José Chaparro has been breeding low-chill peaches for central to south Florida. Here, he is with UFOne.
Photos courtesy of José Chaparro
When devastating freezes strike the Florida citrus industry, it becomes national news immediately, as people want to know how it will affect the price and supply of their orange juice.
Nearly 30 years ago, two really hard freezes badly damaged the Florida citrus industry: A freeze in December 1983 caused $4.5 billion in damage in central and northern Florida. A similar freeze in the same area in January 1985 caused $2.5 billion in damage.
What few people know is what these freezes did to the peach industry.
“Before the eighties, we had a pretty healthy peach industry in the Florida Panhandle and south Georgia, putting some of the earliest peaches into the market,” said Dr. José Chaparro, the peach breeder at the University of Florida at Gainesville. “A series of hundred-year freezes across the southeast United States in 20 years—in the seventies and eighties—almost destroyed the industry, resulting in a significant decrease in acreage in North Carolina, Georgia, and Florida.
“The freezes encouraged peach production in California, which is by far the dominant producer today.”
The freezes drove peaches out of north Florida. Acreage fell from more than 4,000 to fewer than 500. It drove citrus production south, but peaches didn’t follow. Until recently, there was little interest in relocating peach production further south. Now that’s changing, for two reasons.
First, there has been an increase in competition from growers overseas in the orange juice and tangerine fruit markets, Chaparro said. Brazil dominates the world trade in orange juice. Consumer preference for easy-peeling seedless Clementines initially imported from Spain and Morocco has also had a negative impact on tangerine production in Florida. The bacterial diseases, citrus canker and citrus greening, have squeezed profit margins, Chaparro said, and made production more difficult. Freezes continue to damage the crop, and frost protection using irrigation saves trees but not fruit. Therefore, citrus growers are actively searching for and evaluating alternative crops.
The second reason is the availability of new, high-quality peach varieties with low chill-hour requirements that fit into Florida’s subtropical climate from midstate south.
While the freezes damaged the Florida peach industry, it did not damage the University of Florida’s peach-breeding program, which had been turning out new varieties since it began in 1952. It did, however, change the emphasis, Chaparro said.
Instead of breeding peaches with chilling requirements in the 350 to 450 hour range to fit conditions in north Florida and south Georgia, the breeding effort turned toward finding varieties requiring less than 200 chilling hours, some as few as 50.
Instead of releasing varieties as public varieties, the newer ones are patent-protected controlled releases. That means the breeding program can tap into financial resources from a much broader base than just Florida acreage.
“Florida-developed varieties fit into subtropical climates all over the world,” Chaparro said. “They’re licensed and sold in Spain, Morocco, South Africa, and Australia. That helps us support our breeding program.”
Florida has been putting older public varieties in 20 other countries such as Thailand, India, Egypt, Mexico, and across Central and South America.
“Anywhere in the Northern Hemisphere, when you see a peach ripening in March or April, it’s probably a Florida variety,” Chaparro said.
The mission statement of the Florida breeding program still reflects the state-oriented land-grant university philosophy. But targeting varieties to central and southern Florida hits a lot of other places, too.
When Professor Ralph Sharpe started the breeding program in 1952, his idea was to help Florida growers capitalize on their climate and location to produce some of the earliest peaches that would come to market, Chaparro said.
“All our peaches ripen before June 10 here,” he said. “Our season is from April 1 to May 31.” One thing Florida has that southern California does not have is summer rain. “June is the start of the rains and disease pressure from bacterial spot and brown rot becomes overwhelming,” he said. “We have to be in and out of the peach market quickly.”
Peach breeder Sharpe was joined by Dr. Wayne Sherman in 1966. The two worked together until Sharpe retired in 1975. Chaparro moved from breeding citrus at the USDA-ARS program to become the University of Florida peach breeder when Sherman retired in 2004.
Early in the 1960s, Sharpe saw that Florida growers face one unique problem—a root-knot nematode that overcomes the nematode resistance of the then-available rootstocks Nemaguard, Nemared, and Okinawa. The rootstock Guardian, developed as a joint effort between the USDA-ARS and Clemson University, and released in 1993, is also attacked by the Florida nematode. In 2004, the nematode was named as a new species, Meloidogyne floridensis, but ten years before that, Sherman developed and released a resistant rootstock called Flordaguard.
“All the growers in Florida use that rootstock,” Chaparro said. While Flordaguard works well on the acidic soils of Florida, it is not adapted to high pH soils, he said.
Each year, Chaparro produces from 4,000 to 6,000 seedlings from peach crosses he has made.
His search is for peaches that combine some traits not usually thought of as going together. The peach has to be firm so it will ship well, yet juicy and ripe when picked. A peach that matures on the tree has much better flavor, he said.
He wants a minimum of 11 percent soluble solids for sweetness, moderate acidity, firmness, red color, and good size and shape.
The traditional clingstone peach is firm but not juicy and tends to have a rubbery texture. Its nonmelting flesh is also associated with a cantaloupe flavor in overripe fruit that is not desirable in peaches.
“We’re using a different nonmelting gene,” Chaparro said.
Trees grow fast
Modern Florida peaches, those with a UF prefix, are nonmelting and not freestone, like clingstone peaches, but they are firm without being rubbery. They are also juicy and have a high sugar content and good peach flavor. Varieties released from the program include FlordaPrince, UFBest, UFSun, and UFOne for south Florida; UFGold, UFO, UFBlaze, UFBeauty, UFSharp, and FlordaBest for north central Florida; and UFGlo for north Florida. The program has also released UFQueen and UFRoyal, nectarines adapted to north central Florida.
A major factor in raising peaches in Florida is the long growing season. The tree is only making fruit for about three months, and is only dormant for about two months—November and December. The rest of the time, it’s growing.
“We can grow a tree really fast,” Chaparro said. “The problem is containing the growth.”
Florida growers have stayed with the open vase system to help keep trees short. “We tried the perpendicular V system, but with our long growing season, it was a nightmare,” he said. Florida peach trees can produce canopy growth of seven to nine feet each year.
Currently, he is breeding for a reduced branching, spur-type tree that would not require the labor and expense of multiple prunings each year, and will stay open in the center for good light penetration and good flower bud development.
Florida growers have shown their confidence in the program. From only about 20 acres a few years ago, acreage in central and south Florida has grown to 1,200 to 1,400 acres, and is growing about 15 percent a year. “It’s really taking off,” Chaparro said.
A study done two years ago suggested that Florida growers, aiming to fill that void between production in Chile and production in California, could easily sell the fruit produced from between 7,700 and 10,400 acres of peaches. Another study suggested production could expand to 100,000 acres, a far cry from the scattered orchards of today.