We have continued to see short duration drops in temperatures followed by warmer and moist conditions. While the weather has been pleasant we are not accumulating many "chill hours", temperatures at or below 45 degree F., for our deciduous fruit crops. Below are some of the chill hour totals since 1 October through 18 January.
Location -Total Std. chill hours - Last Data
Auburn 448 (847 last year) 01/18/12
Belle Mina 748 (1261 last year) 01/18/12
Brewton 485 (815 last year) 01/18/12
Cleveland 816 (1209 last year) 01/18/12
Cullman 740 (1122 last year) 01/18/12
E.V. Smith 684 (1003 last year) 01/18/12
Headland 355 (733 last year) 01/18/12
Marion Junction 590 (947 last year) 01/18/12
Prattville 493 (1015 last year) 01/18/12
Sand Mountain 764 (1379 last year) 547 (1088 last year) 01/18/12
Semmes 366 (645 last year) 01/18/12
SO Chilton County 491 (862 last year) 01/18/12
Thorsby 620 EST. (958 last year) 01/18/12
Union Springs 591 (994 last year) 01/18/12

What is the 'big' deal? Well, one way to think of it is like different people need different hours of sleep at night to function properly the next day. When an 8 hour a night person gets only 5 hours of sleep they are slow to get up and going the next morning and perform poorly during the day. When a fruit tree doesn't get sufficient chill hours (rest breaking) during the winter months they are delayed in blooming, leafing out, and can have quality issues with fruit development and overall tree health.

While natural rest breaking is preferred, there is a nitrogen containing compound that has been used to advance development of the flower and leaf buds when chill hours for natural rest breaking are lacking. A number of growers in the southeast will be using this product to aid in more normal development of plants in several fruit crops this winter.

Fruit growers throughout Alabama and the southeast are getting concerned about the mild winter we are experiencing this year. Our fruit crops require a certain amount of colder temperatures during the rest period to be able to resume normal growth in the spring when temperatures warm up. Effective colder temperatures that we need range from 32 - 50 degrees F from October 1st through February 15th. The simple method to clock effective temperatures during this time period is for each hour at or below 45 degrees F we obtain '1' chill hour.
Where weather towers are up and operational you can go to our Peach IPM website to view chill hour information for various locations in Alabama. http://www.aces.edu/dept/peaches/peachipm/index.html
Go to "Climate Information" and click on "Chill Hours Collected".

Areas in Alabama from Birminham south will likely be short on needed "chill hours". The deficit in chill hours will likely be higher as you move south. Extended forecasts for central Alabama indicate an estimated accumulation of 100 chill hours over the next 2 weeks. This would put Chilton County ranging from 530 to 700 chill hours by 1/23/12. Only 2.5 weeks more would remain to get the 350 more hours we would need for the highest chill hour requiring varieties of peaches.
Growers need to also keep in mind that with most peach varieties, the leaf buds require 150 to 200 more chill hours than the flower bud. On some farms, growers are considering use of a product to aid in rest-breaking.

March 28, 2005 'Sureprince' Rest-breaking Study Block