Lydia Wairegi, Piet van Asten, Ken Giller and Thomas Fairhurst

Banana-coffee system cropping guide

iii

Africa Soil Health Consortium: Banana–coffee system cropping guideBy Lydia Wairegi (CABI), Piet van Asten (IITA), Ken Giller (WUR) and Thomas Fairhurst (TCCL)© CAB International 2014Please cite this publication as: Wairegi, L.W.I., van Asten, P.J.A., Giller, K.E. & Fairhurst, T. (2014) Banana–coffee system cropping guide. Africa Soil Health Consortium, Nairobi.This publication is licensed under a Creative Commons Attribution 3.0 Unported License.Creative Commons License:

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Limits of liabilityAlthough the authors have used their best efforts to ensurethatthecontentsofthisbookarecorrectatthetime of printing, it is impossible to cover all situations. The informationisdistributedonan‘asis’basis,withoutwarranty.Neither the authors nor the publisher shall be liable for any liability,lossofprofit,orotherdamagescausedorallegedtohavebeencauseddirectlyorindirectlybyfollowingtheguidelinesinthisbook.

About the publisherThe ASHC mission is to improve the livelihoods of smallholder farmers through adoption of integrated soil fertility management (ISFM) approaches that optimize fertilizeruseefficiencyandeffectiveness.ASHCbooksareavailableatspecialdiscountsforbulkpurchases. Special editions, foreign language translations andexcerpts,canalsobearranged.

ISBN: 9781780644929

v

Addresses of authors

Lydia Wairegi Piet van Asten

CABI International Institute of Tropical Agriculture

ICRAFComplex P.O.Box7878

P.O.Box633-00621 Kampala

Nairobi Uganda

Kenya p.vanasten@cgiar.org

ASHC@cabi.org www.iita.org

www.cabi.org/ashc

Ken Giller Thomas Fairhurst

Wageningen University Tropical Crop Consultants Ltd

P.O.Box430 26OxenturnRoad,

6700 AK Wageningen Wye,

The Netherlands Kent TN25 5B

Ken@wur.nl UnitedKingdom

www.pps.wur.nl tfairhurst@tropcropconsult.com

www.tropcropconsult.com

When coffee and bananas are competing for nutrients andwater,bananasgenerallysuffermore.Butundergoodmanagement,coffeebenefitsfromtheshadeandmulchfrombananas.That’swhyProfessorJ.Y.KZake(asoilscientistbased in Uganda) said “...take care of your bananas, and your bananas will take care of your coffee...” as bananas seemtobetheweakerlinkinthesystem.

vi

Acknowledgements

ThepreparationofthisguidewassupportedbytheBill&MelindaGates Foundation.Wethank:DavidMukasaandIsaacSerubiriattheInternationalInstituteofTropicalAgriculture(IITA)fororganizingfieldtripsandprovidinghelpful information.Laurence Jassogne, Ghislaine Bongers and Godfrey Taulya at IITA,CharlesAgwandaatCABIandDickWalyaroatRwandaAgriculture Board for providing helpful information, comments and suggestions.Farmersandcoffeeprocessorsforinformationandforallowingphotographstobetakenintheirpremises.ValentineNakato(IITA)forphotographsofdiseasesofbanana.OtherphotographswereprovidedbyPietvanAsten(IITA),LydiaWairegi(CABI)andDenisOnyodi(Globevideo).Simon Ndonye for the illustrations.WageningenUniversity(WUR)forhostingawrite-shopatwhichalargepartofthisguidewasdeveloped.CABI, IITA, Tropical Crop Consultants Ltd and WUR for the time theauthorsspentwritingthisguide.

vii

Contents

1. Introduction 1

2. Banana and coffee intercrop systems 3

Banana and coffee 3 Banana–coffee intercrop systems 3 Advantages and disadvantages of intercropping banana and coffee 13 Yield gaps 17

3. Requirements for banana–coffee systems 23

Soils 23 Agro–ecological environment 26

4. Establishing banana–coffee systems 29

Introduction 29 Plantingcoffeeinexistingbananafields 30 Plantingbananainexistingcoffeefields 32 Establishmentofnewbanana–coffeefarms 33 Choice of planting material: banana 34 Choice of planting material: coffee 39 Spacing 41

5. Managing banana–coffee systems 43

Integrated soil fertility management practices for banana–coffee systems 43 Canopy management 44 Residue management 46 Fertilizer recommendations 49 The 4Rs + 1R for effective use of fertilizer 53 Keychecks 66

viii

6. What can go wrong? 68

Pest and disease management 68 Nutrition and pest and disease pressure 75 General management 75 Harvest 76

7. Economic analysis 82

Agronomicbenefits 82 Economicbenefits 83 Certificationschemes 85 Integration into the farming system 85 Synergy 86

8. Conclusions 88

9. Look-up tables 89

10. References 91

11. Glossary 96

12. Acronyms and abbreviations 98

Appendices: Banana Pests and Diseases Extension Materials 100

ix

1

1. Introduction

Thisguideisdesignedforpeopleworkingwithsmallholderfarmers,includingextensionworkers,grass-rootNGOs,community-basedorganizations,aswellasresearchers.Itprovidesessentialtechnicalinformationthatwillhelpfarmerstoselectthemostappropriatemethodstomanagefieldsintercroppedwithbananaandcoffee.The importance of banana and coffee crops in Africa cannot be overstated. From the highlands of East Africa to the humid forest zoneofWestAfricaandthelowlandsofCentralAfrica,bananaisakeystaplefoodandanimportantsourceofincomeforfarmerswhotradeinlocal,nationalorregionalmarkets.Bycontrast,coffeeisamajorcashcropforexport,generatingsignificantincomestonationaleconomies.About30%oftheworld’sbananaandplantainand11%oftheworld’scoffeearegrowninAfrica.Thevastmajorityofsmallholderfarmersinregionswherethesecropsaregrownworkwithlessthan2hectares(ha)land.Thesesmallholdersneedtofindwaystoincreaseyieldsbyintensifyingcrop management of both banana and coffee in their limited land holdings.In a banana–coffee cropping system, the banana provides shade forcoffeethatisbeneficialinreducingstressescausedbyextremetemperaturesandstrongwinds.Coffeetreesgrowwellundermoderateshade(lessthan50%),whichcanhelpimproveand stabilize coffee yield and quality. Shade helps to reduce the occurrenceofoverbearingdiebackincoffeeandalsoreduceyieldlosses caused by drought.Thebananaalsoprovidesmulchandthesoilcoverthatbenefitsboth crops. The mulch improves root development in both banana and coffee, and improves availability of potassium (K) in the topsoil, due to the large biomass turnover. The permanent canopy and root systems of banana reduce soil losses due to erosion and

2

surfacewashbyreducingtheimpactofrainfallonthetopsoil.Bananasandcoffeecangrowwelltogether,butoptimizingconditions for both crops requires careful management in order to avoidexcessivecompetitionforlight,waterandnutrientsbetweenthetwocrops.In several parts of East Africa, smallholder farmers have alreadydiscoveredthebenefitsofgrowingbananasandcoffeeintercroppedtogetherinthesamefield.Nonetheless,thepracticedid not receive much attention from researchers, until recently. Thispreventedextensionofficershelpingfarmerstoadoptthepractice in a sustainable and productive manner.Thisguidedescribeshowtointercropbananaandcoffeeinaproductive,profitableandsustainableway.ForaglossaryofwordsandphrasesusedintheguideseeSection 11.

3

2. Banana and coffee intercrop systems

Banana and coffee

Banana and coffee are important crops in East, Central and West Africa (Figure 1).ThemanytypesofbananagrowninAfricacanbegroupedaccordingtohowthefruitisused,i.e.cooked,roasted,processedforjuiceoreatenasadessertfruit(Photo1).ThecookingbananaiscommonintheEastAfricanhighlandswhiletheroastingbanana(or plantain) is more prevalent in West Africa and parts of Central Africa. In this guide, the term banana is used to refer to all types of bananasandplantains,exceptwhereitisnecessarytorefertoaspecifictype.Twotypesofcoffeearecommonlygrown:ArabicacoffeeandRobustacoffee.ThemarketpriceofArabicacoffeeishigherthanforRobustabecauseithasmorerefinedtastecharacteristicsthatgiveitamorefavouredplaceinthemarket.Arabicacoffeerequiresacoolerclimateandisthereforegrownathigheraltitudes(typically1,000–2,000masl)thanRobusta(below1,500masl).

Banana–coffee intercrop systems

Themainadvantageofintercroppingbananawithcoffeeisthatthesystemisusuallymoreprofitableandresilientthantheproductionofeithercropgrownasmonocrops.Thispocketguidedescribeshowtomanageintercroppedbanana–coffeesystems.Wedescribehowyoucan: • establishnewfieldswithbanana–coffeeintercropsusing either Arabica or Robusta coffee, depending on the prevailing agro-ecologicalconditions

• plantcoffeeinexistingbananafields • plantbananasinexistingcoffeefields.Successingrowingintercroppedbananasandcoffeedepends

4

toalargeextentonanadequatesupplyofnutrientsfromthesoil, recycled crop residues that also provide mulch and mineral fertilizers. Both banana and coffee yield much less than their potential if poor soil fertility is not corrected by the addition of manure, compost and/or mineral fertilizers.Fertilizercostscanbereducedbymakingsurethatcropresidues-particularlybananapseudostemsandleavesbutalsocoffeeprunings-arereturnedtothesoil.Inaddition,agoodmulchlayer ensures the development of strong root systems that in turn improvestherecoveryofnutrients,whetherappliedintheformoffertilizers or crop residues. Inthisguidewedescribeanapproachcalledintegratedsoilfertility management (ISFM) that aims to combine organic and mineral sources of nutrients to optimize crop response and sustain the productivity of the farming system. More information on ISFM can be found in the ASHC sister publication Handbook for Integrated Soil Fertility Management (Fairhurst, 2012) downloadablefromtheASHCwebsite.Bananaandcoffeearebothcommonlygrownasmonocrops,butin densely populated regions of Uganda and Tanzania more than halfthefarmersnowgrowthemtogetherinthesamefieldasanintercrop (Photo 2). When intercropped, bananas are planted at a lowerdensitythaninmonocropsandthebananasprovideshadeandmulchtocoffeeplantedbetweenrowsofbananas(seeTable7 on spacing).Banana and coffee are perennial crops – they need to be carefully managedbypruningthecoffeetreesanddesuckeringthebananaplants to maintain an optimal crop leaf canopy of both coffee and banana plants.

5

Temperature decreases by 0.5–0.7oC for every 100 m increase in altitude.Therefore,athigheraltitudes,wheretheweatheriscoolerandwetter,bananacanbeintercroppedwithArabicacoffeewhilstatloweraltitudesbananacanbeintercroppedwithRobustacoffee(Table 1). SomeArabicavarieties(e.g.Catimor)canbegrownatloweraltitudeinregionswhereRobustaiscommon,primarilybecausesuch varieties are resistant to coffee leaf rust (CLR) but at this altitude,thequalitytendstobeimpairedandshademustalwaysbeusedtopreventoverbearingdieback.However,several‘traditional’Arabicavarietiesdonotperformverywellatlowaltitudes(below1400m)duetothelessfavourableweatherandhigherpestand disease pressure.

Figure 1. Mapshowingthedistributionofbanana–coffeesystemsinsub–SaharanAfrica.

Banana growing area

No banana cultivation

No data

6

Photo 1. Banana types. (A)Thehighlandcookingbanana,amajorfoodandcashcropinEastAfrica.Saleofbunchescontributestoexportofnutrientsfromthefarm.(B) Plantain common in West Africa. (C)Beerbananausedtobrewbeerforhouseholdconsumptionandthelocalmarket.(D)FHIA25,acookingbananathatishighlyresistanttoblacksigatokaandproduceslargebunches,producedbytheHonduranFoundationforAgricultural Research.

A B

C D

IITA IITA

IITAIITA

7

When establishing banana and coffee plantations, annual crops can begrowninbetweenthebananaandcoffeeforonetotwoyearstoprovide some income before the bananas and coffee are ready for harvesting.Suitablecropsincludetomatoes(coffeebenefitswhentomatoesaresprayedwithfungicides)andbushbeans(legumecropsprovidenitrogen-richcropresiduesthatbenefitthecoffeeandbanana plants). These short duration crops should be planted so that

Photo 2. Banana–coffeesystemwherebananacanopyisabout1–2mabovecoffeeandprovides good shade for coffee.

IITA

Table 1. Agro-ecologicalconditionsinproductionareasforbanana–coffeesystemsinsub-SaharanAfrica.

System Zone Percentage of cultivated area used for banana–coffee systems

Rainfall Altitude Length of growing period

West Central East mm masl days

Banana-Robusta

Sub-humid 16 29 16 1000–1500 <1500 180–270

Humid 10 59 2 >1500 <1500 >270

Banana-Arabica

Highlands* 0 4 12 >1000 >1500 –

*Definedasthoseareasinthesemi-arid,sub-humidandhumidzonesofSSAwhere,becauseofhigheraltitude,meandailytemperatureduringthegrowingperiodis<20°C.

8

aclearspaceof0.5–1.0mismaintainedbetweentheintercropsandthe banana and coffee plants. Young banana–coffee systems should notbeintercroppedwithclimbingcropplants(e.g.climbingbeans).Althoughthebananaplantsgrowverylargetheyareactuallymonocotyledonous(i.e.likemaize,sugarcaneandgrasses)andhavenowoodyparts.Theyhaveanundergroundstemcalledacormatthebaseoftheplant.Whatlookslikethestemisactuallyapseudostemor‘falsestem’,madeupofoverlappingleafsheaths. Bananasgenerallyflowerbetween8–16monthsaftersuckerplantingandthefirstharvestmatures3–4monthslater(Table2).Farmersmustthereforewait11–20monthsfromplantingsuckersuntilthefirstharvestofbananafruit.Thebananacropcycleduration is generally longer for taller varieties and cooler climates found at higher altitude.Onlyonebunchofbananasisproducedoneachpseudostem,afterwhichthemotherplantdiesandshouldbecutbackatsoillevel and the pseudostem cut into pieces and spread over the soil surface to provide a mulch layer and prevent proliferation of bananaweevils.Astheplantedsuckergrowstobecomethemotherplant,othersuckersdevelopfromitscormtoforma‘bananamat’(orfamilyofbananaplants)(Figure2).Thebestdaughtersuckermustbeselected in each mat and is retained to replace the mother plant thatisfelledatharvest.Othersuckersareremovedtopreventovercrowding.Asuckerthatisgrowingfromamotherplantgetssomenutrientsfromthemother,especiallyifthemotherhasnotyetflowered.Afterflowering,however,theflowofsugarsandnutrientsfromthemotherplanttothesuckerisreducedbecausethemotherstartsto divert all the products of photosynthesis to feed the developing fruit bunch.

9

Bythetimethebunchfromthe‘mother’stemisreadyforharvesting,thematshouldhavetwootheryoungplantsof

Tab

le 2

.Timingofkeyphysiolog

icaleventsinbanana–coffeeintercrops.

Des

crip

tio

nT

imin

gD

urat

ion

Ban

ana

Flow

ering

Productionofleavesstops,flow

eringstalk

emer

ges.

8–18

mon

ths

afte

r th

e suckerisplanted

.

Bunchfilling

Fing

erleng

thincreases,thenfingerdiameter

expands.

3–4

mon

ths

Co

ffee

Flow

ering

Flow

erbud

sop

en.

2–3

year

s af

ter

pla

ntin

g.

Pin

head

Minimalgrowthoffruit.

2–3

mon

ths

Sof

t gr

een

Expansion

,rap

idswellingoffruit.

2–4

mon

ths

Har

d g

reen

Filli

ng o

f bea

ns, b

eans

rea

ch m

atur

ity.

4–7

mon

ths

Rip

enin

gPulpswellsand

turnsfrom

greentoredcolou

r.B

errie

s re

ady

for

harv

est

6–8

(Ara

bic

a) a

nd 9

–11

(Rob

usta

) mon

ths

afte

r flowering.

10

differentages,i.e.a‘daughter’anda‘granddaughter’(Figure2;Photo3).Afterthemotherhasbeenharvested,anothersuckerisselected from the granddaughter, so that three plants of different ages are maintained on each mat at any time. Theperiodbetweenharvestswithinamatdependsonthespeedwithwhichfollowersuckersdevelopandmatureandisinfluencedbythetimingofsuckerselection,rainfallandsoilfertilitystatus,among other factors. With good soil and crop management, a mat can produce a bunch in 10–12 months. With a population of 740 mats/ha, intercropped bananas have a yield potential of about 960bunches/ha.Bunchweightrangesfrom30–50kgsotheyieldpotentialfrombananasinanintercroppedfieldrangesfrom29–48t/ha/year.Inanewbananafield,thefirstgenerationofplantedbananaswillreach maturity and harvest at about the same time. After three to

Figure 2. Evolutionofbananamatsfromplantedsuckerstomaturemats.

Newly plantedsucker

Young banana plant

Immature mother with daughter

Banana mat comprising a mother, daughter and grand-daughter

6–12 months4–6 months 12–24 months

22–42 months

11

Photo 3. Each banana mat should have three generations of plants i.e. mother, daughter and granddaughter to ensure bunch

harvests are regular, the mats do notdie-outthedesiredbanana

population is maintained.

