Potential Effects of FQPA on Fruit Growers in South Carolina

Affects on Insect Pests of Fruits > >

Southeastern Professional Fruit Workers Letter to EPA, October 28, 1998 > >

Effects on Diseases of Fruits

Impact of cancellation of organophosphates, carbamates, B1 and B2 carcinogens on fruit industry in South Carolina from the plant disease perspective

R. Walker Miller, Extension Plant Pathologist

October 1998

It is important to realize that there are two perspectives; the existing industry and future industry that would be possible if appropriate plant pharmaceutical tools are available. The structure of South Carolina Agriculture is changing rapidly from a field crop and large volume commercial packed fruits and vegetable economy to a high value return per acre crops. In the fruit and vegetable industry this is associated with changing market structure. Future fruit markets will be niche markets including direct marketing associated with recreation and fruits and vegetables that have short shelf life and therefore will not face competition from distant markets. In the opinions expressed below these two perspectives will be examined.

 

NEMACUR

Nemacur is the only post plant nematicide available for fruit crops in South Carolina. In peaches, although tolerant root stocks have been developed to Short life they are not resistant to the ring nematode. The ring nematode is present state wide. The rate at which it causes loss in yield varies with soil type. Approximately 30% of our 19,000 acres of peaches are on land where the impact will occur in the 5 th year after planting given that preplant nematode control was practiced. The remaining 70% will be impacted in the third year. The impact will be a 10 to 20% yield loss assuming no peach tree short life. Even with new superior tolerant rootstocks to peach tree short life the disease will still occur. We have had near 100% adoption of Lovell/Halford rootstock with approximately 10% of this replaced to date with Guardian rootstock. Nemaguard rootstock(resistant to root knot nematode) still represents about 5% of the acreage but is demising quickly as Guardian is resistant to root knot nematode also. The anticipated tree death on Lovell/Halford rootstock by the 7th year is 25% and with the new Guardian rootstock will be reduced to 8%. Future income streams from these trees will be lost. Where Nemacur is used these losses would be reduced to 12.5% and 4%. It is anticipated that we will see 100% adoption of Guardian rootstock or improvements there from, in 12 years.

We are near the end of the first generation of apple production for the state. Prime apple land is being replanted with higher density orchards focused on niche markets. Apple replant disease has not been a factor to date but is anticipated to become one. Lesion nematode is present in South Carolina in prime apple growing areas. It is a significant contributing factor to apple replant complex. I estimate that apple replant can have up 20 % impact on tree survival by the 5 th year and a reduction of 10% productivity on the remaining trees. It is estimated that Nemacur would reduce tree loss to 10 % and yield reduction to 5%. It anticipated that the number of acres will experience fluctuations as old operations go out of business and new operations start up to capitalize on niche opportunities. It is anticipated that we will sustain 3000 acres per year with average tree density increasing form 100 trees per acre to 500 trees per acre.

Brambles are found on about 150 acres and represent a potential to increase to 1000 acres or more in the next 7 years. Dagger nematodes are directly pathogenic and also vectors of the ring spot NEPO viruses which result in 50 to 80% loss of fruit. Lesion nematodes also represent a yield loss factor of 10% in South Carolina. Nemacur is very effective for lesion nematode and only moderately effective for dagger nematode but regular applications will suppress it. Direct yield losses to nematodes in the post plant situation are estimated to be 10%. Viruses losses vary greatly depending on variety and potential exists to select/breed tolerance to viruses. No research effort is on the horizon. The current average loss due to virus is estimated at 10% is expected to increase to 20% for at least the next 10 years during a period of acreage increase.

Strawberries will lose methyl bromide by the year 2001. The replacement on the horizon is a combination product of dicloropropene, chloropicrin, and metam sodium. The price is anticipated to be competitive. A potential less costly, lowered environmental impact approach is herbicide, Nemacur, and solarization. Research is unavailable on this approach. Yield losses to nematodes in strawberries without control are estimated at 10%.

Kiwis, grapes, pears, all suffer from poorly understood nematode problems as of this writing. Nemacur is labeled on these use sites. I think a conservative estimate of 10% yield loss now and for the near future of 10 years is fair . Acreage of all these crops is anticipated to increase.

CAPTAN

Captan is an important tool for resistance management of diseases in fruits as well as being directly effective for control. In peaches captan controls scab(on average 90% loss without control), brown rot (on average 100% loss with out control), acts as a safener and activity enhancer for bacterial spot control(on average loss without control 100%). With captan the loss is 1% for scab, 10% for brown rot and 40 % for bacterial spot. Since the dicarboximides (iprodione and vinclozlin), Chlorothalonil (various formulation of Bravo) and benzimidazoles (benomyl and thiophanate methyl) are on the list to be eliminated that are not considered to be viable alternatives.

