Alabama’s next peach season: Blossom or bust?
Signs are pointing to a strong Alabama peach crop this year based on the winter. (Alabama Cooperative Extension System)
For Alabama peach farmers, this time of year is crucial in determining how the growing season will turn out.
To resume adequate growth in the spring, peach trees require a certain amount of exposure to cool temperatures after the tree goes dormant. Chilling is the amount of cool weather it takes for a plant to come out of winter with normal growth in the spring.
“It should be a good season in terms of chilling,” said Edgar Vinson, an Alabama Cooperative Extension System commercial horticulture assistant professor.
After the leaves fall and cold weather rushes in, the growth regulators that inhibit plant growth start to rise. Simultaneously, growth regulators that promote growth start to decline, halting all visible signs of growth and development. As the peach crop meets the required amount of chilling, the plant growth inhibitors then decline and plant growth regulators increase.
Winter is an important time for peach orchards. (Alabama Cooperative Extension System)
Because of technologies that keep track of cooling, Alabama farmers are better equipped to predict growing seasons of deciduous fruit plants like peaches. There are several models that measure plant exposure to cool weather.
How growers measure chilling
The model traditionally used by the peach industry is the Weinberger Model, commonly referred to as the “old 45” model. This model measures the peach tree’s hours of exposure to temperatures at 45 degrees and below. These “chill hours” help professionals better predict what the crop will look like.
Another model that measures chilling is the Modified 45 Model. This model measures hours of exposure to temperature between 32 and 45 degrees. This model was developed after it was found that little chilling was accumulated below freezing.
A productive spring starts with a successful chilling in winter for peach orchards. (Alabama Cooperative Extension System)
If temperatures get to 70 degrees and above during the day, it is possible to cancel out the chill hours that the trees have accumulated. Yet another model, the Dynamic Model was developed for areas that experience warming trends during the winter. It measures chilling in chill portions rather than in chill hours. In addition, this model measures chilling in a temperature range of 29 to 64 degrees with an optimal temperature of 43 degrees. As temperatures rise above or fall below 45 degrees, chill accumulation is less efficient. The other models do not consider when it gets warmer and the negative effects it can have on chilling.
What will Alabama’s upcoming peach season look like?
Preferably, Alabama peach trees need about 850 hours of chilling by Feb. 15. As of mid-February, the northern region of the state had received over 1,200 chill hours, and Chilton and surrounding counties had received more than 900 chill hours.
“Chilling has been satisfied for most of the varieties grown in our state,” Vinson said.
Last year, by the end of January, peach crops had experienced more chill hours compared to the same period in 2022. But the gap was significantly closing in the past few weeks.
Alabama peach farmers are in position to blossom from the cold weather, as long as it doesn’t get too cold after the first swelling of buds. Peach buds and flowers do not like cold weather as much once they are no longer dormant. A steady transition from “cold for chilling” to “warm for growing” is ideal when it comes to growing the best peaches.
For more information on Alabama peaches, visit www.aces.edu.
This story originally appeared on the Alabama Cooperative Extension System website.