IITA

fourcycles(i.e.afteraboutthreeyears),however,plantsmatureatdifferent times during the year and, as a result, crop production is a continuous process. Bananasflowermoreandinitiatelargerbunchesinthewetseasoncomparedwiththedryseasonandthisexplainspronouncedseasonalityofproductioninareaswherethereisadistinctwetseason.Notsurprisingly,bananapricesarelowestduringthepeakproductionperiod,whenthereisaglutinthemarket,andhighestwhenbunchesarescarceduringthelowcropperiod.So,selectionoffollowersuckersshoulddependonfarmer’sobjectives: • Ifproductionisforthemarket,suckersthatwillmatureduringpeakpriceperiodsshouldbeselected.

• Ifproductionisforhouseholdfood,focusshouldbetomakesure that the plantation produces bunches throughout the year.

Rootsofbananagrowfromthecormand vary from 50–200 cm in length. Most of the roots are found in the surface of the soil up to a depth of 30 cm(Photo4)andadensenetworkof roots develops directly under the mulch.Generally, coffee produces the firstcrop3–4yearsafterplantingalthoughsomeofthenewselectionsstart producing about a year earlier (Table2).Forexample,clonalRobusta coffee established from cuttingsproducesthefirstyieldabouttwoyearsafterfieldplanting.Coffeeplantsfloweraboutaweekafter the start of the rainy season,

12

resultingintwoharvestsinregionsclosetotheequatorwithbimodalrainfall.ForexampleinwestUganda,whererainsoccurinApril-MayandSeptember-November,themaincropisharvestedinApril-Juneandthefly-cropinOctober-JanuaryCoffeeberriesareharvested6–8monthsafterfloweringinArabicacoffeeand9–12monthsafterfloweringinRobustacoffee(Figure3).Yieldincreaseswitheachharvestandstabilizesataboutthefifthyearafterplanting,providedproperpruningiscarriedouteach year.

Likebanana,coffeehasashallowrootsystemwithmostofthefeeder roots found in the surface 20 cm of soil. Most of the roots ofcoffeebushesarefoundaround60-90cm(Arabica)and150cm(Robusta) from the base of each coffee bush.

Incontrastwithplantsraisedbyvegetativepropagation(clonal),coffeegrownfromseeddevelopsacentraltaproot,whichpenetratesto a depth of 0.5–1.0 m, and sometimes reaches a depth of >4 m. Plantswithataprootcanscavengeforwatermoreeffectivelywhenthewatertabledropsduringthedryseason.Forthisreason,whenplanting seedlings (particularly wherethetaproothasbentupwardsinseedlingsraisedinpolybags) the tap root should be straightened gently so that the tap rootgrowsdownwards.Thetaprootwillnotpenetratedeepintothesoiliftheseedlingisplantedwitha‘hooked’taproot.Donotcutthetap root – it is not replaced!

Banana and coffee can be planted at the same time in a banana–coffee intercrop

Photo 4. Fertilizer should be placed closetothesoilsurfacewheremostrootsandcareshouldbetakenwhen

carryingoutmanagementpracticeslikeweedingsoasnottodamagetheroots.

IITA

13

system. Alternatively, coffee can beintroducedinexistingbananaplantations but the banana population may need to be thinned toprovidesufficientspaceforthecoffee trees. Similarly, banana can beplantedinanexistingcoffeeplantation but the coffee trees may need to be pruned and thinned to create space for the banana plants.

Robusta has more above–ground biomass and a more dense root system,andthereforecompetesmorestronglywithbananathanArabica coffee. For this reason, the plant population of Robusta coffee in banana–coffee intercrops is smaller at about 1100 trees/hacomparedwithArabicawhichisplantedatabout2200trees/hain intercrops (Table 8).Asweshallsee,tomaintainbananayieldsinbanana–coffeesystems, the coffee must be correctly spaced and pruned to minimizecompetitionfromthecoffeetrees.Insufficientandincorrect pruning is a very common problem in banana–coffee intercrops. Correct timing, frequency, and sequencing of operations (e.g. pruning coffee trees after the harvesting season) are crucial for successful management of banana–coffee systems (Figure 4).

Advantages and disadvantages of intercropping banana and coffee

Bananaprovidesthecoffeewithshade,whichreducesstressoncoffeeduetowidevariationintemperaturewithinthecoffeeleafcanopyandwinddamage.Youngcoffeetreesgrowwellwhengrownundershade,andshadeimprovescoffeeyieldandbeanqualityinmaturecoffeewhenmoderateamountsofmineral

Figure 3. Coffee green beans are enclosed in several layers that comprise the harvested berry.

Epicarp, exocarp (skin)

Pericarp (pulp)

Endocarp (parchment)

Silver skin (bean coat)

Bean

14

fertilizer are used. Shade can also prevent or at least minimize the incidenceoftheconditionoverbearingdiebackincoffee.The banana also provides mulch to the cropping system. The mulch supports good root development for both the banana mats and the coffee trees and can improve the availability of potassium (K) in the topsoil, due to the large biomass turnover. The leaf canopy, root system and mulch provided by banana help to minimize soil losses and improve soil moisture conservation.Bananasandcoffeecangrowwelltogether,butestablishingthebestconditions for both crops requires careful management of the soil and cropleafcanopies.Forexample,iftheshadeprovidedbybananais too dense (more than 50%), coffee yields may also be reduced. Conversely,theyieldofbananaswillbesmallifthereareonlyafewbananamatsandcoffeemaybeinsufficientlyshadedleadingtooverbearingdieback.Robustamayevencompetewithbananasoaggressively that the banana population decreases until banana yieldsareinsignificant.

Figure 4. Annual cropping calendar of banana–coffee system in West Uganda.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Coffee

De-suckering

Pruning

Foliar fertilizer

Pest

Harvesting

Banana

De-suckering

De-trashing

Corm removal

Harvesting

Both crops

External mulch

Hand weeding

Fertilizer

Manure

Timeline

Tasks

15

There is also a strong interactionbetweenshadeand fertilizer use in coffee production. Coffee can producehighyieldswithoutshadewhenlargeamountsofmineral fertilizer are applied. Fertilizerinputswillonlyhavea limited effect on yield if coffee is densely shaded but if fertilizer is not applied to unshaded coffee, the trees may initially yieldwellbutlatermanybrancheswilldieback.Thisiscalled‘overbearingdieback’(Figure5).Thebasicprinciplesformanagingtheinteractionsbetweenshadeand fertilizer on coffee production are: • Wheresoilfertilityispoor,coffeegrownundershadeoftenyieldsbetter and is a more resilient system (i.e. plantation life is longer andproductionmorestable)thancoffeegrownwithoutshade.

• If shade is too dense the yield potential of coffee is reduced and thecoffeewillrespondpoorlytofertilizer.Addingfertilizerstocoffeethat is heavily shaded is not recommended because the increase incoffeeyieldmaynotbesufficienttocovertheinvestmentinfertilizer. Reducing the number of bananas to reduce shade can improvethebenefitsoffertilizerinsuchfields.

So, canopy management is important to ensure the required balancebetweenbananamatsandcoffeeplants.Coffeeneedstobeprunedproperlyotherwisethecoffeetreesgrowtootall,shadethebananamatsandimpedethedevelopmentofnewbananasuckersCoffeebearsmoreberrieson‘new-wood’,therefore,coffeeshouldbe pruned so that stems are replaced continuously by selecting afewsuckersasreplacementstemseachyear.Carbohydratesproducedbyphotosynthesisarewastedwhenlargestumpsand

Figure 5. Effect of shade and fertilizer inputs on yield and yield stability in coffee.

Yie

ld (

t/ha

gree

n be

an)

Shaded Unshaded

+ fertilizergood soil

– fertilizerpoor soil

Unstable but higher yields

possible

Stable but lower yields

16

anexcessivenumberofoldstemsareretainedonthecoffeetrees.The major advantage of properly managed banana–coffee intercrops is that there is increased productivity and revenue per unit area of land (Figures 6 and 7). This is demonstrated by calculating the land equivalent ratio (LER)where:

LERyield of ercropbananayield of monocropbanana

yiel=⎡

⎣⎢

⎤

⎦⎥ +

int dd of ercropcoffeeyield of monocropcoffee

int⎡

⎣⎢

⎤

⎦⎥

Thisequationallowsustocomparetheyieldofintercropwiththe yield of monocrops per unit area. Yields should be measured and entered into the equation in tonnes per hectare (t/ha). When intercropsyieldgreaterthansolecropsgrownoverthesameareatheLER is greater than 1. Forexample,iftheyieldofmonocropsis1.5t/hacoffeeand 25 t/ha banana and the yield of banana–coffee system is 1 t/ha coffeeand15t/habanana,theLERiscalculatedasfollows:

LER =⎡

⎣⎢⎤

⎦⎥+⎡

⎣⎢⎤

⎦⎥=

1525

11 5

1 26.

.

Inthisexample,theoverallyieldisgreaterinintercropscomparedwithmonocrops.

Revenuesandprofitabilityareoftengreaterinbanana–coffeeintercropscomparedwithmonocrops(Figure7).Returntolabouris also often higher in banana–coffee systems because less labour isrequiredwhenthecropsaregrowntogetherthanthesameareaof monocrops.Inaddition,intercroppingbananaandcoffeereducestheriskfacedbyfarmerswhencultivatingmonocrops.Forexample,itisunlikelythatbothcropswillbeaffectedatthesametimebypests,disease,ordroughtstressandmarketpricesforbothcropsaregenerallyunlikelyto‘crash’simultaneously.

Growingbananasinyoungcoffeeplantationsalsoensuresthatthefarmer gets some returns from the land before the coffee reaches the productive stage.

17

Based on the above equation, LERs for the data presented in Figure10werecalculatedasfollows:

LER Arabicasystem =⎡

⎣⎢⎤

⎦⎥+⎡

⎣⎢⎤

⎦⎥=

20 214 8

1 201 23

2 3..

.

..

LERRobustasystem =⎡

⎣⎢⎤

⎦⎥+⎡

⎣⎢⎤

⎦⎥=

8 915 0

1 101 25

1 5..

.

..

Intheseexamples,theadvantage of intercropping comparedwithmonocropping is greater in Arabica–banana compared withRobusta–bananasystem. Intercropping banana and coffee can save on the labour requirements. Forexample,bothcropsbenefitfrommulchappliedto the soil surface. In turn, themulchsuppressesweedgrowth,reducingthelabourrequiredtoweedcoffeewhengrownasamonocrop.

Yield gaps

In perennial cropping systems, mistakesmadeduringcropestablishment mean that there isayieldgapbetweensite–specificattainableyieldandactual yield (Figure 8). Such yield gaps persist throughout the life span of the intercrop but can be minimized by

Figure 6. Yieldsofbananaandcoffeegrownas a monocrop and intercrop in Uganda.

BCB C B C BC

Ban

ana

yiel

d (t

/ha)

0

5

10

15

20

25

Cof

fee

yiel

d (t

/ha

gree

n be

an)

0.0

0.5

1.0

1.5Banana Coffee

Arabica region Robusta region

Figure 7. Revenue of monocropped coffee versus intercropped banana and coffee in Uganda.

C BC C BC

Rev

enue

(U

SD

/ha)

0

1000

2000

3000

4000

5000

Coffee Banana

Arabica region Robusta region

18

careful establishment of the system. Common causes of yield gaps includethefollowing:

• Use of inferior planting materials. • Off–typesofbananaandcoffeeplantedinthefield. • Incorrect plant spacing.

Yieldgapsbetweensite–specificattainableyieldandactualyieldscanbereducedbythefollowingpractices(Figure8): • Planting carefully selected coffee and banana plants at the right spacing

• Use of crop residues as mulch • Application of mineral fertilizers to supply nutrients • Control of pests and diseases • Properagronomicmanagement(i.e.pruning,weedcontrol,drainage) of the crops.

Thiswillensurethatthenutrientsappliedaretakenupandusedefficientlybytheplantandrecycledbacktothesoilincropresidues.

Thefarmershouldalwaysaimforyieldsthatgivethebesteconomic returns. Aiming for the highest possible yield may not givethegreatestprofitandtherefore,asaruleofthumb,farmersshouldaimfor60–80%ofthesitespecificattainableyieldinordertoachieveefficientuseofinputsandgoodeconomicreturns.

The maximum yields recorded in monocrops in Uganda are above 70 t/ha/year for banana, above 3 t/ha/year for Robusta coffee (green bean) and above 2 t/ha/year for Arabica coffee (green bean). In most farms, actual yields of banana and coffee tend to be less than30%ofthesemaximumyields.

Recentfieldsurveysshowthatyieldsobtainedbymostfarmers

19

Figure 8. Contribution of selected agronomic constraints to yield in

banana–coffee systems.

Proportion of potential yield (%)

0 20 40 60 80 100

Current yield

Pests managed

Pests managed +good management

Pests managed + goodmanagement + fertilizers

Potential yield

Site specific attainable yield

in Uganda are about 10–20 t/ha/year of fresh banana but the best farmers achieve more than 30 t/ha/year (Wairegi, 2011).

AccordingtoFAO,coffeeyieldsin Uganda average about 0.6 t/ha/year of green beans but the best yields are about 2 t/ha/year for both Arabica and Robusta coffee. The yields in manyfarmsareobtainedwithlittle or no use of fertilizers, less than optimal management and little attention to pest and disease control.In each production zone it is helpful to collate available informationtodeterminesiteyieldpotentialandmaximumeconomicyieldsforbananasandcoffeegrownasintercropsandmonocrops. Forexample,ineastUgandaweestimatethatthesiteyieldpotential for banana is 66 t/ha/year in monocrops and 44 t/ha/year in intercrops, and for coffee about 2.5 t/ha/year in both monocrops andintercrops.Bycontrast,inwestUganda,theyieldpotentialforbanana is 66 t/ha/year in monocrops but 30 t/ha/year in intercrops, and the yield for coffee is about 3 t/ha/year in both intercrops and monocrops (Table 3). ThesubstantiallyreducedyieldsinbananaintercroppedwithRobusta could be partly because Robusta can form a more extensiverootsystemthanArabicaandhencecouldbemorecompetitive. Pest and disease pressure on banana tends to be localized and the incidence of pests and diseases in coffee depends mainly on thevarietygrown.Often,pestanddiseasepressuredecreasewith

20

anincreaseinaltitude.Forexample,bananaweevilsaregreaterproblemincentralthaninsouthwestUganda.Robustacoffeeishardlyaffectedbycoffeerust,whichcanreduceyieldsinArabicacoffeeverysignificantlyandcoffeerustdamageisoftenmoresevereinArabicacoffeewithpoornutritionalstatus.It is therefore possible to improve yields and achieve good economic returns to investments in improved crop management by using moderate amounts of fertilizers, proper pruning and mulch management, and appropriate investments in pest and disease control.

Table 3. ExampleofsiteyieldpotentialandtargetyieldofmonocropandintercroppedbananaandcoffeeineastandwestUganda.

Crop Yield (t/ha/year)

Site potential Target yield

Banana-Arabica Monocrop banana >66 40

Monocrop coffee >2.5 2

Intercrop banana >44 30

Intercrop coffee >2.5 2

Banana-Robusta Monocrop banana >66 40

Monocrop coffee >3.0 2.5

Intercrop banana >30 25

Intercrop coffee >3.0 2.5

21

Key checks

Intercroppingbananawithcoffeeisusuallymoreprofitableandresilientthantheproductionofeithercropgrownasmonocrops.

Intercropped bananas and coffee require an adequate supply of nutrients from the soil, recycled crop residues that also provide mulch and mineral fertilizers.

Banana and coffee need to be carefully managed by pruning the coffeetreesanddesuckeringthebananaplantstomaintainanoptimal crop leaf canopy of both plants.

Above1500masl,bananacanbeintercroppedwithArabicacoffee;atloweraltitudesbananacanbeintercroppedwithRobusta coffee.

Banana and coffee can be planted at the same time in a banana–coffee intercrop system, or coffee can be introduced in existingbananaplantations(thebananapopulationmayneedtobethinnedtoprovidesufficientspaceforthecoffeetrees),orbananacanbeplantedinanexistingcoffeeplantation(thecoffee trees may need to be pruned and thinned to create space for the banana plants).

The leaf canopy, root system and mulch provided by banana help to minimize soil losses and improve soil moisture conservation.

The major advantage of properly managed banana–coffee intercrops is that there is increased productivity and revenue per unit area of land.

22

Intercroppingbananaandcoffeereducestheriskfacedbyfarmers;itisunlikelythatbothcropswillbeaffectedatthesametimebypests,disease,ordroughtstressandmarketpricesforbothcropsareunlikelyto‘crash’simultaneously.

Yieldgapsbetweensite–specificattainableyieldandactualyields can be reduced by:

• Planting carefully selected coffee and banana plants at the right spacing

• Use of crop residues as mulch • Application of mineral fertilizers to supply nutrients • Control of pests and diseases • Properagronomicmanagement(i.e.pruning,weedcontrol,drainage) of the crops.

Aim for yields that give the best economic returns: as a rule ofthumb,farmersshouldaimfor60–80%ofthesitespecificattainableyieldinordertoachieveefficientuseofinputsandgood economic returns.

