insect ipm in apples: kaolin clay

Kaolin ClayInsect IPM in Apples

Reduced-RiskPest ControlFactsheet

Biopesticides and Risk ReductionBiopesticides and Risk ReductionBiopesticides and Risk ReductionBiopesticides and Risk ReductionBiopesticides and Risk ReductionThis factsheet is part of a series highlightingthe latest breakthroughs in biorational pestcontrol. There is a growing commitmentamong producers to use the least toxic meth-ods for protecting crops. Increased awarenessof the many benefits of advanced integratedpest management (IPM) are at the heart of thischange. Meanwhile, FQPA (Food Quality

Protection Act) and other regulations havegiven short-term urgency to the quest forreduced-risk alternatives to the most toxicchemicals, including the organophosphates.

Effects of SurroundWP� intrial applications on apples:! Control: leafrollers, leafhoppers.! Suppression: mites, codling moth, plum curculio, apple sucker, stink bugs, apple maggot, thrips.! Horticultural Benefits: reduced heat stress and fruit drop, reduced sunburn, improved color in certain cultivars.

The spray was developed by Drs. MichaelGlenn and Gary Puterka of the USDA/ARS atKearneysville, WV, in cooperation with theEngelhard Corporation , which began market-ing the product in 1999 on a limited basis.Surround was available in 2000 in much of theU.S., and it was listed by The Organic Materi-als Review Institute for use in organic produc-tion on March 7, 2000.

Important additions have been made in recentyears to the arsenal of reduced-risk pest man-agement tools. This series of factsheets is in-tended to put the latest information on thesenew tools in a convenient, farmer-friendlyformat. Special effort has been made to includeefficacy information, discussion of relative costs,contact and supplier information, and interviewswith farmers who have used these new tools incommercial production.

This factsheet looks at the use of kaolin (themain ingredient in SurroundWP�) in appleIPM. While kaolin is registered for many crops,it seems especially promising for apple growers.

What is kaolin and how does it work?What is kaolin and how does it work?What is kaolin and how does it work?What is kaolin and how does it work?What is kaolin and how does it work?Surround WP presents a unique form of pestcontrol: a non-toxic particle film that places abarrier between the pest and its host plant. Theactive ingredient is kaolin clay, an edible min-eral long used as an anti-caking agent in pro-cessed foods, and in such products as tooth-paste and Kaopectate. There appears to be nomammalian toxicity or any danger to theenvironment posed by the use of kaolin in pestcontrol.

Surround is sprayed on as a liquid, whichevaporates, leaving a protective powdery filmon the surfaces of leaves, stems, and fruit.Conventional spray equipment can be used,and full coverage is important. The film worksto deter insects in several ways. Tiny particles

Reduced-Risk Pest Control Factsheet / Insect IPM in Apples / Kaolin Clay /

The plum curculio, Contrachelus nenuphar.(Magnified) Adult above at left; larva belowat left; pupa at right, ventral view.

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Appropriate Technology Transfer for Rural Areas

The standard Surround sprayprogram for plum curculio andfirst-generation codling mothstarts at first petal fall and contin-ues for 6 to 8 weekly sprays oruntil the infestation is over.Discontinuing sprays at thispoint will leave little or no resi-due at harvest because of rainand wind attrition. If a full-season program is used to suppress later-season threats such as apple maggot, growerswill need to use a scrubber/washer to removeany dust remaining on the fruit for fresh mar-ket sales. Although this residue is not consid-ered harmful, it might be considered unsightlyby consumers. However, the dust residue isnot a problem for processing fruit.

of the clay attach to the insectswhen they contact the tree,agitating and repelling them.Even if particles don�t attach totheir bodies, the insects find thecoated plant or fruit unsuitablefor feeding and egg-laying. Inaddition, the highly reflectivewhite coating makes the tree lessrecognizable as a host.

The plum curculio:Adult female on plum,showing the circularfeeding punctures andthe crescent-shapedegg-laying punctures(shown larger thannatural size.)