Alternatives for peach scab are myclobutanil(Nova) , Sulfur, azoxystrobin (Abound), ziram and dodine (Syllit). Anticipated control with alternatives are 90%, 80%, 90%, 20% and 20% respectively. Myclobutanil and azoxystrobin will probably experience resistance development in 7 years and 3 years respectively resulting in 50% disease control and 10% disease control respectively. All the alternatives will result in secondary pathogens emerging as primary pathogens. These will include the pocket rots, anthracnose, Phomopsis, and Botryosphaeria. It is anticipated that resistance of secondary organisms will develop in 3 years, 7 years, and 10 years respectively to azoxystrobin and myclobutanil. Botrytis is a secondary pathogen on flower blossoms and maturing fruit Myclobutanil and sulfur have no activity and azoxystrobin has weak activity. Losses from botrytis are anticipated to 30%. Sooty peach and red spot will only be controlled by azoxystrobin or require that 2 materials be used in the spray tank instead of one. The second material is ziram. The additional cost will be about $50 per acre per year.

The alternatives for brown rot control prior to harvest are the DMI compounds. Beyond the DMIs no other alternatives are available. Without captan the rate of resistance development will increase and cross resistance is anticipated. It is anticipated that within 5 years of loss of captan the DMIs will only give 70% control of brown rot.

Apples are impacted by white rot, black rot, and scab that are controlled by captan. Captan plays a role in resistance management for the scab organism. With out control scab can 100% loss, white rot 70%, and black rot 70%. Alternatives to black and white rot will provide no more than 50% control and will increase labor requirement for detailed pruning per acre by 20 hours per acre. Alternatives to Scab control are the preferred control at this time but rate of resistance development by the organism will increase. Cross resistance will occur between all the DMI compounds in apples.

Captan is used on blueberries for ripe rot, mummy berry, foliar anthracnose, and canker control. Without captan no commercial pack will be possible because of ripe rot. Although the incidence of ripe rot is only 4-5% it occurs after packing resulting in dirty looking berries. About 10% of our 300 acre production is sold commercially. This secondary market enables niche marketers to get rid of excess volume while building primary niche markets. Indar is available under section 18 currently for mummy berry control. Captan offers opportunity to reduce the rate that resistance develops in the mummy berry fungus.

Captan, available in South Carolina under a 24 special local needs label, plays a key role in Botrytis management in brambles. No viable alternative exists. Losses prior to harvest in blackberries are 30% and raspberries 70% and post harvest in raspberries, even in direct market situations is 100%. Captan also plays a role in resistance management for benomyl and supplements stem canker and leaf spot control. Without Captan floricane reduction and therefore yield reduction is about 50% in raspberries and 10% in Arapaho blackberries. Raspberry acreage is about 15 acres, blackberries 135 acres with 10% Arapaho variety. This acreage is increasing rapidly and could reach 1000 in as little 3-5 years.

Captan is important in the 230 acres of Muscadine grapes for Macrophoma rot and in all grapes types, approaching 500 acres, for ripe rot control, especially close to harvest when epidemics of this disease occur. In the vinifera grapes which represents about 120 acres, and growing rapidly, captan is significant for Botrytis control. For ripe rot and/or Macrophoma rot control no alternatives exist beyond berry set. Anticipated loss is muscadines is 30%, viniferas and Labruscas 50%. For botrytis control in viniferas available alternatives will offer 30% control at best.

Captan is the mainstay for Botrytis management in strawberries. No alternatives exist now due to resistance or will exist except if we are able to secure a Section 18(s). These product(s) will also be at high risk of resistance development. Losses to Botrytis will be 100%. Currently a crisis situation exists with regards to Botrytis control. Similarly a crisis situation exists for anthracnose control. Captan only affords about 55% control and under continuous conducive conditions this degenerates to 0% control.

CHLOROTHALONIL

Chlorothalonil is currently only labeled for peaches for leaf curl, brown rot blossom blight and scab control. The latter is via a 24 C Special Local Need label. The only non-FQPA impacted fungicides are the DMI's that have adequate control of brown rot blossom blight. Ziram, thiram, ferbam, and sulfur may be used but efficacy is 60, 60, 60 and 30% respectively during this time window. The risk of resistance and cross resistance is significantly increased further by the loss of chlorothalonil. All three of the dithiocarbamates provide adequate control of leaf curl with ferbam being the preferred product except where bacterial spot is a problem. Then the copper compounds become the preferred product. With regards to scab, myclobutanil, azoxystrobin and sulfur are the alternatives and the same comments apply as discussed above under captan except that additional sprays are needed beyond the existing chlorothalonil label. Under the existing 24 C label it will only afford 80% commercial control.

DICARBOXIMIDES

The dicarboximides [captan, vinclozolin and iprodione] are labeled for peaches, vinifera grapes, strawberries and rasberries. They are effective for Botrytis on all four crops except that resistance is wide spread in raspberries, grapes and strawberries thus the product only affords 60% control and declining at maximum allowed dose. No highly effective alternatives exist beyond FQPA impacted products for Botrytis. Thiram is labeled in strawberries and thiram and ziram are labeled in grapes and peaches. Efficacy of the dithiocarbamates for botrytis is at best around 60-70%. Mancozeb is also labeled in grapes but the long preharvest interval reduces its effectiveness to less than 30%. Preharvest intervals reduce the ability to use these products. Resistance to Botrytis in peaches has not been documented or believed to be a problem at this time. In peaches dicarboximides play a key role in resistance management even in the few time slots that it can be used. Loss will significantly increase resistance risk and shorten viable life of the DMI's.