23

3. Requirements for banana–coffee systems

Soils

Bothbananaandcoffeegrowbestonfertilesoilswithloamytextureandgoodwater-holdingcapacity.Soilsshouldbewell-drained,notcompactedorstonyandatleast2mdeep.Deepersoils(morethan3m)thatallowcoffeeplantstodevelopataprootandbothcropstodevelopamoreextensiverootsystem are preferred in areas affected by seasonal drought.Largeinputsofcropresiduesandanimalmanurewillberequiredtoimprovethewaterholdingcapacityoflighttexturedsoils(e.g.sandy loams and loamy sands) and to improve nutrient storage and reduce leaching losses.Coffeegrowswellinmoderatelyacidsoils(pH>5)butbananapreferssoilswithhigherpH(pHabove5.5).Bothcropsgrowbestinsoilswithhighsoilexchangeablepotassium(above0.3cmol/kg)andtotalnitrogen(above0.15%)status (Table 4).Nevertheless,thebanana–coffeesystemisfoundonawiderangeof soils. Banana–coffee systems are found in Uganda on strongly

Table 4. Ideal soil characteristics for banana and coffee production.

Parameter Units Value

pH 1.5soil/water >5

Organicmatter* % >3.0

Soil organic carbon** % >1.7

Total N % >0.15

Available P mg/kg >15

ExchangeableK cmol/kg >0.3

ExchangeableCa cmol/kg >2

ExchangeableMg cmol/kg >2

*Soil organic matter = soil organic carbon × 1.72. **Soil organic carbon = soil organic matter × 0.58

24

weatheredandlowfertilitystatusFerralsolswithsandyclayloam,sandyclay,andclaysoiltexture(Figure9)andinmorefertilesoilsin the Albertine Rift Valley in the Democratic Republic of Congo (DRC) (Figure 10).Soils under the banana–coffee system in Uganda generally contain quite large amounts of soil organic matter (more than

Pest and disease pressure

Soil fertility

Plant density

Rainfall

Central Uganda15 t/ha/cycle

East RwandaEast BurundiSW Uganda

RusiziSemliki

KivuRegion

1100masl

1300–1400masl

1600–2100masl

45 t/ha/cycle

25 t/ha/cycle

Figure 10. CrosssectionshowingregionsfromtheLakeVictoriabasintotheAlbertineRiftValleywherebananas

aregrown.

Silt %

0

10

20

30

40

50

60

70

80

90

100

Clay %

0

10

20

30

40

50

60

70

80

90

100

Sand %

0102030405060708090100

Sand

Clay

Sandy clayloam

Loamy sand

Sandyclay

Clay loam

LoamSilty loam

Silty loam

Silty clay loam

Sandy loam

Silt

Figure 9. Soiltextureinmajor banana–coffee regions in Uganda.

Table 5. SelectedsoilpropertiesforCentral,SouthandSouthwestRegionsinUganda.

Property Units Central South West East

Banana yield t/ha 15 15 22 28

pH – 6.4 6.7 5.6 6.3

Soil organic matter % 3.6 3.7 3.1 3.5

Total nitrogen % 0.2 0.2 0.2 0.2

Available P mg/kg 50 87 47 39

ExchangeableK cmol/kg 1.7 2.5 1.5 3.8

ExchangeableCa cmol/kg 7.7 11.1 5.6 8.2

ExchangeableMg cmol/kg 1.5 2.5 1.3 1.8

K/(Ca+Mg) ratio – 0.2 0.2 0.3 0.4

Clay % 29 31 25 43

25

3%) and are slightly acid (pH less than 7) (Table 5). Based on soil analysis, the soils seem to have large amounts of nutrients but fertilizertrials,foliaranalysisandvisualobservationshaveshownthatdeficienciesexist(seebelow).Anutrientdeficiencymapcanbe constructed based on soil and foliar analysis, and calculated nutrient imbalances in plants (Figure 11).Extensivetrialsinfarmers’fieldsinUgandaandotherpartsofEastAfricahaveshownthatpoorsoilfertilitylimitsproductionof banana and coffee in the vast majority of cases (Wairegi, 2011). Nitrogen, phosphorus, potassium and magnesium are the nutrients most commonly found to be limiting, but the relative importance of each nutrient deficiencyvariesbetweenregions.Forexample,whilstmany soils in Uganda are NandPdeficient,thelownutrient status Ferralsols of central Uganda are also deficientinKandplantsonthe volcanic areas in east Uganda are often affected by Mg imbalances (Figure 11).

Atthefarmscale,fieldsneartothefarmhomesteadaregenerallymorefertilethanmoredistantfieldsbecausehouseholdwaste(e.g.bananapeelings,sweepings),cropresiduesandanimalmanurearegenerallyappliedtofieldsclosetothefarmhomestead.

Onlessfavourablesoils,bananascanbegrownathigherdensities

Figure 11. Nutrientdeficiencymapforbanana–coffee regions of Uganda.

26

(i.e.morethan740mats/ha)withoutaffectingcoffeeyieldsbecause the banana plants are smaller and less competitive for light,nutrientsandwater.

Agro–ecological environment

Banana-Arabicasystemsaremoreprofitablethanbanana-Robustasystemswhenathigheraltitudes(above1,500masl)(Table6).However,somelowlandvarietiesofArabica(e.g.Catimor)yieldwellatloweraltitudes(i.e.above600masl),thoughtheircoffeequalityprofileisoftenconsideredtobeinferiortothetraditional coffee varieties.

Whilst the broad canopy of banana can reduce the impact of rain on the soil and therefore reduce soil losses, terraces and grass stripsshouldbeusedtominimizesoilerosionwherebanana–coffeesystemsareplantedonlandwithslopessteeperthan15%.

Insufficientrainfall(i.e.lessthan900mm/year)andsoilmoisturedeficitscanbemajorlimitationsleadingtoareductioninthesize and number of banana bunches produced (Figure 12). The mulch cover provided by banana pseudostems and leaves and

Table 6. Optimalconditionsforbanana-Arabicaandbanana-Robustasystems.

Parameter Units Banana-Arabica coffee Banana-Robusta coffee

Altitude masl 600–2000 200–800(butdoeswellupto1500inUganda).

Slope % Leveltogentlysloping.Soilconservationrequiredwhereslope>15%.

Rainfall mm/yr 1200–1800 1200–1800 but can tolerate >2000.

Annual mean temperature

°C 18–21 22–26 but cannot tolerate temperatures <5–6 or long periods <15.

Frost Arabica coffee affected by frost. Frost does not occur.

Average annual humidity % 70–80 80–90

Wind and hail Bananaplantsaredamagedbystrongwindsandwindcombinedwithhail.

Shade in banana Banana prefers full sunlight but tolerates light shade.

Shade in coffee Arabica coffee requires moderate shade.

Robusta coffee requires moderate shade and is hardier than Arabica.

27

coffee prunings is therefore particularly valuable in areas withmarginalrainfall.

Shade provided by bananas helps mitigate the adverse effects of hot and dry conditionsoncoffeegrowthand production. Permanent shade is particularly important for Arabica coffee, particularlywhenfertilizeruseis erratic due to problems withavailabilityandcost.

Bananaplantsshouldbeplantedaboutsixmonthsbeforecoffeesothatbananamatsprovidesufficientshadewhencoffeeseedlingsareplantedout.Strongwindscandamageevenmature bananas by shredding and tearing leaves and uprooting plants.Ifstrongwindsareafrequentoccurrence,awindbreakoftrees(e.g.mbula,nkulumire,msenefu,Croton megalocarpus) shouldbeplantedinrowsat5–10mintervalsaroundthefieldbefore planting banana–coffee systems.

Rainfall (mm)700 800 900 1000 1100 1200 1300 1400 1500

Ban

ana

yiel

d (t

/ha)

0

10

20

30

40

South

Southwest

Figure 12. Effect of rainfall on banana yield intworegionsinUganda.

28

Key checks

Selectdeep,well-drainedfertilesoilwithgoodwaterholdingcapacity,withpHabove5.

Deepersoils(morethan3m)thatallowcoffeeplantstodevelopataprootandbothcropstodevelopamoreextensiverootsystem are preferred in areas affected by seasonal drought.

Poor soil fertility limits production of banana and coffee in most cases: N, P, K and Mg are the nutrients most commonly found to be limiting.

Establishsystemwhererainfallismorethan900mm/year.

Install soil conservation measures, such as terraces and grass strips,onlandwithslopes.

Onlessfavourablesoils,bananascanbegrownathigherdensities(i.e.greaterthan740mats/ha)withoutaffectingcoffeeyields:the banana plants are smaller and less competitive for light, nutrientsandwater.

Mulch, provided by banana pseudostems and leaves and coffee prunings,isparticularlyvaluableinareaswithmarginalrainfall.

Ifstrongwindsareafrequentoccurrence,awindbreakoftreesshouldbeplantedaroundthefieldbeforeplantingbanana–coffee systems.

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4. Establishing banana–coffee systems

Introduction

To avoid frequent replanting it is best to select a banana type that canproducebunchesovermanycycles,evenwhenintercroppedwithcoffee.Forexample,suckersofplantainsareslowtoestablish,bycomparisonwiththeEastAfricanhighlandbanana,untilaftertheplantainmotherstemhasflowered.Farmers in Uganda prefer taller banana varieties for intercropping becausethebananacanopyiswellabovethatofcoffeeandthereforedoesnotcompeteforspacewiththelower–storeycoffeetrees.Thechoicewilldependontheproductionobjectivesofthefarmer,suchaswhetherthebananaisgrownforstaplefood,beermakingorasacashcrop.Nurseries should be established or planting material suppliers identifiedsothatbananaplantsandcoffeeseedlingsareavailableattheonsetoftheplantingseason.Bananasuckersrequireabout2–6 months and coffee seedlings about 12–18 months in the nursery.The crops should preferably be planted at the beginning of the rainyseasonsothatplantsestablishwellbeforetheonsetofdryweatherconditions.Toachieveapopulationofabout740bananamats and 2222 Arabica coffee plants per hectare, banana can be spaced at 4.5 m × 3 m, and coffee at 3 m × 1.5 m (Figure 13).When banana–coffee crops are immature, they can be intercropped withshortstatureannualcrops,whichshouldbeplanted0.5–1.0mawayfromthebananaandcoffeeplants.Theannualcropsprovidesome food and income for the farmer before the banana and coffee reach maturity.Legumecropspeciesthatfixnitrogen,suchascommonbushbeans, are preferred because their crop residues provide nitrogen tothebananaandcoffeewhenreturnedtothesoil.

30

Banana Coffee Banana Coffee

Figure 13. ExamplesofspacingandplantarrangementsforArabica(a)andRobusta(b)based banana–coffee systems.

Inaddition,annualcropshelptosuppressgrowthofweedsandprovideanincentivetothefarmertoweedaroundtheyoungbanana and coffee plants before the perennial crops start to yield.

Planting coffee in existing banana fields

Thefirststepistomakeanassessmentofthedensityofbananamatsandtheirdistributiontodeterminewhetherornotthebananasneedtobethinnedbeforeinterplantingwithcoffee.Asaruleofthumb, there should be around 740 banana mats per ha in the area to beinterplantedwithcoffee(seeTable7andFigure13).Ifthinningisrequired,removetheleastproductiveordiseasedmatsfirst.About three months before the planned planting time (i.e. the startoftherains),markholesforplantingcoffeeinthebananaplantation (suggested plant spacings are given in Table 7).Inanoldbananafieldthematsarenolongerfoundinrowsbecause the position of the mother stem moves each time a mat isharvested(Figure2).Markingrowsforcoffeeplantinginevitablyinvolvessomecompromisestofitthecoffeebetweenbananamats. The important point is to try to maintain, as far as possible, the ideal coffee spacing (Figure 13). Holes for planting coffee should be 0.4 m in diameter and 0.4 m deep.

31

Onemonthbeforetherains,filltheholewithtopsoilmixedwithorganicmanures(e.g.1:1:1mixtureofsoil,animalmanureandcompost),0.1kgtriplesuperphosphate(TSP),nematicideorinsecticide(ifpestssuchasrootnematodesortermitesareknowntobeaproblem)and0.1kglime(ifthesoilpHis<4).Heapthesoilovertheholetoallowforsettlingandtop-upwiththesoilafterone month, as required.Plantthecoffeeseedlingswhenrainshavestartedandthegroundismoist to about 60 cm depth.Thespacebetweenthebananaandcoffeecanbeinterplantedwithnon–climbingannualcropssuchastomatoandbushbeans.Iftheshadefrombananaisnotsufficient,shadethecoffeeseedlingsforthefirstsixmonthsafterplantingusingleaves,orotherplantmaterials.Duringthefirsttwoyears(Figure14),managethe banana mats carefully to ensure that they continue to provide shadebutdonot‘move’towithin1moftheyoungcoffeetrees.Growthofbananasuckerscanbeaffectedbycoffeeasthetreesgrowtallerandbushier.Thereforemanagethecanopyofcoffeebypruning,especiallybythethirdyearaftercoffeeplanting,tomakesurethatemergingbananasuckersreceiveadequatelight.

Table 7. Suggested plant spacing and planting densities for banana–coffee systems.

System Crop Spacing

DensityBetween row Within row

m M plants/ha

Monocrop Arabica 3 1.5 2222

Robusta 3 3 1111

Banana 3 3 1111

Intercropped Arabica coffee 3 1.5 2222

Banana 3 4.5 740

Robusta coffee 3 3 1111

Banana* 3,6* 3 740

*Doublerows,3mbetweenthetworows,6mbetweendoublerows

32

Planting banana in existing coffee fields

Makeanassessmentofthedensityofcoffeetreesandtheirdistributiontocheckwhetherthecoffeeneedstobethinnedbeforeinterplantingwithbananas.As a rule of thumb, there should be about 1100 (Robusta) and 2200(Arabica)treesperhaintheareatobeinterplantedwithbanana (Figure 13).Itmaybenecessarytoremovewholerowsofcoffeetocreatesufficientspacetointerplantthecoffeewithbananas.Wherepossible,theleastproductivecoffeetreesshouldberemovedfirst.Over–shadingofbananabymaturecoffeecanbeaseriousproblemfornewlyplantedsuckers.Toavoidover–shadingofyoungbananaplants,thebesttimetointroducebananawouldbewhenchangingthecycleofcoffee(i.e.rejuvenatingcoffeetreesthroughstumpingorheavypruning).Thechangetakesabouttwoyears(Figure14)andthiswouldprovidethebananaplantswithsufficienttimetoreachmaturitybeforethecoffeereturnstoproduction.Bananaplantestablishmentcanalsobecarriedoutwhenimproved coffee tree varieties are introduced in an old coffee plantation,particularlywherethenewcoffeevarietiesareintroducedbytop-working(i.e.graftingnewvarietiesontooldcoffeestems)oruprootingandreplacingtheexistingtrees.Itmayalsobepossibletoconvertafieldofcoffeeoverseveralyearsbyinterplantingaportionofthecoffeefarmwithbananaseachyear.Forexample,tochangethecycleofcoffeeoverathreeyearperiod,thecoffeefieldcanbepartitionedintothreeblocks,andthechangecanbecarriedoutinoneblockeachyear.Aboutthreemonthsbeforeplantingtime,markpositionsforbanana plants and prepare planting holes (0.6 m deep by 0.6 m diameter).Onemonthbeforetherains,filltheholewithtopsoilmixedwithorganicmanures(e.g.1:1:1mixtureofsoil,animal

33

manureandcompost),0.2kgtriplesuperphosphate(TSP)(orotherfertilizerslike0.2kgdiammoniumphosphate(DAP),0.4kgof NPK 17:17:17), nematicide or insecticide (if pests such as root nematodesortermitesareknowntobeaproblem),and0.2kglime(ifthesoilisbelowpH4).Heapthesoilovertheholetoallowforsettlingandtop-upwiththesoilafteronemonth,asrequired.Whenrainsstart,plantbananasuckersintheholesandthensowannualcropsinremainingopenspaces.Bananaplantswillbeshorterthancoffeeinthefirstyear.Thismeansthatthecanopyofcoffee needs to be reduced periodically by pruning to optimize the amountofshadeoverthenewlyplantedbananasuckers.

Establishment of new banana–coffee farms

Preparelandsixmonthsbeforethestartoftherainyseasonbyremovinganystumpsoftreesandwoodyweeds.Markthepositionofplantingholesforbothbananaandcoffee

Year 1 Year 2 Year 3 Year 4

Seedling Young tree Mature matwith bunch

Mother with daughter and

grand daughter

Immature mother

and daughter

Young plantSuckerMature treeImmature tree

0–6 months 6–12 months

New

farm

Pla

nt c

offe

e in

ban

ana

farm

Pla

nt b

anan

ain

cof

fee

farm

Growth stages in bananaGrowth stages in coffee

Figure 14. Stages in the development of banana–coffee systems from planting to harvest.

34

(see Table 7 and Figure 13) and prepare the holes for banana three months before the start of the minor rains and for coffee three months before the start of the major rains. Bananas should be plantedatleastsixmonthsbeforethecoffee(Figure14).Itmaybebeneficialtoestablishsometemporaryshadeoneyearbefore planting coffee seedlings using legume tree species, such as tephrosia (Tephrosia vogelii) or pigeonpeas (Cajanus cajan). Thetemporaryshadecanberemovedgraduallyduringthefirst18monthsaftercoffeeplanting.Overthisperiod,thetephrosiapruningsprovidemulchmaterialwithhighNcontentthatbenefitsboth coffee and banana plants.Sometimes the temporary shade trees are retained after the coffee hasreachedmaturity.Forexample,inbanana–coffeesystemsaround the base of Mount Kilimanjaro in Tanzania, shade and mulch in immature and mature phase is provided by grevillea (Grevillea robusta),anon-legumetimbertree.

Choice of planting material: banana

Choice of planting material is an important part of developing a productiveandprofitablebanana–coffeesystembecauseofthedifferent economic uses and adaptation to different environments.

