LivestockResearchforRuralDevelopment Volume11,Number11999

OverallviewonthetraditionoftappingpalmtreesandprospectsforanimalproductionChristopheDalibard

InternationalRelationsService,MinistryofAgriculture,Paris,France

"Neera[sapextractedfromBorassusflabellifer]canbeconvertedintoJaggerysweetashoneyitself.ThisJaggeryissuperiortocaneJaggery.CaneJaggeryissweet,butPalmJaggeryissweetanddeliciousitcanbeproducedworthcroresofrupees.PalmGurgivesmineralsaltstoo.DoctorshavetoldmetoeatJaggeryandIalwayseatPalmGur.NaturehasmadethisproductinsuchawaythatitcannotbemanufacturedintheMillsitisproducedintheCottages.WheretherearePalmtrees,thisJaggerycanbeeasilyproduced.AndhraDeshahasthousandsofPalmtreesthere,Jaggeryisproducedineveryhamlet.Thisisthewaytobanishpovertyfromtheland.Thisalsoisanantidotetopoverty."MahatmaGandhi[FromaspeechdeliveredattheopeningofthevillageindustryexhibitioninBrindawanBihar(3May1939)]

Abstract

Palmtreeshaveprovedtobeefficientconvertersofsolarenergyintobiomassinmostagroecologicalzonesofthetropicalworld.Mosttappedpalmtreesgivesasapveryrichinsugar(10to20%).Forseveralmillennia,manyspeciesofpalmtrees(includingcoconut)havebeenusedforsugarproduction.HighlysophisticatedtechniquesoftappingweredevelopedthroughthecenturiesinAsia,AfricaandAmerica.Highyieldsofsugarwereobtainedfrompalmsthatcouldcontinueforuptoahundredyearsofproduction.Oneofthemainconstraintsonproductioninrecenttimeshasbeentheincreasinglackoffuelneededforprocessingpalmsapintosugarandthepricethereof.Nevertheless,sincetrialsoffeedingpigswithfreshsugarpalmsapweresuccessfullyinitiatedinanFAOprojectinCambodia,therehasbeenrenewedinterestintappingpalmtreesforsaptobeusedasfeed.AthoroughreviewoftheliteraturehasshownthatintensivepigrearingbasedonpalmsaphasalreadybeenpractisedbytheIndonesiansforcenturiesandwasfoundtobeaveryefficientsystemforintensifyingagricultureinsomehighlypopulatedislands.Intoday'seconomy,developinganimalproductionusingpalmsapasthemainsourceofenergyinthedietlooksverypromising:thelandcouldsustainhigherpopulationdensitiesthroughtheintensificationofcropandanimalproductionwithinsustainableintegratedsystemsforsmallfarmers.

Keywords:sugarpalm,tapping,sap,livestock,feed

Foreword

Therecentdocumentationoftheveryhighpotentialofthesugarpalm(Borassusflabellifer)asasourceofdigestibleenergyforpigproduction(KhieuBorinandPreston1995)hasfocussedattentiononthepalmspeciesingeneralandtheirmultipurposeusesinparticular.Thisreviewdemonstratestheenormousamountofknowledgethatexistsonthetappingofpalmsanduseofthesap,includingthefatteningofpigsdonetraditionallyforcenturiesincertainislandsinIndonesia.Itisclearthatmostoftheinformationisderivedfromindigenoussourcesandthatpalmcultivationhasplayedamajorroleinpovertyalleviationthroughoutthetropics.Theneglectofthisspeciesbyresearchers,otherthanformonoculturalexportpurposes(eg:coconuts,datesandpalmoil),isareflectionofthereductionistthinkingthathasprevailedinagriculturalscienceduringthelast50yearorsoyears.Itishopedthisreviewwillreviveinterestinthepalmspeciesatatimewhenefficientcaptureofsolarenergyandenvironmentalfriendlinesscharacteristicssharedbymostofthepalmspeciesarereceivingpriorityasindicatorsofsustainablefarmingsystems.

...TheEditors

Introduction

Palmsarebelievedtobeamongtheoldestfloweringplantsintheworld(Redhead1989).Forcenturies,manypalmspecieshavebeentappedthroughoutthetropicalworldinordertoproducefreshjuice(sweettoddy),fermenteddrinks(toddy,wine,arak),syrup("honey"),brownsugar(jaggery)orrefinedsugar.Oneofmankind'sfirstsourcesofsugarwasprobablyArengapinnata(Redhead1989).EvidenceoftheuseofBorassusflabellifersugarinIndiahasbeenreportedbytheGreekhistorianMegasthenes,ambassadortothecourtofChandragupta,inthe4thcenturyBC.Hindusknewhowtoextractitabout4,000yearsago(Ferguson1888,citedbyFox1977).JaggeryandtreacleextractedfromCaryotaurenssapinSriLankahasbeenanimportantsourceofsugarfromantiquity(Dissanayake1977).InAfrica,themaintraditionaluseofpalmsapisforwineproduction.IthasbeenreportedinEgypt(datepalm)longbeforethebirthofChrist(Barreveld1993)andontheGuineacoastbyearlynavigatorsinthe15thcentury(SodahAyernorand

Matthews1971).

Mosttappedpalmtreesdonotonlyproducesapbutaremultipurpose(ediblefruits,buildingmaterials,fuel,fibres,wax,etc.)andtheirsocioeconomicimportancecanbecriticalfortheruralpoor:GhandiusedtocallBorassusflabellifer,aremedyagainstpoverty.ATamilclassicalpoem(TalaVilasam)composedbyArunachalaminTamilNaduisentirelydedicatedtothegloryofthistreeandenumerates801articlesmadefromitsvariousparts(Rangaswami1977Kovoor1983).Anotheroutstandingexampleisthecoconutpalm,forwhicheverypartisused.ThistreeiscalledinIndia"TreeofHeaven","Mankind'sgreatestproviderinthetropics","Treeoflife",etc.(Rangaswami1977).Thereareatleast1,000usesforthecoconutpalm(Dissanayake1986).Nypafruticansisalsoanoutstandingproviderofvariousproductswhichareessentialtoeverydaylivingandthereforeissaidtobethemangrove'scounterpartofcoconut(Quimbo1991).Palmtreesarealsooftenassociatedwithcropsandpastures.

Thescopeofthispaperisfocusedonpalmtreesthataretraditionallytappedorwithapotentialfortappinginanondestructivemanner,guaranteeingsugarproductioninthelongrunwithinsustainableproductionsystems.Sugarproductionfromthefruits(asfromdatesofdatepalm)orfromthestarchaccumulatedinthepithofthestem(asforsagopalm)isnotreviewedhere.

Rationale

Theoretically,theadvantagesoftakingthesugarsfromthesapbeforeitgoestothefruitsareobvious.Thesesugarsareinterceptedbeforebeingusedintheproductionofthenonediblepartssuchashuskincoconut,whichrepresents35%ofthefruit(Rangaswami1977),andintheproductionofediblematerialthroughchemicalreactionswhichimplyaloss,mainlyaconversionofsugarintooilasforcoconutandoilpalm.Itisthereforemoreprofitablefromthepointofviewofedibleenergyproductiontotapapalmforthesapratherthanallowingthepalmtoproducefruits.Similarly,itwasdemonstratedthat,inthecontextofharvestableenergyfromthecoconutpalm,theamountofenergyharvestedinthesap(throughproductionofethanol)couldbe5to7timeshigherthanfromtheoilofthenuts(coconutoilismixedwithdieselfuelina510%blendaspartofanationalenergyprograminthePhilippines)(Banzon1984).

Table1:Yieldsofalcoholfuelfromdifferentsources(HamiltonandMurphy1988)Sourceofalcoholfuel Annualyield(litres/ha)Sweetpotato 6,75018,000Tappednipah 6,48015,600Tappedcoconut 5,000Tapioca 3,2408,640Sugarcane 3,3506,700

Comparingfivesourcesofalcoholfuel,HamiltonandMurphy(1988)emphazisetheinterestofnipahintermsofyield(Table1)andmanagement:tappingiseasycomparedtococonutthelandisproperlyusedandtheenvironmentprotectedastherearenowastestogetridofasbagasseinthecaseofsugarcane.

Physiology

Itispossibletoobtainasugarysolutionbytheexcisionofthemeristeminnearlyallpalms(Tuley1965a).Basically,starchreservesfromthetrunkareconvertedtosugarandaretransportedupwardstowardthestemapex(Fox1977).AlthoughthisistrueinthecaseofCorypha,otherexplanationsareneededforpalmssuchascoconutwhichdoesnotaccumulatestarchinitstrunk(Reijne1948citedbyVanDie1974).Pethiyagoda(1978)describestheupwardstreamasawateryliquidcontainingdissolvedsaltsabsorbedfromthesoil,andthedownwardstreamasacomparativelyrichmixtureoffood(principallysugars)manufacturedintheleaves.Thesapflowisinterceptedbyinjuringfibrovasculartissuesoftheapexoroftheinflorescence.Nevertheless,thisauthorrecognizesthatthelargevolumeofexudateproducedduringtappingandthehighsugarconcentrationclearlyindicatethatthematerialisdrawnfromstoredresourcesandisinexcessofcurrentlysynthesisedsugars.

VanDie(1974)considersthatthebleedingsapofCocosnuciferaandArengasaccharifera,andprobablysomeotherpalmstoo,mayberegardedasthemobileaqueousphaseofthesievetubesystemofthesetrees,flowingtoanartificialsink,thebleedingsite.However,therateofbleedingfromasingleinflorescenceisseveraltimeshigherthantherateofassimilateflowintoasinglebunchduringfruitformation.Theoriginofthelargeflowofsapthatoccursinatappedtreeisnotyetclearlydemonstrated.ThisisalsothecaseforBorassusflabelliferwherewaterfromrootabsorptionappearsquiteinsufficient(Kovoor1983).Nypafruticanssapyieldishigherincloudyweather,anditisclaimedthattranspirationcompeteswithsapyieldbutispartlycompensatedbyvariationinsugarcontent(Hinchy1938acitedbyHamiltonandMurphy1988).

Pethiyagoda(1978)suggeststhatthereisasteepriseinrespirationwhichoccurswheneverthereisarapidsolubilisationandmovementofmaterialsfromsitesofstoragetothepointsatwhichtheyareneededsuchasduringseedgermination,floweropeningandfruitripening.Thisphenomenoncanbefostered,heightenedandsustainedbymanipulativeprocesses,theuseofgenerallyyounggrowingsites(merismatictissues)andtheactoffresheningthewound.Preliminarystudies(notpublished)citedbyPethiyagoda(1978)showaconsiderablyincreasedrespirationbyfragmentsofcoconutinflorescencedrawnfromstimulatedspadices.

InCambodia,arecentstudyonBorassusflabellifershowsthatthereisnosignificantdifferencesbetweendaysintheyieldofjuiceanditsBrixvalue,butdifferencesforthesetwoparametersarehighlysignificantbetweenfarms,monthsandsexofthepalmtree(fortheBrixbetweenmaleandfemale,thedifferenceissignificantinsteadofhighlysignificant).Duringtheproductionseason,juiceflowsignificantlydecreasesastheBrixsignificantlyincreases.Sapflowishigherduringcoolnights(KhieuBorinandPreston1995KhieuBorin1996).

Tappingisgenerallypractisedtwiceaday.Forexample,inthecaseofthecoconuttree,thescarshealandthesapflowstopswhenslicingisnotdoneforoneortwodaysand2weekswouldbenecessaryforrestoringthesapflow(Levang1988).

Location,productsandtappedpartsofpalms

Annex1listsmorethan30differentpalmspeciesthataretraditionallytappedinpartsofthetropicalworld.Thiswascompiledfrommorethanahundredreferencesonpalmsintheliterature.Manyreferencesare

severaldecadesoldasthereisnotmuchrecentliteratureonthissubject.ThemajorpartoftheinformationwasfoundonpalmsthataretappedintheOldWorld,withmoreorlessasmanydifferenttappedspeciesinAsiaandinAfrica.VerylittleliteratureseemstobeavailableontappingpalmtreesintheNewWorld.InAmericaandAfrica,itseemsthattappingpalmshasbeenpractisedexclusivelyormainlyforwineproduction,whereasinAsiathesapisusedeitherasfreshjuiceorprocessedintoalargearrayofproducts(wine,arak,sugar,vinegar,etc.).Annex1alsoshowsthattherearetappedpalmspeciesadaptedtoalmostallagroecologicalzonesofthetropicalworldfromtidalareasandswampstodesertsandmountains.

Sapcomposition

Mosttappedpalmtrees(Table2)giveasapveryrichinsugar(10to20%accordingtospeciesandindividualvariation)whereasthemapletree,tappedforsugarproductioninNorthAmericagivesasapcontainingonly3%ofsugar(Annett1913).Gibbs(1911)citedbyVanDie(1974)hasreportedastrikingresemblanceindrymatter,sucrose,andashcontentofthebleedingsapfromthepalmspeciesinvestigatedbyhim(Cocosnucifera,Arengasaccharifera,NypafruticansandCoryphaelata).SugarsfrompalmtreessuchasPhoenixsylvestrisandBorassusflabelliferarereportedtobemorenutritiousthancanesugar(Rangaswami1977Roy1951citedbyMorton1988).Somemedicinalvalueisalsooftenreported:itisthecaseforthesugarfromBorassusflabellifer(Rangaswami1977).InMadagascar,Cocosnuciferasapisusedagainstnephritisandbladderinfections.