HorHorHorHorHorticultural Benefitsticultural Benefitsticultural Benefitsticultural Benefitsticultural BenefitsAlthough at first glance the film mayappear to block light, Surroundactually increases net photosynthesis,and can provide secondary benefits tothe trees� overall health, according toDr. Glenn. Surround keeps the treecool so that photosynthesis cancontinue longer into the afternoon onhot days, after untreated trees havealready shut down because of heatstress. In a two-year study, �Empire�,when sprayed during the first six toeight weeks after petal fall, hadincreased yields and increased redcolor. Growers have reported similarresults with �Stayman� and �Gala�. AnMSU study reported increased returnbloom where Surround had been usedthe previous season. Growers in hot

areas benefit from a marked reduction in sun-burn damage, often 50% or greater.

Trial applications of the spray showed thatwhere plum curculio damage was 20�30% inunsprayed checks, the treatments receiving theparticle film had only .5�1% damage. Dr.Puterka is careful to say that his trials indicate�suppression� of PC damage rather than com-plete control. For the organic grower looking toachieve an economic level of control, the distinc-tion is probably not relevant. What the re-searcher terms �suppression� in these USDAtrials is very close to control, far closer than anyother organically suitable option. For the non-organic grower, kaolin alone will not achievequite as high a level of control as is ensured bythe organophosphates. However, Surround iscomparable to the OPs in that it�s a broad-spectrum tool effective against most of themajor pests of apple. As growers gain experi-ence in timing applications of this new tool,efficacy data will very likely improve.


A Systems ApprA Systems ApprA Systems ApprA Systems ApprA Systems ApproachoachoachoachoachSurround will be most effective when usedwithin a well-managed agro-ecological systemcombining the most appropriate cultural andchemical methods for the specific orchardsituation, pest complex, and local climate. Sucha system will integrate soil building, habitat forbeneficial organisms, and well-tuned nutrientand water management. Soil building andnutrient/water management are two sides ofthe same coin and could be considered preven-tative pest management. A healthy soil high inorganic matter will have better water andnutrient holding capacity. Plants receiving toomuch or too little of either water or nutrients,particularly nitrogen, are more attractive andmore susceptible to damage by insects anddiseases. Good water management, throughwater-stress monitoring, conserves valuable(and expensive) soil nutrients, reduces contami-nated runoff, and conserves water. Providinghabitat for beneficial organisms is like hiringmillions of helpers whose sole aim in life is toeat pests. Nitrogen-fixing cover crops can dodouble duty as habitat for beneficial organismsif managed correctly.

NorNorNorNorNortheastertheastertheastertheastertheastern U.S. Grn U.S. Grn U.S. Grn U.S. Grn U.S. Grower Reporower Reporower Reporower Reporower Report:t:t:t:t:Eric Rice, Middletown, Maryland

One of the first orchardists to usethe kaolin spray, Eric Rice is confi-dent the product will help him farebetter in his packout next year.Rice, whose farm is certified or-ganic, hopes to boost the percent-age of select grade fruit from 50% to70% of his apple crop. He expresses optimismabout Surround�s effectiveness against insectslike the plum curculio, codling moth, leafrollers, mites and aphids. �It doesn�t botherbeneficials,� he says, adding that the ladybugsand other predators continued to thrive in therich ground cover of clover and grass.

SoutheasterSoutheasterSoutheasterSoutheasterSoutheastern U.S. Grn U.S. Grn U.S. Grn U.S. Grn U.S. Grower Reporower Reporower Reporower Reporower Report:t:t:t:t:Guy Ames, Fayetteville, Arkansas

Codling Moth

�I�ve used kaolin clay for twoseasons now. Last year I was slowin getting the first sprays on, andlate May through early June wasan exceedingly wet period duringwhich I had competing interests.In short, I can�t claim to have given

Surround a valid test in 1999.

Another Arkansas growerreports that �it�s a realchallenge to keep the treescovered.� This is his first season using Sur-round. One technical limitation he has encoun-tered is with his sprayer: it has been impossibleto achieve full coverage of the tops of the treesusing his present equipment. Full coverage iscritical to achieiving good pest control.