BENZIMIDAZOLES

The benzimidazoles (benomyl and thiophanate methyl)play a key role in many fruit crops. Due to resistance development the value for Botrytis control has declined significantly in strawberries and brambles, but when used in combination with dicarboximides they still control 80% of the population. Twenty percent Botrytis populations has double resistance to both dicarboximides and benzimidazoles in strawberries. In strawberries benomyl and thiophanate methyl play important roles in controlling secondary organisms like Mycosphaerella, Phomopsis, Gnomia, and Rhizoctinia. Given appropriate Section 18s for Botrytis losses are still anticipated to be 40% to these secondary problems.

In grapes, benomyl, beyond the botrytis resistance issue plays important roles in control of Phomopsis in viniferas, Macrophoma in Muscadines, anthracnose in Labruscas, angular leaf spot in muscadines, Eutypa and Botryosphaeria canker in all three types and powdery mildew in muscadine and viniferas. For canker problems there is no alternative. For Powdery mildew there are several adequate alternatives. For all others a 30% increase in disease incidence is anticipated. Benomyl provides near perfect control of these latter diseases.

In peaches, although resistance was discovered better 20 years ago to both brown rot and scab, judicious management has led to its continued usage about 1-2 times a year and maybe 15 times in the life of an orchard, when needed for special rot or scab control situations. It has become an important tool for resistance management for both organisms. With the cancellations associated with FQPA risk situation there will be no alternatives for resistance management for the DMI's.

CONCLUDING COMMENTS

The fruit situation is very complex and there is no simple way to measure the impact of the proposed action as a result of FQPA. I have probably made errors of omission in terms of interactions as growers would attempt to brew up multiple dose cocktails of compounds of lower efficacy. I have not consider fruit finish aspects which might influence purchase decisions by consumers.

Insect and Mite Pests of South Carolina Tree Fruits and Small Fruits

Clyde S. Gorsuch, Extension Entomologist

October 1998

The following tables provide listings of the insect and mite pests of South Carolina tree fruits and small fruits and what organophosphates and organophosphates are currently available for pest management, and what alternative chemistries may serve as alternatives if they are lost.

With some pests the timing of applications becomes critical with the available alternatives, such as the use of dormant oil for scale crawlers, and Bacillus thuringiensis for tufted apple budmoth on apple. When to apply these requires intensive monitoring that many growers may not be able to accomplish.

APPLE

No alternatives for major pests such as, codling moth, oriental fruit moth, lesser apple worm, plum curculio, and tufted apple bud moth. Pheromone disruption is available for codling moth, oriental fruit moth, and possibly tufted apple bud moth. Disruption does not work on block smaller than ~5 acres or on hilly terrain or if pest pressure was high the year before. Repeated use of pyrethroids leads to build-up of mites, scales, and woolly apple aphid. Using pyrethroids may require additional applications in some cases, driving up production costs.

Yield Loss Estimates on Apple with Loss of FQPA at Risk Pesticides

Losses to apple maggot could reach 10% in two years. There are no alternatives. Losses to codling moth, our worst apple pest, could be 50% in two years. There are no alternative chemistries. Losses to green fruit worm are estimated to be ~5%, with no alternatives. Lesser apple worm losses could run between 5 and 10%, with no alternatives. San Jose scale loses are difficult to estimate. While materials are available for the scaled stages, no alternatives except for dormant oil would be available. While dormant oil is effective, timing of application for this stage is extremely critical. Tufted apple bud moth could produce losses of 50%. The remaining management agent would be Bacillus thuringiensis (Bt). Timing in the use of this material is critical.

Apple Pest Table

Apple Pest OP's Carbamates Alternatives
Aphids oil+chlorpyrifos;
dimethoate;
chlorpyrifos;
diazinon
oxamyl Dormant oil;
imidacloprid;
endosulfan;
permethrin;
esfenvalerate
Apple Maggot:

No alternatives

azinphosmethyl;
phosmet;
chlorpyrifos;
dimethoate
   
Codling Moth:

No alternatives

azinphosmethyl;
phosmet;
chlorpyrifos;
encapsulated methyl parathion
   
Dogwood Borer:

No alternatives

chlorpyrifos;
endosulfan
   
Green Fruit Worm:

No alternatives

chlorpyrifos;
endosulfan;
dimethoate
   
Japanese Beetle:

No alternatives

phosmet carbaryl  
Leafhoppers dimethoate carbaryl;
formetanate hydrochloride
abamectin;
imidacloprid
endosulfan
Leafminers   formetanate hydrochloride;
methomyl;
oxamyl
endosulfan;
permethrin;
esfenvalerate;
imidacloprid
Leafrollers chlorpyrifos;
encapsulated methyl parathion;
azinphosmethyl;
phosmet
  Bacillus thuringiensis
Lesser Apple Worm:

