Although plantain variety Africa is susceptible to black sigatoka, its production is precocious, enabling it to tolerate disease attack and attain harvest with a higher number of functional leaves.

Chemical control. Applications of chemical fungicides can reduce damage caused by black sigatoka, but its use must be justified and supervised to prevent cost overruns, harm to human health, and damage to the environment. Recommendations are to:

•Apply fungicides only under conditions of high inoculum pressure (e.g.,susceptiblevariety,orrainyseasonwithtemperaturesat≥23°C).

•Consultanagronomistforrecommendationsonchemicalcontrol.

•Before applying, remove leaves or conduct leaf surgery.

•Alternate the fungicides’ mode of action (e.g., systemic contact systemic contact)topreventtheappearanceoffungalpopulationsresistant to fungicide applications.

•Use dispersants and additives to improve the effectiveness of applications.

•Carryoutapplicationseitherinthemorningsorevenings,anduseprotective equipment.

Additional readingCuéllarA;ÁlvarezE;CastañoJ.2011.Evaluaciónderesistenciade

genotipos de plátano y banano a la sigatoka negra (Mycosphaerella fijiensisMorelet).RevFacNacAgronMedellín64(1):5853–5865.

FHIA(FundaciónHondureñadeInvestigaciónAgrícola).2014.Homepage.Availableatwww.fhia.org.hn/.

GanryJ;FouréE;deLapeyredeBellaireL;LescotT.2012.Anintegratedapproachtocontroltheblackleafstreakdisease(BLSD)ofbananas,whilereducingfungicideuseandenvironmentalimpact.In:DhanasekaranD;ThajuddinN;PanneerselvamA,eds.Fungicidesforplantandanimaldiseases.DOI:10.5772/29794.

GañánL;LeónJ;AristizábalM;CastañoJ.2007.Prácticasdemanejodelas sigatokas amarilla (Mycosphaerella musicola) y negra (Mycosphaerella fijiensis)enplátanoDominicoHartón(Musa AAB Simmonds).Agronomía15(2):39–48.

HoyosJE;CastañoJ.2007.EvaluaciónderesistenciadeMbouroukou(África1)yFHIA03alasigatokanegra(Mycosphaerella fijiensis Morelet)ysigatokaamarilla(Mycosphaerella musicolaLeach).Agronomía15(2):67–76.

MarínD;RomeroR;GuzmánM;SuttonTB.2003.Blacksigatoka:anincreasingthreattobananacultivation.PlantDisease87(3):208–222.

Orozco-SantosM;Orozco-RomeroJ;Pérez-ZamoraO;Manzo-SánchezG;Farías-LariosJ;daSilvaMoraesW.2008.Prácticasculturalesparaelmanejodelasigatokanegraenbananosyplátanos.TropicalPlantPathology33(3):189–196.

ThisbrochurewasproducedwiththesupportoftheFoodandAgricultureOrganization(FAO)oftheUnitedNationsundertheCIAT–FAOSupportAgreementtovalidaterisk

management strategies for transboundary pest movement, focusing on managing Moko disease and black sigatoka in Musaceae.

Photos:NeilPalmer(CIAT)andAlejandraCuéllar

Figure3. Thereactionsofdifferentbananaandplantainmaterialsto black sigatoka.

Varieties with partial resistance:

Plantain:FHIA-21,FHIA-20,Topocho,Maqueño.

Banana: Fougamou,Sedita,PisangMas,PisangCeylan,FHIA-02, FHIA-03,FHIA-17,FHIA-23(Figure3).

A guide for recognizing and managingthe disease in family agriculture

Black Sigatoka in Plantain and Banana

For more information

Elizabeth Álvarez, Ph.D., Plant Pathologist InternationalCenterforTropicalAgriculture(CIAT) Km17RectaCali-Palmira,ValledelCauca,Colombia

Phone:+5724450000Ext.3385 E-mail:e.alvarez@cgiar.org

Alberto Pantoja, Ph.D. RegionalPlantProductionandProtectionOfficer

FAO–RegionalOfficeforLatinAmericaandtheCaribbean Phone:+5629232295

E-mail:alberto.pantoja@fao.org

Sedita FHIA-23 Gran Enano Valery

FHIA-21 Topocho D. Hartón Africa

ElizabethÁlvarez,AlbertoPantoja,LedersonGañánand GermánCeballos

March2015

ImportanceBlacksigatoka,alsoknownasblackleafstreakdiseaseorBLSD,iscaused by the fungus Mycosphaerella fijiensis.Thisleafdiseaserepresents the principal limitation to the production of musaceas, that is,plantainsandbananas,worldwide.Thediseaseaffectsleavesandthustheplant’sabilitytophotosynthesize,resultinginbunchesandfruitsthatweighlessthanthosefromhealthyplants.Severeinfectionsof black sigatoka can also cause premature ripening of fruit.

