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New Business Development Opportunity for Peach Industry Experts

The Central Florida Media Group attends many trade shows throughout the year.  Several months ago, we attended a very successful citrus trade show. The exhibit hall was sold out.  A vast majority of the vendors were selling plant nutrition solutions.  As I walked around the exhibit hall floor, I couldn’t help but notice many of the vendors had spent a significant amount of time and resources developing sales materials and booth exhibits, but traffic to their booths was almost non-existent. Read More…


Grower’s Thoughts

There’s no denying that it has been a tough season for peaches here in Florida this year. I can’t imagine there’s a corner of the state’s agriculture that hasn’t been affected. At Rafool Ranch and Land in Central Florida, we’re in our fourth year of growing, and our peach production for the year is down 80 percent over the last two years. While many were still picking in late April, I would estimate that peach yields are down 60 to 70 percent or more all across the state.

The first issue we all faced was the warm, wet weather in November and December; it affected many other crops—like blueberries—along with peaches. Not even taking the Dynamic Model into account for calculating chill hours—which has warm weather reversing chill hours ‘in the bank’—our trees basically received zero chill hours in November and December. With an El Nino weather pattern keeping cool air at bay, the warm winter wasn’t unexpected. However, no one could have predicted that the weather would be so warm for so long. According to the National Oceanic and Atmospheric Administration (NOAA), December 2015 through February 2016 was the warmest winter on record in the contiguous United States.

The warm temperatures convinced the peach trees that it was time to grow, and they went into bloom early. Then, a return to colder-than-normal temperatures in January threw the trees for another loop. Ball bearing-sized fruit simply fell from the trees, ending a lot of early harvests. We weren’t picking at all in two out of our three blocks, and the production of the third block was only 10 to 20 percent of expected yields. We tried a spray called Dormex, a plant growth regulator, which helps blueberry farmers in increase fruit size and yields, but we didn’t really find it to be effective.

The next issue started with the cold weather sending the trees back into dormancy. When temperatures again began to rise—like they usually do as the year progresses—the trees put out a secondary bloom. While these peaches we’re harvesting now have kept this year’s season from being a total bust, the turn of events have pushed the season back considerably. Generally, Florida’s peach season is over by the first week of May, and harvest time usually coincides with a slim market lull that occurs after Chile’s harvest and before Georgia’s or California’s peaches flood the U.S. market. Obviously, a high supply does not make for premium prices for growers, and a late Florida season could overlap with Georgia and California peaches.

Furthermore, many growers also witnessed the destruction of peach trees at the hands of Peach Short Life. It’s an issue the peach industry will need to keep an eye on and develop a treatment or cure for.

Lastly, as if to add insult to injury, much of Central Florida suffered inclement weather and hail in the middle of April. Chunks of ice hurtling from the sky do not do nice things to soft peaches ripening on the branch. Many growers saw fruit knocked down or damaged beyond repair by the bad weather.

There are silver linings to the season, however! Firstly, the peaches that are being harvested are big, juicy and as sweet as sugar. That’s exactly what the consumer wants. Secondly, we’re also blessed here in Florida to have a large local market, thanks to the good work of the Fresh From Florida program and Florida residents who love Florida produce. Our market share is large enough to sustain the industry. Thirdly, reports from other parts of the country suggest that California and Georgia are having rough peach season as well, and that their peaches may also be late to hit the market.

Lastly, there’s pride to be had in being a part of Florida’s fledgling peach industry at the moment. We’re essentially pioneers and innovators cutting the trail for others to follow. The University of Florida is still working on low-chill varieties, and it’s not to an exact science yet. You can’t just pull out oranges, stick in peaches and expect a money printing press. Some years are good and some bad.

If being Sunshine State pioneers isn’t enough, peach growers can count their lucky stars they aren’t in Northeast states like Delaware and New Jersey. A similar warm-then-cold weather pattern—obviously much colder than Florida’s temperatures— caused buds to freeze on the branch. Some early reports maintain there might not be a single peach to be had.


