1 /4 Sigatoka diseases control

Yellow and are diseases caused by fungi. They cause significant drying of the leaf surface. The fungi spread in two ways: - by water which carries the conidia (asexual form of reproduction) from the upper to the lower and suckers,

Conidia - yellow and black Sigatoka - by wind which carries the ascospores (sexual form of reproduction) in all directions. The control of Sigatoka(s) enables the plant to conserve a sufficient number of healthy leaves up to harvest to ensure the normal growth of the fruit. The disease reduces the leaf surface and causes disturbances in the functioning of the plant, leading to a reduction in yield and quality di s ea e control Sigatoka (particularly a higher risk of fast ripening).

1. Yellow Sigatoka or leaf streak disease 2. Black Sigatoka or black leaf streak disease ( musicola) (Mycosphaerella fijiensis): a more virulent The development of the fungus occurs in five stages: Black Sigatoka is present in almost all tropical banana producing For Yellow Sigatoka zones but its arrival in the Lesser Antilles is very recent (2009- Stage 1: A tiny yellow spot or light green streak on the upper surface of 2010). leaves. > Hardly observable. Yellow Sigatoka Black Sigatoka Upper surface Lower surface 2.1-Description of symptoms and differentiation with Yellow Stage 2: The spots stretch out Sigatoka into yellow streaks of 3-4mm; this is the optimal stage for treatment. The symptoms of Black Sigatoka are sometimes not distinguishable from those of Yellow Sigatoka, especially in > Streaks 1 to 5 mm. the advanced stages of necrosis, which are very similar. The difference is however evident at the early stages of evolution Stage 3: The streaks widen into large spots; the center developing (1-4): a rusty colouration. > Large spots. Stage 1: Small whitish spots are only visible on the lower Contamination + surface of the leaf. Stage 4: the lesion reaches its Stage 2: Brown rusty streaks are visible especially definite size (12-15 mm on 2-5 on the lower surface. mm) with a yellow halo; the centre Stage 3: Brown streaks lengthen and widen. is dark brown to black. Stage 4: Brown to black, round or elliptical broad stripes. Contamination ++ Stage 5: The lesions become black, usually surrounded Stage 5: The central zone of by a yellow halo. the lesion dries up and turns gray Stage 6: The centre of the stain dries up with a black halo, with a black ring and a yellow itself surrounded by a yellow halo. halo. It is referred to as the 'necrosis' stage. At this stage, the ascospores appear and are then 2.2- More serious consequences dispersed by the wind. > Necrosis. Black Sigatoka is more virulent than Yellow Sigatoka. Symptoms No Contamination + + + appear on younger leaves and cause more damage to the foliar stage 6 Stage 6: No stage 6. system. The economic and environmental consequences are more important: yield loss, reduced shelf life, heavier maintenance Stages of yellow and black Sigatoka tasks (deleafing) and increased plant protection (spraying). Photos: CIRAD, SicaTG, IT ²

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Leaf attacked by Black Sigatoka - Photo IT² Cavendish banana attacked by Black Sigatoka - Photo IT²

Plantains are susceptible to Black Sigatoka but resistant to 3.1- Preventive Practices:

Sigatoka di s ea e control Sigatoka Yellow Sigatoka. Balisiers, heliconia, alpinia and porcelain to limit fungal population roses are not susceptible to Black Sigatoka because they do not belong to the genus Musa. Cut all the leaves on the mother plant during harvest.

Reduce humidity in your plots through a proper management of irrigation and drainage (drip or under foliage spray are less favourable to the development of the fungus than overhead sprinklers). Weeding, up to date de-suckering, a planting density of 1650-1850 plants/ha, and maintenance of edges, will allow good aeration of the plot.

Quickly destroy all fallow plots to avoid creating infestation reserves.

Eliminate all isolated found at the edge of the plots, in the gullies, etc.

Healthy banana, receiving regular and balanced fertilization, resist more easily to the development of the disease.

3.2- Curative practices: eliminate the fungal population

When only Yellow Sigatoka is present, proceed to a regular trimming (weekly) focused on the necrotic parts when they represent less than 20% of leaf surface, beyond this, remove the entire leaf. For Black Sigatoka, cut the entire leaf with necrosis, Ripe bunch on the plant - Photo IT² regardless of the level of infestation.

