Crop Profile for Peaches in Georgia and South Carolina

Prepared: March, 2004

General Production Information

Georgia and South Carolina rank 2nd and 3rd, respectively, in U.S. peach production. Annual production for the combined Georgia and South Carolina peach crops (NASS, 1997–2001) averages 226 million lbs, with an average value of $63 million. Together, Georgia and South Carolina account for 25% of the nation’s fresh peach acreage. The Georgia and South Carolina peach crops are grown almost exclusively for fresh sales. Wholesale grower-shippers, who sell primarily to chain stores, market over 90% of the crop. Both Georgia and South Carolina wholesale grower-shippers view themselves as facets of a single production area, as most use the same brokers and ship to the same markets. Roadside and local sales are next in importance. Processing, primarily for baby food, is limited, accounting for less than 1% of sales.

Production Regions

Peach production is clustered in areas where quality orchard sites offer some measure of freedom from spring frosts, and soils that support good tree growth and orchard longevity. Middle Georgia’s Fort Valley plateau and South Carolina’s Ridge area are the epicenters of production in the two-state area. Collectively, they account for ca. 70% of the bearing acreage in the two states. Significant production is also found in Georgia’s Brooks County (southwest GA) and in South Carolina’s piedmont region (northwest SC). Smaller areas of production are in west central and southeast Georgia and additional scattered production in the north central part of the state. South Carolina has small production areas in the coastal plain and sand hills regions.

Georgia-South Carolina Peach Production

 

Food, Worker and Environmental Safety

Southeastern peach producers want research to develop reliable, affordable pest management options that continue to improve food, worker and environmental safety. The region’s landgrant and USDA-ARS scientists are developing more biologically attuned pest management programs. Genuine improvements will require a more thorough understanding of pest biology. Sampling technologies, predictive models and treatment thresholds are research objectives.

Food Safety- As food safety programs mature, they more systematically embrace mitigation of food-borne microbial contaminants with concomitant attention to pesticide residues on harvested product. Good Agricultural Practice (GAP) programs are being implemented to identify and mitigate production-side food safety concerns. Critical point analysis (HACCP) for both microbial and pesticide residue risks is needed to more accurately access and mitigate risks from harvest through shipment.

Labels & Tolerances- Pesticide residue levels on foods are regulated by labels and tolerances. Pesticide labels stipulate allowable uses and restrictions for each material on labeled crops. Tolerances are crop-specific, maximum-allowable residue levels. In a few cases, tolerances allow importers to use materials that are not labeled for use by U.S.farmers. American produce growers, including peach growers, must receive assurance that foreign producers will be held to the same standards U.S. growers abide by.

Hand Labor- Peaches are highly dependent on hand labor, especially during the thinning and harvest season. Peaches must be hand thinned two times, normally between 30 and 60 days after fruitset, removing up to 90% of the total number of potential fruit, in order to achieve marketable size. Heavy pruning is done early in the dormant season before seasonal application of chemical protectants begins. In some orchards in someyears ‘summer pruning’ is done to improve fruit color, may be donebut insufficient needed labor often precludes this. Peach trees are normally maintained within a weed free zone. Most orchards are maintained with bare ground beneath the trees, and grass or volunteer vegetation between the rows. Middles, in orchards where sod is present, are mowed about two times during the growing season. Herbicides Orchard floor management pre-emergent herbicides are applied using tractor-mount equipment. , as are any applications of post-emergent herbicide! s and those applied post-season. Some orchards maintain bare ground throughout the orchard, but in those orchards with grassed middles they are mowed during the entire growing season. The peach crop is harvested by hand. Post-season applications of oils and/or insecticides for peachtree borer are made with hand guns.

Continued enhancement of worker safety is an industry commitment. Pesticide use, which is necessary to combat high pest pressure, chronically exposes orchard laborers to modest, allowable, pesticide residues on the trees and fruit. Step-wise, in-orchard quantification of acute and chronic worker exposure to key pesticides is needed to facilitate any needed risk mitigation efforts.

Re-Entry Intervals- With the total number of materials that may be applied in an orchard during the season, the number of chemical applications that may be made, and the imperative needto have workers enter the orchard through the season to perform needed production activities, re-entry intervals (REIs) are a very an important consideration. Regulatory decisions on worker REIs must address bothbalance the imperatives of worker safety and with the grower’s need to conduct essential horticultural practices in a timely fashion. essential in-field production activities.