Table2:DataonthecompositionofsapandjaggeryfromBorassusflabelliferProductandreference Freshsap[1] Freshsapbeforecooking[2] Freshsapstabilizedwithsodiumbenzoate[2] Jaggery[3]Specificgravity 1.07pH 6.76.9 6.00to4.00 6.45Nitrogen 0.056g/100ccProtein 0.35g/100cc 0.10to0.20% 0.10% 1.04%Totalsugar 10.93g/100cc 14.00to9.40% 15.78%Sucrose 12.30to8.50% 15.04% 76.86%Reducedsugar 0.96g/100cc 0.80to3.50% 0.62% 1.66%Fat 0.19%Mineralsasash 0.54g/100cc 0.10to0.30% 0.17% 3.15%Calcium Trace 0.861%Phosphorus 0.14g/100cc 0.052%Iron 0.4g/100cc 11.01mgper100gCopper 0.767mgper100gVitaminC 13.25mg/100ccVitaminB1 3.9IUVitaminBcomplex NegligibleReferences:[1]PaulasandMuthukrishnan1983acitedbyDavisandJohnson1987[2]Romera1968[3]Roy1951citedbyMorton1988.

BorassusflabelliferfreshsapisagoodsourceofvitaminBcomplex(Chopraetal1958citedbyMorton1988)anditcontainsascorbicacid(Dissanayake1986).100litresofsapgive78kgofsugarand8kgofmolasses(PaulasandMuthukrishnan1983acitedbyDavisandJohnson1987).Asthesapfromthemorningcollectionhasbeenproducedatlowertemperaturesthantheonecollectedintheevening,itislessfermentedandthereforecontainsmoresucrose(Romera1968).ArecentstudyinCambodiashowedthatsucrosecanrangefrom66to94%orfrom51to81%oftotalsolidsinthejuicerespectivelyinJanuaryorinApril.Glucoseandfructoselevelsincreasedduringthesameperiod(KhieuBorinandPreston1995KhieuBorin1996).InthecaseofBorassusaethiopium,sapcompositionofthemorningcollectionmarkedlydiffersfromtheeveningcollectionandalsosapcompositiondiffersonthelevelofcuttingoftheterminalbud,losingitstastewhenitsbaseisreachedthesapalsocontainslesssucrosethanBorassusflabellifersap(Portres1964).InBurma,thetappersdistinguishupto6differentqualitiesofsapaccordingtothetappingstageandthesexofthetree(Lubeigt1979).

TheCaryotaurenssapalsoconsistsalmostentirelyofsucrosewhichisrapidlyfermentedandinverted(Dissanayake1986).ItspHis6.5anditcontainstracesofacids,0.34%ofreducingsugarsandatotalsugarbetween1516%(Theivendirarajahetal1977).Thejaggeryhasthefollowingcomposition:76.683.5%sucrose,0.760.9%reducingsugar1.651.98%ash1.792.27%proteinand6.68.34%pectingums(Dissanayake1977).FreshsapofcoconuthasapHequalto6andaBrixof17(NaimandHusin1984).Itcontains12to18%sugar(mainlysucroseandsmallamountsofglucose,Norrisetal(1922)citedbyGrimwood1975),0.5%ash,2%organicsolids(Nathanael(1960)citedbyGrimwood1975)andsmallamountofvitamins,suchas1630mgofascorbicacidper10ml(Banerjee(1935)citedbyGrimwood1975).Coconutsugarcontains0.5to1.3%protein,72to88%oftotalsugar,57to81%sucrose1.3to2.5%totalmineralsand5to10%humidity.ThefreshsapoftheAfricanoilpalmcontains9.6to10.6%ofsucrose.Glucoseandfructosearemuchbelow1%(EzeandUzoechiOgan1988).SprechervonBernegg(1929)citedbyVanDie(1974)reports14%totalsugars.ThesapisalsorichinvitaminB(particularlyB12)andinsulphurproteins(Hartley1977Tuley1965a).ThesapofPhoenixsylvestrisisagoodsourceofvitaminsoftheBgroupandcontainsinadditionanappreciableamountofascorbicacid(Rangaswami1977).

Managementoftappedpalmtreesandyieldsofsugar

Themanagementofpalmtreesforsapproductionvariesverymuchaccordingtospecies(SeeAnnex2).Nypafruticans,Phoenixsylvestris,Elaeisguineensis,RaphiahookeriandCocosnuciferacanbetappedataratherearlyage,respectivelywhenthetreesare4,5,6,7and7yearsold(CrevostandLemari1913Abedinetal1987Essiamah1992Profizi1988Levang1988).Ontheotherhand,manyyearsareneededbeforetappingCaryotaurens(10to15),Borassusflabellifer(15to30)orCoryphaelata(20to100)(Redhead1989,Fox1977).

Thenumberofyearsapalmtreecanbetappedisalsoverydifferentdependingonthespecies.CoryphaelataandRaphiahookeriflowerjustonce.Theywillproducesaponlyforafewmonthsbeforedying(Fox1977Profizi1988).ArengapinnataandCaryotaurenswillproducesapforseveralyears,withlargeinterruptionsinthecaseofCaryotaurensasitflowersonlyeverytwoorthreeyears(Redhead1989Dissanayake

1977).Otherpalmtreeswillproducesapformuchlongerperiods:10to15yearsforElaeisguineensis,morethan20yearsforCocosnucifera,50yearsforNypafruticansandPhoenixsylvestrisand30to100yearsforBorassusflabellifer(Adand1954Levang1988Magalon1930Abedinetal1987Lubeigt1977).Somespeciesareabletoproducesapallyearround:Arengapinnata,Cocosnucifera,ElaeisguineensisandNypafruticans(Mogeaetal1991Rangaswami1977Tuley1965aKiew1989).BorassusflabelliferandPhoenixsylvestrisproduceonlyseasonally(CrevostandLemari1913Annett1913).

Mosttappedpalmtreesgivesasapveryrichinsugar(10to20%accordingtospeciesandindividualvariation).Theyieldsarehighlyvariableaccordingtothespeciesandtheirmanagement.InthecaseofBorassusflabellifer,thefemaletreescangiveasmuchas50%moresapthanmaletrees(Lubeigt1979).Underpropermanagement,themaintappedpalmspecies(Arengapinnata,Borassusflabellifer,CocosnuciferaandNypafruticans)canreachyieldsofabout20tonnesofsugarperhectare(VanDie1974WatsoncitedbyKiew1989).Comparedtosugarcaneproduction(515tonnesofsugar/ha/year),theBorassusflabellifertreecanreach18tons/ha/yearunderrainfedconditions(KhieuBorinandPreston1995KhieuBorin1996)andthecoconuttree19tons/ha/year(Jeganathan1974).Accordingtoestimates,Elaeisguineensisproducesmuchlesssugar(1.2tonneperhectare,Udom1987)but,asithasneverbeenexploitedforsugarproductionbutonlyforwineproduction,therearegoodprospectsforobtainingmuchhigheryieldsinaproductionsystemorientedtowardssugarproduction.

Methodsofpalmtappingandsappreservation

Thetechniquesfortappingpalmsarenumerousandcanvarydrasticallyfromonecontinenttoanother,asdemonstratedbythecaseofBorassusaethiopiuminAfricaandBorassusflabelliferinAsia.Refinedtechniquesoftappingtheinflorescenceofthelatterarecompatiblewithproductioninthelongterm.DestructivetechniquesareusuallypractisedontheterminalbudofB.aethiopiumandareoftenresponsibleforthedeathofthetreewithinafewmonths.AstappingismainlydoneinAfricaforwineproduction,theuseoftheAsiantechniqueinAfricawouldpermitsapproductionthroughouttherainyseasonwhereaspalmwineisdrunkmuchmoreduringthedryseason(Portres1964).TheAfricanoilpalmisusedinAfricaforproducingwinemainlythroughtwodifferenttechniques:oneisdestructive(incisionofstemapexoffelledpalm)andispreferredinGhanatheotherisnotdestructive(excisionofmaleinflorescenceandsometimesoffemaleinflorescenceaswell)andhasbeendevelopedwhereeconomicconsiderationshaveforcedthepeopletopreservetheirpalms,e.g.ineasternNigeria(Hartley1977).

Tappingcanbepractisedaftercuttingdownthetrees.Otherwise,exceptforNypafruticans,whichistrunklessanddevelopsitsinflorescenceataheightofabout1m(HamiltonandMurphy1988),otherpalmtreeshavetobeclimbedfortappingastheirterminalbudsandinflorescencesarelocatedatthesummitoftheirtrunkwhichisoftenover10mhigh.Theexcisionoftheterminalbudofstandingtreesisquiteharmfulsincetappedpalmsneverresumevigorousgrowth.Iftheterminalbudisonlyperforated,thenthetreeswillshowmalformationinsubsequentleaves,flowersandtrunkgrowth(Kovoor1983).Nevertheless,ithasbeenobservedthatmultistemmedtreessuchasHyphaenecoriaceaandPhoenixreclinatainsoutheasternAfricagenerallyrecoppiceaftertapping,althoughtappedstemsdieunlesstappingisstoppedbeforetheapicalmeristemistotallydestroyed(Cunningham1990).Theverylowyieldsofsapfromthesetreesareinterpretedasaresultofoverexploitation.Cunningham(1990)suggeststhatifpalmsizeclassesshiftedtotheextentthattherewasagainahighproportionofmaturefruitbearingpalmsinthepopulation,theninflorescencetappingcouldbepractisedasHyphaenecoriaceaisanannuallyfloweringpalm.

Themostadvancedmethodoftappingisthatappliedtotheinflorescencespadixwhichguaranteesahighyieldforlongperiodswithoutaffectingthewellbeingofthetree.Itonlyentailsasacrificeofabunchoffruitinthecaseoftappingfemaleinflorescences.TappingtheinflorescenceispractisedthroughoutS.E.Asiaonallspeciesoftappedpalmtrees(Kovoor1983).Twofeaturesarecommonintapping:manipulativetreatmentorpreparation(applicationofchemicalsandsubstanceofplantorigin,twisting,distortion,kneading,pounding,bruising,beatingortapping)necessaryasapreludetocopiousandsustainedsapflow,andrenewingtheexudingwoundbyshavingoffathinsliceoftissueonceortwiceaday(Pethiyagoda1978).Tappingisanart:sapyieldsdependontheskillsofthetapper(KhieuBorinandPreston1995KhieuBorin1996CoconutResearchInstitute1967).

Onceextracted,sugarcaneorsugarbeetjuicesareimmediatelyprocessedforsugarproduction.Inthecaseofpalmsugar,asthesapflowisslow,intermediatestoragebeforecollectionisnecessary:thejuiceisleftforaminimumof10hoursattemperaturesaround300C,withhighhygrometryandhighcontaminationswithnaturalyeasts,bacterialandfungalspores(Romera1968Pethiyagoda1978).Usually,ifthesapisusedforsugarproduction,itwillbecollectedtwiceadayasfermentationshavetobeavoidedasfaraspossible.However,theinclusionofanantifermentingagentisusual(Kovoor1983):traditionallylimeandbarkorleaves(richintannins)fromvarioustreespeciesareused.Thevesselsareregularlycleanedandrinsedwithwaterandsometimessmoked.Sugarisproducedbyboilingthesaptoevaporationuntilasufficientlythicksyrupisobtainedoutofwhichsugarwillcrystallizeoncooling(Kovoor1983).AstudyconductedonBorassusflabelliferandCaryotaurenssapbyJoachimetKandiah(1938)citedbyDissanayake(1986)showsthatlimedpotsinhibitfermentationandinversionofsucrosebetterthansmokedpotsthelattertechniqueiseffectiveonlyforaperiodof3to4hoursaftercollectionfromthetree.

Methodsofpalmtappingandsappreservationforthemainspecies:

Arengapinnata(Syn.:A.saccharifera)

Therearesignificantdifferencesbetweenthemethodspractisedbythedifferenttribes(Mogeaetal1991).Tappingisgenerallydoneonthemaleinflorescencespadix(Redhead1989Friedberg1977).Infact,thesapfromfemaleinflorescenceisofinferiorqualityandthespadixrequiresmoreeffortduringpreparation(Mogeaetal1991).Awoodenmalletisusedforslowlyhittingseveralminutesadaythetrunkbeneathandabovethestemoftheinflorescencewhileswingingitbeforeincision(Friedberg1977).Thetappercleansthemaleinflorescencestalkfromitsbractsassoonastheflowersarenearlyopen.Thecleanstalkisthenslowlybeatenforseveralminuteseachdayforabout2or3weeksatadistanceofabout4560cmfromthestalkbase,untilthestalkbecomesswollenlaterthestalkiscutattheswollensection.Thesapiscollectedinabamboopipe.Ineverytapping,theapexofthestalkissliced1to5mmdependingonthepretreatment.Anothermethodconsistsofsplittingthestemoftheinflorescenceinto2partsandinremovingsecondarystemsexceptthelastfourthataregroupedintoabamboorecipientwherethejuicewillfallthefoursecondarystemsextremitiesarecutandthenbruisedwithwoodplierstwiceadayduring5daysthetwofollowingdays,theyareputinabamboorecipientcontainingonelitreofwater,thenexttwodays,theyarebruisedagainandthentheproductionstarts(CrevostandLemari1913).Thesimplestmethodconsistsininsertingabamboopipeintothebaseofthemaleflowersandtocollectthesapintoagourd(Redhead1989).Theclosertothegroundthemaleinflorescencearises,thesmallerusuallytheamountofsapitproduces(Mogeaetal1991).InsomeplacesofSulawesi(Indonesia),ArengapinnataandArengawightiiarecutdown,theleavesareloppedandthetrunkisslicedatintervals(Kovoor1983Pethiyagoda1978).

Arengapinnatatappingisaverylabourintensiveactivity.Itisdoneaccordingtoaveryregularworkingscheduleforthegenerallytwiceadayactivity.Beatingandpreparationof20inflorescencestalks(ofwhich1216willproduceeachfor4months)takessome2.5hourseachday.Onehealthypersoncantap1216treesonthebasisofan8hourworkingday,ormoreifthetreesarecloseenoughtogofromonetotheotherbyjumping.Ontheaverage,apersontapsabout10treesand10workersarenecessaryperhectare(Mogeaetal1991).Tappingmustbedonedailyotherwisethesapflowwilldiminishrapidlyastissuehealingoccurs.Toslowdownsapfermentation,thecontainerissterilizedwiththesmokeofawoodfire(Mogeaetal1991).