Types and varieties

TheEastAfricanhighlandbanana(cooking/brewing)iscommoninthehighlandsofEastandCentralAfrica,whileplantainsaremorepopularinthelowlandsofCentralAfricaandhumidforestzoneofWest Africa.

It is generally best to select banana types/cultivars for intercroppingthathavethefollowingcharacteristics: • Tall at maturity. • Tolerant of stress (e.g. poor soil fertility, competition) but not excessivelycompetitive.

• Robust enough to be harvested for many cycles.

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• Tolerantofshade,especiallywhenthesuckersareyoung. • Erectleaves,especiallywhenyoung,butprovideshadewhenmature.

ThefollowingvarietiesareusedcommonlyinEastandWestAfrica: • The East African highland banana can be found in most banana growingareasinEastAfrica.

• PisangAwakorKayinja(anexoticbeerbanana)isgrownonlessfertilesoilsinRwandaandUganda

• Yangambikm5ispopularinEastDRC,WesternRwanda,andtheRusiziValleyontheborderwithBurundi.

Varietiesthathaveaveryvigoroussuckeringhabit(i.e.producemanysuckerspermotherplant)aregenerallynotpreferredbecausetheyrequiremorerigorousandlabourintensivede-suckeringinordertoavoidexcessivecompetition.

Planting materials

Banana planting material for traditional varieties and hybrids is usuallyavailableassuckers,tissuecultured(TC)andmacro–propagatedplants(Photo5).Otherplantingmaterialsthatarenotverycommonlyusedaremaidensuckerswithtopscutoffandcormswithswordsuckersattached.

Whenusingsuckers,useswordsuckersandnotwatersuckers.Swordsuckershavenarrowleavesandproducelargebunches.Watersuckershavebroadleaves,arenotwellattachedtothecorm and produce smaller bunches (Photo 5).

Bananasuckerscanbeuprootedfromanestablishedplantation,aneighbour’sfield,commercialnurseryorresearchstationandtransplantedtoanewfarm.Farmerscancarryoutmacro-propagation but tissue culture is carried out in laboratories by trained personnel.

36

Preparing suckers for planting

Thebasicstepsareasfollows:

• Digupselectedhealthysuckersfromselectedmotherplants. • Removerootsfromthesucker. • Peel the corm. • Sterilizethepeeledcorm,preferablyinboilingwaterfor20–30seconds, or alternatively in a solution containing a pesticide (e.g.ethoprophos)tokillnematodesandweevillarvae.

Uniform,pestanddisease-freebananaplantsthatareeasilytransportableandmorevigorousthansuckersandcanbeproducedinlargenumbersbymacro-propagationortissueculture(Photo5).

Preparing plants by macro-propagation

Thebasicstepsareasfollows: • Digupselectedhealthyanddisease-freeswordsuckersfrommother plants. Mats that are healthy, disease free and have desirabletraitscanbelabeledandsuckersforpropagationretainedduringroutinemanagementoffield.

• Removerootsfromsucker,peelandsterilizethecorm(seeabove).Peelleafsheathsofftoexposebuds.

• Cross-cuteachexposedbudincentretoencouragegrowthofmany plantlets from one bud.

• Killmaingrowingpointoncormbycross-cuttinginthemiddleor removing the soft tissue in the middle.

• Sterilizerootingsubstrate(e.g.sawdust,soil,coffeehusks),forabout 2–4 hours, then place substrate in humidity chamber.

• Placecormsinahigh-humiditychamberandwater.Thehumiditychambercanbeasimplewoodenboxonwhichaframeisraisedandcoveredwithclearpolythenesheeting.

37

A

B C

D E

G H

F

IITA

IITA

IITA

IITA

IITA

Photo 5. Banana planting materials. (A)Swordsuckers,unlikewatersuckers,arecloselyattachedtothemother,haveawell-developedcormandaregoodplantingmaterial.(B) Tocontrolnematodesandweevils,thesuckerispreparedbyremovingallroots,peelingthecorm,dippingthecorminboilingwaterfor30seconds.(C)Macro-propagation,whichcanbedonebyfamers,isawayofmultiplyingplantsrapidly,andcanbeveryusefulinmeetingfarmerdemandfornewlyintroducedcultivars.(D)Onecormcanproduce many plantlets at the same time. (E)Micro-propagation,doneinlaboratories,produces plantlets that are free from pests and diseases, uniform in size, and have vigorousgrowth.(F)Macro-propagatedplantletsneedmorecarefulmanagementthanswordsuckerstoestablishwellandgivegoodyields.(G)Watersucker,moresuperficiallyattachedtoastemfromwhichthemotherwasharvested,arenotgoodplantingmaterial.(H)Waterandswordsuckersareeasytotellapartbecauseleavesofwatersuckersarelargeandwideandthoseofswordsuckersaresmallandsharp.

38

• Plantlets start to sprout after 1–2 months. Detach plantlets that have three leaves.

• If only one plant sprouts from a bud, cut off the plant, then cut across the centre of the bud to stimulate sprouting of multiple plantlets.

• Potdetachedplantletswithatleastthreerootsinpolybagscontainingpottingmix(1:1mixtureofsoilandwell-rottedanimalmanure).Plantletswithlessthanthreerootsshouldbeplantedbackinhumiditychamber

• Harden plantlets for one month in a nursery under shade and keepthemwellwatered.

• Discardabnormalplantsbeforeplantingoutinthefield.

Preparing plants by micro-propagation

Micro-propagatedplants(ortissueculturedplants)arefirstgrownin a laboratory then moved to a nursery for hardening. The main advantageofmicro-propagatedplantsisthattheyareuniform,diseasefreeandcanbeproducedinlargenumbersandatlowcost.Farmers can carry out the hardening process or can acquire plantsafterhardeningwhentheyarereadyforplanting.If hardening is required: • Placeplantsinhumiditychamberfor3–6weeks. • Remove from humidity chamber and place in shade for up to twomonths.

• Theplantsarethenplantedinfield.

Plantletsfrommacro-propagationandtissueculturearemorefragilethanplantsestablishedfromsuckersandrequirecarefulmanagement(i.e.carefultransplanting,watering,fertilizerapplication)forthefirstsixmonthsafterfieldplanting.

39

Choice of planting material: coffee

Types and varieties

Consider planting the most recently released varieties (e.g. Ruiru 11 and Batian in Kenya,TaCRI Arabica coffee hybrids in Tanzania) as they are often not only more resistant to pests and diseases but also have higher yield potential.Forexample,inUganda,sevenRobustacoffeelinesthatareresistanttoFusariumwilthavebeenreleasedandinKenyasomeArabicavarieties(e.g.Ruiru11,adwarfhybrid)havebeenreleasedthat are more resistant to leave rust and coffee berry disease than the commonly cultivated varieties such as Bourbon.It is generally best to select types/cultivars for intercropping that are: • Tolerant of competition but not too competitive. • Not too tall at maturity to avoid shading banana (i.e. about 1–2 m shorter than banana at maturity).

• Compactinstaturetoallowspaceforbanana.Apartfromselectingcoffeewiththesecharacteristics,managethecanopyofbananaandcoffeewelltoreducecompetitionbetweenthetwocrops.

Planting materials

Arabicacoffeeisself-pollinated,highlyuniformandinvariablygrownfromseedwhilstRobustacoffee,whichiscross–pollinated,is usually propagated vegetatively (Photo 6).Arabicacoffeeplantsgrownfromseedhaveadeeptaprootandcanscavengeforwaterfromagreatersoildepth.Itisalsoconvenient to produce large numbers of plants from seed. Because Arabica coffee is self pollinated, seedlings are very uniform.

40

A B

C D

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IITA IITA

Photo 6. Coffee planting materials. (A)Robustaseedlinggrownfromcutting(left)andArabicaseedlinggrownfromseed(right).TheRobustaseedlingismorevigorous.(B) Roots of Robusta seedling propagated vegetatively. The roots of Robusta propagated vegetativelyaremorefibrousandentwinewiththoseofbananamorethanthoseofArabica. (C)RootsofArabicaseedlingpropagatedfromseed.Arabicagrownfromseedhasatap-rootandcangetnutrientsfromgreatersoildepth.(D) Tissue culture is carried out in laboratories to multiply clean planting materials rapidly.

41

Uniformity in Robusta coffee is achieved by propagating cuttings from carefully selective and highly productive individual mother trees. Vegetatively propagated plants are identical to and have same characteristics as the mother tree. Vegetatively propagated plantsarereferredtoas‘clonal’coffee.Theimmaturephaseisshorterintreesraisedfromcuttingscomparedwithtreesraisedfrom seed.Alternatively, high yielding scion material from selected mother trees can be grafted onto old Arabica and Robusta coffee stumps toupgradeanexistingplantation.Theadvantagehereisthatanewvarietycanbeintroducedrapidlywithoutremovingandreplantingtheexistingcoffee.Whateverthetechniqueused,itisadvisable to plant Robusta coffee plants produced from a range of mothertreestoencouragepollinationofflowersandsubsequentlyenhancedfruitset,andalsotoreducetheriskofasinglevarietybeing affected by a particular pest or disease.Farmers should buy Robusta plants, raised from cuttings, from a recognized nursery.Arabica seedlings can be raised from seed by the farmer or purchased‘readytoplant’fromarecognizednursery.Insomecountries (e.g. Kenya, Uganda), nurseries can only be established afterconsultationwithmandatedinstitutionsthatmaintainpopulations of coffee and supply planting materials to the seedling producers.To produce seedlings from cuttings, producers establish mother gardens to provide material for cuttings.

Spacing

The plant spacing for both banana and coffee must be selected so thatbothcropscancontinuetoyieldwelloverthelongterm.Ifthebananasarespacedtooclosetogethertheywillshadeandreducetheyieldinthecoffee;ifcoffeetreesareplantedtooclosetothebananatheymayshadeoutyoungsuckersonadjacentbananamats.

42

Aim for about 700–800 banana mats/ha, 2000–2400 trees/ha for Arabicaor1000–1200trees/haforRobusta(Table7).Optimaldensitywilldependonthelocalsoiltype,waterandnutrientavailability, plant stature, commodity prices and production objectives.Theplantspacingandarrangementforcoffeeshouldbemodifiedaccordingtothestatureandgrowthhabitofaparticularvariety,topography(i.e.flatversuscontourplanting)andifweedingandother practices are carried out using tractors. Spacing is generally wider(lowerplantpopulation)onmorefertilesoilswithbetterrainfallbecausethetreeswillbelargercomparedwithtreesgrownonpoorsoilswithlowrainfall.Closerspacingcanbeusedwithsmallstaturedvarietiesandwiderspacingforvarietieswithlongerbranchesandlargerstature.Theseed producer can usually provide advice on suitable tree spacing.Forexample,inKenya,thegeneralrecommendedspacingforArabicais2mby2mtoallowsufficientspacebetweenrowsforchemicalweedcontrol.Bycontrast,asmallerwithinrowspacingof 1.5 m is recommended for the Arabica varieties Ruiru and Batianonflatland,givingaslightlylargerplantpopulation.Because the position of the mother banana stem moves about 0.3–0.5mpergeneration,distinctrowsofbananamatsdisappearafterafewyears.Atthispointitisimportanttocheckthatthebananapopulationremainsbetween700–800mats/habycarryingout a census.Thematpopulationinanexistingbananafieldcanbeestimatedbycountingthenumberofmotherplantswithintheradius(measuredwithapieceofcord)ofacentralmotherplant.Forexample: • Ifthenumberofmatswithina9mradiuscircleis15,thematpopulation is 15 × 40 = 600 mats/ha.

• Ifthenumberofmatswithina9mradiuscircleis20,thematpopulation is 20 × 40 = 800 mats/ha.

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5. Managing banana–coffee systems

Integrated soil fertility management practices for banana–coffee systems

Integratedsoilfertilitymanagement(ISFM)canbedefinedas:‘A set of soil fertility management practices that necessarily include the use of fertilizer, organic inputs, and improved germplasm combined with the knowledge on how to adapt these practices to local conditions, aiming at optimizing agronomic use efficiency of the applied nutrients and improving crop productivity. All inputs need to be managed following sound agronomic and economic principles.’

More simply, ISFM is ‘improved seed plus fertilizer plus more’. Thisdefinitioncombinesalltheagronomiccomponentsnecessary

Key checks • Select banana and coffee types that are not greatly affected by intercropping.

• Digplantingholesthreemonthsbeforerains;fillwithmixtureof manure, fertilizer, soil one month before rains.

• Plantaton-setofrainswhengroundismoisttoatleast60cmdepth.

• Plantshortannualcrops0.5–1.0mawayfromimmaturebanana mats and coffee plants.

• Intercroptallbananavarietieswithshort,compactcoffeevarieties.

• Plantcleanbananasuckersandseedlingsofcoffeevarietiesrecommended for your area.

• Aim for 700–800 banana mats/ha, 2000–2400 Arabica trees/ha or 1000–1200 Robusta trees/ha.

44

tomakecropsgrowandyieldwell:incorporatingmoreorganicmatterintothesoil;moreuseoflegumestofixnitrogeninthesoil;morecarefulweeding,watermanagementandmanagementofpestanddiseases.Inthissectionwediscussthestepsthatneedtobetakentoensurethebestyieldofbananaandcoffee,startingwithsimpleagronomicmanagementpractices.

Canopy management

Canopy management means establishing the correct number ofbananaandcoffeeplantswithinthefieldandthenadjustingthe leaf area of the bananas, coffee trees and temporary and permanent shade by pruning, training and thinning to achieve the following: • Bananas provide the right amount of shade to the coffee trees. • Coffeetreesareprunedsothatbananasuckersreceivesufficientsunlighttodevelopproperly.

• Coffee trees are pruned so that stems are replaced continuously andsufficientlightpenetrateseachtreetostimulateflowering.

• Thematurebananaleafcanopyiswellabovethecoffeecanopy(e.g. 1 m above) and provides dispersed shade.

• Competitionbetweenplantsisreduced,pestanddiseaseattackarereducedandapplicationofagrochemicalsusingknapsacksprayers is convenient.

Banana canopy management

Replacementbananasuckersmustgrowupthroughthecoffeecanopy. Therefore the coffee should be pruned to ensure that emergingsuckersreceivesufficientlight.Etiolatedbananasuckers(plantsthatareweakandyellow)areasignthatnewlyemergedsuckershavebeenexcessivelyshadedbythecoffeeduringthefirstsixmonthsofbananasuckergrowth.As a result, the banana stem population may decrease and the coffeebecomesmoreexposedtofullsunlight,whichmayleadto

45

coffeedie-back.Each fully developed banana mat should at any time contain (see Photo 3, Figure 2): • a mother plant that is fruiting • a large daughter • a small granddaughter.Ifthemathastoomanysuckerstheyshouldberemoved.Suckersdrawonthecarbohydratesuppliedbythemotherstemandexcessivesuckerretention reduces the amount of carbohydrate available for bunch growth.Desuckeringshouldbe carried out very carefully to avoid damaging bunches.Dried leaves should be removed from the banana plants and used tomulchtheinter–rowspace(Photo 7).

Coffee canopy management

Both Robusta and Arabica coffee areusuallygrownasmulti–stemtrees to increase the amount of yieldbearingwood.Threetofourstems should be established oneachtreeby‘arching’(sometimescalledagobiado training) or ‘capping’youngcoffeetrees(Photos8).Maturecoffeetreesarepartlyself-shadingandrequirelessshadethan immature trees. In general, Arabica needs more pruning that Robusta.There are many different pruning systems for coffee but an overarching basic principle is that coffee berries are produced in

IITA

Photo 7. Removal of dead leaves frombananaplantsallowsgoodlightpenetrationforthegrowingbanana

suckersandthecoffeetrees.

46

greaterquantityonyoungwood.Therefore,eachyear,startinginthe second or third year of bearing, one stem is removed and a suckerretainedthatwillbecomeareplacementstem.Inthisway,thetreealwayscontainsthreetofourstemsthatarelessthan4years old.Eachyearalltreesshouldbe‘skirted’toremovelateralbranchesuptoaheightof0.5m.Thismakesiteasiertorecoverberriesthatfallonthegroundduringandbetweenharvests.Removingbranchesthat touch the ground stops insect pests from using these branches to climb onto the tree.Onmaturecoffeetrees,stemheightcanbemanagedbycappingeach stem 2 m from ground level or removing inner branches on eachstemtoencouragethestemstobendoutwards.UnwantedsuckersareremovedfrombothArabicaandRobustaatthree to four month intervals throughout the year.Acommonproblemoccurswhereoldcoffeetreesneedtoberejuvenated because annual pruning operations have not been carried out and the stems are old and unproductive. In such situations the trees can be stumped or the best stem is retained andallotherstemsremoved.Threetofoursuckersarethenretainedfromamongstthesuckersthatdeveloponthestumpandallowedtodevelopintostems.Afteroneyeartheremainingoldstem is removed and the tree is effectively rejuvenated.

Residue management

Inmatureplantations,someofthenutrientstakenupbyplantsarereturnedorrecycledtothesoilthroughleaf-fall,coffeeprunings,unwantedsuckersandbananapseudostemsfelledatbunchharvestand corms from banana. In addition, there may be prunings from shade trees, banana peels from locally consumed bananas and plantains,andcoffeehusksandpulpfromthecoffeepulpery.In addition to providing mulch cover, retaining these plant materialsintheplantationmeansthatlessexternalinputsare

47

B

C D

A

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IITA IITA

Photo 8. Coffee canopy management. (A) Young Robusta plant bent over by pegging toencouragegrowthofmultiplestems.(B) Capped stem of Arabica coffee to control height. Crop is mainly borne on secondary and tertiary branches. (C)Unwantedsuckersare continuously removed throughout the year. (D)Coffeetreesagewithtimeandproductiondeclines,andthemainstemsarecut-offtorejuvenatetreeandimproveproduction.

