Valdosta Daily Times

National, International News

March 3, 2013

Clemson research tackles peach-growing mystery

JOHNSTON, S.C. — Four generations of growing peaches in South Carolina have taught the Yonce family where to plant trees for the best crop, how to prune for the best yield and what to do to in a late freeze to prevent a devastating frost.

But what the Yonces and thousands of other peach growers still don’t know is this: How does a peach know when the cold winter weather is over and it is time to grow?

A group of Clemson University researchers is trying to find the answer.

“It’s an interesting phenomenon,” Clemson plant biologist Doug Bielenberg said. “These plants count the cold hours and days. If it gets warm for a bit, they stop, and then they pick up counting where they left off.”

The concept has been known for decades in the plant world as chill hours. What Bielenberg is trying to figure out is how a plant has this memory for cold weather and which genes control the process.

If scientists learn out how to manipulate the peach’s chill hours, the research could be groundbreaking. By reducing the hours, plants could be grown in a large number of climates across the earth. For peach farmers, it could mean getting larger, juicer varieties into stores faster, Bielenberg said

Peaches are ideal for this kind of research because they have a fairly simple genetic structure and are closely related to a number of other fruits, such as berries, apples and plums, Bielenberg said.

Peach farmers are watching the research carefully. Blooms are just starting to come out on the earliest varieties, meaning Larry Yonce will again hang on to the weather forecast through April, when he can be sure freezing temperatures are over until the fall.

“The weather controls our destiny, basically,” said Yonce, who has been growing peaches for four decades. The family business is J.W. Yonce & Sons farm, founded by his grandfather in 1932 in Edgefield County.

Yonce’s 3,000-acre site is the second-largest peach farm in the second-highest peach-producing state in the country, behind California. The area produced cotton for decades before the boll weevil wiped them out. Farmers along the rolling hills of the ridge of South Carolina eventually turned to peaches.

The fruit was perfect for the area. Winter nights are cold enough for the chemical reactions that make peaches sweet, but not cold enough to kill the fruit as it grows. Peaches later need warm to hot weather for the fruit to mature. That’s why the Georgia joins California and South Carolina as the nation’s leading peach-producing states.

Research from Clemson and the University of Georgia has helped up farmers considerably over the years. One of the Yonce farm’s best-sellers is a peach, developed through years of breeding, that doesn’t need as many chill hours so it ripens in May, but has the color, texture and sweetness of peaches that used to not hit the market until July.

But with all the science, there is still plenty of uncertainty in peach farming. Last year’s crop looked promising until a warmer-than-usual March and April left the fruit without enough chilling hours to reach its best taste and appearance. And peach farmers like the Yonces get downright depressed when the April 7 freeze of 2007 is brought up. Temperatures fell into the low 20s on the ridge. The state produced just 9,000 tons of peaches that year, compared with an already fairly sparse crop of 60,000 tons the year before.

In the family’s orchards, Chris Yonce points to blooms already on the tree. What should become a peach is already inside, no larger than an eyelash and about a quarter of the length. In about a month, roughly a third of the blooms will be removed from the tree by hand to maximize yield, a process that will go on for weeks on each of the farm’s roughly 500,000 trees.

Yonce takes his knife and cuts open a bloom. The tiny fleck inside is black. That flower would yield no peach, but Yonce wouldn’t have known until after the pruning.

“Growing peaches is like legalized gambling,” he said.

And that’s something that science will likely never be able to change.

1
Text Only
National, International News
  • Dollar Tree-Family Do_Rich copy.jpg Dollar Tree buys Family Dollar

    The fight for penny pinchers is intensifying.

    July 29, 2014 1 Photo

  • APTOPIX Mideast Israe_Rich copy.jpg Gaza war rages despite Hamas, Israel truce pledges

    Israel and Hamas launched new attacks Sunday in the raging Gaza war, despite going back and forth over proposals for a temporary halt to nearly three weeks of fighting ahead of a major Muslim holiday.
    The failure to reach even a brief humanitarian lull in the fighting illustrated the difficulties in securing a more permanent truce as the sides remain far apart on their terms.

    July 29, 2014 1 Photo

  • AP81072904918 copy.jpg Today in History for Tuesday, July 29, 2014

    Today is Tuesday, July 29, the 210th day of 2014. There are 155 days left in the year.

    July 29, 2014 1 Photo

  • AP4507280123 copy.jpg Today in History for Monday, July 28, 2014
    Today is Monday, July 28, the 209th day of 2014. There are 156 days left in the year. 
     

    July 28, 2014 1 Photo

  • Tentative deal reached on VA reform

    The chairmen of the House and Senate Veterans Affairs committees have reached a tentative agreement on a plan to fix a veterans’ health program scandalized by long patient wait times and falsified records covering up delays.

    July 27, 2014

  • United States-Libya_Rich.jpg US evacuates embassy in Libya amid clashes

    The United States shuttered its embassy in Libya on Saturday and evacuated its diplomats to neighboring Tunisia under U.S. military escort as fighting intensified between rival militias. Secretary of State John Kerry said “free-wheeling militia violence” prompted the move.

    July 27, 2014 1 Photo

  • AP9607270692 copy.jpg Today in History for Sunday, July 27, 2014

    Today is Sunday, July 27, the 208th day of 2014. There are 157 days left in the year.

    July 27, 2014 1 Photo

  • No ticket for Shrek over loud musical, chief says

    A musical being performed in a New Hampshire park has drawn some noise complaints, but the deputy police chief says he’s “not giving Shrek a ticket.”

    July 26, 2014

  • Arizona Execution Dru_Rich copy.jpg Arizona’s McCain: Execution was torture

    U.S. Sen. John McCain says the execution of an Arizona inmate that lasted two hours was torture.

    July 26, 2014 1 Photo

  • Ukraine Plane_Rich copy.jpg US: Russia firing into Ukraine

    Russia is launching artillery attacks from its soil on Ukrainian troops and preparing to move heavier weaponry across the border, the U.S. and Ukraine charged Friday in what appeared to be an ominous escalation of the crisis.
    Russia accused Washington of lying and charged Ukraine with firing across the border on a Russian village. It also toughened its economic measures against Ukraine by banning dairy imports.

    July 26, 2014 1 Photo

Top News
Poll

Do you agree with the millage rate increases?

Yes. We need to maintain services
No. Services should have been cut.
     View Results