Borassusaethiopium

InBanfora(BurkinaFaso),thetechniqueinvolvesthelateralportionoftheyoungstemanddoesnotkillthetree(Redhead1989).Ahole(10cmdiameter)ismadeabovetheleavecrowninordertoreachtheextremityoftheterminalbudwhichisessentiallymadeofsofttissuesoftheyoungleaves.Theterminalbudisperforatedsuperficiallyandhorizontallyandthesapiscollectedinacalabashthroughaguttermadeofayoungfoldedleaveputattheperipheryoftheterminalbud(Portres1964).Aheapofleavesisputontheentryoftheholetoprotectthecutbudfromdesiccationandinsects.Theperforationisrefreshedtwiceadayaslongasthetreelookshealthy.Oncethetreelooksexhausted,theperforationislefttohealandnewleaveswillcomebutthetrunkwillremainstuntedanddeformed(Bellouard1950).

InIvoryCoast,inthepast,maletreesonlyweretappedasfemaletreeswerepreservedforguaranteeingregeneration.Atreewithamarkedbulgeandattheendofitsdevelopment(ataheightof68monthetrunk)ispreferredasitensuresregularity,goodquantityandqualityofthesap.A"ladder",madeofrattancreeper,bambooorrachisofRaphiasp,istiedtothenortheastsideofthetrunk.A"safetybelt"madeofrattancreeperisalsousedbytheclimberwhileworkingatthetopofthetree.Theleavesarecutexcept2to4sixmontholdleavesonthesouthwestwhichservefordrawingthesapupwardsand2or3petiolesarealsolefttoserveasaseat.Oneortwotopyoungleavesoftheterminalbudarepreserved.Oneortwodayslater,alateralwindowismadeinthenortheastpetioleinordertoassessthelevelofthebasisoftheterminalyoungleave.Theterminalbudwillbesectioned10cmbelowthejunctionpetiolelimbofthemoreinternalterminalleave(neithertoolowtoavoidshorteningtotalperiodofproduction,nortoohighasitwilldelayprofusesapflow).Allyoungleavesabovethispointaredelicatelycutwithoutdamagingtheterminalbud.Thewindowisenlargedandtheterminalbudsectionedwithaslightslopetowardstheentranceofthehole.Itisclosedandprotectedtoavoidinsectsanddesiccation.Thefollowingdaytheterminalbudiscutagainwithmoreslopetowardsthewindow.Aguttermadefromaleaveisputandgoestoacalabashandtheprotectionisputagain.Thentwiceaday,theterminalbudiscut24mmfurtherandthesapcollected(Portres1964).

InotherAfricanregions(asinSenegal),thetreesareoftentappedtodeathafterseveralmonths.Usedfortheleavesduringthefirstyears,thetreesarethentappedoncetheyhavereached23mhigh.Theheartisreachedwithaknifeattheleveloftheterminalbud.Ahole,30cmlong15cmbroadand10cmdeepismade.From1to6litresofsap(thereismorecollectionofsapduringthecoldmonthsandwhenthereisfog)willbecollectedeverydayduring4to6months(Bellouard1950Giffard1967).Anothertechniqueconsistsinbruisingandcuttingbuncheswhichisharmlessforthetrees(Chevalier1930).

Borassusflabellifer

Variousmethodsareusedtoclimbthetree(sixrecordedbyKovoor1983),usingankleloops,aerialropewaysbetweentrees,hoopbelt,rivetedbamboo,mobile49mlongladdersandfixedonesontheupperpartofthetrunks,notchesinthetrunk,etc.TappingtechniquesofBorassusflabelliferaresimilartothatofcoconutexceptforslightdifferences.Sapiscollectedtwiceadayinallcases.Insomecountries(Cambodia),differenttongsareusedaccordingtothesexofinflorescenceandstageoftapping(Kovoor1983).

InSriLanka,fourdifferentmethodsareusedaccordingtothesexandageoftheinflorescence(Kovoor1983):

Twoweekoldmaleinflorescences:theyarecleanedfromtheiroutersheathsandlefttodryfor3daysthenafreshsurfaceiscutdailyandabout1litreofsapisobtaineddailyforoneandhalfmonths.Onemontholdmaleinflorescences:allitsspikes(12)arepressed,strokedandgrouped3to6togethertobefittedtoapot.Youngfemaleinflorescences:themainaxisisstruckwithanironrodtosoftenthetissuesandaforkisusedtocrushthenodeswherefruitswouldarise.Twotothreemontholdfemaleinflorescences:theyalreadybearfruitswhicharesliceddaily.

InUpperBurma,the8monthdurationtappingseasonconsistsin3tappingphaseswhichalsoincludespecificoperationssuchasfourdifferenttappingtechniques,twoforbothmaleandfemaletrees(Aubert1911).InCentralBurma,sapcollectioncanbecontinuedallyearroundbutwithlowyieldsbetweenNovemberandJanuary(Lubeigt1977).InCambodia,ifatreestartsgivingmanyinflorescencesatthesametime,someofthem(1to7accordingtotree,climateandlocation)willreceivetheusualtreatmentwhiletheotherswillbeslicedandcrushedfor58daysandthenpreserved(3to5months)forjuicecollectionsomemonthslater(KhieuBorinandPreston1995KhieuBorin1996).Claypots,bamboosinternodes,calabashesorleafbucketsareusedforsapcollection.

Anothertappingtechniqueisasfollows.Theinflorescenceisbruisedinitsparticularstageofgrowththroughbeatingandcrushingitwithwoodentongs.Thenitisboundinto"torches"andtappedbycuttingoffthebandagedtips(Redhead1989).Amalletisusedforslowlyhittingseveralminutesadaythetrunkbeneathandabovethestemoftheinflorescencewhileswingingitandfinallypinchingitbeforeincision.Anewincisionismadeaftereverycollection(Friedberg1977).ThemethoddescribedbyCrevostandLemari(1913)forArengapinnataisalsopractisedonBorassusflabellifer.

Inordertoslowdownthefermentationofthesap,thevesselsaresmokedandcoatedwithlime(Redhead1989).Barkorleavesfromdifferentspeciesarealsoused:Schleicheraoleosabarkorleaves(Friedberg1977Kovoor1983),ShoreacochinchinensisbarkinCambodia(CrevostandLemari1913Kovoor1983),ShoreaobtusainBurma,ShoreatalurainThailand(Lubeigt1977),Voticahermandianabark(Magalon1930),Launaeacoromandelicadriedbark,Anacardiumoccidentaleleaves(Kovoor1983),VateriaacumintabarkorCyminosmapedunculata(Dissanayake1986).Thesepiecesofbarkarefinelystampedandaddedtoeachreceivingbucket(Fox1977).Tkatchenko(citedbyKovoor1983)hasfoundthat5to7goflimeperlitreconservethesapquitesatisfactorilyformorethanadayagainstfermentation.InRotiisland(Indonesia),thetapperusesforeveryproducingpairofrachillaeasetoftwoleafbuckets.Twiceaday,hebrushestheinsideandcleanswithwatertheleafbucketsfromwhichhehasjustcollectedthesapandwhicharegoingtodryasheplacestheotherleafbucketofthepairforthefollowingsapcollection.Thisisreputedtoslowdownthefermentationofthefreshjuicewithoutchangingitstasteaswoulddolimeorbarkadditives(Fox1977).InUpperBurma,theearthenvesselsusedforsapcollectionreceivespecialtreatment.Beforebeingusedforthefirsttime,theyarewashedandexposed,stillwet,withtheiropeningstowardsafiremadeofdriedbranchesandleavesforabout10minutes.Thentheyarechangedtwicedailyaftereverysapcollection.Theyarebroughtbacktothehouseandwashedanddriedandjustbeforereplacingthemonthetree,afewchipsofthebarkofShorearobustaareputinthevessel(Aubert1911).

Caryotaurens

Theinflorescenceinitsparticularstageofgrowthisboundintoa"candle"formandtappedbyrepeatedlyslicingofftheendofthecandle(Redhead1989).ThebruisingtechniqueissimilartotheoneusedforBorassusflabellifer(Magalon1930).InSriLanka,thetechniquehasbeendescribedindetailsbyDissanayake(1977):"Whentheflowerappears,itistappedbeforeitreachesmaturity.TheartoftappingaCaryotaurensflowerisverymuchavillagecraftrequiringahighdegreeoftraditionalexpertise.Alongbamboopoleiserectedalongthetrunkwithsuitablesupporttoreachthecrown.Theselectedflowerispreparedfortappingfirstbybeatingitwithastoneorwoodandthentiedwithastringinseveralplacestokeepitinpropershape.Aconcoctionmadeofherbs,ashandsaltisthenappliedtotheendoftheflower,whereafineangularslashismade.Tappingbegins34daysafterthisapplicationabigearthenpotisplacedattheendoftheflowertocollectthesap."

ThemostcommonmethodsusedinSriLankatopreventfermentationofthesapare:liningtheinsideofthecollectingpotwithfreshlimeplacingVateriacopalliferabark,CareyaarboreabarkorAchronychialaurifolialeavesinacleanpotbeforeitisusedforcollectingsap(TheivendirarajahandJeyaseelan1977).Studiesshowedthatlimeisthemosteffective,nextVateriacopalliferabark,followedbyCareyaarboreabarkandAchronychialaurifolialeavesVateriacopalliferabarkcouldbeusedaseffectivelyaslimetopreservesweettoddyfor39hours(TheivendirarajahandJeyaseelan1977).

Cocosnucifera

InSriLanka,segmentsofcoconuthuskaregenerallyfastenedallthewayupthetrunkforclimbingthecoconuttreealooproundtheanklesisusedsometimes(CoconutResearchInstitute1967).InsouthSumatra,simplenotchesarecarvedinthetrunk.Theinflorescenceinitsparticularstageofgrowthistapped(Redhead1989).Thedevelopmentoffemaleflowersinsidethespathe(about60cmlong)causesaswellingatthebasisofthespathe.Theappearanceoftheswellingistakenasthecorrectstagefortapping.Theinflorescenceselectedfortappingisfirsttrained,byagentleuniformbeatingalloverthespathe,twiceaday,inthemorningandintheevening,thespathebeingwoundaroundwithastrongcoirorcoconutfibrestringtopreventitfrombursting.Afteraweek'sbeating,about710cmofthetipofthespatheiscutoff.Onthethirdday,thecutendiscarefullypounded(CoconutResearchInstitute1967).Beatingiscontinuedforaboutaweek,whileanearthenpot(inSriLanka)orabambootube(Thailand)ishungfromthespadixtocollecttheoozingliquidfromthecutsurface(Grimwood1975).Thefreeendofthespadixisgraduallybentdown(CoconutResearchInstitute1967).Ifthetreesaretappedforsweetjuice,theyarecollectedinthemorning(Rangaswami1977).Thesapgenerallybeginstodripafter1215days,orupto35afterthebeginningofthetappingprocessaccordingtothetapper'sskill,seasonalconditionsandnatureofthepalm.Thenslicingabout2mmandcollectingsaparedonetwiceadaywhiletappingandbruisingoperationsarediscontinued(Nathanael1970,citedbyKovoor1983CoconutResearchInstitute1967).Nevertheless,lighttappingoftheendofthespathewithamalletmaybecontinuedandtheslicedsurfaceofthespatheissometimessmearedwithamixtureofbruisedleaveswhichcontainssaponinandstimulatesthesapflow(Child(1964)citedbyGrimwood1975).Asinglespathewillbetappeduntilitisreducedtoastumpabout1015cminlength.Aboutthreeweeksbeforereachingthispoint,anotherspatheispreparedinordertoensurecontinuityofsapproductionwithoutanybreakforaperiodofoneyearongoodpalms(Nathanael(1970,citedbyKovoor1983).

AccordingtoRedhead(1989),coconutsaptobeusedforjaggeryiscollectedinthemorningsonly,incleanvesselscontainingafermentationinhibitorsuchaslime.InThailand,thebarkofVateriaacuminataorShoreataluramaybeadded.Theslicedsurfaceofthespathemightalsobedaubedwithlime(Levang1988).InIndonesia,theearthenwarepotsaresterilizedinanakedflameandaboutateaspoonfull(5g)offinelycutchipsofVateriaacuminatabarkisadded(Purnomo1992).InMalaysia,aquarterofthecontainerisfilledwithamildsolutionoflimewatertogetherwithdriedlatexfrommangosteenbark(NaimandHusin1984).

Coryphaelata(Syn.:C.utan)

Theentiregrowingpointoftheterminalinflorescenceisexcisedjustbeforethedevelopmentoftheinflorescencestarts(Redhead1989Kovoor1983VanDie1974).Ashallowdepressionisscoopedoutatthetopofthenakedstem,andthejuiceiscollectedfromthedepression(Redhead1989Kovoor1983).InRoti(Indonesia),thetechniqueconsistsinbreachingtheinflorescence(Fox1977).Incisionsoftheflowerstalkarealsoreported(Pethiyagoda1978).