48

required to replace nutrients removed in harvested products (coffee berries, banana bunches) and to increase yields of coffee and bananas.Theamountofnutrientscontainedinsuckers,pseudostems,trashandleavesofbananaandleavesandhusksofcoffeeinaplantation yielding 10 t/ha/year fresh banana and 0.5 t/ha/year greenbeansofcoffee,isabout90kgN,10kgPand190kgKperha(Figure15),equivalenttoabout200kgurea,50kgtriplesuperphosphateand370kgpotassiumchloridefertilizer.Ifbananaresiduesareremovedfromthefarmandfedtolivestock,animalmanurecollectedfromthelivestockpenscanbereturnedtothefield.Nutrientsreleasedbydecompositionofsoilorganicmatterorweatheringfromthesoilmineralfractionisonlyasmallpart(lessthan10%)ofwhatisrecycledeveryyearwithcropresiduesandisinsufficienttomeetthecrops’requirementsforgood yields. For this reason, mineral fertilizers are required.Alwayskeepinmindthat: • Removalofplantpartsfromthefieldsdepletesthenutrientcapital contained in the banana–coffee system.

• Returning crop residues to the system, or feeding such residues tolivestockandthenapplyingmanurefromtheselivestocktothe system, recycles but does not add nutrients to the system (Photo 9).

• Applyingresiduesofcrops/plantsthathavebeengrownelsewheretothefield/farmaddsnutrientstothesystem(photo9).

• Grazinglivestockinotherfields(e.g.grazinglandsonhillsides)andusingmanurefromsuchlivestockonthefarmaddsnutrients to the system.

Apart from supplying nutrients, applying crop residues to the soil alsoprovidesbenefitsincludingthefollowing: • Conservation of soil moisture. • Mulch layer helps to reduce soil erosion on sloping land.

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BA

IITA

Photo 9. Crop residues. (A)Ifcropresiduesarefedtoanimals,recyclingnutrientsbackto the soil by applying manure can reduce on costs of fertilizer. (B) Both banana and coffeebenefitfromselfandexternalmulchlikegrass.

• Weedsuppressionandreducedrequirementforweedingoperations and therefore reduced soil disturbance and damage to banana and coffee feeder roots that lie close to the soil surface (Photo 10).

• Increased root development in the surface soil. • Replenishment of soil organic matter.

Fertilizer recommendations

BananaK

kg/h

a nu

trien

t

0

20

40

60

80

100

120

140

160

180

CoffeeN P N P K

Banana pseudostem, corm,suckers, fruit stalk

Banana trash, coffee husks Leaves

Fruit

Figure 15. Nutrient removal in banana–coffee systems.

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Photo 10. Bananabenefitsfromfertilizerappliedtocoffeeandcoffeebenefitsfromnutrients applied to banana as roots of both crops crisscross.

Allplantsrequireanadequatesupplyofnutrientstogrowandyieldwellandbananaandcoffeearenoexception.Forexample,young plants require phosphorus for root establishment and growth,andmatureplantsrequirepotassiumforfloweringandfruitfilling(Table8).Ifthesupplyofnutrientsisinsufficient,productiondecreasesandcoffeemaybeaffectedbydieback.Unlikelegumes,whichrequiredphosphorus,andcereals,whichrequirenitrogenandphosphorus, both banana and coffee need large amounts of potassiumaswellasphosphorusandnitrogen(Table8&9).Deficienciesofmacronutrientsnitrogen,phosphorus,potassium,sulphur, magnesium and calcium, and the micronutrients zinc, boronoriron,leadtotheappearanceofleafnutrientdeficiencysymptoms in banana (Photo 11) and coffee (Photo 12) that can be detectedinthefield.Nutrient requirements can be supplied as organic inputs (i.e. crop residues or animal manure), fertilizers or a combination of both.

51

Usingorganicinputsincombinationwithfertilizersmayincreasetheefficiencyoffertilizeruse.Inotherwords,whenfertilizersareapplied in the presence of organic residues, more of the nutrients containedinthefertilizeraretakenupbythecrops.Unlikefertilizernutrients,whicharereadilyavailabletoplants,organic inputs need time to decompose and release nutrients andarethereforea‘slowrelease’sourceofnutrientstoplants.ResidueswithanarrowC:Nratio(e.g.legumecropresidues)decompose and release their nutrient content more rapidly than materialswithawideC:Nratio(e.g.cerealstraw).Theconcentrationofnutrientsinorganicresourcesislowandtherefore much larger quantities of organic resources are required tosupplyagivenquantityofnutrientsbycomparisonwithmineralfertilizers.Forexample,freshgoatmanureonaveragecontains7kg/tPor16kg/tP2O5(seeLook-upTable1fornutrientcontentinmanuresandcropresidues,andLook-upTable2fornutrientconversionfactors). By comparison, one tonne of triple superphosphate (TSP) fertilizercontains200kgPor460kgP2O5. If the goal is to apply 50kg/haP2O5, this could be delivered in about 3 t goat manure or 109kgTSP.Ifthefarmerdoesnothavelivestockandplanstobuyanimalmanuresitisworthwhiletocomparethecostofnutrientsinfertilizers and animal manures and then select the least costly source.

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Table 8. Role of major nutrients in banana and coffee.

All plants Banana Coffee

N Vegetativegrowth Size of bunch, frequency of harvesting.

Crop bearing capacity, size of beans.

P Root development, energy reactions,flowering,seedandfruit development.

Size of bunch, amount of sugar in fruits, strength of stem.

Wood development, flowering, ripening,fruitsize,suckerdevelopment.

K Translocation of products of photosynthesis,waterbalance, disease resistance.

Numberoffingers/bunch,fruitfilling,fruitquality.

Fruit development, mucilage formation, fruit quality.

Ca Growthofterminalbuds, flowerformation,rootand leaf development.

Yield, fruit quality. Fruit ripening and quality.

Mg Photosynthesis,plantgrowth Hands per bunch, quality of fruit. Bean color.

S Formation of plant proteins Size of bunch. Bean color and aroma.

Bo Growth,metabolismofcarbohydrates,growthofnewshoots and roots

Flowering,fruitsetanddevelopment.

Cu Photosynthesis, development ofpigmentsthatinfluencecolor

Resistance to fungal diseases.

Cl Water balance, ionic balance, photosynthesis

Fe Chlorophyll formation Bean color and aroma.

Mn Chlorophyll formation Bunch size.

Mo Nitrogen metabolism

Zn Plantheight,leafsize,flower initiation and formation

Finger development.

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Table 9. Amount of nitrogen (N), phosphorus (P) and potassium (K) contained in different plant parts for production of 1 t of banana and 1 t coffee (green bean).

Crop and plant part Nitrogen Phosphorus Potassium

kg

Banana

Pseudostem,corm,suckers,fruitstalk 2.3 0.4 7.2

Leaves 0.5 0.1 0.6

Trash 1.6 0.2 2.0

Fruit 1.8 0.2 5.5

Total 6.2 0.8 15.3

Coffee

Leaves, stems 20.6 3.4 18.6

Green bean, parchment, pulp 33.9 2.5 40.5

Green bean 21.5 1.7 17.5

Total 76.0 7.6 76.6

The 4Rs + 1R for effective use of fertilizer

Therearefour‘rights’thathelpthefarmertogetthemostbenefitfrom fertilizers: • apply the right fertilizer product(s) • at the right rate • at the right time • in the right place.

Because fertilizers are costly inputs it is important also to prioritize theuseofscarcefertilizersonthecropthatwilldeliverthegreatest return on fertilizer inputs.Wenowreviewthefourrightsindetail.

54

The right fertilizer type

• Ifyouarenotsurewhichnutrientsyourcropsneed,inspectthecropforthepresenceofnutrientdeficiencysymptoms(Photos11and12).Youcanalsotakesoilandleafsamplesforanalysisatreputablelaboratory(seeboxforguidelinesonhowtocollectsoiland foliar samples).

• Use fertilizers that are suitable for the soil conditions, that have nutrients in available forms and that have the right combinations of nutrients required.

Suitable compound fertilizers for mature banana–coffee system should contain more K2OthanNandP2O5 (i.e. about 10% N, 3% P2O5 and 23% K2O).Unfortunately, the most common fertilizers available in local stores contain 20:10:10 and 17:17:17 of N:P2O5:K2O,whichare clearly not the most suitable fertilizers for the banana–coffee systems. It may therefore be necessary to apply ‘straight’fertilizersoracompoundfertilizertogetherwithadditional straight fertilizer. Alternatively, farmers can buy straightfertilizersandpreparetheirownmixturesimmediatelyprior to field application.

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A

D E

F G H

I J

B C

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IITA IITA

IITAIITA IITA

IITAIITA

Photo 11. Nutrientdeficienciesinbanana.(A)Ndeficiency,leavesturngreen,thenyellow.(B)LeafpetiolesandsheathturnpinkinNdeficientbanana.(C)Pdeficiency,leafmarginsturnscorchedbrown.(D)Kdeficiency,leafmarginsandtipsturnyellowfromtip,then orange, scorching along margins hangs. (E)AsscorchingonleavesofKdeficientplantsprogress,mid-ribisunabletosupportleaf,mid-ribbreaksandhalfofleafclosetotiphangsdownwards.(F)Plantssuppliedwithadequatenutrienthavemorevigorousgrowth(e.g.plantonextremeleft)thanplantdeficientinN(secondfromleft),P(thirdfromleft)orK(extremeright).(G)Mgdeficiency,lightyellowbandalongleaf.(H) In Mg deficientplants,leafsheathscanseparatefromthepseudostem.(I)DarkcoloralongleafmarginobservedinEastAfricanhighlandbananagrowinginsoilwithlowpH.(J)withoutmicronutrientsleavesareyellow(right)insteadofgreen(left).

56

B

C

A

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Photo 12. Nutrientdeficienciesincoffee.(A)YellowingofleavescausedbywithdrawalofNfromleavestomaturingcrop.Thesymptomiscommonduringthedryweather.(B) Pdeficiency,olderleavesgoyellow,thenred-bronze(red-purple).(C) Normal Leaf (left) andprogressionofPdeficiencysymptoms.

Box. Howtotakesoilandfoliarsamplesinbananacoffeesystems

How to take soil samples

1. Decideonasamplingpattern(e.g.every30mby30m)thatwilldeliverabout 10 subsamples per ha.

2. At each sampling point remove litter from the soil surface.

3. Use an Edleman soil auger to sample soil from 0–30 cm depth.

4. Mixthesub-samplesthoroughlytoproduceacompositesample.

5. Place samples in clean, labeled plastic bag.

6. Deliver the samples to the laboratory.

57

The right fertilizer rates

Itisdifficulttomakefertilizerrecommendationswithoutinformation on soil fertility and crop nutrient status: • The essential soil test parameters are soil organic carbon, total nitrogen,availableP,exchangeableKandMg,andsoilpH.

How to take foliar samples

Banana

1. Acompositesampleispreparedforeachfield.

2. Intercroppedbanana–coffeefieldscontain700–800bananaplantsperha.

3. Decideonasamplinggrid(e.g.every5thplantinevery5throwinnewlyestablished plantations) to provide about 15–20 sub–samples per ha.

4. Samplesareonlytakenfromfloweringplants.

5. Select the 3rd fully opened leaf.

6. Removeastripoftissue20cmlongby10cmwideonbothsidesofthe central vein in the middle of the leaf. The long side of the strip should be parallel to the central vein.

7. Place samples in clean, labeled paper bag.

8. Deliver the samples to the laboratory.

Coffee

1. Acompositesampleispreparedforeachfield.

2. Intercroppedbanana–coffeefieldscontainabout1000Robustaand2–2500 Arabica coffee trees per ha

3. Decideonasamplinggrid(e.g.every10thplantinevery5throwinnewlyestablished plantations) to provide about 15–20 sub–samples per ha.

4. Select four bearing lateral branches at mid–height of the tree.

5. Selectthe3rdor4thpairofnewlymaturedleavescountingfromthebranch tip from each of the four selected branches.

6. Place samples in clean, labeled paper bag.

7. Deliver the samples to the laboratory.

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Ideallysoilsamplesshouldbetakenateachfarmsiteoratleast at a representative farm site and analysed at a reputable laboratory.Soilscanthenbeclassifiedintermsofsoilfertilitystatus (Table 3).

• The essential foliar analysis parameters are nitrogen, phosphorus, potassium and magnesium. Information on micronutrients is useful but not essential because nutrient deficienciescanbedetectedbycropinspection.

ComparesitesoilandleafanalysisvalueswithTable3andTable10respectively,todeterminewhetherthesiteis‘lowfertilitystatus’or‘highfertilitystatus’.Suggestedrangesforfertilizernutrient application rates for immature coffee and banana and maturebanana–coffeesystemson‘lowfertilitystatus’and‘highfertilitystatussoils’areprovidedinTables13–16.Notethatdifferent recommendations are provided for different yield targets for each soil fertility status category.If the farmer plans to apply large quantities of organic resources (i.e. more than 5 t/ha) estimate the nutrient inputs provided intheorganicresourcesfromLook-upTable1andadjusttherecommended fertilizer rates accordingly.Worked hypothetical example: Soil analysis and banana leaf analysis data is available for a mature banana–Robusta coffee farminSouthwestUganda.Thepresentyieldis20t/habananaand1.5t/hagreenbeanwithbothcropproductssoldasacashcrop. The farmer purchases and applies 5 t/ha farmyard manure toherbanana–coffeefarm.Resultsofsoilanalysisshowthatthesoilsarepoorinallnutrientsexceptphosphorus(Table11).Leafanalysisshowsthatbananasaredeficientinnitrogenandphosphorus but leaf potassium status is above the critical value (Table 11).

59

Tab

le 1

0. C

ritic

al a

nd a

deq

uate

leaf

nut

rient

con

cent

ratio

ns fo

r b

anan

a an

d c

offe

e.

Ele

men

tU

nits

Ban

ana

Ara

bic

a co

ffee

Cri

tica

lA

deq

uate

Cri

tica

lA

deq

uate

N%

>2.

62.

8–4.

0>

2.2

2.5–

3.0

P%

>0.

130.

2–0.

25>

0.1

0.15

–0.2

0

K%

>2.

53.

1–4.

0>

1.5

2.1–

2.6

Ca

%>

0.5

0.8–

1.2

>0.

40.

75–1

.5

Mg

%>

0.2

0.3–

0.46

>0.

10.

25–0

.4

Cu

mg/kg

7–20

>10

16–2

0

Zn

mg/kg

>14

21–3

5>

1015

–30

Mn

mg/kg

>10

100–

2200

>25

50–1

00

Femg/kg

70–2

00>

4070

–200

Bmg/kg

>10

20–8

0>

2540

–100

Tab

le 1

1.S

oiland

leafanalysisdatafrom

afarm

insou

thwestUgand

acompared

withcriticalvaluesforsoil

par

amet

ers

and

ad

equa

te r

ange

s fo

r le

af a

naly

sis

dat

a.

Par

amet

erU

nits

Sit

e va

lue

Cri

tica

l v

alue

Ad

equa

te

ra

nge

So

il fe

rtili

ty s

tatu

s

Ava

ilab

le P

mg/kg

315

Low

Exchang

eableK

cmol/kg

0.4

0.3

Hig

h

Soi

l org

anic

car

bon

%1.

31.

7Lo

w

Tota

l nitr

ogen

%0.

120.

15Lo

w

Leaf

N b

anan

a%

2.3

>2.

62.

8–4.

0Lo

w

Leaf

P b

anan

a%

0.10

>0.

130.

2–0.

25Lo

w

Leaf

K b

anan

a%

3.3

>2.

53.

1–4.

0H

igh

60

Tab

le 1

2.W

orkedexamplefertilizerrecommendationsfo

rabanana–Rob

ustacoffeefarm

in

Sou

thwestUgand

a.

Uni

tsN

P2O

5K

2O

Rec

omm

end

ed r

ate

Firs

t Ye

arkg/ha

230–

280

60–8

023

0–27

0

From

sec

ond

yea

rK

g/ha

140–

160

35–4

514

0–17

0

Fert

ilize

r m

ater

ial

–U

rea

TSP

KC

l

Nut

rient

con

cent

ratio

n%

4646

60

Fert

ilize

r am

ount

Firs

t ye

arkg/ha

500–

610

130–

175

380–

450

From

sec

ond

yea

rK

g/ha

300–

350

75–1

0023

0–28

0

TSPistrip

lesup

erpho

sphate,K

Clispotassium

chloridealsokno

wnasm

uriateofp

otash

Tab

le 1

3. S

ugge

sted

fert

ilize

r ap

plic

atio

n ra

tes

for

imm

atur

e b

anan

a in

sub

–Sah

aran

Afr

ica.