Pre-Harvest Intervals- Late-season pest pressures can be high. Pesticide manufacturers understandably strive to optimize risk -cup utilization, very often by not labeling newer, low-risk materials for pre-harvest uses. The societal goal of progressively lowering food and worker safety risks makes it imperative that U.S. EPA encourages labeling of low-risk pesticides when they will most effectively mitigate risks. In the absence of EPA action on this issue, low-risk materials will most often be labeled when they do little to mitigate dietary and worker safety concerns.

 

Varietal Influences on Peach Pest Management

Varieties & Length of Season Influences on Pesticide Use- Due to high pest pressures, southeastern peaches are dependent on preventative pesticide use. Accordingly, the most telling predictors of pesticide use in southeastern peaches are actually--—length of growing season for each variety, season of ripening,rainfall and varietal susceptibility to select pests. Wholesale markets require nearly flawless fruit. Scheduled sprays are required season-long, because the risk of pest injury is present throughout the growing season. The absencelack of monitoring tools and thresholds make it impossible to make as-needed responses to key pests.

Length of Season- Wholesale peach shippers in Georgia and South Carolina typically grow 25 to 30 varieties, which mature fruit over a season of eight to 10 weeks. Most varieties ripen and are harvested over a period of ca. 10 days. Wholesale market windows, commonly called seasons, are broken down into intervals of ca. 10 days. Each of the eight 10-day seasons is known by its dominant variety. Growers vary the frequency of sprays, rates, and materials in response to perceived pest pressure, but sprays are made throughout the season. Accordingly, early season varieties that mature fruit in ca. 90 days will be sprayed far less than full season varieties that require 180 days to mature their fruit.

Weather- Humidity is almost always high in the Southeast, but disease pressure is typically highest during periods of frequent rainfall. Rain also shortens the residual efficacy of pesticides, necessitating more frequent applications, higher rates or use of stronger materials.

Varietal Susceptibility- Marketability is the overriding consideration in varietal selection Varieties that do not meet, or exceed, the quality of varietal standards each week of the season are non-competitive. Varietal differences in pest susceptibility certainly exist. are well known to growers. For instance, Peaches are more tolerant of mites than most tree fruit. Unfortunately, but useful levels of resistance to key peach pests is frequently largely unavailable in commercially competitive varieties. However most southeastern varieties have come from distant breeding programs where different pest complexes and lower pest pressures, especially from diseases, exist.

Bacterial spot is a key disease in Georgia and South Carolina, but commercially competitive resistant, or at least less susceptible, varieties are only available for portions of the long growing season. UnfortunatelyIn fact, ssome of the very best wholesale peaches are quite susceptible to bacterial spot. Bacterial spot susceptible varieties, such as the highly susceptible O’Henry, are planted because they are otherwise superior peaches that dominate markets during their respective seasons. Growers will only plant bacterial spot resistant varieties that are competitive during their market window. To do otherwise is to court financial ruin. Bacterial spot sensitive varieties are planted with full knowledge of their pest susceptibility and higher production costs. Consequently, growers are concerned over the potential impact of adverse pesticide regulatory decisions.

Peach breeding programs, public or private, are few in number. Until very recently, the primary southeastern peach breeder lacked the complementary IPM personnel needed to implement meaningful pest resistance/susceptibility evaluations. On a positive note, Clemson University’s peach genome project is progressing well, offering long-term potential for accelerating incorporation of pest resistance traits into commercial selection.

 

Pest Management

Peach pest management in the eastern U.S. is seriously under-researched. Vandeman et al. (1994) observed that pest management in peaches was less evolved than in the other major tree fruits. Georgia and South Carolina peach growers must deal with diverse pest complexes; heavy pest pressures occur season-long. Producers, especially wholesale fresh market shippers, must provide a product that satisfies expectations of very high quality fruit. Currently, our most evolved fresh market programs require multiple, scheduled pesticide applications to manage fruit and tree pests.

Growers need research-backed, reliable, cost-effective IPM options that will simultaneously provides greater assurance of food, environmental and worker safety. Development of more sophisticated peach IPM options for the southeastern U.S. is being held back by insufficient knowledge of pest and beneficial species biologies. We also lack pest monitoring and thresholds for key southeastern peach pests.