No alternatives

encapsulated methyl parathion;
azinphosmethyl;
phosmet
   
Mites   formetanate hydrochloride;
oxamyl
dormant oil;
clofantezine;
hexythiazox;
abamectin;
pyridaben;
dicofol;
hexakis;
sulfur;
summer oil
Oriental Fruit Moth:

No alternatives

azinphosmethyl;
phosmet;
chlorpyrifos
   
Plant Bugs dimethoate;
diazinon
  endosulfan;
permethrin;
esfenvalerate
Plum Curculio:

No alternatives

azinphosmethyl;
phosmet;
chlorpyrifos
   
Scale, San Jose:

No alternative for crawlers

dormant oil + chlorpyrifos;
chlorpyrifos;
dimethoate;
diazinon;
azinphosmethyl;
phosmet
  dormant oil
Tufted Apple Bud Moth chlorpyrifos;
encapsulated methyl parathion
  Bacillus thuringiensis


PEACH

The pyrethroids, esfenvalerate and permethrin, provide good control of the key pests. Repeated use of these materials will lead to heavy mite and scale populations. These can reduce the vigor of the trees. Scales populations can kill individual limbs or whole trees if uncontrolled in three years. With the loss of the organophosphates and carbamates, the management of insect pests on peaches falls mainly to endosulfan and the pyrethroids, with some use ofdormant oil and Bacillus thuringiensis.

There are few miticides available for peaches, but peach trees are resilient to mite populations. However, high mite populations at harvest time prevent workers from picking peaches; they simply will not go into the orchards because of the high numbers of mites.

While some alternative chemistries would remain for most pests, the pre-harvest intervals on these materials may mean that unacceptable damage, and thus yield loss, may occur between the last application and harvest.

Yield Loss Estimates on Peach with Loss of FQPA at Risk Pesticides

Catfacing injury from plant bugs will cause some loses but this is difficult to estimate. Damage levels are, in part, related to how well the orchard floor weeds are managed. Losses to plum curculio, the major peach pest insect, could be in the range of 85-90%.

Peach Pest Table

Peach Pest OP's Carbamates Alternatives
Aphid malathion   endosulfan
Borers chlorpyrifos   endosulfan;
esfenvalerate
Catfacing plant bugs azinfosmethyl;
methomyl;
phosmet;
encapsulated methyl parathion;
carbaryl esfenvalerate;
permethrin
Japanese beetle   carbaryl  
Mites   formetanate hydrochloride dormant oil;
hexakis;
clofantezine
Oriental fruit moth azinphosmethyl;
encapsulated methyl parathion;
phosmet
methomyl esfenvalerate;
permethrin
Plum curculio azinphosmethyl;
encapsulated methyl parathion;
malathion;
phosmet
carbaryl esfenvalerate;
permethrin
Scale dormant oil + chlorpyrifos;
azinfosmethyl;
encapsulated methyl parathion;
malathion
carbaryl dormant oil
Thrips   formetanate hydrochloride  


STRAWBERRY

With annual production loss of OP's and carbamates would not be limiting. However, reliance on only pyrethroids and old chlorinated hydrocarbon materials is risky.

Yield Loss Estimates on Strawberry with Loss of FQPA at Risk Pesticides

Losses on strawberries with the loss of FQPA could be minimal. One potential problem is resistance in mites, but newer pyrethroids may not produce the same mite problems on strawberries that exist now with pyrethroid use.

Strawberry Pest Table

Strawberry Pest OP's Carbamates Alternatives
Aphid diazinon;
malathion
  endosulfan;
bifenthrin
Crickets malathion carbaryl  
Cyclamen mite diazinon   endosulfan;
dicofol
Japanese beetle   carbaryl  
Lygus bug malathion   endosulfan;
fenpropathrin;
bifenthrin
Leafrollers/tiers malathion;
azinphosmethyl;
diazinon
carbaryl Bacillus thuringiensis;
bifenthrin
Slug/Snail     metaldehyde
Spider Mite     hexakis;
dicofol;
abamectin;
bifenthrin;
fenpropathrin
Spittlebug azinphosmethyl;
malathion;
carbaryl endosulfan;
bifenthrin;
fenpropathrin
Strawberry weevil
(clipper)
chlorpyrifos carbaryl bifenthrin
Strawberry sap beetle     bifenthrin
Thrips malathion    
Whitefly: azinphosmethyl;
malathion
   


BLUEBERRY

There are no alternatives to the OP's and Carbamates for the major blueberry pests, blueberry maggot and cranberry fruitworm.

Yield Loss Estimates on Blueberry with Loss of FQPA at Risk Pesticides

With the loss of the organophoshates and carbaryl, we are at risk of 40% loss of yield due to cranberry fruitworm. Other pests will cause some degree of damage, but this is hard to estimate on this crop because the high variability in damage susceptibility between varieties.

