By Clint Thompson

Cooler temperatures are needed this winter to avoid another disastrous peach season, according to Jeff Cook, University of Georgia Cooperative Extension County coordinator in Taylor and Peach counties.

Last year’s mild winter contributed to Georgia’s peach industry suffering an 80 percent loss. Cook estimates that 70 percent of those losses were attributed to Georgia’s lack of chill hours. The late freeze this past spring contributed to the other 10 to 15 percent peach loss, Cook said.

“Chill hours are vital to the development of a peach. We didn’t have enough cold weather last year and it showed once we got to harvest time,” said Cook, who specializes in peaches.

“Chill hours” refers to the time in which temperatures dip below 45 degrees Fahrenheit. From Oct. 1 through Feb. 15, chill hours are required for peach production.

According to Cook, one Georgia peach variety requires 850 chill hours, the highest chill requirement of all varieties grown in Georgia. When that particular variety only got around 450 chill hours last winter, the result was devastating for Georgia peach farmers. At least 800 hours are needed to make a “decent crop,” he said.

“We had between 650 and 700 (chill hours) year before last and did okay. Last year we were below 500 and we really need about 800,” Cook said.

The biggest hit to Georgia’s 2017 peach crop was the lack of peaches from July to August, which is typically the largest yielding period. “The packing sheds were shut down the first of July,” Cook said.

Unfortunately for Georgia peach producers, this year’s winter forecast is projecting a warmer winter due to La Nina weather conditions. UGA Extension agricultural climatologist Pam Knox predicts a 70 percent chance of La Nina conditions occurring from November 2017 through January 2018. La Nina is associated with above-normal temperatures and below-normal precipitation, especially in the southern half of Georgia.

Knox emphasizes that even in a La Nina winter, outbreaks of cold air could still provide chill hours to the peach crop.

“My expectation this year is that chill hours will be lower than normal but are likely to be higher than last year’s low numbers,” Knox said. “As we transition to neutral conditions in the spring, we also need to be mindful of the possibility of a late frost. Growers will have to keep an eye on conditions in the spring for any cold outbreaks that might come.”

Dario Chavez, a UGA College of Agricultural and Environmental Sciences assistant professor in peach research on the UGA Griffin campus, said the peach industry in Georgia should know by the end of December or early January how this winter will compare to previous years.

“It’s a weather factor so we really can’t do anything about it. It would be different if it were cold and we wanted to protect (the peaches) against the cold. That’s something we can do. Making it cold when it’s warm — it’s impossible,” Chavez said.

For more information on Georgia’s peach industry, see the UGA Extension blog at blog.extension.uga.edu/peaches/.