Chill Portions [2.0]
IN THIS ARTICLE
Chill Portions calculates the number of effective chill for dormancy and bud development. Understanding and accurately calculating chill portions is crucial for fruit growers to ensure their trees meet the chilling requirements necessary for healthy growth and fruit production. The Utah model is one of the methods used to calculate chill portions. In the Utah model, chill units are calculated based on the number of hours within specific temperature ranges.
The ranges for the Utah model as defined by ZENTRA Cloud:
- 1 hour below 34°F = 0.0 chill unit
- 1 hour 34.01 - 36°F = 0.5 chill unit
- 1 hour 36.01 - 48°F = 1.0 chill unit
- 1 hour 48.01 - 54°F = 0.5 chill unit
- 1 hour 54.01 - 60°F = 0.0 chill unit
- 1 hour 60.01 - 65°F = 0.5 chill unit
- 1 hour >65.01°F = -1.0 chill unit
Support
Chill portions can be calculated from any temperature measurement.
Recommended sensors
- ATMOS 41
- ATMOS 41W
- ATMOS 14
- VP-4
- VP-3
- ECT
New Chill Portions
- On the Data page, select New Data.
- Select Chill Accumulation as the type.
- Select one or more temperature data sources.
- Edit the data stream color.
- Edit the data stream name.
- Select the temperature defaults to change the model type to "Chill Portions (Utah Model)."
- Select Create to finish.
- The new data stream(s) will now be in your data list.
Chill portions

Model variants