So

il fe

rtili

tyYe

arN

P2O

5K

2OM

gO

g/t

ree

Hig

h1

6020

200

20

270

4025

025

Low

170

3026

025

290

8030

035

61

Thefarmer’stargetistoincreasebananaandcoffeeyields.Asalready mentioned, soil fertility status for nitrogen and phosphorus is poor. Therefore, for a target yield of 30 t/ha/year banana and 2.5t/ha/yearcoffee,therecommendationis230–280kg/haNand60–80kg/haP2O5(Table12)inthefirstyear.Soil potassium status is good and the recommendation for potassiumis230–270kgK2O/ha.Nutrientapplicationratesarethen converted into amounts of fertilizer (Table 12). In this case straight fertilizers have been used but a combination of compound and straight fertilizer could also be used.Fertilizerinputscouldbereducedbyabout50kgN,90kgP2O5and70kgK2Otoallowforthenutrientssuppliedin5t/hafarmyardmanureappliedtothebanana–coffeefield.The ratio of N:P2O5:K2Oisequivalentto10:3:23andacompoundwithsimilarnutrientcontentcouldbeusedinsteadofstraightfertilizers.Ifthefarmerlackstheresourcestoimplementtherecommendation in full, reduce the recommended rate to an amountconsideredaffordablebythefarmerwhilstmaintainingthesameratiobetweennutrients.Example: Calculation for straight and compound fertilizersThe nutrients can be from straight fertilizers (i.e. that supply one nutrient) or from compound fertilizers (i.e. that supply more than one nutrient).Forexample,ifthegoalistoapply232kg/haofN,62kg/haofP2O5and226kg/haofK2O.If using straight fertilizers, N can be supplied as urea (46% N), P as triple superphosphate (TSP) (46% P2O5), and K as potassium chloride (KCl) (60% K2O).Theamountoffertilizerrequiredwouldbe:

Amount of urea =x

=232 100

46503 kg ha/

Amount of TSP =x

=62 100

46136 kg/ha

62

Amount of KCl =x

=226 100

60376 kg/ha

If using compound fertilizers, a fertilizer that contains nutrients in the proportions close to those that are required should be selected. Forexample,ifthenutrientsrequiredabovearetobesuppliedbyacompoundfertilizer,agoodchoicewouldbeNPK18:4:12,containing 18% N, 4% P2O5 and 12% K2O,whichisamongthe‘coffeefertilizers’recommendedinKenya.Thecalculationwouldbe:

Amount of NPK18 4 12232 100

181286: : =

x= kg/ha

Thiswouldprovideabout232kgN,51kgP2O5and154kgK2O.Theshortfallof11kgP2O5and71kgK2Ocanbeprovidedbyapplying24kgTSPand119kgKClperha.Ingeneral,firstdeterminetheamountsofnutrientsrequired,thencheckwhichofthefertilizersavailableonthemarketcansupplythenutrientsthatyourcropneedsandfinallyselectfertilizersthatprovidetherequirednutrientsatthelowestcost.A calibrated measure should be used to apply fertilizer accurately toeachplant.Forexample,asoda–bottlecapcontains5–6gfertilizer.Calibratedcupscanalsobemadefromtinsandwashingpowdercontainers.Suchmeasurescanbecalibratedroughlybycounting the number of soda–caps of fertilizer that are required to fillthereceptacle.Whenapplyingfertilizerinamaturebananaplantation,newlyintercroppedwithyoungcoffee,ormaturecoffeenewlyintercroppedwithyoungbanana,fertilizercanbeappliedtothetwocropsseparatelyinthefirsttwoyearsoftheintercrop(seeTable 15 for proposed recommendation for the mature crop and Tables 13 and 14 for immature crop). In mature banana–coffee intercrops fertilizers can be applied to both crops at once by broadcasting the fertilizers over the soil surface.

63

Table 14. Suggestedfertilizerratesforimmaturecoffeeinsub-SaharanAfrica.

Crop Soil fertility status

Year N P2O5 K2O MgO

g/tree

Arabica coffee

High

1 20 5 20 5

2 30 10 30 10

3 50 15 50 15

Low

1 30 10 30 10

2 50 15 50 15

3 90 25 90 25

Robusta coffee

High

1 40 10 40 10

2 60 20 60 20

3 120 30 100 30

Low

1 60 20 60 20

2 100 30 100 30

3 180 50 180 50

Table 15. Suggested fertilizer application rates for mature banana–coffee systems in sub–Saharan Africa.

Deficiencies Crop Yield increase (t/ha) N P2O5 K2O MgO

Banana Coffee kg/ha

First year

N, P, K Banana-Arabica 10 0.5 170–200 50–65 380–460 30–35

Banana-Robusta 10 1 230–280 60–80 450–550 40–45

P Banana-Arabica 10 0.5 170–200 50–65 190–230 30–35

Banana-Robusta 10 1 230–280 60–80 230–270 40–45

K Banana-Arabica 10 0.5 170–200 25–30 380–460 30–35

Banana-Robusta 10 1 230–280 30–40 450–540 40–45

From the second year

N, P, K Banana-Arabica 10 0.5 100–115 25–35 230–270 14–17

Banana-Robusta 10 1 140–160 35–45 280–330 18–21

P Banana-Arabica 10 0.5 100–110 25–35 110–140 14–17

Banana-Robusta 10 1 140–160 35–45 140–170 18–21

K Banana-Arabica 10 0.5 100–110 11–20 230–270 14–17

Banana-Robusta 10 1 140–160 15–25 280–330 18–21

64

The right time for application

Applyfertilizerwhensoilismoist,duringtherainyseasons.To minimise losses, fertilizer N application should be applied intwosplitapplications–forexampleatthebeginning,theninthemiddleoftherainyseason(about2monthsafterthefirstapplication). It is not usually necessary to apply phosphate and potash fertilizers in split applications as they are released more slowly.

The right placement of fertilizer

Fertilizer should be applied over thesoilsurfacewherefeederrootsare found (Photo 13). Remove trash onthesurfacewherefertilizeristobe applied, apply fertilizer and then replace the trash.Foryoungbananamats,makeafurrowabout30cmfromthemat.Placefertilizerinthefurrowandcoverwithsoil.Ifthemotherplanthas a bunch approaching maturity, apply fertilizer to the daughter and granddaughter.Donotworkthefertilizerintothesoilusingahoeas you may damage roots of the crops.For fertilizer N in young coffee plants, apply under the leaf canopy, extendingupto20cmbeyondthedrip-line.Inmatureplantationswherecanopiesofbananaandcoffeeoverlap,applyunderandbetweenbananamatsandcoffeeplants.Do not apply fertilizer too close to banana mats (i.e. at least 30 cm from the mat).All fertilizers should be spread evenly over the target zone – fertilizersappliedinlumpsmayburnthecrop’sroots.

IITA

Photo 13. Nitrogen fertilizer applied inafurrowaroundthecoffeetree,thencoveredwithsoil,canbeaccessedbyroots of banana.

65

Tab

le 1

6.S

uggested

fertilizerap

plicationratesfortargeted

yieldincreaseinm

aturebananaintercropped

withyou

ng

coffee,and

maturecoffee(ArabicaorRob

usta)intercrop

ped

withyou

ngbanana.Thefertilizerratesforimmaturecrop

sre

mai

n as

sug

gest

ed in

Tab

les

13 fo

r b

anan

a an

d T

able

14

for

coffe

e.

Defi

cien

cies

Mat

ure

cro

pY

ield

incr

ease

(t

/ha)

NP

2O5

K2O

Mg

O

kg/h

a

Firs

t ye

ar

N, P

, KB

anan

a10

100–

125

35–5

030

5–37

025

–30

Cof

fee

112

5–15

525

–35

145–

175

15–2

0

PB

anan

a10

100–

125

35–5

015

5–18

525

–30

Cof

fee

112

5–15

525

–35

75–9

515

–20

KB

anan

a10

100–

125

20–2

530

5–37

025

–30

Cof

fee

112

5–15

510

–15

145–

175

15–2

0

From

the

sec

ond

ye

ar

N, P

, KB

anan

a10

55–6

520

–25

175–

210

10–1

2

Cof

fee

180

–100

15–2

010

0–12

58–

9

PB

anan

a10

55–6

520

–25

85–1

0510

–12

Cof

fee

180

–100

15–2

050

–60

8–9

KB

anan

a10

55–6

59–

1117

5–21

010

–12

Cof

fee

180

–100

8–10

100–

125

8–9

66

The right crop for fertilizer

Farmerswithlimitedcashtoinvestinfertilizersmustdecidewhichcropwillgivethegreatestreturnonfertilizerapplication.Fertilizerscan be applied separately to each crop during the immature growthphase(Table12and13).Inmaturebanana–coffeeintercrops,however,itisnotreallypracticabletotargetfertilizerstooneorotherofthetwocropsbecause by the time the system has started to yield, root systems ofbothcropswillhaveformedanoverlappingcontinuouswebofroots.Therefore,aswithmulchandanimalmanure,thebestapproach is to broadcast fertilizers over the soil surface under the banana–coffee system.Notethatalthoughgenerallyapplyingfertilizermakescropshealthier,applyingexcessiveamountsofnutrientscanmakeplantsunhealthy(Table17).Monitoryourcropcloselyandseekadvicewhennecessary.

Key checks

Prune banana and coffee to ensure that the coffee canopy remainsbelowthebananacanopy.

Replaceoldcoffeestemswithnewsuckerssothatbearingstemsarealwayslessthan4yearsold.

Leavepruningsonthegroundandreturnnon-edibleplantmaterials to the plantation.

Applyfertilizerstoaddressnutrientdeficienciesandmeettargeted yields, as recommended.

Compound fertilizers for mature banana–coffee system should contain more K2OthanNandP2O5 (i.e. about 10% N, 3% P2O5 and 23% K2O).

67

Table 17. Effectofexcessiveapplicationofnutrientsonbananaandcoffee.

Banana Coffee

N Bunchesaresmaller,breakbeforematurationandhave reduced green life after harvest.

Excessivevegetativegrowth,pooryields

P MayinduceMg,Zndeficiency. MayinduceZnorFedeficiency.

K MayinduceCa,Mgdeficiency. MayinduceMgdeficiency.

Mn ReducesuptakeofCa,MgandZn,maypredisposeconditionof‘mixedripe’i.e.harvestedfruit ripen prematurely.

Scorching of older leaves.

Cl Fruitnotfilled Scorching of older leaves.

Cu Stunted roots Fe chlorosis, stunted roots.

Fe Blackmarginsofleaflamina. Mndeficiency.

Mn Blackmarginsofleaflamina Leafchlorosis,brownspots.

Zn Fedeficiency.

Al Leaf chlorosis.

Na Marginal chlorosis and necrosis of leaves.

B Marginalpalingofleaveswithnecrosis. Mottled leaf margin and chlorosis near leaf margins. Purple base of leaf midrib.

68

6. What can go wrong?

Pest and disease management

Pests and diseases can damage roots, stem and leaves of plants therebyaffectinguptakeofnutrientsandwaterfromthesoil,movementwithintheplantandphotosynthesis.Pestsanddiseasescan also damage the fruits directly.

Pests

Themostimportantpestsforbananaareweevils,whichdamagethecorm,andnematodeswhichdamagetheroots(Photo14).For coffee, some of the most important pests are coffee berry borer, antesiabugs,twigborers,scales,stemborersandmealybugs,whichcanattackaerialpartsoftheplantorroots(Photo15).

Diseases

Therearetwonewdiseaseswhichhavebecomemajorthreatstobanana production.ThebananaXanthomonaswilt(BXW)(Photo16),whichiscausedby a bacterium, has been spreading in East and Central African region. The disease has been reported in Ethiopia, Uganda, Kenya, Rwanda,DRCandTanzania.Bananabunchytopdisease(BBTD)(Photo16),whichiscausedbya virus, has been reported in Central, South and North Africa.Otherimportantdiseasesofbananaarebunchy-top,fusariumwilt(Panamadisease),bananastreakdisease,bananamosaicdisease,yellowsigatokaandblacksigatoka(Photo16).For coffee, some of the common diseases are coffee berry disease (CBD,afungaldiseasemainlyinhigh,wetandcoolaltitudes),coffeeleafrust(CLR,fungal,lowaltitude),bacterialblightofcoffee(BBC)andcoffeewiltdisease(CWD,alsoknownasFusariumwiltor Tracheomycosis,whichaffectsbothArabicaandRobustacoffee)(seePhoto17forexamples).Coffeewiltdiseasehasincreasingly

69

A B

DC

IITA IITA

IITAIITA

Photo 14. Pests of banana. (A)Thebananaweevilwhoselarvaeboreintothecormcausing damage and subsequently affecting movement of nutrients in the plant. (B) Cormdamagedextensivelybythebananaweevillarvae.(C) Root nematodes damage rootsaffectinguptakeofwaterandnutrients(left-healthyroot,right-damagedroot).(D) Serious root damage by nematodes can cause plants to topple.

70

A B

D E

G H

F

C

IITA IITA IITA

IITA IITA IITA

IITA IITA

Photo 15. Pests of coffee. (A)Femaleberryborersmakeholesonberriesandlay eggs inside. The eggs hatch into larvae inside the berries, larvae feed on berry causing damage. (B) Berry damaged by berry borer. (C) Larvae of the berry borer. (D)Asmallholemadebythefemalecoffeetwigborer.(E)Thetwigborerisasmallflying insect that spreads fast and is difficult to control. (F) The borer lays eggs insideatwig,andtheeggshatchintolarvae.Theinfectedtwigstartsdryingupfromthedamagedparttowardsthetipofthetwig.(G) Damaged by the stem borer, can causeleafyellowing,anddryingofyoungplants.(H)Scalessuckmoisturefromplantsandproducehoneydew.Thehoneydewencouragesgrowthofsootymould,whichreducesthephotosyntheticareaonleaves.

71

A B

D E F

C

IITA IITA IITA

IITA IITA IITA

Photo 16. Diseases of banana. (A)BXWattackshighlandandexoticbananacausingyellowingofleaves.(B) Premature ripening of fruit due to BXW. (C) Wilting of male bud duetoBXW.(D)andyellowoozeinstemduetoBXW.(E)Fusariumwiltattacksexoticbananascausingyellowingofleaves,andcollapsingofleavestoforma“skirt”aroundthe pseudostem. (F) Bunchy top due to banana bunchy top virus. If severe, plants do not fruitorcanformfruitswithdeformedfingers.

72

A B

DC

IITA IITA

IITA IITA

Photo 17. Diseases of coffee. (A)Berriesinfectedwithcoffeeberrydiseasebecomedark,andmayfalloff.Thefunguslivesinthebarkofthetree.Diseaseismorecommonly found in Arabica. (B) Red spots on green and ripe berries, caused by the “red blister disease” (Cercospora coffeicola). The disease can cause premature fall of berries and leaf defoliation. The disease is more commonly found in Robusta coffee. (C) Atwo-stemcoffeetreeinfectedbycoffeewiltdisease.Thestemonthelefthasdriedupduetodiseasewhilethatontherightisyettoshowsymptoms.(D) coffee leaf rust, more commoninlowaltitudes(e.g.seriousinArabicagrowninwarmhumidconditionsbelow1500), can cause shedding of leaves and lead to reduces yield.

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become a major constraint to Robusta production in DRC, Tanzania and Uganda.

Control of diseases and pests (IPM)

Thebestwayofcontrollingpestsanddiseasesisbyuseofacombinationofmanagementpracticestogetherwiththeuseofresistantvarieties,referredtoas‘integratedpestmanagement’(IPM).At planting, use pest– and disease–free planting materials and, ifpossible,useresistantplantingmaterials.Forexample,somebanana hybrids (e.g. FHIA 17 and FHIA in East Africa and PITA14, PITA17 in West Africa) are available that are more resistant toblacksigatokadiseaseandproducelargerbunchesthantraditional varieties.After crop establishment, monitor the crop closely for the presence of pests and diseases by carrying out regular crop inspections. When pests and diseases are detected early, control measures may only be required over small areas and economic damage to the crop is small.Alsobeonthelookoutfordiseasesandpestsintheneighbouringfieldsorinthesurrounding area.Control diseases and pests using the recommended methods (see Appendix1–8forfarmer-friendlyextensionmaterials).Some pests transmit disease from planttoplant.Forexamplebananastreakdiseaseisspreadbymealybugs and banana mosaic disease can be spread by aphids. Therefore control of pests can often reduce the spread of diseases.

IITA

Photo 18. Cutting the male bud after floweringcontrolsspreadofdiseases

likeBXW.

74

Removethemalebudfrombananaswhenfloweringhascompleted (Photo 18). This stops insects that transmit diseases likecigarendrot(afruitdisease)andBXWfromvisitingtheflowers.If using chemicals, apply insecticides and fungicides that are recommended(seeexamplesofinsecticides(Table18)andfungicides(Table19)foruseincoffeeandfollowinstructionsonpackfortheiruse.Usethechemicalssafely(seePhoto19andbox).

Table 18. Examplesofinsecticidesthatcanbeusedtocontrolinsectpestsincoffee.

Insect pest Chemical Additional management practices

Coffee berry borer Endosulfan, Chlorpyrifos, Fenitrothion, Fenthion

Timely harvesting of ripe berries, placing tarpaulin on ground at harvesting to catch berries that fall, removing and destroying old dried berries left on trees and on ground after harvest period

Stem borer Fipronil Good crop management, uprooting and destroying infested trees

Twigborer* Imidacloprid Pruning and destroying of infected plant parts, good canopymanagement,keepingfieldsweed-free

*Theadulttwigborercanfly.So,controlshouldbeinallcoffeefieldsinaninfestedareatoavoidre-infestationfromneighboringfields.

Table 19. Examplesoffungicidesthatcanbeusedtocontrolcoffeeberrydisease(CBD),coffeeleafrust(CLR),bacterialblightofcoffee(BBC)andcoffeewiltdisease(CWD).