Maintaining Peach Fruit Firmness and Quality

When plant growth regulators can make a difference

It is that time of the year when we finally have a marvelous surprise when visiting our preferred grocery store – Peaches are finally here and will be here for months!  There is a lot of management and preparation that goes in peach production to deliver to the stores a peach fruit with wonderful quality and aroma. Achieving and maintaining this quality is one of the most important goals in peach production from pre- to post-harvest decisions. The University of Georgia, in collaboration with the Georgia Peach producers, evaluated the use of plant growth regulators to maintain peach firmness and quality in 2014 and 2015. The results from these studies are presented in this article.

Traditionally, peach fruit is harvested using commercial standards that allow the peach producers to offer fruit that maintain firmness and quality during transport, delivery, and commercialization.  Peach growers generally have multiple varieties in their production inventory (approx. 30-40 different varieties in middle Georgia) allowing them to offer fresh peaches throughout their whole marketing season. Each variety can ripen in a period approximately of 1-2 weeks. However, sometimes there are production gaps that cannot be filled with the ripening window of the peach varieties currently available. There is great interest in extending the season of certain peach varieties to fill these gaps by both delaying fruit ripening on the tree and/or prolonging the storage life of the peaches. We at the University of Georgia Peach Team in collaboration with the Georgia Peach producers evaluated the use of plant growth regulators to maintain peach fruit firmness and quality in the tree by delaying fruit ripening in 2014 and 2015. The use of the growth regulators will allow peach growers to fill certain marketing gaps and maintain fruit quality.

Plant growth regulators have been used to improve growth, flowering, and fruit quality in different fruit crops. In peach, Valent BioSciences Corporation, IL has been offering two products, ProGibb® and Retain®, to improve peach fruit firmness and quality during harvest in the Southeastern US. ProGibb® is 4% gibberellic acid (GA3 – promotes growth and elongation of cells) liquid formulation and Retain® is 15% aminoethoxyvinylglycine (AVG – ethylene inhibitor) soluble powder formulation, both produced by fermentation.

Gibberellin has been reported to improve fruit quality, increase fruit size and firmness by delaying fruit maturity in peach (Dagar et al., 2012; Jackson, 1968; Ju et al., 1999; Olmstead and Futch, 2012; Zilkah et al., 1997). AVG is an inhibitor of ethylene synthesis, which is associated with fruit ripening and softening in peach. AVG has been reported to decrease fruit drop pre-harvest, delay fruit development, slow fruit softening, and increase firmness in peach (Byers, 1997; Ju et al., 1999; McGlasson et al., 2005; Olmstead and Futch, 2012; Rath and Wargo, 2004; Torrigiani et al., 2004).

In 2014 and 2015, the use of GA3 and AVG were evaluated in selected peach varieties. GA3 and AVG were applied with an airblast sprayer (333g/A of Retain® plus 20fl oz/A of ProGibb® 4% in a 100 gal/A spray volume, plus organosilicone surfactant). Applications were made two to three weeks before commercial harvest. Control plots were left untreated at the same locations for comparisons. Orchards were maintained following standard commercial management practices for the Southeastern US. Fruit was harvested from treated and untreated trees and fruit characteristics were taken for ‘Early August Prince’ and for ‘Ruston Red’ in 2014; and ‘Springprince’, ‘Juneprince’, and ‘Babygold’ in 2015. ‘Early August Prince’, ‘Ruston Red’ and ‘Juneprince’ are melting varieties. ‘Springprince’ and ‘Babygold’ are non-melting varieties.

Fruit was harvested from treated and untreated trees and fruit quality characteristics were taken. Single tree plots, a total of three to nine replications, were used for treated and untreated comparisons. Five fruit were harvested every three days starting approx. one week and ahalf before commercial harvest. Each fruit was rated individually. Fruit evaluations included rating the: blush, redness in the flesh, peach fuzz (1-9 scale), fruit tip (1-9 scale), firmness (1-9 scale, kgf, N), split pit, weight (g), and perimeter (mm). The subjective 1-9 scale represented values of 1 = undesirable to 9 = optimal. Blush and redness in flesh were rated as percent coverage. Split pit was rated as present or absent. Firmness was measured using a Wagner Model FT 30 fruit penetrometer (Figure 1).