Oriental Fruit Moth

Apple Maggot


It seems likely that kaolin clay, when used in a well-managed IPM program, will be an appropriateand effective reduced-risk replacement for synthetic insect pesticides. To be viable in commercialproduction however, it must be cost-effective as well. At this time, Surround seems to be roughlycomparable in relative cost to the commonly used OP insecticides, while providing comparable broad-spectrum coverage. Of course, there are variables that make this a tentative statement: relative pestpressure and rainfall, for example, influence how many sprays of Surround must be made in a season.Over the next few years we will gather data on the cost of using kaolin and report our findings.

Rice says that Surround is far more useful thanany other organic options available on themarket. The only disadvantage he cites is thenecessity of washing the clay off the fruit afterharvest. Referring to the uniformly whiteappearance of the trees after spraying, Ricesays, �It looks like Christmas. People whodrive by stop to inquire if something is wrong.�

Trials at the Rice or-chard have shown over90% control of the �bigones�� codling moth,plum curculio, andapple maggot. WhileSurround has also had apositive effect on fungaldiseases like sootyblotch, fly speck, andfire blight, Rice cautions

that it is not a panacea. It has had no effect onapple scab, a disease that often poses a biggerproblem to growers than insect pests (initialresearch with kaolin focused on disease sup-pression, but the results were inconsistent.)

�However, in 2000 I�ve been more attentive tokeeping Surround on the trees in the early partof the season. Compared to last year I appearto be getting good to excellent control of tar-nished plant bugs and stink bugs, two of thepests that I was targeting with Surround.

�Other observations: It did not wash off inrain as readily as I had feared; didn�t seemsto clog up or corrode any sprayer parts; Ilike being able to see my spray coverage;too early to see if it has helped to controloriental fruit moth as Ihope it will.� Ames addsthat Surround may provekey to making organicapple production eco-nomically viable in theEastern U.S. by providingthe long-sought organiccontrol for plum curculio.

EconomicsEconomicsEconomicsEconomicsEconomics

SummarSummarSummarSummarSummaryyyyySurround is an environmentally benign,worker-friendly and cost-effective tool that canprovide many pest management and horticul-tural benefits. It is most effective when used inan agricultural ecosystem managed for healthysoils with well-balanced nutrient and waterbudgets. Providing habitat for beneficial organ-isms (in the form of cover crops and unmownwildflower strips) complements the pest controlbenefits of kaolin clay and builds soil quality aswell.

CompatibilityCompatibilityCompatibilityCompatibilityCompatibilitySurround is generally not affected by mostother insecticides, miticides, and fungicides.However, the user should test tank-mixesbefore use. When mixing with other products,make up a small batch and observe slurry andfilm characteristics. Curdling, precipitation,lack of film formation, or changes in viscosityare signs of incompatibility. Do not tank-mixwith sulfur or Bordeaux mixture fungicides.

Note: “Raw” kaolin clay is not the same...Note: “Raw” kaolin clay is not the same...Note: “Raw” kaolin clay is not the same...Note: “Raw” kaolin clay is not the same...Note: “Raw” kaolin clay is not the same...as SurroundWP. We have heard of one growerwho bought a traincar load of �generic� kaolinclay, and killed most of his apple trees! Sur-round is, at this point in time, the only kaolinproduct suitable and registered for horticulturaluse. The kaolin in Surround is processed to avery fine particulate size, and combined with asticker-spreader. Other forms of kaolin clay arephytotoxic and should be used under no cir-cumstances.


Further Resources

SurroundWP manufacturer:Engelhard Corporation101 Wood Avenue, P.O. Box 770Iselin, NJ 08830-0770877-240-0421 (toll free)732-321-1598 FAXhttp://www.surround.engelhard.com

EPA biopesticides website:http://www.epa.gov/pesticides/biopesticidesLatest information and news, with fact-sheets on individual biopesticides.

Pesticide Environmental Steward-ship Program Website:http://www.pesp.org/A public/private coalition committed toreducing the risks from pesticide use.Risk-reduction strategies, informationon least-toxic pest control, grants, newsupdates, links to IPM websites.

Organic & Low-SprayApple Productionhttp://www.attra.org/attra-pub/apple.htmlDetailed info on IPM in Apples, featuringa chart of disease-resistant cultivars andan extensive Resources section withsupplier contacts and sources of furtherinformation. A free print copy of this 38-page booklet is available by callingATTRA at 800-346-9140.

insect ipm in apples: kaolin clay

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