Control methods against Black Sigatoka are the same as To maintain a sufficient number of healthy leaves at harvest, be those against Yellow Sigatoka: cultural practices (preventive and precise in the operations that can reduce leaf area (trimming and harvest of neighboring bunches). The objective is to maintain one curative) and chemical control. functional leaf without necrosis per hand with a minimum of six leaves. Below six, the risk of advanced maturation of the bunch is high. 3. Cultural control methods

Good agricultural practices, preventive or curative, are essential to reduce pest pressure. Chemical treatments only act effectively on the young stages of development.

Sigatoka diseases control 2/4 prohibited fromaerialspraying(ZITA): 4.1- GeneralizedaerialTreatment basedonwarning 4. Chemicalcontrol treatment. evolution, oftheteamforgeneralised underthesupervision indicators. programisestablished,A treatment basedonthis the diseaseismeasuredweeklybasedonclimatic andbiological and isrealisedthroughageneralisedaerialspray. The evolutionof 4.2- Treatment onthegroundwithZIT Thefungicidesavailable areof2types: The farmer is responsible for treatment on the ground in The areas farmer is responsible for treatment Sigatoka control is rendered obligatory byaprefectorialorder controlisrenderedobligatory Sigatoka appropriate personalprotectiveequipment (PPE). appropriate according tothechemicalbeing used. with Protectoperator interval, tore-entretheplotandpre-harvest time lapse less thanBeaufortforce3(19km/h), phenomenon andphytotoxicityonbanana. The windmustbe thedrift 28°C (earlyinthemorningorafter4PM)toavoid the schedulespecifiedbytechnicalteamofcentres, following centres and do the application generalised treatment required. withoilalonethenoil/fungicideis treatment why alternating risk ofresistanceinregardtosystemicproductsishigh, that's Indies, fewfamiliesoffungicidesarecurrently allowed. The ofthedisease.action ontheearlystages IntheFrench West symptoms, development ofthefungusanddelaysonset1st

Respect thedoses(15lmixture/ha), areas of non-treatment, Carry out the treatment when temperatures are less than when temperatures outthe treatment Carry Systemic fungicides, preventive andcurative whichhave Collect the products (fungicide and /oroil) from the Paraffin action, oilwithfungistatic whichblocksthe Aerial treatment-PhotoSica TG A Sigatoka diseae s 3 /4 4.3- Treatment onthegroundwithamistblower 4.4- Treatment withacanon: ha perpersonday. being experimented. is fourmajorrows every at a smallcarrier permitting passage meters. moving alongthecorridors. This coversawidthof15to20 Beforetreatmentwiththemistblower: withtwopossiblemodifications: Usingamistblower

control With treatment on every row, on every With treatment surface is about 3 to 4 the treated A new system comprising of a sprayer towed ormounted on A newsystemcomprisingofa sprayer towed The treatment can be done with a gun carried by The a treatment tractor bunches. touching sidewaystoavoid swaying facilitates operator amount ofchemicalreceivedbytheoperator, movement oftheoperator. reaches thetopleaves, Mountingthesprayerguninaverticalpositionabove thereartolimit 45°towards Fixing tubeat oftheblower the Attach proppingropesinsuchawayastofacilitate oilspotsonfruits Sleevebunchestoavoid the product easily plotso that out trimming to aerate Carry Modified mistblower:verticalgun/V-shaped doubleoutletnozzle Photo Banamart 3

Sigatoka diseases control /4 4

Sigatoka diseases control /4 Reference linksBanagapV5:CB7.1to7.6IPM. marketing). on a whole (production,of the banana industry transport, and meets thecriteria aresistanthybridthat succeed increating Yellow andBlackSigatoka. Inthemediumterm, thegoalisto areresistanttodiseases,dessert bananavarietiesthat including new theexistingprocessofcreating to intensifyandaccelerate in Guadeloupe. of Neufchâteau experimental station put inplacepartnershipwithCIRADandT², theCIRAD at In 2009, fortheselectionofbananahybridshadbeen aplatform 5.2- Useofresistantvarieties program. treatment inanintegrated biological preparations The objectiveistoreducetheuseofchemicalsbyincluding yeast, defencesystems. ofnatural vegetableoilsandstimulators addition tochemicalcontrollimittheemergenceofresistance: IT² in is working on the possibility of using biological preparations 5.1- Organicproducts 5. Alternative controlmethods Its aim is Sigatoka diseae s 4 /4 control