In our study, we observed that the overall fruit characteristics, fuzz, tip, and split pit, showed no difference between treated and untreated for all the varieties across years. Percent blush, red flesh, perimeter, and weight for the treated and untreated did show some significant differences; however, these differences were not observed for most of the harvest dates. The fruit treated with plant growth regulators, GA3 and AVG, were firmer than the untreated fruit. In 2014, differences in fruit firmness were seen for ‘Early August Prince’ and ‘Ruston Red’ in Lane Southern Orchards for almost all plots after the first commercial harvest, but not for ‘Early August Prince’ in Pearson Farms. In 2015, differences in fruit firmness were seen in ‘Springprince’ and ‘Juneprince’ in the Fort Valley State University peach farm, and not for ‘Babygold’ in Fitzgerald farm (Figure 2).

The results from these trials were consistent with results from previous research of GA3 and AVG in peach. In this study, we observed variation in the effect of these plant growth regulators by varieties and locations. The evaluation of the fruit in this experiment was meant to determine the positive and negative effects of GA3 and AVG applications on fruit quality, primarily firmness.  It is necessary to study in the future the potential economic gain by using these products and the effect in the flowering vigor of the plant for the next season, as GA3 applications have been previously reported to affect return bloom in peach (Lurie and Crisosto, 2005). For additional results and information about this study please contact Dario Chavez at


Byers, D.H. 1997. Peach and nectarine fruit softening following aminoethoxyvinylglycine sprays and dips. HortScience 32:86-88.

Dagar, A., A. Weksler, H. Friedman, S. Lurie. 2012. Gibberellic acid (GA3) application at the end of pit ripening: Effect on ripening and storage of two harvests of ‘September Snow’ peach. Scientia Horticulturae, 140:125-130.

Jackson, D.I. 1968. Gibberellin and the growth of peach and apricot fruits. Austral. J. Biolog. Sci. 21:209-215.

Ju, Z., Y. Duan, Z. Ju. 1999. Combinations of GA3 and AVG delay fruit maturation, increase fruit size and improve storage life of `Feicheng’ peaches. J. Hort. Sci. Biotech. 74:579-583.

Lurie, S. and C.H. Crisosto. 2005. Chilling injury in peach and nectarine. Postharvest Biol. Technol. 37:195-208.

McGlasson, W.B., A.C. Rath, L. Legendre. 2005. Preharvest application of aminoethoxyvinylglycine (AVG) modifies harvest maturity and cold storage life of ‘Artic Snow’ nectarines. Postharvest Biol. Technol. 36:93-102.

Olmstead, M. and S. Futch. 2012. Using an ethylene inhibitor to increase fruit size, firmness, and storage quality in Florida peach production. Proc. Fla. State Hort. Soc. 125:13-16.

Rath, A.C. and J.M. Wargo. 2004. Aminoethoxyvinylglycine (AVG) applications to commercial blocs of ‘Tatura 204’, ‘Golden Queen’ and ‘Taylor Queen’ peaches delays fruit maturity and increases fruit size and quality. Acta Hort. 653:167-171.  

Torrigiani, P., A.M. Bregoli, V. Ziosi, S. Scaramagli, T. Ciriaci, A. Rasori, S. Biondi, G. Costa. 2004. Pre-harvest polyamine and aminoethoxyvinylglycine (AVG) applications modulate fruit ripening in Stark Red Gold nectarines (Prunus persica L. Batsch). Postharvest Biol. Technol. 33:293-308.

Zilkah, S., S. Lurie, R. Ben Arie, S. Antman, I. David, Y. Zuthi, Z. Lapsker. 1997. Preharvest sprays of gibberellin on ‘Flamekist’ nectarine trees to improve fruit storage potential. J. Hort. Sci. 72:355-362.

Figure 1. Peach fruit evaluation from green to commercially mature. Wagner Model FT 30 fruit penetrometer with the FT 516 tip. Photos by D.J. Chavez.

Figure 2. Fruit firmness (kgf) measured using a penetrometer in the GA3 and AVG trial for ‘Early August Prince’  in Lane Southern Orchards, Fort Valley, GA in 2014 (A), ‘Early August Prince’ in Pearson Farms, Marshallville, GA in 2014 (B), ‘Ruston Red’ in Lane Southern Orchards, Byron, GA in 2014 (C), ‘Springprince’ in Fort Valley State University peach orchard, Fort Valley, GA in 2015 (D), ‘Juneprince’ in Fort Valley State University peach orchard, Fort Valley, GA in 2015 (E), and ‘Babygold’ in Fitzgerald Farms, Woodbury, GA in 2015 (E). Green dotted line represents the date of commercial harvest. Red arrows represent dates with statistical significant differences between treated and untreated fruit.



