Many temperate fruit plants have a chill requirement in order to come out of dormancy and grow and fruit normally in the following spring. In our case, a chill hour is defined as each hour below 45℉. These are added together to get the number of chill hours. Some fruit plants can have a high chill hour requirement (like some apples, cherries, etc.), whereas others can be low to none (some peaches, blueberries, grapes, etc.). Another model tallies the hours when temperatures are between 45℉ and 32℉. Both are given for purposes of comparison. The most accurate measurement of chill hours is from a device within a field of interest. Although the data within this application is based on actual measurements, it should be used as a general guideline and not as an exact value because weather can vary from location to location. Some variation at the same location may occur for multiple recalls of the data. The reason for this is that the data being accessed is freely available and may have slight instability when it is retrieved. Thus, it is important to remember that these chill hour results are estimates. Multiple runs could be done and averaged if desired; however, the percentage difference is usually small and of little consequence. This app has been created to help Mississippi fruit growers assess growing conditions that impact plant physiology and to help them prepare for events in the upcoming season. If you have questions or comments, please contact Eric Stafne at firstname.lastname@example.org.
A map of long term chill hour averages for Mississippi and other states can be found HERE
NOTE for iOS 10 users: If your iPhone or iPad is running iOS version 10, you will have to update to iOS version 10.2.1 for this app to work. There is a bug in the earlier versions of iOS 10 that keeps the app from calculating chills hours. To check for the version of iOS, go to Settings/General/About and look down the list until you see Version. This problem does not effect devices running iOS 9 or below.
To add an icon to your homescreen for iPhone: Tap the icon at the bottom of the screen and then tap on Add to Home Screen.
To add an icon to your homescreen for Android: Tap the icon or MORE at the top, right of the screen and then tap on Add shortcut to Home screen.
For technical support, please contact the Extension Center for Technology Outreach at 662-325-3226.