daily temperature, is structured as follows: DD60 = (F max + F min)/2 - base temp (60).

In this formula, F max represents the maximum daily temperature, while F min denotes the minimum daily temperature. The average of these two values provides a better representation of the daily temperature experienced by the cotton plant. The base temperature of 60°F is used as a threshold because cotton begins to develop once temperatures exceed this level. By subtracting the base temperature from the average temperature, you can determine the effective heat accumulation for cotton, which is vital for predicting growth stages and managing planting times.

This approach ensures that only temperatures within a growing range that support plant development are factored into the GDD calculation, thereby providing more accurate insights for agricultural practices.