SymptomsAccordingtoFouré’sscale,symptomsofblacksigatokapassthroughsixstagesofdevelopment(Figure1):

Stage 1. Small(<1mm)lesionsorspots,yellowish-whitetobrownin color, that are barely visible on the lower surfaces of leaves.

Stage 2. Chloroticbrownstreaks,3–4x1mminsize.

Stage 3. Thestreakslengthenbyasmuchas2cmandalsowiden,giving the impression of having been painted on by brush. Edgesarebrownbutnotwell-defined.

Stage 4. Oval-shapedblotches,coffee-coloredonthelowersurfacesand black on the upper surfaces of leaves.

Stage 5. Black blotches, each surrounded by a black ring and sometimesayellowishhalo;centersaredryandsemi-sunken.

Stage 6. Lightbrownblotchessurroundedbychlorotictissue;centers are dry and sunken.

EpidemiologyDiseasedevelopmentisdirectlyinfluencedbyclimaticconditions,varietal susceptibility, and crop management. Geographical areas most affected by black sigatoka typically have rainfall of more than 1400mmperyear,relativehumidityofmorethan80%,andtemperaturesaveragingbetween23and28°C.Thediseaseismostaggressive during rainy seasons because of the continuous presence of water films on leaves, thus favoring the release and infestation of spores.HowblacksigatokadevelopsonaMusaplantisshowninFigure2.

Figure1.Sixstagesofsymptomatologyofblacksigatoka.

1 and 2 2 and 3 4 and 5 6

Sporesaredispersedbywindor water splash onto a new leaf

(e.g.,cigarleaf)

Fungalsporesareproducedduringstages3to6

Sporesgerminateand infect the leaf through stomata

Asymptomatic but infected tissue

Stages1and2arefirstobserved on the lower

surfaceofleaf3at10to30days after infection

10to30days

10to30days

2to4 days

Figure2. Diseasecycleofblacksigatoka.

ManagementBlack sigatoka can be controlled through integrated disease management(IDM),anapproachthatoffersfarmerseffective,safe,andsustainablesolutions.Successdependsonskillincombiningdifferent practices that are compatible and applicable to the agroecosystem according to ecological, economic, and technical principles.Themainmethodsformanagingthediseasearedescribed below.

Cultural Control. Seekstoreducepathogeninoculumsourcesandimprovegrowingconditionsforplantainorbananaplantstominimizeimpactfromthedisease.Thefollowingpracticesareused:

•Use of healthy or certified planting materials.

•Constructionofdrainstopreventwater-saturatedsoil.

•Plantingofassociated cropssuchasmaizeandcoffee.

•Applications of mineral fertilizer that contribute, in particular, phosphorus (P),potassium(K),andcalcium(Ca),togetherwithsupplementsoforganicmatter,plantainrachislixiviates,andbiofertilizers.

•Deleafingisrecommendedwhereleavesaremorethan50%affected.Otherwise,surgery is performed, where fragments of affected leaves (stages3to6)areremovedevery15daysduringrainyseasonsandevery20to30daysduringdryseasons.Theleavesmustthenbechoppeduptoaccelerate their degradation in soil.

•Management of weeds and pests, including phytoparasitic nematodes and crop diseases.

•Suckersandmalebudspruned, dried plant materials trimmed, and bunches dehanded and covered with translucent plastic bags.

Genetic resistance.Somevarietiesofmusaceashaveshownpartialresistance to black sigatoka, that is, the plant may be affected by the disease, but lesion areas and sporulation capacity are reduced, and the time of symptom evolution is slower than in more susceptible varieties.

InstitutionssuchastheHondurasFoundationforAgriculturalResearch(FHIA)have developed plantain and banana cultivars with partial resistance to black sigatoka.

Itshouldberememberedthatknownresistantvarietiesdifferincharacteristicssuchasappearance,size,flavor,texture,andpost-harvestmaturation.