Posts Tagged ‘Brenda Eggert Brader’

Chill Hours Update: Watching the Weather and Tallying the Time


PEACH GROWERS from Florida, Georgia, and South and North Carolina are concerned. For a second fall/winter season, 2016-17, climatologists are saying there will be the same warm fall and early winter season the growers had last winter. Orchards need cold weather called chill hours to break dormancy and yield fruit.

“Climatologists are saying we are to have a warmer-than-normal fall and early winter,” says Jeff Cook, University of Georgia Cooperative Extension Taylor/Peach County Ag and Natural Resources Agent. “Last year we were historically warm … too warm. October starts the chill hours counting and we didn’t have any chill hours to amount to anything until January … not a killing frost until January.”

Peaches need chill hours and most varieties in middle Georgia need between 700 and 1,000 hours, Cook points out. Lack of chill hours can cause erratic fruiting and blooming, which can make it hard for farmers to organize their harvest and contributes to decreased yields.

“It depends on where you are as to how the peach crop is,” Cook states. “In middle Georgia, if we get 800 hours, we will be in good shape. Normally, we have 1,100 hours by January 15. We didn’t make it last year, for temperatures were in the mid-70s. I think it definitely had an effect on the fruit quality this year.”

Flooding waters in orchards can be an issue for peaches, but the fields in Georgia have been dry. In fact, no rain was even received in mid- Georgia by recent Hurricane Matthew. “We got breezy days that made the dryness even worse,” Cook recalls. “I don’t know how much rain they received in South and North Carolina, but they were dry and in need of rain so it probably helped.”

“We are in reduction in the number of buds and maybe quality,” Cook observes of the peach crop this year. “Some spots have gone seven to eight weeks now without rain. I would say middle Georgia is part of that exceptional drought, it is so extremely dry.”

“Peach trees set flower buds in summer and normally set too many so we should be okay. Flower bud numbers are not as big a deal as getting the chill hours we need.”

From a growers’ standpoint, they usually don’t start worrying until December, Cook shares. “At this point, the growers are thinking about it, but trying not to worry too much about things we can’t do anything about.”

There is help in creating a manmade chill-hours effect for the peach tree with hydrogen cyanamide (known by brand names as Dormex or Kropmax) that is supposed to boost up to 300 hours of chill to let the tree start breaking dormancy, Cook notes.

The research arm of the extension has been working on ways to make peach trees produce around the chill hours, but haven’t show any effects from it, Cook cites, reminding that researchers like to have multiple years of data — not just one year to share. If this is another light winter, he says that they will at least have another year of research on the problem.

“Right now, we are looking at a warmer winter, but we are still hopeful,” Cook concludes. “If we normally get a couple hundred less chill hours, it would be fine. We just hope we have a winter this year.”




Expanding Organic Research with Recent Funding


Clemson Will Partner with Other Southeastern Universities on Peach-Bagging Study

THANKS TO A RELATIVELY NEW PROCEDURE, more organic peaches may be entering the market to satisfy consumer demand. The process, which is still under research, involves bagging the individual fruit while it’s on the peach tree.

Clemson University pomologist Juan Carlos Melgar and pathologist Guido Schnabel are tying paper bags on peaches as they grow on trees, an unconventional method of protecting them from insects and disease while reducing reliance on pesticides. Testing for the method began two years ago and research will expand to more orchards in South Carolina, Georgia, and Florida with a $999,770 four-year grant awarded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture (NIFA). They will analyze optimal bagging times, harvesting strategies, and the impact of variable weather conditions while working with scientists at the Universities of Florida and Georgia. Together, they will evaluate production using bags, educating growers throughout the Southeast about growing peaches organically with this method, and analyzing the economics of bagged peaches.

“There is only one organic peach producer in South Carolina,” Melgar states. “Organic peach production in the Southeastern U.S. is very difficult due to the high pest and disease pressure, plus the lack of efficacious organic pesticides. And while there is a great demand among consumers for organic peaches, its production is concentrated in western states, such as California and Washington. This project will provide organic peach growers and growers in transition to organics in the Southeastern U.S. with an innovative strategy to increase peach orchard productivity and economic returns, to produce high-quality, low-residue peaches; and to reduce reliance on insecticide/fungicide applications.”

Melgar explains that they have tested bags in commercial orchards in South Carolina under two settings — conventional production and organic production. In their trials, they found that the use of bags increased pack out (marketable yield) in the organic orchard since they reduce the presence of fruit pests and the incidence of fruit diseases. There is no increase in yield in the conventional orchard because the spray programs used for peach production in the Southwest already do a great job at controlling pests and diseases.

But how cost effective can it be to wrap each piece of fruit on a tree in a bag? It takes one hour for a person to bag all the fruit in a mature peach tree, approximately 400 pieces of fruit, Melgar reports.

“It mostly depends on the availability of workers. Bagging cost (based on an average wage of $10-$12 per hour and a few dollars for bags per tree) is between $15 and $17 per tree,” he says. “For a conventional orchard, if a mature tree produces 200 to 250 pounds, a grower would only need to receive 10 cents per pound extra to cover the costs.”

Surveys of potential consumers say they would be willing to pay an average of 40 cents extra per pound, with a group of consumers normally above 50 years old and with high income saying they would be willing to pay up to $1 extra per pound of bagged peaches, notes Melgar, who thinks the opportunity for conventional growers would be there if these peaches are sold to this niche market with people looking for a premium peach.

“On the other hand, organic growers may benefit of both an increase in production and an increase in price,” Melgar points out.  “Thus, we think this strategy can benefit organic producers more than conventional producers.”

Harvesting the bagged peaches doesn’t seem to be a problem either. Growers know when their varieties should be harvested.  At the predicted harvest time, it is recommended to rip the bags open and harvest the first pick (those that are ready), leaving the other fruit bagged on the tree, bags open at the bottom, doing the second and third picking when they are ready.

Initial tests on bagged peaches show sugar and acidic content, and the ratio between the two, to be the same in both bagged peaches and peaches applied with pesticides, so flavor is not affected, according to Melgar.  Fruit size and weight are the same.  For some varieties, only the color is different with the bagged peaches not having the blush red as conventionally grown peaches due to not getting as much sunlight.

South Carolina growers harvest more than $64 million in peaches a year, according to figures from the National Agricultural Statistics Service.  That puts South Carolina second only to California in peach production, and the Southeast as a whole produces nearly one third of the peach crop grown in the United States.

What is the program’s outlook?  “We see there is a great opportunity for the organic growers for two reasons — demand for organic peaches is growing in the U.S. while production in the Southeastern U.S. is almost nonexistent, and, second, they are the ones that can benefit the most from the price and the increase pack out,” Melgar states.

Going forward, program plans include focusing on improving strategy, spray programs, comparing bagging at small versus large scale, and studying the long-term impact of bags on decreasing pests and disease populations in the field when a big acreage is bagged.