Disease Chemicals Other management practices

CBD Azoxystrobin+Chlorothalonil,Pyraclostrobin, Chlorothalonil Fluazinam

For CBD, CLR and BBC, good canopy management through regular pruning and desuckering,regularchangeofcycle,plantingresistant varieties if availableCBD, CLR Dithianon, Cupric chloride (green copper)

CBD, CLR, BBC Cuprousoxide(redcopper),Cuprichydroxide(bluecopper)

CWD* - ForCWD,plantingdisease-freematerials,uprooting and burning infected plants, planting resistant varieties

*Pathogenlivesinsoil,difficulttocontrolusingchemicals

75

Nutrition and pest and disease pressure

Althoughresearchfindingsontherelationshipbetweennutrients and pest pressure are notalwaysconclusive,plantsarebetterabletowithstandpestanddiseaseattackswhensuppliedwithanadequatesupply of nutrients.Pests and diseases have often been thought to be the major constraints to production of banana and coffee, but an increasing body of evidence suggests that pests and diseases are largely secondary problems.The primaryconstraintstoproductionaredeficienciesofnutrientsthatrenderthecropsweakandsusceptibletodamage.Inthecaseofbanana,weevilandnematodedamagecanbeveryapparentonweakplants,butmaynotbethemaincauseofpoorgrowth.Inaddition,itisimportanttomaintainawellventilatedcanopy by proper pruning of both coffee and banana.Inthecaseofcoffee,leafrustislessprevalentinplantsgrownonmoderatelyacidicsoilswithadequatefertilizerinputscomparedwithcropsgrownonmoreacidsoilswithinsufficientfertilizer.

General management

Keepthefieldsweed-freetoreducecompetition.Weedscanbecontrolledbymulching,hand-pullingorsprayingwithherbicides(Table 20).Thebanana–coffeesystemdoeswellinsoilswithadequatedrainage(i.e.soilsthatallowmovementofairandwater).Ensurethatsufficientdrains(0.5–1.0mdeep)havebeeninstalledtoprovideadequatesoildrainageandtopreventwaterstandinginthefieldaftermajorrainfallevents.

IITA

Photo 19. Herbicide damage on leaves canbeconfusedwithnutrientdeficiencies.

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Usepegsortwinetosupportbananapseudostemsthatarecarrying bunches and prevent them from toppling over before the fruits are ready for harvesting (Photo 20).In large plantations, bananas are bagged to prevent damage by animals before harvesting. Smallholder farmers do not bag their producebecausetheytargetthelocalmarket.Butifproducingforexport,theytooneedtobagbananabunchestomeetexportquality requirements.Inmatureplantations,rootsofRobustacanformathickmassclosetothebananaandinterferewithgrowthofbananarootsleadingtoexcessivecompetitionbetweenthetwocrops.Ifthematistoothick,disturbthesoilaroundthebananatodamagesomeofthecoffeeroots.Forexample,inUgandaithas been found that loosening the soil around banana mats usingaforked-hoehelpstocontrolthegrowthofcoffeeroots.

Harvest

A substantial amount of the crop yield produced can be lost ifharvestingisnotdonecorrectly.Tomakesurethatlossesatharvest are minimal, harvest at the right time, using the right method and handle the harvest carefully.Banana cannot be stored for long periods after harvesting becauseripeningisrapidfollowingbunchharvest.Mostmatswillproducebunchesataboutthesametimeatthefirstharvestaftersuckerplanting.Insubsequentyears,as‘daughter’replace‘mother’plants,bunchesareharvestedthroughouttheyearwithapeakcropseasonfollowingfloweringintherainyseason.Coffee,ontheotherhand,isharvestedduringflushesandtheberries are either sold to the processing plant or dried on a tarpaulin and stored for sale at a later date.Harvestcoffeeonceperweektoavoidlossesofoverripeberries.

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Box. Guidelines for safe use of agricultural chemicals

1. Place of purchase

• Purchasechemicalsfromlicensed/registereddealers

• Pesticideshouldbeaccompaniedbyaninformationleafletonguidelinesonproperuseandhandling of chemical

• Donotusebannedorprohibitedchemicals.Ifunsure,consultyourlocalagriculturalagent,orbuyers of your produce

2. Choice of chemical

• Usethecorrectchemicalforcropandpest.Followinformationleafletonpestandcrop

• Userecommendedchemicalsthatareacceptedinthemarket.Confirmwithyourlocalextensionagent or buyer of coffee

3. Correct timing

• Followguidelines.Checkhowmanydaysyoumustallowbetweensprayingandharvesting

4. Correct quantity

• Applytherecommendedquantities

5. Correctmixing

• Followguidelinesoncompatibilities

6. Correct application

• Followguidelinesoncorrectapplicationmethod

7. Correct handling

• Wearprotectiveclothingcoveringbody,headandfacetopreventcontactwithskin,eyes,orinhaling.Donotfaceintothewindwhenspraying.

• Keepmaterialsforhandlingspillagesreadyforuseifneeded

• Washoffchemicalthatcomesintocontactwithbodywithwaterandsoap

• Washyourhandswithsoapandwaterbeforeeating,smokingorgoingtothetoilet

• Batheandchangeclothesafterspraying

• Washcontainersusedtomixandspraychemicals

• Visitdoctorifsickafterspraying.Providedoctorwithnameofchemicalandtheinformationleafletfor chemical to read.

8. Disposal of chemicals and containers

• Disposeexcessdilutedchemicalaspermanufactures’guidelines

• Donotleaveemptycontainerslyingaround

• Followmanufacturers’instructionsondisposal

9. Storage and storage period

• Storepesticidesawayfromhumanandanimalfood,awayfromchildren,inlockedplace,withwarningsigns

• Keepchemicalsintheiroriginalcontainers

• Storageforperiodrecommendedbymanufacture.Donotuseafterexpirydate

10. Records

• Keeprecordsofchemicalsused,whenused,whereused

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Bananasareharvestedgreenbutonlywhenthefingershavefilledproperly.Ifbunchesaretobesold,checkthefieldonceeachweektodeterminetheamountofcropthatwillbereadyeachweeksothatharvestandcropcollectioncanbearrangedingoodtime.To reduce harvest losses of banana: • Harvestwhenfingersarefullbutstillgreen. • Cutthepeduncle(i.e.thestalkconnectingthebunchtothepseudostem) carefully above the last hand. If the bunch is cut offabovethehookedpartofthepeduncle,thehookcanserveasahandlewhenliftingthebunch.Wherethisisnotnecessary,leaveasmuchofthestalkinthefieldtoreducenutrientremovalandtheweightofmaterialtobetransported.

• Lowerthecutbunchtothegroundcarefully,avoidbruisingafterharvest and store in a cool place.

To reduce harvest losses in coffee: • Pickonlyripe,redberries(Photo21).Leavegreenberriesonthetree to ripen.

• Avoiddroppingberriesontothesoilsurfacebycarefulpickingandharvestingthefieldeverysevendays.Harvestingismucheasierwhencoffeetreesareproperlypruned.

Table 20. Examplesofherbicidesthatcanbeusedtocontrolweedsin banana–coffee system.

Chemical Types of weeds controlled When to apply

Glyphosate Non-selective,controlsgrassesandbroad-leafedplants Appliedtoweedsaftertheyemerge

Sulfosate Non-selective,controlsgrassesandbroad-leafedplants Appliedtoweedsaftertheyemerge

Glufosinate-ammonium

Non-selective,controlsgrassesandbroad-leafedplants Can be applied to soil to prevent emergenceofweeds,andalsobeappliedtoweedsaftertheyemerge

*Avoid herbicide drift to banana and coffee plants

79

• If coffee is to be sold as dried berries, dry the ripe berries soon after harvesting.Dryaboutfor3–5weekson a good quality canvas tarpaulin, turn the coffee as it dries and store dried beans in a cool dry environment. Ifrainsfallwhenthecoffeehasbeenspreadouttodry,coverthecoffeewitha tarpaulin or move to shade to avoid re-wetting.Berriesbecomemouldyifthey are not dried properly (Photo 21). Moulds cause taints to the taste of coffee, discolour or even form poisons inthebeansandthereforelowerthequality of coffee

• Ifthecoffeeissoldtoapulperymakesure the quality of berries meets the required criteria (i.e. limits on dirt content, number of green berries). IITAPhoto 20. Bunch bearing

plants, can be supported using pegs, to prevent

them from toppling.

80

A B

D

C

IITA

IITA

IITA IITA

Photo 21. Coffee harvesting and drying. (A) Harvest ripe berries carefully and place in a dry container. (B) For dry processing, dry berries in the sun on clean surface (e.g. tarpaulin) before delivery to the collection point. (C) Sometimes harvesting is in the rainy season (e.g. in parts of Uganda), drying can be a challenge. Berries harvested on different daysshouldbedriedseparatelytoavoidre-wetting.(D) Berries go mouldy and lose qualityiftheyarecontaminatedwithsoilorarenotdriedproperly.

81

Key checks

Use pest– and disease–free planting materials and, if possible, use resistant planting materials.

Monitor the crop closely for the presence of pests and diseases bycarryingoutregularcropinspections:whenpestsanddiseases are detected early, control measures may only be required over small areas and economic damage to the crop is small.

Beonthelookoutfordiseasesandpestsintheneighbouringfieldsorinthesurroundingarea.

If using chemicals, apply insecticides and fungicides that are recommendedforuseincoffeeandalwaysfollowinstructionsonpack.

Keepfieldsweed-freetoreducecompetitionbymulching,hand-pullingorsprayingwithrecommendedherbicides.

In mature plantations of Robusta, if the mass of roots is too thick,disturbthesoilaroundthebananatodamagesomeofthecoffee roots.

Harvestbananabuncheswhenfingersarefullbutstillgreen,andcoffeeberrieswhenripeandred.

Handle harvested banana bunches and coffee berries as requiredbythemarket.

82

7. Economic analysis

Beforeintroducingnewfarmingpractices,itisimportanttohaveanideaofthekindofbenefitsthatwillbeobtained.Oncethetechnologyhasbeenintroduced,actualbenefitsobtainedcanthenbecalculated.Thebenefitscanbeintermsofyieldincrease,reduction in investments (e.g. on time and labour) and increased profitability.Thelikelybenefitsofanewtechnologyarecalculatedbasedonestimateddatawhileactualbenefitsarebasedonactualdatacollectedonintroductionofthenewfarmingpractice.Belowaresomesimplecalculationsthatcanprovideusefulinsightsintothelikelycostsandbenefitswhileneedingonlyaminimal amount of data/information.

Agronomic benefits

The agronomic efficiency (AE)offertilizer,whichistheeffectofaunit of nutrient applied on yield, can be calculated as:

AEY Y

Amount of nutrient appliedfert no fert=-( )

Where Yfert is yield of fertilized crop, Ynofertisyieldofcropwithoutfertilizer,yieldandamountofnutrientcanbeinkg/ha,orkg/acre.Forexample,ifYfertwas2217andYnofertwas1249formono-croppedcoffee,and200kgofureawasappliedtosupplynitrogen(urea has 46% nitrogen), then:

Amount of nitrogenapplied =x

=200 46

10092

and

AE =−

=( )

.2217 1249

9210 5

So,foreverykgofNapplied,anadditional10.5kgcoffeewasproduced.

83

Economic benefits

The economic returns from investments in fertilizer can be estimated by calculating the amount of yield required to buy one kilogramoffertilizer.Thisiscalledtheinput/output price ratio and is calculated as:

input output price ratioP

Pfert

yield

/ =

Pfert ispriceofonekgoffertilizerandPyieldispriceofonekgofyield.ForexampleifPfertwasUSD1.2andPyieldwasUSD0.07forbanana, then

input output price/..

.= =1 20 07

17 1

To estimate the return on investments in fertilizer, the value of additionalyieldwithfertilizercanbecomparedwiththecostoffertilizer. The value/cost ratio (VCR),alsoknownasthebenefit cost ratio, is calculated as:

( )VCR

Y Y P

Amount of fertilizer applied Pfert no fert yield

fert

=- x

x

Yieldsandamountoffertilizercanbeinkg/haorkg/acre,andpriceperkg.In the intercrop system, the returns to money invested in fertilizer can be calculated as:

( )VCR

Y Y P Y Yfert no fert yield fert no=[ ] + -(

Banana

ffert yieldP

Amount of fertilizer applie

)x[ ]

Coffee

dd Pfertx

- x

As a rule of thumb, a value/cost ratio greater than 2 is needed for an investment to be economically attractive to farmers.

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Ifadditionalinformation,forexampleoncostsoflabour,weeding,pruning,de-suckeringandpestcontrolisavailable,moredetailedcalculationscanbecarriedout.(SeeTable21,belowforexampleonuseoffertilizerinmono-cropsandinter–crops).

Table 21. Economicbenefitsoffertilizeruseincoffeemono-cropsandbanana-coffeeintercrops in Robusta system.

Mono-crop Intercrop

Without fertilizer With fertilizer Without fertilizer With fertilizer

Priceofcoffee($/kg) 1.03 1.03 1.03 1.03

Priceofbanana($/kg) 0.07 0.07 0.07 0.07

Yieldofcoffee(kg/ha/year) 1249 2217 1088 2197

Yieldofbanana(kg/ha/year) 9271 11071

Cost of fertilizer

Purchase 243 193

Transport 4 3

Labor for application 3 3

Calculations:

Value of coffee 1249 × 1.03 = 1286

2217 × 1.03 = 2283

1088 × 1.03 = 1120 2197 × 1.03 = 2262

Value of banana 9271 × 0.07 = 649 11071 × 0.07 = 775

Total value of system 1286 2283 1120 + 649 = 1769 2262 + 775 = 3037

Total cost of using fertilizer 243 + 4 + 3 = 250 193 + 3 + 3 = 199

Change in value of yield(s) withfertilizeruse

2283-1286=998 3037-1769=1268

Value cost ratio (VCR) for fertilizer use

998 ÷ 250 = 4.0 1268 ÷ 199 = 6.4

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Certification schemes

Certificationandverificationschemesforcoffeecanhelpimprovequality and therefore the price of produce sold. Find out if such schemesexistinyourlocationandjoin.Ifnoneexist,explorewithneighbouring farmers the possibility of joining such schemes. CoffeecertificationschemescurrentlyfoundinSSAinclude‘Fairtrade,‘RainforestAlliance’and‘UTZcertified’.Choosecertificationschemesthatcontributetoincreasedproductivityaswellassustainability!

Integration into the farming system

Whilstfarmerscangetbetterreturnsbygrowingbanana–coffeetogether, the system can have impacts on other enterprises or activities on the farm. There are several issues that should be takenintoconsiderationwhentailoringthecroppingsystemintothe farming system:

Nutrient use efficiency

Veryfewfarmersapplymineralfertilizerstobanana,despiteclear evidence that moderate applications can double yields. By contrast, farmers recognise the need for fertilizers on coffee. Whenintercroppedwithcoffee,thebananacanscavengefertilizernutrientsthatarenottakenupbythecoffeecrop.Theefficientuse of the applied nutrients that results contributes to both cash income from coffee and enhanced banana production.

Labour

Unlikeannualcrops,thebanana–coffeecroppingsystemrequireslabour throughout the year. It is therefore more labour demanding andcancompetewithotheractivitiesonthefarm.Itisimportanttoplantheactivitiesonthefarmwellsothattheavailablelabourisusedefficiently.

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Livestock and nutrient cycling

Banana–coffeeintercropsperformwellinregionsthatarealsosuitableforlivestock.Often,farmsaresmallandfarmerscannotgrowsufficientfodderforlivestock.Insuchcases,cropresiduesfromthebananasmaybefedtolivestockratherthanretainedinfieldasmulch.Wherebananaresiduesarefedtolivestock,mostof the nutrients contained in the residues can be returned to the banana–coffee system as animal manure. Coarse grasses that arenotsuitableforfeedingoflivestockoroldthatchcanbeusedas an alternative source of mulch material.

Risk

Before introducing the banana–coffee system, remember that unlikeannualcroppingsystem,thebanana–coffeesystemispermanent.Onceestablished,itisnoteasytochangetoanothercropping system.Whenfacedwithpoorpricesofcoffee,somefarmerslettheircoffeegrowwild,thenrehabilitatewhenpricesimprove.Butinthebanana–coffeesystem,itmaybebesttocutbackthecoffeetreestorejuvenatethetreeswhencoffeepricesarepoor.

Synergy

Thesystemcanbeintroducedwithoutnecessarilyaffectingproductionofannualcropsinthefirstyear.Whenbananaandcoffee are young, farmers can continue to plant other crops in the fieldasbefore.Thebanana–coffeesystemcanalsobenefitfromthe annual crops.Forexample,ifcoffeeseedlingsareplantedwithinatomatofield,copper sprayed on tomatoes also controls diseases in the young coffee.Iftheannualcropisalegumethatfixesnitrogen,bananaandcoffeecanbenefitfromtheimprovedsoilfertility.

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Key checks

Keepgoodrecordsforuseincalculationofbenefitsandcosts.

A value/cost ratio greater than 2 is needed for an investment to be economically attractive to farmers.

Choosecertificationschemesthatcontributetoincreasedproductivityaswellassustainability!

Before introducing the banana–coffee system, remember that unlikeannualcroppingsystem,thebanana–coffeesystemispermanent.Onceestablished,itisnoteasytochangetoanother cropping system.

Whenfacedwithpoorpricesofcoffee,itmaybebesttocutbackthecoffeetreestorejuvenatethetreeswhencoffeepricesare poor.