New IPM research projects have been initiated, but years of highly focused effort will be required before IPM options available to southeastern peach growers mirror those seen in crops such as cotton or apples. The commodity's high value, coupled with the wholesale market's intolerance of pest injury, compels reliance on highly dependable, broad-spectrum pesticides. Until more sophisticated IPM systems are developed for multiple pest complexes, reliance on broad-spectrum, protective sprays will be necessary.

Pesticide Resistance- Resistance risk is high in peaches, a long-term perennial crop that harbors and attracts diverse pest complexes that must be controlled each year. For example, strains of DMI-resistant brown rot were isolated from GA in 2003. IPM systems must account for the risk of pest resistance. Rotating the toxic mode-of-action of pesticides is the most feasible management option; however pesticide options for some pests are quite narrow. It is imperative to maintain multiple modes-of-action for use against key pests. Regulatory decisions should thoroughly consider resistance management concerns.

Pest Complexes- Peach pests are more easily considered when grouped into tree pests and fruit pests. Pest management efforts must efficiently address both fruit and tree pests. Overlapping periods of injury and the sheer number of key pests strongly favors use of broad-spectrum materials that afford protection from multiple diseases, or pest insect or weed complexes.

Biological Control- From a crop management perspective, biocontrol agents presently offer little opportunity for use as management tools; predators, parasites and antagonists have not been adequately examined in the southeastern peach system. While biological controls are presently not clearlysufficient to protect against forkey southeastern peach pests, natural enemy complexes are perceived as helping to regulate indirect pests such as aphids and mites. As pesticide use patterns change, it will be important to examine anychanges in the abundance and utility of beneficial complexes.

Cultural Controls- Cultural practices that consistently help to lower pest pressures are successfully employed in GA and SC peaches. Herbicidal control of broadleaf weeds on the orchard floor from pre-bloom until near pit hardening improves control of sucking bugs by rendering the orchard less attractive to this polyphagous group of flower bud and fruit feeders. Similarly, pre-harvest removal of water sprouts on trees to improve light penetration also improves spray coverage and may lower disease pressure.

Orchard Floor Management- Weed control is critical to the integrated management of other orchard pests. Weeds compete readily with trees for water, nutrients, and sometimes light and reduce yield and fruit size, and also serve as hosts to fruit deforming (cat-facing) insects. Weed competition reducing tree growth and fruit yield, results in decreased crop value. In peach, weeds must be managed within a holistic orchard floor management program.

The orchard floor management program of choice uses herbicides to maintain bare-ground in the tree row with grass sod between rows. The herbicide strip minimizes competition, while the perennial grass sod reduces erosion and provides an adequate surface for equipment movement through the orchard even during periods of wet weather.

Eliminating winter annual weeds from the entire orchard floor reduces cat-facing insect populations, aiding in their management. Voles, small rodents that feed on plant roots at or below the soil line, can quickly kill or debilitate otherwise healthy peach trees. Vegetation around trees makes orchards attractive to voles. Maintenance of a clean, herbicide strip beneath trees is a key cultural control for voles. Further, a herbicide maintained bare strip beneath trees also provides a sometimes critical radiant heat benefit in the spring during frost/freeze events. Bare soils absorb heat from the sun and release the heat at night. Elevating the orchard temperature by only a few degrees may be enough to prevent or reduce fruit losses during spring freeze events.



Key Tree Pests

Tree longevity, along with consistent cropping and high fruit quality, are the major predictors of an orchard’s overall profitability- Armillaria root rot, peachtree short life (PTSL) syndrome, and the peach tree borer and scale complexes, all reduce orchard longevity, hence they are particularly injurious. While these pests most certainly reduce yields, their true significance comes from debilitating trees and hastening premature tree mortality. Armillaria root rot is highly persistent, with no good means of control; where Armillaria occurs any subsequent plantings to peach will be subject to rapid, often devastating tree mortality.