Dario J. Chavez, Research and Extension Peach Specialist, Assistant Professor, Department of Horticulture, University of Georgia, Griffin, GA.

Jeff Cook, Georgia Peach Area Agent and County Extension Agent, Taylor and Peach Counties, University of Georgia, Fort Valley, GA.


It’s in the Bag

Peach bagging has potential to bring the organic peach market to the Southeast

Credit: Juan Carlos Melgar, assistant professor of pomology – Clemson University, and Guido Schnabel, professor & plant pathologist – Clemson University

Peach growers in the southeastern United States must control many pests and diseases to be able to produce high-quality peaches. From brown rot, peach scab, bacterial spot, and anthracnose to plum curculio, thrips, scale, and mites, the extensive list of problems make peaches one of the most sprayed fruit. Frequent pesticide application creates residue issues, hastens resistance development, and causes environmental concerns. Many conventional growers are trying to counter these problems by reducing the amount of pesticides applied to their crop, but pest and disease control remain a major challenge in the humidity of the southeast.

Consumer demand for high-quality and pesticide-free fruit is growing, and the alternative to conventional production is organic production. However, production of organic peaches is almost impossible in the conditions of the Southeast, and very few growers are taking this chance. For this reason, reports the USDA Economic Research Service, southeastern states are not benefiting from the market opportunities of organic peach production, which underwent explosive production growth in states like California, Washington, and Oregon.

At Clemson University, Extension specialists Juan Carlos Melgar and Guido Schnabel are trying to solve the dilemma that the southeast US growers are facing. They bag peaches as they grow on trees, an unconventional method of protecting them from insects and diseases while reducing reliance on pesticides. Field bagging of fruits has been practiced in Japan, China, Australia, and Spain, but has never been studied in the conditions of the southeastern United States. The two have a hypothesis that this technique has potential to drastically reduce pesticide application for both conventional and organic fruit production.

“For conventional growers, I could imagine people bagging some fruit and selling them as priority peaches or low-residue peaches for a premium,” Schnabel says. “I believe this could also be a key component for organic producers, who currently don’t really have the tools to produce quality fruits. It is very tough to keep the insects and the disease off the peaches—these bags might be the answer.

Melgar and Schnabel bag peaches when the fruits are very small, at the time trees are thinned, and the paper (is it really paper? I saw pictures and I think they’re plastic. Or is this a paper bag over the plastic bag? – LB) bags protect the fruit during the rest of the season.

Last year, they bagged at two farms in the Ridge, South Carolina’s predominant peach-growing region in the western counties of Edgefield, Saluda and Lexington. Tests showed sugar content, acidity, and the ratio between them to be the same in both bagged peaches and conventionally-grown peaches—that meant flavor was not affected. Fruit size and weight were also the same, Melgar said.

While bagged peaches were not as blush red as conventional peaches due to the decreased sunlight they received while in the bag, they did acquire a nice “peachy” color, and their blush percentage was comparable to non-bagged peaches. In fact, surveyed at Upstate (is this a term that people know? Is it upstate south carolina? Or a proper noun? – LB) farmers markets, potential consumers overwhelmingly preferred the less red peaches when they knew that they were grown in bags.

“People were excited to know these peaches had not received pesticide applications and many people were willing to pay a premium of up to 80% more than peaches grown with pesticides,” Melgar said. While bagging peaches may not displace pesticide applications in large-scale operations, Melgar and Schnabel envision a niche market serving healthy-minded consumers willing to pay a premium for chemical-free produce.

Growing peaches in bags adds cost in form of increased supplies and labor, although growers would save money on pesticides while still combating fungicide resistance. Also, the ratio of cull fruit in the packout may be reduced. Based on last year results, they calculated that growers might have to sell the bagged peaches at $0.10-$0.15 more per pound to make up for the increased costs.