Elaeisguineensis

ThemostcommonmethodinWestAfrica,andparticularlyinIvoryCoastandGhanaisdestructive.Justbeforethefructification,theyoungtreeisfelleddownbylooseningtherootswithaspadeandpullingdownthetree.Foroldertrees,thetrunkiscutat3060cm.Allfrondsinthemerismaticregionareremovedafteroneortwoweeks.Acavityismadeintheterminalbud.Itiseitherarectangularwellabout7.5cmdeepwitharoundholeboredinitsfloororabowlshapedhollow10cmx9cm,abouttwothird(15cm)thediameterofthestemindepth.Abrandisputinitinordertoactivatethesapflowandreducetheinfestationofthewellbyinsectsandtheirlarvae,bacteria,mouldsandyeasts.Collectionofthesapstarts2to4dayslater,usingabamboogutter(15cmlong)whichgoesintoacontainer(calabash)underthestem.Itisdonetwiceaday:eachtime,thetappercutsawayfromtheterminalbuda1mmlayeroftissueandflareswithfirethestemsurfacearoundthetappingwound.Thesapflowlasts1to2months(BlancPamard1980Kovoor1983Essiamah1992Hartley1977SodahAyernorandMatthews1971).AlessdestructivemethodispractisedinNigeria(Igbos)andconsistsinpiercingthestemofthestandingtreeuptothebud(Tuley(1965)citedbyKovoor1983).AdetaileddescriptionisgivenbyEssiamah(1992).Severalleavesarecutoffthesideofthestem.Arectangularhole(8cmx510cm)iscutinthestemtoadepthofabout30cmormoreaccordingtothesizeofthepalmtree.Asuctionpipemadeofbambooisusedtocollectthesapintoajughungonthestem.Asthesapflowisveryintense,thetappermustclimbthetree3timesadaytocollectit.Eachtime,hecutsawayathinlayeroftissuefromthewoundsurfaceinadownwarddirection.Thelengthoftherectangularholecanthusextendto30cmormoreaccordingtothedurationofsapflow.Thetreedies2or3weeksafterbeingtapped.InMadagascar(Sakalava),theterminalbudisalsoincised(Decary1964).

Anondestructivemethodconsistsintappingthemaleinflorescences(SprechervonBernegg1929,citedbyVanDie1974).ItisespeciallypractisedbytheJorubasinNigeria,butitisalsofoundinBeninandIvoryCoast.IthasbeendescribedindetailbyEssiamah(1992)andSodahAyernorandMatthews(1971).Allfrondsbelowanunopenedmaleinflorescence(beforethedifferentiationoftheflowerspikesstarts)arecutoffandtheleafsubtendingitisremovedtoobtainaccesstotheinflorescenceenclosedinitsspathes.About7.5cmabovethebaseofthemaleinflorescence,aneattriangularholeismadeinthefrontspathe(about2.5to6cmdeepinthemainstemofthespadixand2.5cmonthesides).Theholeisthencoveredandthefollowingdayafunnelofsmallbamboo(16cmlongand2cmindiameter)isinsertedinthecutinsuchapositionthatthesapflowsintocalabashes(vessels).Toensurecontinuousflow,theholeisextendeddownwardsbyremovingadailysliceofabout3mm.Thetappingisstoppedwhenthebaseofthemaleinflorescenceisreached.Thesapiscollectedmorningandeveningandanewslicetakenateachcollection.Palmtreestappedinthismannersetfruitonetotwoyearsaftertapping(SodahAyernorandMatthews1971).InCasamance(Senegal),theDiolauseasimilartechniquebutbothmaleandfemaleinflorescencesareused.Whilepreparingtheinflorescence,itsstemiscoveredwithamattressofleaveswhichisstruckvigorouslywiththeheadofanaxeinordertostimulatethearrivalofthesap(Adand1954).

Hyphaenecoriacea

ThetechniqueisdescribedindetailsbyCunningham(1990).Palmclumpsareselectedandlargestemswithintheseclumpsarepreparedfortappingafterburningeachclumptoremoveundergrowthandleafspines.Selectedstemsaretrimmedtoinitiatesapflowusingarazorsharpbushknifewhettedagainstastickkeptforthatpurpose.Thestemandyoungleafbasesarecutataslightangletoguidesapontoaleafgutterandintotheclaycollectioncontainer.Bytheendofthetappingperiod,theseyoungleafbaseshavebeenremovedbytrimming2to3timesperdayovera5to7week'speriod.Thereforetheterminalbudiscuttodeathofthestembuttheclumpsurvives(Cunningham1990).

Hyphaenethebaica

InDjiboutiandEritrea,theterminalbudisoftencuttodeathofthestem(Jahiel1993Fanshawe1966).AsHyphaenethebaicaisamultistemmedpalm,thispracticedoesnotmeanalwaysthedeathoftheclump.Thereisalsoalessdestructivetechnique.Theselectedstemiscleanedfromallleaves.Thenonlythebasesofthefutureleavesarecutbutnottheterminalbuditself.Newcutsarepractisedupto4timesadayforacoupleofweeksandgenerallystoppedbeforereachingtheterminalbud.Sometapperswillreachthisterminalbudinordertogetmoresapbeforehavingtoprepareanothertree(Audru1985).

Jubaeaspectabilis

Thetreeisfirstfelled,theleavesloppedandthetrunksliceddailyoveraperiodofsixtoeightweeksduringwhichthebleedingsapiscollected(Pethiyagoda1978).Darwin(1860,citedbyKovoor1983)reportedyieldsofaround400litres.

Mauritiaflexuosa(Syn.:M.vinifera)

Thepalmsarecutdown,defoliatedandscorchedforincreasingsapflow.Thesapistappedfromtheinflorescencestalksorbyholesmadeintothetrunkduringthedevelopmentofinflorescences(Kovoor1983Pethiyagoda1978).

Nypafruticans

Thestalkoftheinflorescenceiscutataproperstage(Redhead1989).Nevertheless,pretreatmentofthestalkispossibleatvariousstagesofinfructescencedevelopmentfromfloweringtomaturefruitingstages.Plantsatmorematurestagesrequirelongerperiodsofpretreatmentthanatyoungstages.Kiew(1989)characterizestheproperstageasfollows:thefruitingheadiswelldevelopedbuthasnotbeguntodarken.Spathesandbractsatthebaseofthefruitheadarecleanedoff(Davis1988).Thefruitingheadisfirstoscillatedgently,thenwithincreasingseverityuntilafter3weeks,itissubjectedtoviolentshaking(Watson1928,citedbyKiew1989).AccordingtoDennett(1927),thisoperationpreventsthecellsfromhardeningandatrophyingasthestalkmatures.Thestalkkeepssoftandsupplecomparedtoanontreatedstalk.Studyingthelabourcosts,thesameauthorfoundthat3weekswasthemostprofitabledurationforthistreatment.Thebruisedinflorescenceistappedbylighthammeringandbyincisingthetissuesabovethebruisedportionascloseaspossibletotheyoungfruit.Thealmostfullgrownfruitheadiscutaway(HamiltonandMurphy1988).Eachdayaftercollectingthejuice,athinsliceofabout2mmisremoved.Cuttingtoolsaredisinfectedsinceflowisreducedbybacterialgrowth(HamiltonandMurphy1988).Sapflowdependsmainlyonpriorpreparationofthestalk:ifnoneisdone,flowwillbelowandwilllastonlyafewdays.Thebaseofthestalkiskickedinmostcountrieswherethistreeistapped.InPapuaNewGuinea,asophisticatedprotocolhasbeendevelopedbyPivke(1985):bendingthestalk12timesinonedirectionpattingthelengthofthestalkbackwardsandforwardswiththebarehands64timeskickingthebaseofthestalk4timesandrepeatingthis4timesaweek.Yieldsof1,800ml/day/treeoveramonthwerereachedinintensivelytreatedyoungeragedstandswhereasonly155ml/day/treewereproducedwhenthetreatmentwasdoneonlyonceaweek(Pivke1985).InthePhilippines,thescheduleofkickinglastsfor3monthsand10daysperpalm:onceaweekduringthefirstmonthafterflowering,twiceaweekduringthesecondmonth,onceeverytwodaysduringthethirdmonthandfinallydailyfor10days(Melana(1980,citedbyHamiltonandMurphy1988).Tappinglifedependsonthelengthofthestalkwhichcanvaryalot:0.6to1minthePhilippines,1.4minSumatraand1.9minPapuaNewGuinea(HamiltonandMurphy1988).Toslowdowntheveryrapidfermentationofthesap,thebamboorecipients(2litrescapacity)arewashedwithlimeandwater(Redhead1989CrevostandLemari1913).

Phoenixdactylifera

Theentiregrowingpointiscutoffandashallowdepressionisscoopedoutatthetopofthenakedstem.Thejuiceiscollectedfromthedepression(Redhead1989Kovoor1983).Anothertechniqueconsistsincuttingoffthefronds:exudationofsapoccursinthecavitycreatedbydefoliation(Pethiyagoda1978).Tappingadatepalmisasevereinterventionasitdeprivesthepalmofmostofitsleavesandfoodreservesgreatcareisrequiredduringthetwicedailyscarring,becauseifitiscarriedontoofar,thepalmwilldie.Every20daysorso,thecone,canalandspoutarereadjusted.Aftertappingiscompleted(uptothreeorfourmonths),threetofouryearsareneededforthetreetobeabletobearafullcropoffruitagainandfiveyearsbeforetappingitagain(Barreveld1993).UsingtheIndianmethodoftappingforPhoenixsylvestrisonPhoenixdactylifera,Barreveld(1993)reportedinferiordailyyieldsbutconsideringthatannualtappingwouldbepractisedinthiscase,therewouldbehigheryieldsofsappertreeoveraperiodof3to4yearsnevertheless,labourhoursinvolvedperunitsapharvestedisdefinitelyhigher.

Phoenixreclinata

InIvoryCoast,thetreeiscutdownanduprooted,allleavesareremovedandtheterminalbudiscut.Acavityismadeinwhichabrandisputinordertoactivatethesapflow.Collectionofthesapstarts3to4dayslaterthroughagutterlinkedtoacalabash.Collectionisdonetwiceaday,eachtime,theterminalbudisfurthercut.Itlasts1to2months(BlancPamard1980).Anothertechniqueconsistsinincisingthelateralportionoftheyoungstem(Redhead1989).InsoutheasternAfrica,thesametechniqueasdescribedbyCunningham(1990)forHyphaenecoriaceaisused.

Phoenixsylvestris

Thestemispierceduptotheterminalbud(Kovoor1983).InBangladesh,theoldestleavesareremovedattheendofOctoberononesideofthepalmtreealongabout35cm.Thebasesofthepetiolesandthesheathsarecarefullyremoved.Atrianglepieceofbark(pointdownwards)iscutbutgreatcaremustbetakennottoexposethesapsupplyinginnerzone.Aweeklater,asthefinecoveringofsofttissuesgetsalittlehardenedandbeginstocrack,thiscoveringisremovedwithoutdamagingtheinnerzone.Thencomesarestof12to14daysafterwhichalateralincisionisdoneinthetriangle.Thesapexudingfromthescoopedsurfaceisrunthroughabamboospoutintoavessel.Anewincisionismadethe2followingdaysandthenthereisa4dayperiodofrestandthesamecycleisrepeateduntiltheheartisreached.Thefollowingyear,thesametreatmentisdoneontheothersideofthetreewhichgivesazigzagconfigurationtothetrunktappingcanbepractisedeveryyearforseveraldecades(averageof25years)(Fealy1925Annett1913Barreveld1993).Inordertoslowdownthefermentationofthesap,theearthenvesselarecoatedwithlimeinBangladesh,theyarewellsmokedeverymorning(Annett1913).

Raphiahookeri

InsomepartsofNigeria,thepalmsarecutdownandscorchedforincreasingsapflow(Kovoor1983).ThesapcanalsobecollectedfromtheupperstempiercedtodeathasitiscurrentlypractisedinWestAfricathemethodisthesameastheonedescribedforoilpalmsbyIgbosinNigeria(Tuley1965,citedbyKovoor1983Essiamah1992).Thetappersextractthesapjustbeforetheappearanceofthespadixandtappingisdoneonfloweringtrunks(Profizi1988).InCameroon,thebaseofthetreeissplitbeforefruitproduction(Fyot1973).

Multipurposeuses

AsdescribedinAnnex1,mostpalmtreeshavemultipurposeuses(seealsothereviewbyJohnson1997).Theseusesarenotalwayscompatible.Sapproductionisatitsmaximumjustbeforeorduringfruitformation,whenstarchesinthestemareconvertedintosugarswhichenterthesapandflowtothesiteoffruitformation.Tappingthetreecompeteswiththeproductionoftheripeningfruit(Redhead1989).Nevertheless,somespeciescanbeexploitedforbothfruitandsap,butthetreesmightdieprematurelyinthecaseofoverexploitation(Redhead1989).TappingBorassusaethiopiumimpedesfruitproductionandisdetrimentaltothequalityofthewoodcollectingyoungleavesreducessapyields(Bellouard1950).InMaduraisland(Indonesia),pruningtheBorassusleavestwiceayearwilldrasticallyreducethejuiceproducinglifeofthetreefrom3040yearsto810whilemoderatepruningwillstillpermit2030yearsofjuiceproduction(Fox1977).Nypafruticansimmatureleavesarecutforcigarettepapers,matureleavesforthatchbutharvestingleavesreducestheyieldofsugar(Kiew1989).InIvoryCoast,theAfricanoilpalmistappedbeforefructificationwhichkillsthetreewithinoneortwomonths(BlancPamard1980).

Tappingcanalsostimulatefruitproduction:ayoungcoconutpalmtappedduring612monthsforsugarproductionwillthenproducemorenuts(Magalon1930Fealy1925).ThishasbeenclearlydemonstratedbyMathes(1984):low(inregardtonutproduction)yieldingpalms,aftertapping,hadafruitproductionthreetimesthatofthehighyieldingpalms,anddoublethatoftheveryhighyieldinguntappedpalms.AtechniquecalledsequentialcoconuttoddyandnutproductionhasbeendevelopedinthePhilippinesattheDavaoResearchCentre.Thefirsthalfofthespatheistappedandthesecondhalfisleftforfruitproductionasfemaleflowersthatdeveloptomaturenutsaresituatedinthislowerportion.Nutandcoprayieldsareabout50%lowerthannontappedpalmshowever,thistechniquehasbeendemonstratedtobeveryfeasibleandhighlyprofitableforsmallproducers(MaravillaandMagat1993).