Pest-Induced Premature Tree Mortality - Growers typically have ca $2,400/acre invested before trees begin to bear a harvestable crop in the 3rd year of production. In many Georgia and South Carolina orchards, tree pests are lengthening the period of establishment and shortening orchard longevity. Orchard longevity averages 12 years for most Georgia and South Carolina growers. Most southeastern peach orchards are in their 6th year before full recovery of establishment costs. An orchard that produces efficiently through its 12th year is considerably more profitable than one that must be pushed out earlier. Loss associated with sacrificing one year of production projects to a 17% loss of profit potential [12 yrs - 6 yrs to recoup costs = 6 yrs profitable production, less 1 yr lost to pest-induced orchard decline]. Scale, lesser peachtree borer, Armillaria root rot and the short-life complex are key causes of premature orchard decline! and mortality in Georgia and South Carolina. Viruses and phytoplasmas, which are prevalent in Georgia and South Carolina, can also decrease orchard longevity.

Lesser peachtree borer and scale have become dominant pests that clearly are forcing shorter re-plant rotations (best indicator of reduced orchard life). Low risk control options for scale are available. Growers need dormant season thresholds to determine the level of response required each year on a block-specific basis. Borers, particularly lesser peachtree borer (Synanthedon pictipes), are shortening the productivity of many orchards. No control, or suppression, is available for lesser peachtree borer in the southeast. However, preliminary trials in Georgia suggest that mating disruption with lesser peachtree borer pheromone may control both the peachtree borer and the lesser peachtree borer. This would dramatically reduce the need for persistent organophosphate insecticides.

Tree Borers- Borers are key tree pests. Lesser peachtree borer (Synanthedon pictipes) has become the most significant FQPA-related pest of southeastern peaches. Borer infestations weaken trees, make them more susceptible to disease and can kill young trees. Lesser peachtree borer infestations have become increasingly injurious key pest to orchards in their prime productive years. Lesser peachtree borers kill scaffold limbs and accelerate premature orchard decline. Sampling techniques and thresholds for Ppost-harvest borer treatment thresholds are lacking.

Post-harvest sprays for peachtree borer (Synanthedon exitiosa) are directed at the base of the tree, just above the soil line. Unfortunately, these borer sprays directed at the tree base do notlittle to suppress lesser peachtree borer, which attacks structural limbs to just above head high. Lesser peachtree borer’s ascending pest status has made initiation of research to thoroughly investigate its biology and control a key priority.

Under Georgia conditions, pheromone induced mating disruption of borers has been consistently unreliable at the rates used successfully in more northerly (e.g. Michigan) production areas. Rates that have shown promise in preliminary trials to work well in the southeast are up to 4Xs higher than are required in the upper mid-West. As such, essentially no commercial use of mating disruption for the borer complex are now being employed in Georgia or South Carolina. Thorough evaluation of the higher pheromone rates apparently needed for control in southeastern orchards is imperative. Long-term studies on large orchards, young and old, are needed to determine approaches that work consistently under heavy southeastern pressure Sampling and treatment thresholds, cultural or tree training options, and pest biology are all in need of additional research.

Peachtree borer (Synanthedon exiitiosa) control is excellent. Well over 90% of Georgia and South Carolina peaches receive a single, post-harvest, hand-gun directed spray with the organophosphate chlorpyrifos (Lorsban™) for borers. In the Southeast, the timing of borer flights allows growers to delay this spray until after harvest. Chlorpyrifos borer sprays also significantly suppress scale.

Scale Insects- Scale infestations in Georgia and South Carolina increased dramatically during the 1990s. Scale populations increased after regulatory actions eliminated use of two broad-spectrum organophosphates that effectively suppressed damaging infestations. Severe scale infestations can easily shorten an orchard’s productive life by 2 years. A new low-risk insecticide with good scale efficacy (pyriproxyfen, Esteem™) will be available in 2003. Predictive models for both scale species are in development. These models should make pesticide applications for scale more timely and cost-effective.

A complex of nematodes directly damage peach trees and plays a pivotal role in peach tree short life. On replant sites, nematodes are key risk factors influencing orchard health and productivity. Root knot (Meloidogyne spp.), ring (Mesocriconema xenoplax) and lesion (Pratylenchus vulnus) nematodes are the region’s major peach nematodes.

Cultural controls of nematodes are valued, but their utility is often limited. Insufficient availability of suitable alternative orchard sites makes rotation out of peach for several years quite difficult. Short-term rotation to wheat is used, but typically for only one season. Guardian™ rootstock has become a very widely used control option on short-life sites.

Pre-plant use of 1,3-dichloropropene (Telone II ™) plays a crucial role in control strategies for peach nematodes. The best option for combating short life is pre-plant soil treatment with Telone II ™ plus use of Guardian™ rootstock. Research to enhance nematode management options is a key need.