Blueberry Pest Table

Blueberry Pest OP's Carbamates Alternatives
Blueberry maggot azinphosmethyl;
diazinon;
phosmet
carbaryl  
Cranberry fruitworm azinphosmethyl;
diazinon;
malathion;
phosmet
carbaryl  
Japanese beetle carbaryl    
Plum curculio azinphosmethyl;
phosmet;
malathion
   
Scale azinphosmethyl carbaryl dormant oil

GRAPE

There are no acceptable alternatives to the OP's and carbamates. Bacillus thuringiensis is too narrow in efficacy to be of much value.

Yield Loss Estimates on Grape with Loss of FQPA at Risk Pesticides

Grape berry moth could produce losses of 5-10%. The biggest pest would be the grape root borer. Yield losses to this pest could easily reach 40%. This pest has a two year life cycle and in two to four years maximum yield losses would occur. This pest will kill individual vines. While mounding can be effective, this is a costly measure. Timing of mounding the soil around the vines, and then removing the mounds is extremely critical. The monitoring and effort needed may not be possible or economically feasible. Further, mounding runs counter to current horticultural recommendations for grape culture.

Grape Pest

Grape Pest OP's Carbamates Alternatives
Fruit fly diazinon    
Grape berry moth azinphosmethyl;
diazinon;
phosmet;
encapsulated methyl parathion
carbaryl Bacillus thuringiensis
Grape leaffolder diazinon   Bacillus thuringiensis
Grape leafhopper diazinon;
malathion;
encapsulated methyl parathion;
phosmet
carbaryl  
Grape root borer chlorpyrifos   soil mounding
Japanese beetle   carbaryl  


BRAMBLE (blackberry and red raspberry)

There are no alternatives available. Strawberry weevil (clipper) and Raspberry crown borer can cause significant losses if uncontrolled.

Yield Loss Estimates on Brambles with Loss of FQPA at Risk Pesticides

Strawberry weevil could produce losses of 20-25%. Raspberry crown borer could cause 50% loss in as little as 5-7 years. [Note: Dr. Walker Miller feels that this pest can cause total loss of production in as little as 3 years.]

Bramble Pest Table

Bramble Pest OP's Carbamates Alternatives
Aphids malathion    
Strawberry weevil
(clipper)
malathion carbaryl  
Japanese beetle   carbaryl  
Raspberry crown borer azinphosmethyl    


PECAN

The pyrethroids are not a good alternative because repeated use leads to rapid build-up of aphid populations and aggravates mite problems. Pecan weevil is a major limiting factor in production.

Yield Loss Estimates on Pecan with Loss of FQPA at Risk Pesticides

Losses in excess of 85% from pecan weevil can occur without proper management. There are no acceptable alternatives to carbaryl.

Pecan Pest Table

Pecan Pest OP's Carbamates Alternatives
Aphids dimethoate;
chlorpyrifos;
malathion
aldicarb esfenvalerate;
endosulfan;
zeta-cypermethrin;
cypermethrin
Fall webworm chlorpyrifos;
azinphosmethyl
carbaryl  
Hickory shuckworm azinphosmethyl carbaryl esfenvalerate;
cypermethrin;
zeta-cypermethrin
Leafminer azinphosmethyl    
Mites     hexakis;
dicofol
Pecan nut casebearer azinphosmethyl;
chlorpyrifos
carbaryl endosulfan;
zeta-cypermethrin;
cypermethrin
Pecan phylloxera chlorpyrifos   endosulfan
Pecan spittlebug azinphosmethyl;
chlorpyrifos
carbaryl endosulfan
Pecan weevil   carbaryl  
Stink bugs encapsulated methyl parathion   cypermethrin
Twig girdler azinphosmethyl carbaryl  

Southeastern Professional Fruit Workers Letter to EPA


Return to Summary of Fruit Crop Index

October 28, 1998

Letter to:

U.S. Environmental Protection Agency
Office of Pesticide Assessment Public Docket
Room 119 Crystal Mall 2
1921 Jefferson Davis Highway
Arlington, VA 20460
Elf Atochem North America, Inc.
Agrichemicals Group
2000 Market St., 21st Floor
Philadelphia, PA 19103-3222
Agrevo USA Company
2711 Centerville Rd.
Wilmington, DE 19808
Gowan Company
644 Engler Avenue
PO Box 5569
Yuma, AZ 85366-5569
BASF Corporation
Agricultural Products
Consumer Products & Life Science Division
26 Davis Drive
PO Box 13528
Research Triangle Park, NC 27709-3528
ISK Biosciences Corporation
5966 Heisley Rd.
PO Box 8000
Mentor, OH 44061-8000
Bayer Corporation
Crop Protection Products
8400 Hawthorne Rd.
Box 4913
Kansas City, MO 64120-0013
Micro Flo Company
PO Box 5948
Lakeland, FL 338707
Dow Agrosciences
US Crop Production
9330 Zionsville Road
Indianapolis, IN 46268-1054
Rhone-Poulenc AG Company
2 T.W. Alexander Drive
Research Triangle Park, NC 27709
Du Pont
Agricultural Products
Walker's Mill, Barley Mill Plaza
Wilmington, DE 19898
 

 

To Whom it May Concern:

The Southeastern Professional Fruit Workers Conference, an annual gathering of applied fruit scientists, met 14-15 October in Clemson, SC. As scientists and pest management practitioners, we are interested in how the Food Quality Protection Act (FQPA) implementation is carried out. We anticipate evaluation of organophosphates, carbamates and B-1/B-2 carcinogens as the first of several class-by-class FQPA evaluations. Accordingly we emphasize retention of resistance management alternatives. We offer our pest management perspective in hopes it will facilitate FQPA goal of reduced pesticide residue in our food supply while retaining stable, workable IPM systems for southeastern fruit growers.