Arengapinnatacanbetappedwhentheyarebetween1215andmorethan30yearsoldthentheycanbecutforsagoproduction(Sumadi1988).Nevertheless,inWestJava,wheresagoisobtainedfromtrees1012yearsold,notappingwillbedonepreviously,farmersarguingthatitwouldreducethequantityofstarchinthetrunk(Mogeaetal1991).InEasternNigeria,oilpalmsthathavebeenabandonedasuneconomicbunchproducersusuallygivegoodeconomicreturnsforwineproduction(usinganondestructivetappingtechniqueonmaleinflorescences)beforeoldplantingsareclearedandreplanted(Tuley1965a).

Roleinsustainableintegratedproductionsystemsandintheprotectionoftheenvironment

TherearevarioustypesofpalmcropassociationsinBangladesh.PhoenixsylvestrisandBorassusflabellifercanbothbeassociatedwithseveralofthefollowingcrops:rice,wheat,chickpea,mustard,jute,lentil,potato,linseed,wintervegetablesandsugarcane(Abedinetal1987).Palmtreesoftenhaveadvantagescomparedwithothercropsasfarassustainabilityisconcerned:inpartsofwestJavawhereArengapinnataisstilltendedingroves,soilsappearmuchmorestableandproductiveofothercropsthanwherecassavaiscultivated(Dransfield1977).Furthermoretheadvantagesofthistreeareitsgreatecologicaltolerance,itsabilitytogrowandstabilizeunproductiveerosionpronesitessuchassteepdrylandslopes(e.g.,coffeeorchardsonstonyslopesinNorthSulawesi,Mogeaetal1991),itspotentialtogrowonalmostanytypeofsoil,toincreasesoilfertilityandwaterconservation,itsgreattoleranceofaccidentalburning(theonlysurvivingtreeintheMinahassa,Sulawesi,aftervolcanicactivity),therelativelyfastgrowthrate,thefactthatitneedsalmostnomaintenanceandusuallydoesnotsufferfromanyseriouspestsordisease,andthewiderangeofsecondaryoralternateproductsobtainable.Arengapinnataisconsideredasoneofthemostdiversemultipurposetreespeciesandthemostimportantsugarpalmofthehumidtropicsafurtheradvantageisthatthistreegrowswildinmanyplaces(Mogeaetal1991).

BorassusflabelliferisoftenplantedonboundariesofpaddyfieldsinCambodiaandIndia.Theeffectsofshadingonunderstoreycropsarelikelytobenegligibleduetothesmallsizedcrownsandtothelargespace(1015m)betweentrees(JambulingamandFernandes1986).InCambodia,ricecultivationandBorassusflabellifersugarproductionareassociatedinmanyareas:anaveragefamilyowns2425Borassusflabellifertreesand22.5haricefield(Romera1968).Thistreethrivesinreputedlythepoorest,infertileandaridregions.IncentralBurma,afterayearofdrought,itstillcanproducesapduringayearbuttheyieldwilldecreaseandtheflowwillfinallystop(Lubeigt1977Lubeigt1979).Italsosuffersremarkablylittlefromprolongedflooding.Itisextraordinarilypestanddiseaseresistant,requiringlimitedmeansofcultivationifany.Asitgrowsinsandyplains,itisusedforblockingerosionandfixingdunes,thankstoitsdeeprootsystem(Kovoor1983).Itisalso,likeCoryphaelata,afireresistantpalmthatispioneerspeciesonregularlyburntlandsuchasthoseexploitedbytheslashandburntechnique(Ormeling1956,citedbyFox1977).Theyoungtrees(upto15to40years)areusedinBurmaaswindbreakinareascroppedwithgroundnut(Lubeigt1977Lubeigt1979).ItplaysamajorroleinSavuandRotiislands(Indonesia)wherethesoilfertilityisacrucialconstraint.Thetraditionalslashandburnsystem,whichiscurrentlypractisedinneighbouringislands(TimorandSumbaforexample),hasbeenreplacedbysemipermanentgardeningthroughtheuseoflargeamountsofoldBorassusleavesthatareburntinthefields.Thispermitsfertilegardenstobekeptinthevicinityofthehouses.Animalmanureisalsousedinselectedgardens.Inadditiontoanintensivepigrearing,theseislandsarealsofamousforhavingwelldevelopedgoatandsheepherdsandforhavingkeptwaterbuffalowhereasinneighbouringislandsthesehavebeendisplacedbyBalicattle.GardensareeasilyfencedwithpalmleafstalksbutinmanycasesinSavu,animalsarepennedorcorralledandfieldsareleftunfenced.Thereforethesetwoislandswhicharedrier,morewindsweptandmoreerodedthatlargerneighbouringislands,havebasedtheirmainrelianceonpalmutilizationintegratedwithwetricecultivation,dryfieldcultivation,gardening,herdingandfishing.allthesecomponentsoftheintegratedfarmingsystemsvaryinproportionaccordingtoareaandyearsandshowthegreatsenseofadaptabilitythatthesepeoplehavereached.Whereashungerperiodsandfaminesusedtooccurfollowingdroughtsinneighbouringislands,calculationswerealwaysmadeinSavuandRotiinorderthatfailedcropscouldbealwaysreplacedbyotherfoods,Borassussaporsyrupbeingtheultimateonethatwasnevermissing(Fox1977).Borassusforestspossessapotentiallyuniquepatternofnutrientcycling,whichenablesthemtosupportrelativelyproductiveandstableformsofagricultureaswellastocontributetorecoveryofdisturbedsites(Anderson1987).

InthePeruvianAmazonia,Mauritiaflexuosaconstitutesdensepopulationsinseasonalswampforestsonwaterloggedsoilsoronsandysoils,whicharegenerallyconsideredasunfitforagriculture(Kahn1988).Unlikesugarcane,Nypafruticansdoesnotcompetewithothercropsforagriculturallandexceptwheretotalreclamationisundertakenonmangroveland(HamiltonandMurphy1988).

Socioeconomicaspectsoftappingpalmtrees

Nowadays,thefivemajoreconomicpalmsoftheworldarecoconut(Cocosnucifera),Africanoilpalm(Elaeisguineensis),date(Phoenixdactylifera),betelnutpalm(Arecacatechu)andpejibaye(Bactrisgasipaes).Evenifthethreefirstspeciesmentionedarecurrentlytapped,thisremainshighlymarginalintheireconomicrole.

Intheyear1910,93%ofthetotalamountofalcoholandalcoholicbeveragesproducedinthePhilippineislandswasprocessedin68distilleriesfrom90millionslitresofthesapexudingfrompalmtrees(mainlynipahandcoconutpalms)thisindustrywasconstantlyincreasingandnipahpalmwasconsideredthecheapestsourceofalcoholintheworld(Gibbs1911).Besidesthis,therewasalsoaverylargeconsumptionofundistilledpalmsap.InBurma,duringthebeginningoftheseventies,upto28millionbottleofarakmadefromBorassusflabellifersapwerecommercializedperyearthroughshopsandbars,whichmeansaboutabottleperinhabitant(Lubeigt1979).In1969,palmwineproducedinNigeriawasestimatedatroughly2millionmetrictons(FMANR1974,citedbyOkereke1982).Inthiscountry,thetradeinpalmwineprovidesasourceofincome,notonlytothetappersthemselves,butalsotoawiderangeofmarketintermediaries(Okereke1982).ThespeciesofRaphia(R.hookeri,R.vinifera,R.sudanica)areveryimportantintheeconomyofthevillagesaroundtheswampsinWestAfrica(SouthernBeninandNigeria):mostofthepeopleusesthefruitsandtheleaves,andpalmwineismadefromthesapwhichisconsumedfreshordistilled(Profizi1988Tuley1965b).PalmwineisalsostilllargelyproducedandcommercializedinIvoryCoastwhereitprovidesgoodopportunitiesofemployment(BlancPamard1980).InmanypartsofNigeria,andotherpartsofWestAfrica,theoilpalmssurroundinglargetownsareregularlytappedforwineproduction.Itisanindustryofconsiderableeconomicandnutritionalimportancewhichsatisfiesasteadymarketintheseareaswherehigherreturnsareensuredusingoilpalmforwineproductioninsteadofoilproduction(Hartley1977).InSouthEasternAfrica,palmwinetappingofHyphaenecoriaceaandPhoenixreclinataisalabourintensiveactivity(highdensitiesofsmallpalmswithlowyields)providingasubsistenceincometogetherwithpastoralismandgatheringofwildfruits(Cunningham1990).

AsestimatedbyPethiyagoda(1978),intheearlydecadesofthiscentury,inSouthEastAsiancountries,hundredsofthousandsoftonnesofsugarwereproducedannuallythroughthetapping,mainlyofArengasp,Borassussp,Cocossp,NypaspandPhoenixsp.Between10and17%(estimateof480,000tonnesofpalmsugarin1911)ofIndia'ssugarwasproducedfrompalms(Annett1913).InBangladesh,theindustryofsugarmadefromPhoenixsylvestrisisanoldoneanddatesugarwasreportedaslargelymanufacturedandexportedattheendoftheeighteencentury.Inthemiddleofthelastcentury,afterslaveemancipationmeasuresgraduallydecreasedthesuppliesofsugarfromtheWestIndies,arapidriseindatesugarproductionoccurred.In1849,onefifth(10,000tonnes)ofthewholeannualquantityofsugarexportedfromIndiatoEnglandwasdatesugar(Annett1913).

Palmtapperscanbeeitherprosperousoramongthepoorest:thisismainlyrelatedtothetreeandlandproperty.InSavuisland(Indonesia),tappingisanactivityamongothersandtappersowntheirlandandtrees.InUpperBurma,mosttappersarelandlessandthepalmtreesarethepropertyofawelloffminoritywhichgetsonethirdofthesapproduced(Aubert1911).InSriLanka,theartoftappingCaryotaurensandmakingjaggeryhasbeenrecognizedasanimportantfunctiontowarranttheexistenceofaseparatesubcastewhichstillexiststoday(Dissanayake1977).InthelowrainfallGangesfloodplainofBangladesh,juiceextractionfromPhoenixsylvestrisandmolassesmakingsupportaspecialgroupoftechnicians,whoareusuallypoorfarmers(Abedinetal1987).Arengapinnata,throughproductionandprocessingofitssapandsagoensuresincreasedfarmers'incomesandruralemploymentopportunities(Sumadi1988).InWestJava,itcontributeswidelytothedailylifeofmanyvillagersforwhomitisalsoaconsiderablesourceofincome.InNorthSulawesi,thedowryisstillpayableintheformofanumberofsugarpalms,indicatingthegreateconomicvalueplacedonthesetrees.There,anaverageof6fullygrownpalmscanprovideagoodincomeforonefamily(Mogeaetal1991).InthePhilippines,mostcoastalfarmersdependonNypafruticanssapproductionfortheirincome(Quimbo1991).In1986,118tonnesofNypafruticanssugarvaluedatM$237,464wasexportedfromMalaysia(Kiew1991).InSarawak(Malaysia),nipahtappingiscarriedoutasacottageindustryandprovidesalivelihoodtoagroupofpeoplewhohavenoothermeansofearningaliving(Pearce1991).InmanyAsiancountries,theuseofthismultipurposepalmtreecontinuesandinsomeplaces,theyhavebecomethebasisforcottageindustriesandcommercialoperation.AccordingtoKiew(1991),coconutpalmsugarisstillforsaleineverygroceryshopinpeninsularMalaysia.Recently,somelargescalecommercialinteresthasdeveloped:inparticular,thehighcostoffossilfuelandfertilizerhasinitiatedanewlookatthefuelalcoholandsugarpotentialofpalmtrees(HamiltonandMurphy1988).