Viruses- Viruses are important pathogens in peaches. Plum pox virus (PPV), a scourge of Prunus species worldwide, was discovered in Pennsylvania and Ontario in the late 1990s. Infected orchards have been systematically eliminated to reduce the risk of plum pox spreading elsewhere in North America. Two other viral diseases shown to be endemic in Georgia and South Carolina are Prunus necrotic ring spot (PNRSV) and prune dwarf virus (PDV). They debilitate trees, reducing longevity and yield.

Virus-tested, varietally true-to-type peach trees are available for eastern peach growers courtesy of a cooperative, grower-led testing program. They significantly reduce the risk of PPV, while also reducing the incidence of PNRSV and PDV. Tennessee tree nurseries produce most peach trees grown in the eastern U.S. South Carolina and Georgia growers, working with Tennessee’s major peach tree nurseries, and Clemson University and University of Georgia scientists, have made virus-tested trees available to commercial producers over much of the eastern U.S.



Key Fruit Pests

Pest-related loss of reputation in the market place is untenable. A favorable, competitive standing in the market takes years to attain, but it can be easily and quickly lost. The wholesale market’s intolerance to pest injury requires pest management systems that are unfailingly reliable and able to provide a very high level of protection.

Scab, bacterial spot, brown rot, plum curculio, Oriental fruit moth, stink bugs, scale and borers are key fruit pests of southeastern peaches. Growers of fresh peaches are strongly rewarded for producing high quality peaches, or punished if, on any given day, they fail to produce the best peach they can. Noticeable pest injury will demonstrably reduce returns. Any signs of internal fruit-feeding from plum curculio (Conotrachelus nenuphar) or Oriental fruit moth (Grapholitha molesta), will prompt rejection of entire loads of fruit by wholesale buyers.

Crop phenology is the standard by which pesticide applications are timed in many deciduous fruits, including eastern peaches. Timing pesticide applications to coincide with crop phenology is practical and has typically provided reliable control. Timing pesticide applications to crop development is far from optimal, but in the absence of reliable pest monitoring and treatment thresholds, timing of sprays by crop phenology is the most feasible option. Images of peach phenology may be seen at [http://www.msue.msu.edu/fruit/indexbud.htm].

Fruit disease control options are generally quite effective.

Brown rot (Monilinia fructicola), the key fruit rot organism, is controlled by demethylation inhibitor (DMI) fungicides. Even with the best management practices, brown rot is still responsible for substantial losses in wet years. This pathogen is prone to resistance development, as demonstrated in the 1980s when resistance to benomyl caused control failures. In 2003 isolated cases of DMI-resistant brown rot was documented in Georgia. Accordingly, tThere is an obvious need for more detailed understanding of the organism’s biology to lessen dependence on fungicides, and for non-DMI control options to avoid reliance on a single class of fungicides.

Scab Fusicladosporium (Cladosporium) carpophilum) control is typically good. Scab infections typically develop between petal fall and pit hardening, but multiple, often very brief, infection periods can necessitate protection of fruit until 30 days before harvest.

Bacterial spot (Xanthomonas campestris pv. pruni) is a damaging, sometimes devastating, disease. Varietal resistance to bacterial spot is a very valuable tool. Unfortunately, some of the very best wholesale peaches are quite spot sensitive. And, under heavy bacterial spot pressure, even resistant varieties need some protective sprays. Bacterial spot pressure varies with season, site and production area within the two-state region. Resistant varieties are being planted as commercially competitive selections become available. In Georgia and South Carolina, perhaps 25% of the bearing acreage requires some level of bacterial spot control. Controls are based on early-season use of coppers and the key in-season antibiotic oxytetracycline (Mycoshield™). Resistance management options are very limited and regulatory scrutiny is expected, making low-risk, alternative bacterial spot chemistries an important priority.

Minor Diseases- Rhizopus and gilbertella rots are not controlled by the pre-harvest fungicides in current use. The post-harvest fungicide fludioxonil (Scholar™), does provide effective control of these pathogens, but there is an obvious need for efficacious, pre-harvest fungicides.

Anthracnose, peach red spot and sooty peach are occasional diseases that, when present and severe, are only controlled with older fungicides such as captan, Ziram or Ferbam. Low-risk materials with efficacy against forthese diseases are neededa long-term need.