While Melgar and Schnabel explore ways to benefit conventional growers with this technique, especially using it in varieties that easily develop skin blemishes, they know that this method is most easily marketable to organic farmers. Since consumers of organic produce are already willing to pay a premium, the bagging method might finally open opportunities for an organic peach market in the southeastern United States.
Potential pulled-out box:

Bagging peaches could also enable homeowners to grow peaches in the backyard. Many people, from multiple states, have shown interest in these bags, so Schnabel and Melgar prepared a homeowner instruction fact sheet available by scanning this QR code with your smart device:

Funding for this project came from a 2015 Southern IPM Center IPM Enhancement Grant (maybe small at bottom… because I’m unsure about what all the “project” entails, (just the initial research? Bagging in SC?) I don’t know exactly where is accurate to work into the body text.) LB


Control of the Peachtree Borer Using Beneficial Nematodes


David I. Shapiro-Ilan & Ted E. Cottrell, USDA-ARS, Southeastern Fruit and Tree Nut Research Laboratory, Byron, GA
Russell F. Mizell III, Department of Entomology, NFREC, University of Florida, Quincy, FL
Mercy A. Olmstead, Horticultural Sciences Department, UF/IFAS, University of Florida, Gainesville, FL

The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. Beneficial nematodes are safe and natural bio-insecticides. They’re produced commercially by several companies, and are used to control a variety of economically important insect pests such as the black vine weevil, diaprepres (diaprepes… not sure which spelling is correct – LB) root weevil, fungus gnats, and various white grubs.

Unlike harmful plant-parasitic nematodes, beneficial nematodes only attack insects. The nematodes enter insects’ bodies through natural openings or sometimes directly through the insect’s cuticle. The insect dies, usually within 24 to 48 hours.  The nematodes reproduce within the body, after which the offspring exit the corpse to find new insects to attack.

Current peachtree borer management across the southeastern US relies solely upon preventative post-harvest chemical control, particularly, chlorpyrifos. Due to environmental and regulatory concerns, research toward developing alternative pest control measures is warranted.

We conducted an experiment to determine beneficial nematode efficacy in controlling peachtree borer in a preventative manner with summer/fall applications. This follows the same approach commonly used by growers to manage peachtree borer; insecticides are sprayed in the later summer or fall to prevent damage to the tree. For nematode application, we compared common equipment that commercial growers could use for nematode application including a boom sprayer, trunk sprayer and handgun. Treatment applications were made in two consecutive years, September 2012 and September 2013. Results were combined for both years. All nematode treatments and chlorpyrifos reduced peachtree borer infestation relative to the non-treated control; there was no difference between chlorpyrifos and the nematode treatments.

We also measure the efficacy of the beneficial nematode as a curative control for existing infestations of peachtree borer, as missed applications, poor application timing or other factors may result in high levels of peachtree borer infestation through the following spring. Prior to our research, curative control did not exist. The effects of treatment on infected trees were assessed 3-6 weeks later by determining the number of surviving peachtree borer larvae per tree. All nematode treatments provided significant curative control; in contrast, chlorpyrifos failed to significantly reduce the number of surviving larvae.

The nematodes can be applied using standard agricultural equipment. It is important to keep the soil moist for at least two weeks after applying nematodes. Alternatively, if irrigation does not exist in the orchard, a gel can be applied to the soil surface to keep the nematodes moist.

Our research concluded that the beneficial nematode, Steinernema carpocapsae, can be applied effectively for control of peachtree borer.  Applications can be made preventatively in the summer/fall or curatively in the spring. Nematode efficacy is similar to chlorpyrifos in preventative applications and superior in fall applications, offering farmers an alternative to traditional pest treatments.


Fig 1: Hatched larvae of the peachtree borer, Synanthedon exitiosa, bore into the trunk near the soil surface and tunnel into the roots. Photo by Stacy Byrd, USDA-ARS

fig 2: Beneficial nematodes, genera Steinernema and Heterorhabditis, are safe and natural bio-insecticides. Photo by J. Morales-Ramos, USDA-ARS

fig 3: Chart: percentage peachtree borer infestation following preventative applications of beneficial nematodes (N) via boom sprayer, handgun or trunk sprayer. Chlorpyrifos and a non-treated control were included for comparison.

Fig 4: Chart: Percentage peachtree borer infestation following curative applications of beneficial nematodes (N) via boom sprayer, handgun or trunk sprayer. Chlorpyrifos and a non-treated control were included for comparison.