PalmsofthegeniusBorassuscomesecondonlytothecoconutinthepalmpopulationoftheworldandtheyspantwocontinentsacrossagoodthirdoftheequator(Kovoor1983)wheretheyhavebeentappedforcenturies.Kovoor(1983)notesthatthesimplerationaleofavoidingsinglecropeconomiesbyallpossiblemeansisbyitselfsufficienttofosterthesystematiccultivationandexploitationofthispalm.Generallyspeaking,itisthepoorandthelandlessthatbenefitmostfromtheBorassuspalm(Fox1977).InIndia,itistappedbymembersofthelowestcastesanditplaysanimportantroleintheeconomyoftheruralpoor,especiallyindroughtproneareas(Rangaswami1977).InTamilNadu,itprovidesfarmerswithacashincomethroughoutthedryseasonwhenthereisnocroponthefieldsandwhendemandforonfarmlabourislow(JambulingamandFernandes1986).Ferguson(1850,citedbyFox1977)givessomedetailsontheimportanceofthistree:"ItisnotthewholesomenessornourishingqualitiesoftheedibleproductsoftheBorassusflabellifertreethatmakeitsoimportanttotheinhabitantsofIndiabutsimplythefact,thatthousands,perhapsmillionsofthepeoplecanprocurethesefromtheirBorassusflabellifergroves,orpurchasethemforalowratefromtheirneighbourswhilstRiceandotherarticlesoffood,arefrequentlysoexpensiveastobeplacedbeyondtheirmeans.TheBorassusflabellifertreeis,inthisrespect,whatthePotatohassolongbeentothepoorIrishandScotch".InBurma,halfofthesugarconsumedinthecountrycomesfromBorassusflabellifer(Lubeigt1977).InUpperBurma,thetappersformaspecialclass,theprofessionishandeddownfromfathertoson,requiringlongtrainingandgoodskills.Themenonlyaretappersbutallthefamilyisinvolvedinsapcollectionandprocessing.Thelifeishard,badlyremuneratedandattendedoftenwithsadaccidents(Aubert1911).SeveralhundredthousandsofpeopleliveonBorassusflabelliferinCentralBurmaandmorethanonemillionforallBurma(Lubeigt1977Lubeigt1979).Thislimitsthedriftfromtheland.BorassusflabelliferisalsoimportantintheBurmesemythology:theKingAnoratha(10441077),founderofthefirstgreatBurmeseEmpire,hadfourclosepaladins,oneofthemwellknownforhisconsiderablestrengthdemonstratedbyhisabilitytoclimbonethousandsugarpalmtreesinasingleday(Lubeigt1979).InIndonesia,thousandsofpoorfamiliesintheMaduraandSundaislandgroupmaketheirlivingfromthispalmbecauseofitsmultipleuses,thesweetsaprepresentingitsmosteconomicallyvaluableproduct(Davis1988).IntwoIndonesianislands,RotiandSavu,studiedbyFox(1977),thepopulationsdependfortheirsurvivalonutilizationoftheBorassus.Thereisanearlytotalexploitationofthistreewhichisharvestedfordailyneedsandwhichconstitutesthepivotofacomplexdiverseeconomy.ThepotentialissuchthatFoxnotesthattheprecisecarryingcapacityofthiseconomicadaptationtopalmutilizationremainsunknown.RotineseandSavuneselivelargelyfromthesugaroftheirtrees:freshsapthroughouttheproductionseasonordilutedsyrupotherwiseisconsumedseveraltimesaday,ofteninplaceofanysolidfood.Fox(1977)notesthatitcanbeliterallysaidoftheRotineseandSavunesethattheyarefed,equipped,attired,buried,andrememberedaftertheirdeceasebytheproductsoftheirpalms.Greaterspecializationhasaccompaniedincreaseofpopulationdensity:asBorassustappingisalabourintensiveactivity,andaslongastherearesufficientpalms,newlabourisabsorbed.ButinsomeareasinSavu,wherethepopulationdensitiesarethehighest,nativepalmswerenotsufficientandthereforepeoplehaveplantedclustersofpalmsinfencedenclosures,whichinturnpermitsincreasedefficiencyintappingandfurtherintensifiesallthecomponentsoftheintegratedsystemsguaranteeingbetteryields.SomeRotineseandSavuneseestablishedthemselvesinpartsofSumbaandTimorislandswheretheyreproducedtheirtraditionalfarmingsystembasedonBorassusandbecameeconomicallystrongerthanthenativepeople(Ormeling1956,citedbyFox1977).BorassuspalmsareessentialbuffersforensuringfoodsecurityofmanypeopleinAsiawhendroughtsoccurandothercropsfail(Fox1977).InCambodia,whereBorassusisassociatedwithrice,ifthericeyieldsarelow,theharvestofBorassussapisincreased(Romera1968).There,theareaswhereBorassusflabellifertreesaremorenumerousarealsoareaswithhigherpopulationdensities.Borassusflabellifersugarproductionisessentialfortheruralcommunityhavingreachedacertaindensity.Oncefuelwoodbecomesscarce,immigrationstarts(Romera1968).Sugarpalmsyrupproductionisstilltodaythemainactivityinmostofrural

Cambodiaafterricegrowing(KhieuBorinandPreston1995KhieuBorin1996).InthecaseofBorassusflabelliferandCaryotaurens,themostimportantandprimarymaterialistheirsap,andwhileotherproductsofthesepalmshavebeenreplacedbysubstitutes,jaggeryandtoddystilldemonstratecostadvantagestothecommunitieswhousethem(Dissanayake1986).

Originofthedeclineinpalmtreetappingactivity

Oneofthemainreasonsforthedeclineofsugarproductionfrompalmtreesistheincreasinglackoffuelwoodanditsincreasingprice.SugarproductionfromArengapinnatarequires23m3woodfor100to120kgofsugar(Mogeaetal1991).InSouthSumatra,3to4kgofdryclovetreeleavesor0.02m3ofdurianorheveawoodarenecessarytoprepare1kgofsugar(Levang1988).InMaduraisland(Indonesia),thecostofthefirewoodforproducingBorassussugaramountstoathirdofthepriceofthesugar(GebuisandKadir1928,citedbyFox1977).InCambodia160to200kgoffuelwoodarenecessaryformaking35kgofsugar(Lubeigt1977Romera1968)andthisisthemostexpensivecomponentinthecostofsugarsyrupproduction(KhieuBorinandPreston1995KhieuBorin1996).There,Borassusflabellifersugarmakinghasbeenresponsibleformajorforestcuttingandthissugarisnotproducedanymoreincertainruralareasbecauseofthelackoffuelwood.Ontheotherhand,themarketforfreshjuiceisverylimitediftheareaisnotclosetoacity(Romera1968).InUpperBurma,thesugarindustryfromBorassusflabelliferconsumesalargeamountoffuelandhasforcenturiesledtoindiscriminateforestcutting.Insomeareas,fuelfordomesticuseisevenbecomingscarce(Aubert1911).InBurma,everytapperusesabout3tonnesoffirewoodperyear4.4kgareneededperkgofpalmsugar(Lubeigt1979).InCentralBurma,thepriceoffuelwoodisrapidlyincreasingandtapperscanhardlyaffordit(Lubeigt1977).ThisfuelproblemstartedtobecomecrucialinBurmaattheendofthefiftieswhenthegovernmentinitiatedmeasurestoenforceprotectionoftheforest(Lubeigt1979).

Inthecaseofwineproducingpalmtrees,thedeclineoftenoccurredunderreligiousorcolonialpressurewithintheframeworkofageneralpolicyaimedatpreventingpeoplefromdrinkingalcoholicbeverages.Thus,tappingofBorassusaethiopiuminAfricamainlydoneforwineproductionhasbeendisruptedwhereverMuslimreligionhasbecomedominant.ThishappenedinpartsofSenegalwherethecatholicsereerhadtoleavetheirfieldstoMuslimwolofcomingfromthenorth.Before,inthecatholicsereerareas,somepeoplewerefullyemployedastappingprofessionals(Niang1975).InIvoryCoast,theFrenchcolonialpressuretriedtodiscouragetheproductionofpalmwine.In1914,intheBaoulregion,theaverageconsumptionofpalmwinewas135litres/man/yearbut2yearslatertheFrenchgovernorforbademakingandcommercializingpalmwine(whichwasalsomadefromtheAfricanoilpalmandPhoenixreclinata)exceptforfamilyconsumptionandtraditionalevents(BlancPamard1980).InMadagascar,makingwinefromRaphiaruffiaalsousedtobeforbidden(Decary1964).InSriLanka,a10thcenturyrockinscriptionprohibitsroyalofficersfromdemandingtoddyfromvillagersorengaginginillicittrade(Dissanayake1977).Centurieslater,undercolonialruleandthereafter,therewasalsoageneralbanontheproductionandsaleoftoddyatvillagelevelthevillageheadmenandthelocalconstabularywhoenforcedtheseregulationsweresorepressivethatveryfewvillagerswouldhavetakentheriskoftappingCaryotaurensevenformakingjaggeryandtreacle(Dissanayake1977).

InAfrica,somedestructivetechniquesoftappingwereresponsibleforthedisappearanceofthetreesinsomeareas.InIvoryCoast,Portres(1964)mentionedthehighconsumptionofpalmwineandthenumerousspecializedbarsalongtheroadsandinthevillages,allthisofferingalotofemploymentopportunities.Thepalmwinebecameverypopularasthroughbettermeansofcommunication,itcouldbemadeavailablethroughoutthecountry.Thetreesdisappearedinentireareaswithin10yearsasthetechniquesusedfortappingtreesweredestructiveandregenerationoftreeswasneglected.

Inmanyplaces,socioeconomicchangeswereresponsibleforthedeclineinpalmtreetappingactivity.InIvoryCoast,theimportantmovesofpopulationinthefifties(settlerssettingupcoffee,cocoa,rubbertreesandoilpalmplantations)werealsoresponsibleforlossoftraditionalcodesofmanagingthetreesandlesslongtermconcerns.Thusthetraditionaltechniqueoftappingonlymaletreesandkeepingfemalesforregenerationwasabandoned(Portres1964BlancPamard1980).Inmanyareasofthiscountry,wineproducingpalmtreeswerereplacedbyrubbertreesandoilpalmsundertheFrenchcolonialpressure.In1940,inBurma,theareasplantedwithBorassusflabelliferwerereducedbymorethanonesixthbecauseofthemilitaryoperationsconsecutivetotheJapaneseinvasion(Lubeigt1979).InCambodia,thedeclineoftheproductionofBorassusflabellifersugarstartedin1955withtheendoftheexportsofsugartoVietnamandtheincreasingconsumptionofimportedcanesugar:Borassusflabellifersugarpricescollapsed(Romera1968).InSriLanka,undercolonialruleandthereafter,widespreadcultivationofcoconutasanexportedorientedcropdrasticallychangedthelocaleconomyandimportedsugarbecamecheaper(Dissanayake1977).InPeninsularMalaysia,swampareasweredrainedforcoconutplantationswhereNypafruticanswasbeforepredominant(Kiew1989).Fishponddevelopersalsofoundgreatprofitsinvariousfishpondoperationsmadepossiblebyconvertingmangroveswamps,includingNypafruticansareas,forfishproduction(Encendencia1985).

Tappingsugarpalmsisverylabourintensive.Itmustbedonedailyotherwisethesapflowrapidlydiminishesastissuehealingoccursandrestartingthesapflowrequireslongandhardwork.Whenevereasierandbetterpaidjobswereavailable,tappingwasgivenup.TheemergenceoftheoileconomyinMalaysiahascollapsedtheindustryofalcoholfromNypafruticanssap(labourtooexpensive).DuringthecolonialperiodinIndia,BorassustapperswererecruitedintheBritishplantationsabroad,particularlyontherubberandoilpalmestateswheretheirskillscouldbeeasilyadaptedtothoserequiredforthesetrees(Fox1977).

Inmanycountries,incomparisontoothercropsorcommodities,thereisagenerallackofinterestshownbythedecisionmakersaboutthesocioeconomicpotentialoftappingpalms.Noneorlittleresearch,selectionofhigheryieldingvarietiesortrainingandextensionservicesarefundedandthetappersareseldomexposedtotechnologicalinnovationsiftheydonotgeneratethembythemselves.

Originofthenewinterestforpalmtreetappingactivity

Intoday'seconomy,theprofitabilityoftappingpalmsforsugarhassometimesimproved:thisisthecaseforcoconutandCaryotaurensinSriLanka.Inthemidseventies,withcontinuingforeignexchangecrises,areductionintheimportofsugaroccurredandwasimmediatelyfollowedbyasuddenriseinitsprice.Thegovernmentwasthenforcedtorelaxtheoldcolonialregulationsandinmanyareas,palmsugaragainbecamealowcostsourceofsugar(Dissanayake1977).InpartsofSouthSumatra(Sriwangi),tappingcoconutforsugarproductionis8to10timesmoreprofitablethansellingnuts.Onefamilyisratherwelloffwith35treesandin1987,morethan40%ofthefamiliesoftheareawereinvolvedintappingastheirmainsourceofincome.Theiraverageearningsweremorethantwicethoseofneighbouringareaswherecoconuttappingwasnotpractised.Atapperearnsperdaytwicetothreetimesmorethanafieldworker,thatistosayaboutwhatearnsacarpenterorabricklayer.Animportantadvantageforthetapperisthathehasadailyincomethroughouttheyear.Thisgiveshimaneasieraccesstocreditfacilities(Levang1988).InSriLanka,about0.5%(i.e.2,025ha)ofthetotalsurfaceforcoconutlandistappedfortoddybyatleast5,000tappers(Abeysekera1979).InthePhilippines,asequentialcoconuttoddyandnutproductionsystemcanprovidethesmallscalecoconutfarmerswithincomesnearly10timeshigherperhectareandperyearcomparedtothetraditionalpracticeofproducingnutsonly(MaravillaandMagat1993).Inthiscountry,aprogrammelabelledas"EstablishmentofBuriPlantationforTechnologyDevelopmentandEmploymentGeneration"is

promotingthemultipurposesugarproducingpalmtreeCoryphaelatainordertostimulatethecottageindustry(Abrenillaetal1988).InNigeria,anoilpalmestateislikelytobebetteroffdevotingallitsresourcestotheproductionof9,770litres/ha/yearofoilpalmwinethanproducing10tonnesoffreshfruitbunchperhectareperannum.Furthermore,asoilpalmwineproductionismorelabourintensivethanfreshfruitbunchproduction,tappingoilpalmtreesforwineislikelytocreatemorejobsthanharvestingfruitbunches(Udom1987).

Producingsugarforpalmtreesthatcanbetappedallyearround(likecoconutandNypafruticans)isanadvantagecomparedtotheseasonalproductionofsugarfromsugarcane.Productionisnotinterruptedbyreplantingandrotationandthecontinuousproductivitymeansnodisplacedlabour,whichisamajorproblemincaneeconomy.Furthermore,thereisnobagassedisposalproblemandthereisnoexpensivecrushingmilltomaintain(HamiltonandMurphy1988).Ontheotherhand,themaindrawbackistheneedforfirewoodorotherfuel:forexample,thedeadleavesfromNypafruticansusedasfuelarefarfrombeingsufficienttomakesugarfromthesapofthistree.Palmtreesthatproducesugarseasonally,likePhoenixsylvestrisfromNovembertoMarch(coldweather)andBorassusflabelliferfromApriltoSeptember(hotweather)wouldgrowverywellsidebysideassuggestedbyAnnett(1913)inBangladeshandwouldensurecontinuoussugarproductionallyearround.

InLatinAmerica,themostabundantpalm,Mauritiaflexuosa,hasaconsiderablepotentialfromaneconomicdevelopmentstandpointasitisasourceofmanydifferentproductsamongwhichpalmwineshouldbepromoted(Johnson1997).InatentativelistofpalmswithdevelopmentpotentialcompiledbyJohnson(1997),itisinterestingtonotethatforaboutoneoutoftwopalmsofthelist,thesapisamajorproduct.