As fruit IPM professionals we emphasized resistance management and alluded to minimalist use patterns that we hope would be stable. In all cases we considered efficacy, resistance management and avoidance of secondary pesticide-induced pest outbreaks. Our suggestions would function if and only if growers retain this compliment of pesticides. Loss or radical limitation of any group of materials severely lessens the stability and effectiveness of IPM systems using the materials that remain.

We did not address apples. Apples are important in the Southeast; however we assumed that inputs from the larger mid-Atlantic and eastern production areas would be offering you needed apple IPM inputs.

PEACHES Fungicides dicarboximides: iprodione (Rovral) and vinclozolin (Ronilan)

The dicarboximides are among our best blossom blight materials. Blossom blight is the bloom stage of brown rot (Monilinia fructicola). Ronilan and Rovral are important resistance management tools to help mitigate selective pressure on the demethylation inhibitor (DMI) fungicides. DMIs are essential and must be protected from resistance, as they are our most effective pre-harvest brown rot fungicides. We suggest retention of 2 dicarboximide applications, at least retaining bloom application. Nectarines are quite sensitive to brown rot. Retention of Ronilan's 14-day pre-harvest use would improve resistance management and control.

chlorothalonil (Bravo, Bravo Ultrex, Bravo Weather Stik)

Chlorothalonil is the best single material for scab (Cladosporium carpophilum) and brown rot (Monilinia fructicola) from bloom through 2nd cover (with 24c labels in most Southeastern states). Because of its multi-site mode of action it is an excellent resistance management tool in that it controls blossom blight while providing strong residual control of scab. Chlorothalonil's current federal label precludes use after the shuck split stage. Many southeastern states have obtained 24c labels for use through shuck off. Retention of a bloom to shuck split application window and the associated 24c's enabling use through shuck off (second cover) is strongly encouraged.

benzimidazols: benomyl (Benlate) and thiophanate methyl (Topsin-M)

Benzimidazol resistance to scab (Cladosporium carpophilum) and brown rot (Monilinia fructicola) was scattered but widespread. Where sensitive strains are present these materials are excellent. Incidence of resistance is declining due to judicious use of these compounds associated with removal of old orchards and replanting new. Their primary niche is occasional use for blossom blight, the subsequent green fruit rot stage of brown rot, preharvest sprays for brown rot and scab control in the season following a freeze out year. In areas that experience heavy scab or brown rot pressure, a typical use pattern would be once or twice per season throughout an orchard's bearing life. We favor retaining peach benzimidazole labels for bloom, cover sprays and pre-harvest. Benzimidazole utility as a resistance management tool to protect the vital DMIs would function with a 7-day pre-harvest interval.

captan

Captan is effective against scab and brown rot. It is perhaps our most important resistance management tool for protecting the DMI fungicides because of it close preharvest interval. Current labels limit captan use to 0 days pre-harvest. Captan's pre-harvest resistance management utility would remain intact with extension of its pre-harvest interval to 3 days. Captan is no longer used post-harvest, so elimination of that use should be considered. Captan is effective for the secondary pathogens gummosis and pocket rot caused by Botryosphaeria dothidea, anthracnose caused by Collectotrichum acutatum and a complex known as sooty peach. Its use in the cover sprays is considered critical.

Nematicides fenamiphos (Nemacur)

Nemacur is the only labeled post-harvest peach nematicide. Nematodes are key pests of peaches. Nemacur use lengthens the productive life of nematode infested orchards and increases yields in orchards where peach tree short life tolerant rootstocks are used. We could accept as-needed extension of Nemacur's in-season from the current 45 day PHI up to as much as 60 days PHI.

Insecticides/Miticides Organophosphates (OPs)
in-season: azinphosmethyl (Guthion), encapsulated methyl parathion (Penncap-M), phosmet (Imidan)

Imidan, Penncap-M and Guthion are critical in-season pest management tools in eastern peach production. These OPs provide excellent control of our key pests, they suppress secondary pests such as scale, and they offer protection to our alternative class of insecticides, the resistance-prone pyrethroids.

Our diverse pest complexes coupled with voids in pest sampling technology that prevent as-need insecticide use -- force preventative sprays. Prophylactic chemical use in a long-lived perennial magnifies the weaknesses of any pesticide. Organophosphates are the only insecticides that control our key pest and suppress secondary pests without severe resistance risk.

