Published on 03/06/02

Freeze Good for Some Crops, Bad for Others

Record low temperatures froze much of Georgia last week. When it comes to freezing temperatures, survival depends on timing and location for some Georgia crops, say University of Georgia experts.

Tough on Early Peaches

Freeze destroyed about 60 to70 percent of the south Georgia peach crop last week, said Kathryn Taylor, an Extension horticulturist with the UGA College of Agricultural and Environmental Sciences.

About five to 10 percent of Georgia's peach crop grows in south Georgia.

Peach tree varieties in south Georgia bud, flower and develop fruit earlier than those in middle Georgia. These early varieties go to market first. Therefore, they bring the most income for south Georgia growers.

As a tree progresses to full flowering, the developing flowers' ability to resist freezing temperatures is diminished, she said.

"The freeze had a devastating effect on the three earliest south Georgia varieties," Taylor said. "These trees were in full bloom. . . . This (freeze) resulted in a large economic loss for them."

At 20 degrees, trees in full bloom will lose 90 percent or more of their flowers.

No flowers, no fruit.

Warm weather in February caused south Georgia trees to bloom.

"But this is not particularly early," Taylor said. " It was just time for (these) varieties to bloom."

Timing Is Everything

Ironically, the freeze may help middle Georgia peach farmers.

Most of the middle Georgia crop remains in the bud stage of development. Tight buds can stand the freeze. The loss of slightly swollen buds is only about 10 percent. A peach tree grows about 10 times as many buds as it needs to produce a full fruit crop.

"We can spare that 10 percent (loss)," Taylor said. The freeze reduced the potential fruit load and necessary thinning costs for growers.

"The (recent) freeze in middle Georgia did not reduce the expected yield for this summer," Taylor said.

A later freeze in middle Georgia would be much more damaging to the state's peach crop.

How damaging?

"Timing is everything," Taylor said.

The risk of freeze for much of Georgia usually passes with Easter.

Chilled Greens

Freezing temperatures raised eyebrows of Georgia's cabbage and carrot farmers, said Terry Kelley, UGA Extension Service horticulturist.

A mature cabbage "can freeze as hard as a rock," Kelley said. But when it thaws out, it's usually fine. However, freezing temperatures can damage newly planted, young cabbage.

"I'm not nearly as concerned with the mature cabbage as I am for the ones being planted," Kelley said. Farmers are currently harvesting mature cabbage while planting another cabbage crop.

It's hard to tell just how damaging the freeze will be, Kelley said. Many weeks from now, as the next cabbage crop progresses, this freeze could cause plants to flower early instead of producing a cabbage head, cutting heavily into producers' bottom line.

Georgia farmers also have about 3,500 acres of carrots in the ground right now.

"Carrots can take a pretty stiff freeze," Kelley said. "In general you won't get root damage unless the ground freezes."

There was some damage to the tops of carrots, he said. The tops will grow back, but it exposes the plant to disease and insect pressure and quality problems at harvest time.

Leafy greens, such as mustard, turnips, kale and collards, received some damage from the freeze, too.

"Some of the young greens got hammered pretty hard," Kelley said. "I'm sure there will be some replanting to do."

Sweet and Established

Georgia's $90 million Vidalia onion crop fared the freeze well, according to Reid Torrance, Tattnall County Extension Service agent, where about 60 percent of the Vidalia onion crop is grown.

"Once an onion plant is established, you can have a blistering cold. It will usually come back out from the cold fairly easy," he said.

Some foliage was damaged.

"But you're going to get that more from the frost than the freeze," Torrance said.

Much like carrots, the actual onion bulb isn't damaged unless the ground freezes for extended periods. The ground around Tattnall County froze only a quarter to half an inch, Torrance said, and for only a short period.

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.