Constriction canker, caused by Phomopsis amygdali, is a poorly understood disease that has considerable damage potential. Certain varieties are quite susceptible. Infections occur during leaf fall, winter and early spring. Cultural control by hand pruning out strikes is very costly. Chemical controls are wanting with few fungicides registered for late season or winter applications.


Fruit Insects

Plum curculio (Conotrachulus nenuphar) is the dominant fruit insect of southeastern peaches. Oriental fruit moth (Grapholitha molesta ) and stink bugs (Pentatomidae) are also major fruit attacking insect pests in Georgia and South Carolina. Plum curculio is very reliably controlled with existing organophosphate-based programs. However, declining availability of older materials, plus the considerably greater cost and required precision in time of application of newer materials, mandates detailed study of pest biology in order to develop sampling tools, modeling capability and thresholds to facilitate cost-effective use of newer materials.

Educational Needs

Integrated pest management carries with it considerable management costs that are seldom given due weight for high-value commodities such as peaches. Growers need orchard consultants to successfully implement increasingly complex pest management options. The economics of pest management must be re-examined in light of its non-farm benefits to society in order to sustain a badly needed cadre of pest management consultants. IPM is a key element needed to sustain improvements in food, worker and environmental safety.



Contacts

Insect Pest Management

Dan L. Horton (GA, SC)
706-542-9035
dlhorton@uga.edu

Disease Pest Management

Phil Brannen (GA)
706-542-1250
pbrannen@uga.edu

Guido Schnabel (SC)
864-656-6705
schnabe@clemson.edu

Orchard Weed Management

Wayne Mitchem (NC, SC, GA)
704-276-1584
Wayne_Mitchem@ncsu.edu

Peach Crop Production

Kathryn Taylor (GA)
478-956-6417
kctaylor@uga.edu

Desmond Layne (SC)
864-656-4961
dlayne@clemson.edu

Pesticide Policy

Dan L. Horton (GA, SC)
706-542-9035
dlhorton@uga.edu

Bob Bellinger
864-656-5042
bbllngr@clemson.edu

Paul Guillebeau
706-542-9031
pguillebeau@bugs.ent.uga.edu


References

  1. Bellinger, R., R. Rowe, C. Gorsuch & W. Newall. 1995. SC Peach pesticide use survey. Clemson University, Pesticide Impact A97-01, Dec 1997.
  2. Horton, Dan, Bellinger, Bob & David Ritchie, Senior Editors. 2003. Southeastern peach, nectarine & plum pest management & culture guide. UGA Extension Bulletin 1171. 43pp.
  3. Horton, Dan L. 1998. Southeastern peach insect pest management—its evolution and implementation. University of Georgia, Cooperative Extension Service, Miscellaneous report. 27pp.
  4. Myers, S.C., Editor. 1988. Peach production handbook. UGA Extension Handbook 1. 221pp.
  5. Vandeman, A., J. Fernandez-Cornejo, S. Jans and B. Lin. 1994. Adoption of integrated pest management in U.S. agriculture. USDA Agriculture Information Bulletin No. 707. Washington, DC, 26pp.
  6. Taylor, K.C., P. Brannen, W. Mitchem and D. Horton. Peach Orchard Management Calendar for Georgia. (2003) [http://www.griffin.peachnet.edu.caes.gapeach/]
  7. Peach Information, Clemson University, Department of Horticulture [http://www.clemson.edu/hort/peach/]
  8. The Georgia Peach, University of Georgia [http://www.griffin.peachnet.edu/caes/gapeach/]
  9. USDA, Office of Pest Management Policy Crop Profiles & Pest Management Strategic Plans [http://www.ars.usda/opmp/]
  10. Dan L. Horton and Robert G. (Bob) Bellinger, Editors
  11. Phil Brannen, Ted Cottrell, Frank Funderburk, Paul Guillebeau, Greg Henderson, Desmond Layne, Wayne Mitchem, David Ritchie, Guido Schnabel, Kathryn Taylor, Associate Editors
  12. Data and support provided by the Georgia Peach Council and South Carolina Peach Council

 


Appendix

Pesticide Use Patterns

2002 Pesticide-Use Patterns for Early-, Mid- and Full-Season Varieties in Georgia and South Carolina. Use patterns for key materials or classes of materials summarized below. Data from ca. 5,000 bearing acres.