When banana and coffee are young, farmers can continue to plantothercropsinthefieldasbefore.Thebanana–coffeesystemcanalsobenefitfromtheannualcrops.

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8. Conclusions

Inthisguidewehavedescribedthecharacteristics,use,advantages and disadvantages, and soil and climate requirements of banana–coffee intercropping systems in Africa. Yield gap is a usefulwaytoinvestigatethepotentialforyieldimprovementataparticularsite.Wereviewedthefieldpracticesforestablishingbanana–coffeesystemseitherasnewfarmsorbyintroducingbanana in coffee farms or vice versa.We have described the use of integrated soil fertility management to improve the productivity of banana–coffee systems by focusing on the use of suitable high quality germplasm, proper plant spacing to achieve a balanced canopy of banana and coffee plants, crop residue and pest and disease management.We then consider methods to assess the economics of introducing banana–coffeesystemsandhowtheycanbeintegratedintoafarmsystem.Wehopethatextensionworkersandotherswillfindthisguideusefulintheirworktoimprovetheproductivityofbanana–coffee systems in Africa.

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9. Look-up tables

Look-up Table 1. Nutrientandwatercontentofmanuresandresiduescommonlyavailableinsub-SaharanAfrica.

MaterialN P K Ca

Water content

kg/t material %

Human faeces 10 2 3

Cattle faeces 3 1 1

Pig faeces 5 2 4

Fresh cattle manure 4.0–6.0 1.0–2.0 4.0–6.0 2.0–4.0 60

Composted cattle manure 15 12 21 20 35

Farmyard manure 10 8 12 8 50

Goat manure 8 7 15 8 50

Sheep manure 10 7 15 17 80

Pig manure 7.0–10.0 2.0–3.0 5.0–7.0 12 80

Poultry manure 14–16 2.5–8 7.0–8.0 23 55

Garbage compost 6 2 23 11 40

Sewagesludge 16 8 2 16 50

Sugarcanefiltercake 3 2 0.6 5 75–80

Castorbeancake 45 7 11 18 10

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Look-up Table 2. Nutrient conversion factors.

From Multiply by To get/From Multiply by To get

NO30.226 N 4.426 NO3

NH30.823 N 1.216 NH3

NH40.777 N 1.288 NH4

P2O50.436 P 2.292 P2O5

K2O 0.83 K 1.205 K2O

SO20.500 S 1.998 SO2

SO40.334 S 2.996 SO4

SiO20.468 Si 2.139 SiO2

MgO 0.603 Mg 1.658 MgO

CaO 0.715 Ca 1.399 CaO

CaCO30.560 CaO 1.785 CaCO3

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10. References

Themajorreferencematerialsusedinthepocketguidearelistedbelow.Briefexplanationsoftherelevanceofthereferencesareprovided in italics.Beer, J., (1988) Litter production and nutrient cycling in coffee (Coffea arabica) or cacao (Theobroma cacao)plantationswithshade trees. Agroforestry Systems 7, 103–114.Beer, J., Muschler, R., Kass, D., Somarriba, E. (1998) Shade management in coffee and cacao plantations. Agroforestry Systems 38, 139–164.

This reference and Beer (1988) explore the advantages and disadvantages of shade on coffee yield, and the role of soil fertility)

Bouwmeester,H.,Rieffel,P.(2010)Bananaproductionarea,IITA-Banana production area project.

Source of Figure 1

CIALCA,2008FinalReportPhaseI-CIALCA:January2006–December2008,inCIALCAProgressReports05.http://www.cialca.org/files/files/CIALCA-I_final_technical_report.pdf

Source of Figure 10

CIALCA,Bananatissueculture.Bananaextensionmaterials.CIALCA,Bananamacropropagation.Bananaextensionmaterials.CIALCA,Bananasoilfertilityproblems1/2.Bananaextensionmaterials.CIALCA,Bananasoilfertilityproblems2/2.Bananaextensionmaterials.CIALCA,Zerotillagemulchbananasystem.Bananaextensionmaterials.CIALCA, Damage to bananas caused by nematodes. Banana

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extensionmaterials.CIALCA,BananaweevilCosmopolites sordidus.Bananaextensionmaterials.CIALCA, Banana Xanthomonaswilt(BXW)factsheet.Bananaextensionmaterials.CIALCA,Bananabunchytopdisease.Bananaextensionmaterials.CIALCA, Fusarium disease of banana (Panama disease). Banana extensionmaterials.CIALCA,Bananastreakdiseaseandbananamosaicdisease.Bananaextensionmaterials.CIALCA,Bananafungaldiseases.Bananaextensionmaterials.CIALCA,Bananaleafspotdiseases:YellowSigatoka(Mycosphaerella musicola)andBlackSigatoka(Mycosphaerella fijiensis).Bananaextensionmaterials.

The banana extension materials developed by the Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA) provide useful information on management of the system. www.cialca.org/index331b.html?option=com_content&view=article&id=82&Itemid=96

DaMatta, F.M., Ronchi, C.P., Maestri, M., Barros, R.S. (2007) Ecophysiologyofcoffeegrowthandproduction.BrazilianJournalof Plant Physiology 19, 485–510.

Source of information on timing of critical physiological stages of coffee presented in Table 2

Eledu,C.A.,Karamura,E.B.,and.Tushemereirwe,W.K(2004)AgroecologicaldistributionofbananasystemsintheGreatLakesregion. African Crop Science Journal 12, 33–42.

The reference describes the principal banana growing areas in the Great Lakes region of east and central Africa

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Fairhurst,T.(ed)(2012)HandbookforIntegratedSoilFertilityManagement. Africa Soil Health Consortium, Nairobi

Introduction to the principles and practice of integrated soil fertility management.

Harding, P. (1992) Coffee [Coffea arabicaL.(Arabicacoffee);Coffea canephora Pierre ex Froehner(Robustacoffee);Coffea liberica Bull ex Hiern.(Libericacoffee);Coffea excels Chev.(Excelsacoffee)].In Wichmann, W. (Ed), World Fertilizer use Manual. International Fertilizer Association, Paris.

Source of data on nutrients in coffee. The data was used in Figure 15

Jahnke,H.E.(1982)LivestockproductionsystemsandlivestockdevelopmentintropicalAfrica,KielerWissenschafsverlagVauk,Kiel, Germany.

Source for characteristics of zones included in Table 1

Kelly,V.(2006)FactorsAffectingDemandforFertilizerinSub-Saharan Africa. Agriculture and Rural Development Discussion Paper23,WashingtonDC:WorldBank.RetrievedAugust2012fromhttp://siteresources.worldbank.org/INTARD/Resources/ARD_DP23_FINAL.pdf.

The reference provides useful information on economic analysis of data.

Magambo, M.J.S. (2000). Clonal robusta coffee farming. Uganda NationalFarmers’Associationfarmerguideseries,Uganda.UgandaNationalFarmers’association,Uganda.

The reference has useful information on Robusta coffee production

Martin-Prevel,P.(1992)Banana.InW.Wichmann(Ed.),Worldfertilizer use manual, International Fertilizer Association, Paris.

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Source of data on nutrients in plant parts of banana. The data was used in Figure 15

Minai, J.N., Nyaga, M.K., Mburu, J.N., Nzue, J., Wanja, E. (Eds) (2009). The Coffee Atlas. Coffee Research Foundation, Ruiru, Kenya.

The atlas provides information on nutrient deficiencies, pests and diseases of coffee

Minai, J.N. (2011) Coffee Production Recommendations, the Coffee Research Foundation, Ruiru, Kenya.

This is a good source of information on fertilizer recommendations and management of coffee.

Newley,P.,Akehurst,A.,Campbel,B.(2008).BananaGrowingGuide: Cavendish Bananas. Published by N.S.W. Department of PrimaryIndustries.StateofNewSouthWales.

The guide is a good source of information on management of banana.

Okalebo,J.R.,Gathua,K.W.,Woomer,P.L.(2002)Laboratorymethodsofsoilandplantanalysis:aworkingmanual.2ndedition.

The reference was the source of data for foliar nutrients in Arabica coffee and banana presented in Table 10

Robinson, J.C., Sauco, V.G. (2010) Bananas and plantains. 2nd ed, CABI.

A useful book on scientific principles of banana production and how these relate to practices.

Tushemereirwe,W.K.,Kashaija,I.N.,Tinzara,W.,Nankinga,C.,New,S.(Eds.)(2001).Bananaproductionmanual:aguidetosuccessful banana production in Uganda. National Agricultural ResearchOrganisation,Uganda.

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The reference has useful information on banana production

Twyford,I.T.(1967)Banananutrition:Areviewofprinciplesandpractice. Journal of Science and Food Agriculture 18, 177–183.Twyford,I.T.,Walmsley,D.(1974)Themineralcompositionoftherobusta banana plant IV: The application of fertilizers for high yields. Plant and Soil 41, 493–508.

This reference and Twyford (1967) discuss nutrient requirements for banana

VanAsten,P.J.A.,Wairegi,L.W.I.,Mukasa,D.,Uringi,N.O.(2011)Agronomicandeconomicbenefitsofcoffee–bananainter–croppinginUganda’ssmallholderfarmingsystems.AgriculturalSystems 104, 326–334.

Source of data used in Figures 6 and 7

vanAsten,P.J.A.Wanyama,I.,Mukasa,D.,Nansamba,Kisaakye,J., Sserubiri, I., Bongers, G., Jassogne, L. (2012) Mapping and evaluating improved inter–crop and soil management options for Ugandan coffee farmers. Technical Report.

Source of Figure 11: map of nutrient deficiencies in Uganda.

Wairegi,L.W.I.,vanAsten,P.J.A.,Tenywa,M.M.,Bekunda,M.A.(2010) Abiotic constraints override biotic constraints in East African highland banana systems. Field Crops Research 117, 146–153.

Source of Figure 8 and source of some of the data used for Figure 12

Wintgens,J.N.(Ed.)(2009)Coffee:growing,processing,sustainableproduction.Aguidebookforgrowers,processors,traders and researchers. Wiley.

A useful reference book for coffee production, e.g. some of the information in Table 6 was adapted from this book.

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11. Glossary

Arching: Young plants are bent over, string is tied to bent stem, thentiedtostakepushedintothegroundtoholdsteminposition.Bi-modal rainfall:Rainfallthatcomesintwoseasonsinayear.Bunch: Fruit of banana plantCapping:Thetipofstemiscut-offCompound fertilizers: A fertilizer that has contains more than one nutrient.Corm: A short vertical underground stem.Cross-pollination:PollenfromoneflowerpollinatesanotherflowerCuttings:Single-nodesectionsarecutfromsuckers.Thesuckersare harvested from a mother plantDesuckering:Removingtwigsthatgrowfromthemainstemincoffee,andsmallplantsgrowingatthebaseofabananastem.Dieback: Leaves fall off, branches die. Caused by having more coffee cherries than the plant can sustain.Drip-line:Thelinearoundthecoffeetreewheremostoftherainthat falls on the tree is shed.Etiolated:Plantsthatareweakandyellowduetolackofsufficientlight.Fly crop:Whencoffeeisharvestedtwiceayear,oneharvesttendstobesmallerandiscalledtheflycrop.Fruit set:ChangefromflowertofruitGrafting:Asuckeriscut-offfromaplant,placedincleftmadeonarootstock,andtheunionistiedtofacilitatejoining.Hybrids:MadebycrossingtwodifferentvarietiesMain crop:Thelargerharvestincoffeeharvestedtwiceinayear.Mat:Afamilyofbananaplantswithinterconnectedlivingcorms. Ideally should be a single mother plant, daughter and

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granddaughter.Mono-crops:growingsinglecropsMonocotyledonous:Plantswhoseseedshaveonecotyledon.Theplantshaveleaveswithparallelveins.Mother plant:Theoldestplantinamat.CanbefloweringorbearingabananabunchIncoffee,plantfromwhichmaterialsforpropagation(e.g.suckersforcuttings,seeds)aregot.Phenology:Forbananaandcoffee,thegrowthstagesfromplanting to maturityPruning: Cutting off selected branchesPseudostem: A false stem made up of rolled leaf sheathsSelf-pollination:flowerpollinatesitselfStraight fertilizers: A fertilizer that has contains one nutrientStumping: In coffee, cutting off most of the main stem and leaving a small part above the soil surfaceSuckers:Twigsgrowingupwardsfromthemainstemincoffee.Sword suckers:suckersthatarecloselyattachedtothemotherplant.Theyhavesmallleavesthataresword-shaped.Tap root:Usuallyasinglerootthatgrowsdownwards,fromwhichsmallrootsgrow.Top-working: Cuttings of improved coffee are grafted on old trees.Overbearing: Coffee trees has more fruit than it can support sustainably.Overcrowding: Presence of too many plants in a given area. The plantscompetefornutrients,waterandlight.Propagated vegetatively: Produced from cuttings and not from seed.Water suckers:Suckerslooselyattachedtomotherplant.Thesuckershavelargebroadleaves.Weed-free:Withoutweeds

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12. Acronyms and abbreviations

Al aluminiumASHC African Soil Health ConsortiumB BoronBBC bacterial blight of coffeeBBTD banana bunchy top diseaseBXW bananaXanthomonaswiltC CentigradeC:N carbon to nitrogen ratioCa CalciumCBD coffee berry diseaseCl ChlorineCLR coffee leaf rustCLR coffee leaf rustcm centimetreCu CopperCWD coffeewiltdiseaseDAP diammonium phosphateDRC Democratic Republic of the CongoFAO FoodandAgricultureOrganisationoftheUnitedNationsFe IronG Gramha hectare (1 ha = 2.47 acres)IITA International Institute of Tropical AgricultureISFM integrated soil fertility managementK potassiumK20 potassiumoxideKCl potassium chloride

99

kg kilogramLER land equivalent ratiom metremasl metres above sea levelMg magnesiumMgO magnesiumoxidemm millimetreMn manganeseN nitrogenNa sodiumNGO non-governmentalorganisationsP phosphorusP205 phosphoric acidSSA sub-SaharanAfricaSi silicat tonneTSP triple superphospateVCR value/cost ratioWUR Wageningen UniversityZn Zinc

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Appendices: Banana Pests and Diseases Extension Materials

Thesefarmer-friendlyextensionmaterialshavebeenproducedbyCIALCA–theconsortiumforimprovingagriculture-basedlivelihoods in Central Africa (cialca.org). They are reproduced here withkindpermissionfromtheconsortium.1. Banana tissue culture

http://www.cialca.org/files/files/extension_materials/tissue-culture_english.pdf

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2. Banana macropropagation

http://www.cialca.org/files/files/extension_materials/macro-propagation_english.pdf

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3. Banana soil fertility problems 1/2

http://www.cialca.org/files/files/extension_materials/fertilite_nutrients1_english.pdf

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4. Banana soil fertility problems 2/2

http://www.cialca.org/files/files/extension_materials/fertilite_nutrients2_english.pdf

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5. Zerotillagemulchbananasystem.Bananaextensionmaterials

http://www.cialca.org/files/files/extension_materials/zerotillage_english.pdf

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6. Damage to bananas caused by nematodes

http://www.cialca.org/files/files/extension_materials/sheet_degatsnematode_english.pdf

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7. BananaweevilCosmopolites sordidus

http://www.cialca.org/files/files/extension_materials/sheet_weevil_english.pdf

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8. BananaXanthomonaswilt(BXW)

http://www.cialca.org/files/files/extension_materials/bxw_english.pdf

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9. Banana bunchy top disease

http://www.cialca.org/files/files/extension_materials/BBTV_english.pdf

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10. Fusarium disease of banana (Panama disease)

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11. Bananastreakdiseaseandbananamosaicdisease

http://www.cialca.org/files/files/extension_materials/BSV-CMV_english.pdf

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12. Banana fungal diseases

http://www.cialca.org/files/files/extension_materials/fruit_fungal_diseases_english.pdf

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13. Bananaleafspotdiseases:YellowSigatoka(Mycosphaerella musicola)andBlackSigatoka(Mycosphaerella fijiensis)

http://www.cialca.org/files/files/extension_materials/sheet_leafspots_english.pdf

Africa Soil Health Consortium – improving soil fertility, improving food production, improving livelihoods

ASHCworkswithinitiativesinsub-SaharanAfricatoencouragetheuptakeof integrated soil fertility management (ISFM) practices. It does this primarily bysupportingthedevelopmentofdowntoearthinformationandmaterialsdesigned to improve understanding of ISFM approaches.

ASHCworksthroughmultidisciplinaryteamsincludingsoilscientistsandexpertsoncroppingsystems;communicationspecialists,technicalwritersandeditors;economists;monitoringandevaluationandgenderspecialists.This approach is helping the ASHC to facilitate the production of innovative, practical information resources.

ASHC defines ISFM as: A set of soil fertility management practices that necessarily include the use of fertilizer, organic inputs and improved germplasm combinedwiththeknowledgeonhowtoadaptthesepracticestolocalconditions,aimingatoptimizingagronomicuseefficiencyoftheappliednutrients and improving crop productivity. All inputs need to be managed followingsoundagronomicandeconomicprinciples.

The Integrated Soil Fertility Management Cropping Systems Pocket Guide series is an output of the Africa Soil Health Consortium (ASHC), which is coordinated by CABI.

Thispocketguidewasfirstpublishedin2014byASHC

CABI,ICRAFcomplex,P.O.Box633-00621,Nairobi,Kenya

Tel:+254-20-7224450/62Fax:+254-20-7122150Email:Africa@cabi.org Website: www.cabi.org/ashc