New Chilling Model Website

The NC State Climate Office has updated their chilling model page. Here is the link and I have shown an example for Hendersonville NC for Jan 3, 2022 below.

https://products.climate.ncsu.edu/ag/chill-models/

First you select a model (I prefer the Warmund and Krumme) Model, it takes into account when the temperatures get warm.

The Yazetti and Clark model is also popular.

Select Model(s):

Blueberries (Mainland Model)
Blackberries (Yazetti and Clark Model)
Blackberries (0° to 7°C model with first incidence of  -2.2°C)
Blackberries (Modified Richardson Model)
Blackberries (Warmund and Krumme)
Peaches (Richardson Model)
Apples (Shaltout and Unrath Model)
7.2°C Model (45°F Model)
0° to 7.2°C Model (32° to 45°F Model)

 

Then click on the map to a location that you want, here I chose Hendersonville, NC. 

For Hendersonville Jan 3, 2022, there are 590 chilling hours. On the website, you can see how the chilling has accumulated over time. Late in December there were 621 but the warmer temperatures in the last few days there has been a loss of chilling at this (and probably many other locations).
 

What does this mean? 

Most fruit crops grown in NC require a period of cool weather before they break dormancy and start to grow.  Most blackberries require 400-800 units of chilling. If they do not receive enough chilling you can see irregular bud break (this is common in southern GA, LA, AL, MS and FL). If they have received enough chilling, they will break bud when it is warm. Often times those buds that have started to emerge may get injured by late season cool weather. 

So it is good to monitor what chilling has occurred in an area so you can match those units with the stage of your crop. 

There is also a handy tutorial if you want more informationn

https://products.climate.ncsu.edu/ag/chill-models/#tutorial