Active Ingredient or Class

Time of Use(s)

Target Pests

Early-Season Varieties, est. % of acres treated

Mid-Season Varieties, est. % of acres treated

Late-Season Varieties, est. % of acres treated

Fungicides

         
Sulfur Petal fall to ca. 30 days pre-harvest Scab 4-6, 100% 6-7, 100% 8-10, 100%
chlorothalonil/Bravo, Equus Bloom to shuck off Primarily for scab, also for blossom blight 0 to 1, 20% 0 to 1, 30% 0 to 2, 60% of acres
trifloxystrobin/Flint Petal fall to shuck off Primarily for scab, also powdery mildew 0 to 1, 05% 0 to 1, 05% 0 to 1, 05%
Captan Shuck split-shuck off, as-needed up to pre-harvest interval Primarily for Scab, also for green fruit rot & anthracnose 0-2, 20% 0-2, 30% 0-4, 60%
azoxystrobin/Abound Shuck split-shuck off Primary uses for scab, an important option for green fruit rot and the 1st pre-harvest brown rot application 0-1, 05% 0-2, 15% 0-2, 30%
sterol inhibitors/Elite, Indar, Orbit Primarily pre-harvest, as-needed for blossom blight and/or green fruit rot Brown rot 1-2, 100% 2-3, 100% 2-4, 100%
fludioxonil/ Scholar Post-harvest Brown, Rhizopus & Gilbertella rots 1, 20% 1, 50% 1, 50%

Bactericides

         
coppers, rates must be reduced as tree phenology advances Primarily pre-bloom up to shuck split, occasional very low rate use thereafter Bacterial spot 0 to 1, 20% 0 to 5, 25% 0 to 6, 60%
oxytetracycline/Mycoshield Applied from shuck split to pre-harvest Bacterial spot 0 to 1, 20% 0 to 2, 25% 0 to 8, 60%

Insecticides

         
Dormant oil(s) From full leaf drop to early pink Scale, to a minor degree for European red mite 1-2, 100% 1-2, 80% 1-2, 65%
pyrethroids/ Ambush, Asana, Pounce Primarily for plant bug, also Oriental fruit moth, stink bugs, plum curculio Most applications at petal fall, also as general cover spray between plum curculio generations 0-2, 30% 0-3, 40% 0-4, 50%
phosmet/Imidan Plum curculio, scale, all other pests almost every acre at shuck split & 14-days PH 2-4, 100% 4-6, 100% 6-10, 100%
azinphos methyl/Guthion, Sniper Plum curculio, scale, all other pests As permissible with REI 0-2, 20% 1-3, 60% 1-3, 80%
chlorpyrifos/ Lorsban Peachtree borer, lesser peachtree borer, scale Post harvest, handgun applied trunk spray 1, 100% 1, 100% 1, 100%

Herbicides

         
2,4-D amine Winter annual broadleaf weed control Winter application to the entire orchard floor 0 to1, 10% 0 to 1, 10% 0 to1, 10%
paraquat/ Gramoxone Chemical mowing, burns back green growth without killing roots of perennial species Late Winter to Delayed dormant 1 to 4, 100% 1 to 5, 100% 1 to 5, 100%
glyphosate/ Round Up Chemical mowing Primarily in season in May to early June 0-2, 70% 0 to 2, 70% 0 to 2, 70%
terbacil/Sinbar, often tank mixed with diuron to broaden spectrum of activity Pre-emergence control of broadleaf and annual grasses Late winter, applied as a banded application beneath the tree row 0 to 1, 80% 0 to1, 80% 0 to 1, 80%
diuron/Karmex, Diuron, often tank mixed with terbacil to broaden the spectrum of activity Pre-emergence control of broadleaf weed and annual grasses Late winter, applied as a banded application beneath the tree row 0 to 1, 80% 0 to 1, 80% 0 to 1, 80%
Simazine Pre-emergence control of broadleaf weeds and annual grasses Late winter, applied as a banded application beneath the tree row 0 to 1, 20% 0 to 1, 30% 0 to 1, 40%
norflurazon/ Solicam Pre-emergence control of annual grasses Applied in late fall or winter 0 to 1, 10% 0 to 1, 10% 0 to 1, 10%