Growing degree days
What is GDD?
Growing degree day (GDD) is a measure of heat the plant has accumulated to date to enter the new stage of the development, a phenophase.
How we calculate GDD
The chart starts from the sowing date which you need to specify yourself. Otherwise, you will get a “No data” alert.
To calculate GGD we use the following formula:
- Add the maximum and minimum temperatures for each day
- Divide the sum by two to get the average temperature
- Subtract the base temperature for the plant
The base temperature is the minimum threshold below which the plant development stops. For different crops in different countries, base temperatures may vary.
Growth stages and notes
Growing degree days allow predicting plant phenophases. This info is crucial for planning field works such as fertilizer and pesticide application, as well as harvesting. Using the GDD chart, you can easily add notes and track growth stages!
To add notes and growth stages, hover your mouse over the graph. A green bubble will appear on the lower axis. Click on it and choose between “Note” and “Growth stage”. Fill in the data in the new window. It’ll be shown on the graph after saving.
The chart of accumulated precipitation
The chart of accumulated precipitation allows evaluating the soil moisture reserve. Use this information to predict the yield and calculate fertilizer rates more accurately.
The chart of vegetation change
The chart shows the change in the NDVI index on the fields. The purple line stands for the average value of the NDVI for a field. The upper and the lower points of the light-purple range indicate the maximum and the minimum NDVI values for the day.
If you want to see the visual representation of the NDVI index, simply choose the day and click on the chart. The fields with the NDVI visualization will open in a separate browser tab.
Still have questions?
You can find more detailed information about the charts on our blog: https://blog.onesoil.ai/en/how-to-use-growing-degree-days-andaccumulated-precipitation-charts.