Industrializedprocessingofthesap:

BorassusflabellifersugarproductionisindustrializedinSriLanka(Morton1988).InIndia,differentproductsfromthesapofthistreeareindustriallyprocessed:sapassoftdrink(600,000bottlesin19821983inMadras),chocolatebars,candies,applejam,mixedfruitjamandpalmsyrup(DavisandJohnson1987).InWestAfrica,thesealedbottlingofpalmwinefromtheAfricanoilpalmisbeingundertaken(Bassir(1968,citedbyHartley1977).InCameroon,in1969/1970,theconsumptionoflocallymadeorimporteddrinksamountedto405millionlitresoutofwhich280millionlitreswerepalmwine.In1971thefirstindustrializedunitwithacapacityof1,000litres/dayofRaphiaspwineinsealedbottleswassetup(Fyot1973).InGhana,thepalmwineindustry(largedistilleriesinthecitiesandsmallscalefactorieslocatedinvillages)wasalsoofgrowingimportancewiththedeclineinthepalmoilindustry(SodahAyernorandMatthews1971).

Prospectsforincreasingsugaryields

Asstatedbefore,comparedtosugarcaneproduction(515tonnesofsugar/ha/year),theBorassusflabellifertreecanreach18tons/ha/yearunderrainfedconditions(KhieuBorinandPreston1995KhieuBorin1996)andthecoconuttree19tons/ha/year(Jeganathan1974).Nevertheless,thepotentialofincreasingsugarproductionfrompalmtreesislikelytobemuchhigherthanfromsugarcaneasmuchlessresearchhasbeendevotedtopalmtreesinthisrespect.

Indigenousknowledgeisavailableincountriesthathavehadalongexperienceintappingpalmtrees.Thetappergenerallymakesaselectionbeforestartingtapping:hechoosesthetreesthat,accordingtohisexperience,shouldfulfilthefollowingobjectives:highsapyieldreducedtimebetweencommencementofworkinganinflorescenceandthefirstflowofsapmaximumvolumeofsapsustainedforaslongaspossiblehealthandwellbeingofthetreemaintainedduringtapping(Pethiyagoda1978).

Tallvarietiesofcoconuttreesyieldtwiceasmuchsapasdwarfpalmsandaremoreresistanttopestsandtodroughtsandwindsbecausetheirrootsystemismoredeveloped(Jeganathan1974).Considerablevariationsoccuraccordingtotapper'sskills,day,season,prevailingweather,spadix,natureofthepalm,localityandmanure(Pethiyagoda1978).Aperiodof31daysofsapflowperspatheistheaverageinSriLanka.There,coconutpalmscanbetappedthroughouttheyearaslongasrainfallissatisfactoryandeverypalmisrestedfor4monthsayear(CoconutResearchInstitute1967).Elsewhere,itispossibletoencountersituationswheretreeshavebeencontinuallytappedformanyyearswithoutapparentilleffects(Pethiyagoda1978).Thereareconsiderablyvaryingestimatesofdailysapyields:from0.9to15litrespertree.Thesameoccursforsugarconcentrationofthesap(from4to22%):thelowerconcentration(4%)isrelatedwiththehigheryield(15litres).Thehighyieldingcoconuttreeswithregardtotheproductionofnutsarenotnecessarilythebestsapyielders(Pethiyagoda1978).Nathanael(1956)citedbyPethiyagoda(1978)liststhefollowingcriteriaforpromisingsapyields:shiny,pliableleaflets,longinternodes,uniforminflorescenceproductionandthinnerinflorescencesheaths.InSriLanka,throughhybridizationworktoidentifythemostpromisingspecieswithregardtonutproduction,ahybridbetweenatallvariety(Typica)andadwarfone(Pumila)wasfoundtobethebest.ItssapproducingcapacitywasstudiedlaterbyJeganathan(1974):onthebasisof158treestothehectare,thedailysapyieldperhectarewas346litres(with15%sugarasforTypicasap)forthehybrid,whileitwas247forTypicaandonly74forPumila(with247treestothehectareforthislattervariety).ThedifferencebetweenthehybridandTypicawasmainlyduetothehigherproductionofspadicesinthehybrid(17.7peryearagainst11.7forTypica)whichsupersedesthelowerandshorterproductionofeveryspadixforthehybrid(45litres/21days)comparedtoTypica(nearly50litres/31days).

Theimpactofmanuringonsapyieldsisreportedtobehighforcoconutsbutscientificdataarescarce.TheSriLankanCoconutResearchInstituteispresentlydoingsomeresearchandarecentsurveyhasidentifiedthefollowingfactorsaffectingtoddyyields:moisturestress,failuretoapplyamulcharoundthemanurecircle(2maroundthepalm),nutritionaldeficiencies,rainstorms,winds,lackofexperienceandshortageofskilledtappers.Afertilizermixturehasbeendevelopedfortoddytappingpalms:rockphosphate(4partsbyweight),potassiumchloride(18parts),dolomite(8parts).2to3kgofthismixturearegivenperpalmperyearaccordingtosoiltypeandclimaticconditions600gureaand1kgagriculturalsaltarealsogivenperpalmperyearwithanincreaseof50%forthehigherproducingpalms(CoconutResearchInstitute1986).

SelectionandbreedingoftheAfricanoilpalmforhighsapyieldsandhighconcentrationofsugarhavenotyetstartedonalargescale.Itislikelythatyieldimprovementresearchwillproducevarietiesthatwillyieldmorethan100litresofsapperpalmandmorethan14,800litresperhectareperannum(Udom1987).ItisabsolutelyessentialformosttappedpalmspeciesinAsiatohaveasophisticatedpreparatoryphase,sometimescontinuedthroughoutthetappingperiod,inordertoensurehighyieldsofsap.Itinvolvesallsortsoftechniquessuchasbending,kicking,hammering,kneading,bruisingtheinflorescenceanditsstalk.SuchapreparatoryphasehasnotbeenreportedinAfricafortheAfricanoilpalmanditislikelythatsouthsouthtransferoftechnologycouldpermitamajorincreaseinsapproductionfromthistree.

Differentmanagementtechniquespermitincreasedsugarproductionfrompalmtrees.Nypafruticansproducesmoreinflorescences(andpotentiallymoresap)whenthestandsarekeptthinnedofoldleaves.SapproductioncanbeimprovedbywiderspacingbetweentreesthaninwildalmostpurestandsofNypafruticans:from2,500/hadownto500orlessbyremovingtherhizomesoftheothersplantstopreventthemfrom

regenerating(HamiltonandMurphy1988).InthePhilippines,Quimbo(1991)developedanew,highlyprofitablemethodoftappingthatincreasesthesapyieldfromlessthan60,000litres/hatomorethan100,000.Thistechniqueconsistsinusingclenchedfistsaspressureapplicator,whichloosensthesilicaandcrystallikedepositsinthetrachealelementsofthepeduncle,thusenhancingfreesapflowatasimilarratebutformuchlongerperiods(111daysinsteadof60days).Treatmentcouldalsobereducedfrom94days(ofwhich52contactdays)to43days(ofwhich22contactdays)withtotalsapyieldstillhigheronaperplantbasis.SimilarlyinPapuaNewGuinea,Pivke(1985)hasdevelopedasophisticatedprotocolofpretreatmentthatpermitsmuchhighersapyields.

ForArengapinnatainNorthSulawesi,a10x10mspacingproducedthehighestyieldsofsap(Sumadi1988).HighyieldingstrainsofArengapinnatahavebeenisolatedintheintensivesugarpalmcultivationinMinahassa,NorthSulawesi(Mogeaetal1991).Thetrees,withanaverageof19m(upto25m)aremuchhigherthanelsewhere.NearTomohon,atanaltitudeof700800ma.s.l.,thesapproductionamountsto1215litresaday,containing1215%ofsugarwithconsiderablylongertappingperiods(612months)foreachinflorescence(normallymorethan1mlong).Asuperiorsugarpalminthislocationproducesallyearroundanaverageof30litresaday(Mogeaetal1991).

DailyBorassusflabellifersapyieldsaveragebetween6and10litrespertreebutcanbeaslowas1litreorashighas20litrespertree(Paulas(1983TjitrosoepomoandPudjoarinto1983,citedbyKovoor1983).Thiscanbeexplainedbygeneticandenvironmentalfactors.Moresappertreecanbeobtainedifeachinflorescenceproducesmore,overalongerperiod(skilloftheoperator),iftherearemoreinflorescencesinagiventime,iffloweringstartsonyoungertreesandlastslonger(geneticfactors)andiftheresponsetotappingishigher(geneticfactors)(Kovoor1983).BorassusaethiopiumiscommonlytappedforwineproductioninwestAfricabuttheproductionofsugarhasneverbeenrecorded.Nevertheless,ithasagoodpotentialforsugarproductionand,inareaswheresugarcanedoesnotgrowifnotirrigated(Sudaneseareaswithlongdryseason),thistreecouldreplaceitforsugarproduction(Chevalier1930).

Researchisneededtoassesstherelativeimportanceofgeneticvsenvironmentalvstechnologicalfactorsinordertoestablishapriorityagendaforincreasingsapproductionandsapqualityeitherthroughbreedingprogrammesormanagementtechniquesoracombinationofboth.

Prospectsforfacilitatingsapcollection

Formostnondestructivetappingtechniques,ahighdegreeoftraditionalexpertiseisneededandwherethistechniqueisnottraditionallypractised,greatdifficultiesmightbeencounteredintrainingpeople.Usually,thefatherteacheshissonaboutpalmtappingduringaverylongperiod.Inthecaseofthehighsugarproducingpalms,reducedheightwouldbeamuchappreciatedcharacteristicdecreasinglabourtime,effortandrisks.Unlikethecoconut,dwarfmutantsandraceshavenotbeenreportedtooccurinthecaseofBorassusflabellifer(Kovoor1983).Thismaybeattributedtothelackofsystematicresearch.Analternativewouldbetoselectthemostprecocioustrees(thatstartfloweringataverylowheight)asprecocityisagenetictrait(Kovoor1983).

Devicesforsaferandmoreefficientwaysofclimbingpalmtreeshavebeeninvented:onebyDavis(1984)citedbyDavisandJohnson(1987)anotherwasdevelopedbythePalmyraDevelopmentBoardofSriLankaand,usingit,thetapperwouldbeabletotapabout100treesaday,morethantwicethepresentaverage(Dissanayake1986).TheergonomicproblemsoftoddytappershavebeenreviewedinSriLankabyAbeysekera(1979).

HybridizationoftheAfricanoilpalmwiththeAmericanspecies,Elaeisoleifera,whichhasacreepingtrunkandbetterresistancetodisease(Kahn1988)couldproduceaproductivevariety,easytotapbecauseoflowandstableheight.

Prospectsforanimalproductionwithinsustainableintegratedfarmingsystems

Storageofsapatlocallevelisnotpossibleasfermentationrapidlyoccursevenifdelayedbysomechemicalagents.Fermentedsapisnotsuitablefortheproductionofgoodqualitysugarandthisusuallylimitstheexpansionofpalmsugarmakingatvillagelevel.Processingsapintogoodqualityjaggeryisalsoadifficultandtimeconsumingtask:upto16hoursperdayinCambodia(KhieuBorinandPreston1995KhieuBorin1996).Italsorequiresanexperiencedandskilledworker,oftenawoman(stirring,removingoffroth,maintainingtheappropriatetemperature,etc.).Thisisalsoamajorbottleneckwhichlimitssapprocessing(Dissanayake1986).Furthermore,inmanycountries,productionandsaleoftoddyisprohibitedbyregulationsandsomerawmaterialiswasted(Dissanayake1986).AccordingtoMogea(Mogeaetal1991),ArengapinnatainNorthSulawesi(Indonesia)couldconsiderablycontributetotheincreaseofthelocalincomesandprovidemanyjobopportunitiesiftheproblemsduetotheenormousamountsoffuelwoodrequiredformakingsugarandthelimitedmarketingpossibilitiesoftheproductscouldbesolved.Itisdifficulttobringthefreshsapandthepalmwinetotheremotemarketswhereastheneighbouringonesareoftensaturated.Ifthesugarisbettercommercialized,thenthefuelconstraintacutelyoccurs.InRotiandSavuislands(Indonesia),thetappersclaimthattheycouldtap20to30Borassustrees,butrarelydoesanyonetapmorethan10to15atanyonetimeascookingthesaptoproducesyrupisthelimitingfactor(Fox1977).Thereisahugepotentialforcapitalisingonunderexploitedsugarpalmtreeswhicharenotusedbecauseofthelackoffuelwoodformakingsugarorthelimitedmarketingpossibilities.InCambodia,twosurveysconductedin1938and1960showedthatrespectivelyonly26%and30%oftappablepalmyratreeswereactuallytapped(Romera1968).InSriLanka,onlyabout2%ofthetotalareasuitablefortappingisreportedtobeactuallytapped(Sivilingam1983,citedbyDissanayake1986).IncoastalNigeriaandCameroon,Nypafruticanswhichwasintroducedearlyinthiscentury,hasnaturalizedandisunderutilized(Johnson1997).Therefore,thereisanichefordiversification.Inthesecases,thesapcouldbeusedforanimalproduction.Presentlabourconstraintscanbeovercomethroughtheuseofclimbingdevicesthatenablethetappertotaptwiceasmanypalmtrees(Dissanayake1986).