Resistance management overwhelming favors continued OP use in peaches, if for no other reason than to protect the pyrethroids. Pyrethroid insecticides, the only labeled alternative for peaches not under similar FQPA scrutiny, are among the most resistance prone insecticide classes. OPs in peaches have, on the other hand, been remarkably free of resistance problems. OPs have been used preventatively in southeastern peaches since the 1950's without resistance problems.

Secondary pests--scale and mites--are far more manageable using OP insecticide programs than with pyrethroids. Growers who have used more than 3 pyrethroid applications per season have experienced severe scale problems that kill limbs and even trees. Pyrethroid-related increases in scale and mites require additional, previously unneeded pesticide applications. Little imagination is needed to visualize extreme scale and mite problems if southeastern peaches were to receive pyrethroid applications season-long. We feel season-long pyrethroid use would result in an additional 4-6 additional prophylactic insecticide/miticide applications annually.

To our knowledge every major eastern peach shipper uses chlorinated dump tank and hydrocooling to clean and cool peaches. Hydrocooling exposes fruit to approximately 30 minutes of moving water at 50-200 ppm chlorine at pH 6.5-7.5. Hydrocooling has consistently reduced pesticide residue levels, especially OP insecticide levels, to well below tolerance.

carbamates: carbaryl (Sevin), methomyl (Lannate), formetanate hydrochloride (Carzol)

Sevin is an important, as-needed pre-harvest spray for control of Japanese and/or June beetles. These fruit feeders emerge in large numbers some years. They feed on and ruin ripening fruit, plus they scratch the fruit surface and physically inoculate brown rot spores below fungicide barriers. Sevin's residual efficacy in this use is short. Its current PHI is 1 day, we recommend lengthening this interval to 3 days.

Lannate is our most effective thrips material; used pre-bloom and petal fall. In the Mid-Atlantic States Lannate is a necessary component of pre-harvest tank mixes to control tufted apple budmoth.

Carzol provides early-season thrips control, and it is one of two remaining curative miticides in peaches. Mites are an occasional, but sometimes-important eastern peach pest. Recommendations already emphasize miticide use well before harvest. We suggest limiting use to two applications per season. Retaining Carzol's already conservative 21 day pre-harvest interval is encouraged.

If the current peach carbamate (carbaryl, Sevin; methomyl, Lannate) and pyrethroid (permethrin, Ambush/Pounce; esfenvalerate, Asana) labels are not seriously altered we feel optimal grower IPM efforts could adapt to fewer in-season OP applications. Given continued carbamate and pyrethroid availability, we are hopeful growers could retain stable IPM in eastern peaches with a maximum of six in-season OP applications (12 lbs ai/acre of Imidan, Penncap-M or Guthion). A single, low rate, pre-harvest OP 14 days pre-harvest is sometimes crucially important.

post-harvest OP: chlorpyriphos (Lorsban)

Lorsban (chlorpyriphos) is applied post-harvest. Post-harvest Lorsban use obviously does not constitute a fruit residue risk. Chlorpyriphos is applied post-harvest to virtually all southeastern peaches (young, non-bearing trees and mature trees) for control of peachtree borers. Grower commitment to minimizing pesticide residues on fruit restricts use to the post-harvest control window, even though the Lorsban label allows directed, in-season trunk sprays. Labeled alternatives are less durable. Endosulfan must be applied two times. Single applications of esfenvalerate must be very carefully timed to borer oviposition to get control comparable to that offered by chlorpyriphos. We urge alteration of the Lorsban label to limit borer sprays to post-harvest application.

BLUEBERRIES Fungicides Captan

Captan is needed in the Southeast for ripe rot control and resistance management for Botrytis. Ripe rot is a post harvest problem that is initiated during the cover spray period. Its presence is extremely damaging to markets. Captan's current PHI is day of harvest; this could be lengthened to 3 days PHI without undue harm to growers.

Benlate

Benlate is needed to control Botrytis. The commonly used DMI (demethylation inhibitor) fungicides (Orbit in Georgia and Indar in South and North Carolina under a Section 18 labels in 1998), tend to exacerbate Botrytis. DMIs are necessary to control mummy berry typically our most important disease.

Insecticides

At this time, there are no alternatives to the OP and carbamate insecticides on blueberries. While blueberries do not tend to receive heavy applications of insecticides, blueberry maggot, cranberry fruitworm, and plum curculio can cause significant yield losses. Japanese beetles and scale insects are sporadic problems as well. The OP insecticides azinphosmethyl, diazinon, malathion, and phosmet (24c label in the Southeast) and the carbamate carbaryl are currently labeled for use. Horticultural oils can be used as a dormant application for scale suppression. Lengthening the PHI would be a possibility except for blueberry maggot and Japanese beetle management. Both of these pests are a threat through harvest. We urge the continued use of these materials on blueberry.

