Chill Hours a Concern for Peach Producers

Clint Thompson Alabama, Georgia, Peaches, Top Posts

Peach trees need chill accumulation every fall and winter to produce a substantial crop the following season. Edgar Vinson, assistant research professor and Extension specialist in the Department of Horticulture at Auburn University, is concerned Alabama producers may be lagging behind.

“We’re still a little concerned about having enough chill by the end of this month. Typically, we’d like to have about half of the recommended chilling for our area by the end of the year,” Vinson said on Friday. “So far, we have about 172 hours, I think last time I checked. Looking at the extended forecasts, we don’t really see as many opportunities to collect chill as we’d like.”

Optimal Chilling Temperature

Vinson said peach growers long to have between 450 and 500 chill hours by the end of the year. He added that temperatures do not need to reach below freezing for chill accumulation to occur. Optimal chilling is at 42 degrees Fahrenheit.

“Just as an example, you can have a relative warm winter and still get the recommended chilling for your area. The temperature does not have to be at freezing. In fact, anything below freezing, you’re not getting much chill at all. Anywhere below 29, you’re not getting any chill accumulation,” Vinson said.

“You’re not losing any, but you’re not gaining any. You can have a relatively warm winter where you’re hovering around mid-40s, low 50s; somewhere around there and still get the recommended amount of chilling. It doesn’t have to be bitter cold to get chilling.”

Peaches need chill hours to mature. The required chill hours depend on the peach variety, but most growers hope to get around 1,000 chill hours before spring.

Temperatures were relatively warm in Alabama towards the end of last week and weekend which did not help with chill accumulation.

“Warm days like that, especially at 24-hour cycles at a time like that tend to be pretty detrimental to chill accumulation. Looking at extended forecasts, at least right now, we’ll keep checking extended forecasts and they’ll likely change, but as we look now at the extended forecasts, there doesn’t appear to be as much of an opportunity to collect chill,” Vinson said. “Not saying that there won’t, but we’re a little bit concerned about that.”