Ontheotherhand,meatdemandisincreasinginmanydevelopingcountriesaspopulationgrowsandlivingstandardsimprove:inthecaseofCambodia,thepigpopulationisincreasingatarateof16.6%peryear(Devendra1993,citedbyKhieuBorinandPreston1995KhieuBorin1996).Insteadofpreparingsugarfromthesapofsugarproducingpalmtrees,thesapcanbedirectlyfedtotheanimalsandprovidemostoftheenergyneededinthediet.ThishasbeendoneforcenturiesintwoIndonesianislands,RotiandSavu.TheyhaveacomplexdiverseeconomythathasBorassusasthecentreandwhichincludesasmallscalesemiintensiveorintensivepigrearingcomponent(78pigsperhousehold).InaBorassuseconomy,pigsareaprimemeansofconvertingpalmproductstoprotein.Pigsarefedfreshsapthroughoutmostofthetappingseasonandthereforefattenduringthedryseasonwhileotherlivestockusuallyloseweight.Inaddition,pigsoftenreceivetheresidue(froth)andspillfromthesyrupcookingprocess.Duringtherainyseason,theyarefrequentlyfedsyrupmixedwithwater(nevertheless,whenCoryphaelataisavailableasinRoti,peoplewillgenerallyfavourstheuseofitssagoaspigfeedinsteadofpalmsyrup).Foxconcludesinthesewords:

"BorassussyrupandfruitconstitutetheprimaryfoodforpigspigsinturnareaprincipalmeansbywhichSavu'spalmeconomyisabletosupportitsdensepopulationpigsandpalmsgotogetherandonecanviewpigsasareasonableindicatorofpalmutilization".Thisisfurtherdemonstratedbythestrongcorrelations(muchhigherthanforotherlivestockspecies)betweenpigandhumanpopulationsinthedifferentareasofthesetwoislands.Theareaswherethepopulationdensitiesarehighest,aretheareasofmostintensivepigrearingpigsalsorepresentingthehighestproportionsofthetotallivestock(Fox1977).CaptainJamesCook,sailingwestfromNewGuineastoppedattheSavuislandfrom17to21September1770,atthehighpointofthetappingseason.Hereportedinhisbook"Voyages"detailedinformationontheuseofBorassus.Inthisparticularyear,thecropswerereportedtohavefailed.Thereforethemaximumharvestofsapwastakingplaceinordertosecure6to8monthsfoodsupply.Despitethisthreatenedfoodsecuritysituation,Cookwitnessedthatsyrupwasgiventopigsandusedevenforotheranimalproduction:"Ihavealreadyobserved,thatitisgivenwiththehusksofricetothehogs,andthattheygrowenormouslyfatwithouttakinganyotherfood:weweretoldalso,thatthissyrupisusedtofattentheirdogsandtheirfowls..."(CookcitedbyFox1977).

TheauthorofthispaperspentaweekinRotiinmidNovember1997.Itwasattheendofalongandseveredryseason(duetoElNio).AsRotiisthemostsouthernIndonesianisland,itgetstheshortestrainyseasonofthecountry.Borassustappingisstillpractisedeverywhereontheisland.Tapperswereinterviewedintwoplaces,aMuslimfishingvillageonthenortheastcoast(Papela)andaChristianvillagealongabeachonthesouthwestcoast(Nemberala).Freshsapisstillcommonlyusedforanimalproduction.Pigsarefedwithfreshsaptwiceaday,justaftersapcollection(earlymorningandatdusk).Whenfreshpalmsapisnotavailable(rainyseason),palmsyrup(onelitreofsyrupcomesfrom4to5litresofsap)isdilutedwithwatertofeedthepigs.Thequantityofpalmsapgivenperpigperdayvariesaccordingtotheavailabilityofotherfeeds.Herearetwoexamplesofadailypigdiet,respectivelyduringtherainyseason,inPapela,andduringthetappingseasoninNemberala:threemeals,eachoneincludingonelitreofsyrupdilutedintwolitresofwaterandabout170gofricetwomealsperday,eachoneincluding1.5litreoffreshsapandchoppedmeatfromabouttwoandhalfcoconuts.Apartfromthesefeeds,thepigsgenerallysatisfythegreatestpartoftheirproteinneedsthroughscavengingonthebeach,especiallyatlowtide.Thepigsspendalldaysandevenpartofthenight,digginglongditchesinthesand,goingfarfromtheseashoreandclosetothecorralreefandturningoverthestonesineverypoolaccessibleatlowtide.Theygetcrabs,snailsandvariousothershells,smallfishes,seacucumbersandseaweeds.Thepigsaresoldonthemarketoncetheyareaboutoneyearold,weighingaround40kg.Thepoultryalsodrinksthepalmjuice.InNemberala,thejuiceisalsogiventothedogs.Everydoggetsaboutalitreofsapperdaysharedinthreemeals.Theotherpartofthedietismadeofrice,fishandmeatwastesandbones.Apartfromguardingthehouse,theuseofthedogisforitsmeatasitisstillatraditionalfoodforthenonMuslimpeopleoftheisland.Themalesaregenerallyslaughteredwhentheyarearound2yearsold.

TrialsonfeedingpigswithpalmjuicehavebeeninitiatedrecentlyinCambodiawithintheframeworkofanFAOTechnicalCooperationProject(FAO1995).Pigswererearedfrom20to80kg,withADGof356gusingthefollowingdailydiet:approximately8kgofpalmjuice156gofprotein(fromsoyabean),lime,saltand500goffreshwaterspinachperday.Twelvefarmswerestudied.Takingintoaccountthepriceoffuelwood,theprofitpertreeperdaywasnearly14timeshigherwhenthejuicewasusedforfeedingpigsinsteadofmakingsugarsyrup(KhieuBorinandPreston1995KhieuBorin1996).

Usingfreshsapforfeedinganimalswillavoidburninglargequantitiesoffuel.Nevertheless,aspartofthisfuelgenerallycomesfromthepalmtreeitself,itmightbepossibletomakesyruporsugarthatwillbeeasytopreserveandthatwillbelaterfedtotheanimalswhenthesugarproductionseasonisover.Ifthisisnotpossible,sapproductioncanbeentirelyusedasfreshjuiceforfeedingfatteninganimalsandthefatteningcyclecancoincidewiththesometimesrathershorttappingseason.Thiscaneasilybedonewithpigsandducks.Apartfromgivingalotofaddedvaluetothesap,thisalsopermitsthesmallfarmers,whousuallyhaveverylowstoragecapacityforsyruporsugar,toavoidsellingsapatlowpriceduringthetappingseason.Sap,syruporsugarcouldalsobeusedasemergencyfeeds,replacingotherfeedswhoseproductionhasbeencompromizedbydroughtsorothercalamities,whenevernecessary.

Tobalancemonogastricdietsbasedonsugarpalmjuiceorsyrup,agoodsourceofproteinisrequired.Assoyabeanishardlyavailableatareasonablepriceinmanytropicalareas,somealternativesourcesofproteinareneeded:possiblesourcesincludecassavaleaves,sweetpotatoesleaves,foddertreeleaves,aquaticplants(duckweed,Azolla),wholesoyaplantatmilkygrainstageandfishwastes.Properuseandmanagementofthesedifferentalternativesourcesofproteincancontributetoreducingpollution,increasingcarbonsinksanddecreasingerosion.Animalfeedingsystemsbasedonpalmjuice/syrupfavourkeepingtheanimalsinconfinementinsteadofgrazingorscavengingsystems.Thisprotectstheenvironment,limitsthedisseminationofcontagiousdiseasesandalsooptimizestheintegrationoflivestockwithinanintensivefarmingsystem(Figure1).Manurecanbeprocessedthroughabiodigestor,producingtheenergyforfamilycookingneeds,andtheeffluentcanbeusedasafertilizereitherforcropsorforfishponds.

Ruminantsalsobenefitfromthesugarpalmtrees.AsmentionedbyKhieuBorinandPrestonduringtheSecondFAOElectronicConferenceonTropicalFeeds,Borassussapandthescumobtainedduringsapcookingaretraditionallyusedforsofteningricestrawusedforcattlefeeding(especiallydraughtanimals)inCambodia(Speedyetal1997).Cattlearealsofedwithmaturefruitsorpartsofthemthatarenotusedforhumanconsumption.DuringhisstayinRoti,theauthorofthispaperdidnotgetanytestimonyrelatedtofeedingfreshsaporsyruptotheruminants.Nevertheless,thegoatsgetthefoamproducedduringthesapcooking.Greentwigswiththeirleaves,takenfromthetreethatalsoprovidesthefirewoodusedforcookingthesap,areslightlycookedtogetherwiththesapandusedtoremovethefoam.Then,theyareimmediatelygiventothegoats.Thankstothisfeed,thegoatswerestillinaverygoodbodyconditiondespiteofthefactthatitwastheendofalongandseveredryseason.

Thepotentialoffeedinggoatsandcowswithpalmsapasthemainsourceofenergyformilkproductionshouldbeinvestigatedaswellasthesourceofnitrogen(nonproteinnitrogenandbypassproteins),mineralsandfibretocompletethediet.Incidentally,tappingpalmtreeswillalsoalwaysofferaneasysourceofsugarforbeeswhichwilltendtospontaneouslyharvestallwastedsugar.Honeyproductionisthereforeincreasedinareaswherepalmtreesaretapped(Fox1977).

Conclusion

Borassuspalmsarethemostnumerouspalmsintheworldafterthecoconutpalm(Fox1977).Despitethis,theyareamongtheleaststudiedofallthepalmspeciesintheworld.AsformanyothersugarproducingpalmtreessuchasCaryotaurens,verylittleisknownabouttheireconomicpotential(Dissanayake1977).Thislackofinterestcanbeexplainedduringcolonialhistorybythefactthat,fromthecolonizer'spointofview,itwasmucheasiertosetup,manageandcontrollargesugarcaneplantationstoproducesugarthantouseexistingscatteredpalmtreesthathadbeenmanagedforcenturiesbythelocalpeople,oftenwithinasubsistenceeconomy.Besidethis,thesetreesareoftenassociatedwiththepoor.Thefactthattheirjuicequicklyfermentsandmakesalcoholmadetappingactivitiesundesirabletogovernments,andalsofortheHindus,BuddhistsandMuslimsorthodoxes(Fox1977).

Nevertheless,therearemanygoodargumentsforrevitalizingknowledgeandresearchonsugarproducingpalmtrees.Consideringtheirmultipurposeuses,theycancontributeinmanywaystothesustainabilityofintegratedfarmingsystems.Forexample,inIndonesia,Mogea(1991)suggeststopromoteanddevelopthroughresearchprojectsthreeparticulartaxawithinthenativepalmresources.Twoofthemhavesugarastheirmainproduct:ArengapinnataandBorassusflabellifer.Assugarproducingpalmtreesareoftenthemainsubsistenceresourceforthepoorestpeople,improvingthewaythesetreesareusedwillcontributetothealleviationofpoverty.Palmtapping,especiallyasfaraswildandsemiwildspeciesareconcerned,isanactivitythatdoesnotrequirecapitaltostart.Inhighlypopulatedruralareas,itcanbeamajorsourceofselfemploymentforthepoorestpeopleandavoidmajordriftsfromtheland.Inthecaseofcoconut(inSriLankaforexample)orAfricanoilpalm(inColombiaandNigeriaforexample),withthelowandunpredictableworldpricesofcopraandpalmoil,ithasbecomeincreasinglydifficultforsmallfarmerstodependontheirproduction.Thisencouragesattemptstofindotherwaysofusingthesetrees,includingdiversificationforbettersustainabilityofthesystem.Sugarproductionandanimalproductionarealternativestoconsiderifmarketscanbedevelopedfortheseproducts.

Whenselectingpalmssuitableforsmallfarmers,itisimportanttoconsidertheamountofknowledgeavailableaboutthecandidatespecies.Agoodindicatoristhedegreetowhichapalmhasbeendomesticated.Generally,themoreadvancedthestageofdomestication,theeasierthespeciescanbecultivatedsuccessfully(Johnson1987).Consideringthehighcostanddurationofadomesticationprogram,inthecaseofnondomesticatedsapproducingpalms,itissuggestedtoevaluateandselectonefordomestication(Arengapinnata,CoryphaumbraculiferaandC.utanarestrongcandidates)whereastheotherspeciesshouldbeconsideredformanagementimprovement(Johnson1997).

Futureresearchonusingpalmtreesapforanimalproductionshouldconsiderthefollowingissues:

Assessmentofexistingstandsofwildpalms(Nypafruticans,Borassussp.,etc.)andtheeconomicprospectsfromtappingthesetrees.Assessmentoftheeconomicpotentialofpalmtreesselectedovercenturiesforsapproductiontobeusedinotherregions:BorassusflabelliferfromCambodiaorIndonesiacouldbeinstalledinAfricawhereecologicalconditionsaresimilarArengapinnatafromNorthSulawesicouldbeinstalledonunproductiveerosionpronesoilsinLatinAmericaCaryotaurenscouldbedevelopedinmarginallands.Identificationofcriteriaforproperselectionofindividualstobetappedandforrecognizingtheproperplantstageforinitiatingsuccessfultappingoperations.Physiologyoftheproductionofsapflowandprecisesignificanceofthevariousactsthatconstitutetheartoftappinginordertodevelopimprovedtechnologiesforincreasingsugaryields(techniquesoftapping,frequency,fertilization,treespacing)andtooptimizetheuseoflabour.Selectionofearlyfloweringpalmtrees.Improvedtechnologiesforsafelytappingtrees.Techniquestopreservethejuiceandavoidfermentation.Identificationofproductionsystemswithpalmtrees,cropsandanimals:accordingtothepresenteconomicandenvironmentalchanges,assessmentoftherelevanceoftappingsugarpalmtreesforanimalproductionincomparisonwithenergyproduction(ethanol)orotherproductions(coprafromcoconutoroilfromoilpalm).

Whatisneededisathoroughfieldsurveyreviewingindetailallindigenousknowledgerelatedtotappingpalmtreesforsugarandanimalproduction.Thiswouldpermitamajorbreakthroughforassessingthefuturepotentialofthesetreesandforsharingtechniquesandexperiencesbetweenreg