BRAMBLES or CANEBERRIES (Blackberries & Raspberries in the SE) Fungicides

Botrytis is the number one fruit rot problem on brambles. Tools to manage Botrytis are captan, vinclozolin (Ronilan DF) and benomyl (Benlate). In brambles benomyl also plays an important role in anthracnose (Elsinoe veneta), double blossom (Cercosporella rubi) and bot canker (Botryosphaeria dothidea) control thus complicating the Botrytis resistance management Thus captan (available under 24c in South Carolina) and vinclozolin are key for Botrytis management. Captan also controls ripe rot in brambles, which can be serious in some years. Because captan and benomyl have a 3-day PHI it is important to retain the 0-day PHI for Ronilan. In raspberries cane blight and spur blight are also effectively controlled by benomyl. Benlate's current PHI is 3 days, as-needed extension to 7 days would continue to provide reasonable control of above diseases along with cultural tactics and post harvest sprays.

Insecticides

There are no alternatives available. Malathion and azinphosmethyl (OP) and carbaryl (carbamate) are the only materials currently labeled on brambles in the Eastern United States. Diazinon is labeled only in California, Washington and Oregon. Strawberry weevil (clipper) and raspberry crown borer can cause significant losses if uncontrolled. Azinphosmethyl is the only material available for control of crown borer. With no alternatives, continued labeling of the OP and carbamate materials is essential for bramble production. Increasing the PHI would be an option since most of the pests, except Japanese beetle, can be managed well before harvest.

STRAWBERRIES Fungicides Captan

Captan is labeled for use 0 day PHI for Botrytis and anthracnose (C. acutatum) control. Strawberries ripen over an extended period; disease pressure in the Southeast is frequently severe. Captan's 0 day PHI is imperative, from an IPM perspective no change is the PHI should be considered. Captan is an important resistance management tool.

Rovral Rovral is a very important Botrytis material. For the present Rovral is essential. New chemistries may lessen the need for the dicarboximides within the next few years, but even then they should be retained with more conservative PHIs to provide resistance management alternatives to protect new chemistries. Benomyl Benomyl provides important control of secondary organism Mycosphaerella fragariae, Gnomonia spp., Phomopsis obscurans and Diplocarpon earliana as well as Botrytis. Resistance is wide spread to both dicarboximides and benomyl. Insecticides Alternatives to the OP and carbamate insecticides are available for strawberry producers.

Chlorpyrifos is labeled for prebloom use only. Malathion is labeled for use to within three days of harvest, azinphosmethyl within five days of harvest, and diazinon within five days of harvest. Carbaryl is labeled for use within one day of harvest. While these are important tools in insect management, the PHI's could be lengthened without causing any significant problems. However, the loss of the OP and carbamate materials would force producers to rely completely on the pyrethroids and endosulfan, an organochlorine material. Endosulfan is restricted to three applications/season with 35 days between applications when fruit is present. The loss of the OP and carbamate insecticides would put tremendous pressure on the pyrethroids raising the distinct possibility or resistance problems. Increased reliance on the pyrethroids could also aggrevate mite problems. If so, additional miticide applications would have to be made.

GRAPES Fungicides

The Grape situation is complicated by growing three different types of grapes in the southeast. They are Vitis rotundifolia, V. labrusca, and V. vinifera.

Captan

Captan plays an important role in controlling Macrophoma, Botrytis (including resistance management), ripe rot, and anthracnose as well as having activity for black rot, bitter rot and Phomopsis. This broad spectrum makes it essential for Botrytis resistance management and late season control for Macrophoma and ripe rot control in the appropriate species. The zero day PHI might be extended to 4 days for commercially picked operations but should be maintained at 0 day for pick your own operations.

dicarboximides and Benomyl

The dicarboximides are important for Botrytis management in vinifera types. Benomyl is important for a broad spectrum of diseases including Botrytis, black rot, and anthracnose. Phomopsis, Macrophoma rot, angular leaf spot and Eutypa/Botryosphaeria canker. The 7 day PHI should not be changed to facilitate management of Macrophoma rot in rotundifolias and Botrytis in viniferas.

Insecticides

There are no acceptable alternatives to the OP's and carbamates. The OP's azinphosmethyl, chlorpyrifos, diazinon, phosmet, and encapsulated methyl parathion (Penncap-M) and the carbamate carbaryl are currently labeled on grapes. Several Bt. products are labeled for control of lepidopterous pests. However, they are limited in scope and provide control of other pests.

Chlorpyrifos

Chlorpyrifos is labeled for grape root borer control. This is an essential label. The current PHI is 35 days. This often restricts growers to a slightly earlier than optimal application or an application after harvest, which often is later than optimal. The alternative control, soil mounding, is labor intensive, time sensitive, and not an optimal horticultural practice. Loss of this label would cause significant vine loss in the Southeast.

Current PHI's need to be maintained.

Thank you for your consideration.

Sincerely,

Dan Horton and Harald Scherm, University of Georgia
Clyde Gorsuch, Walker Miller, David Parker, Edmund Taylor, James Cummings and Bob Bellinger, Clemson University
John McVay, Jim Pitts, Arlie Powell and Wheeler Foshee, Auburn University
Dean Polk, Rutgers University
Freddie Raspberry, Mississippi State University
Steve Bost, University of Tennessee
Bill Hanlin, North Carolina State University