Dieases of Annona (Custard Apple)

This deals with diseases of annona (custard apple)

1. DISEASES OF ANNONA
STUDENT COURSE TEACHER
Krishna Kumar.R.V Dr.Parthasarathy.S
ID.NO:2015021066 Asst.Prof.,(Plant Pathology)

2. DiseaseName Pathogen Name
Fruit rot and anthracnoseColletotrichumgloeosporioides
Alternarialeaf spot Alternariaalternata
Cylindrocladiumleaf spotCylindrocladiumcolhounii
Diplodiarot Botryodiplodiatheobromae
Black canker Phomopsisannonacearum

3. Disease Name:
Fruit rot and anthracnose
Pathogen Name:
•Colletotrichumgloeosporioides(Anamorphstage)
•Glomerellacingulata(Telomorphstage)

4. Systematic position:
Kingdom : Fungi
Phylum : Ascomycota
Class : Sordariomycetes
Order : Incertae sedis
Family : Glomerellaceae
Genus : Colletotrichum
Species :C. gloeosporioides

5. Pathogen description:
•Hemibiotrophproduceshyalineseptatebranched
mycelia.
•Fungusproducesacervuliwithblacksetae.
•Conidiaaresinglecelled,hyaline,thinwalledwith
fullofoilglobules.

6. Pathogen:

7. Favourable conditions:
•Wetandwindyconditionsfavourthedisease.
•Temperature:28-32ºC.
Survivalandspread:
•Olderfruitsleftonthetreesprovideinoculumfor
diseasespread.
•Secondaryspreadthroughairborneconidia.

8. Symptoms:
•Infectionbeginsatblossomendofthefruitandlater
spreadsonentirefruitsurface,affectedfruitsshrivel
andtheymayclingtothetreeorfalldown.
•Necroticspotsappearonunripefruitswhichturninto
darkbrowntoblackspots.
•Later,thesespotscoalesceandcoverentirefruit.

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10. Management:
CulturalMethods:
•Usemulchingundertreestoreducesoilsplash.
•Regularlymonitorthediseasesandremovedead
twigsandmummifiedfruits.
•Prunetrees50cmabovetheground.
Chemicalmethods:
•Spraycarbendazim0.1%orchlorothalonil0.2%.

11. Disease Name:
Alternaria leaf spot
Causal agent:
Alternaria alternata

12. Systematic Position:
Kingdom : Fungi
Phylum : Ascomycota
Class : Dothediomycetes
Order : Pleosporales
Family : Pleosporaceae
Genus :Alternaria
Species:A. alternata

13. Pathogen description:
•Conidiaisdarkbrownorolivebrownincolour,short
beaked,borneinlongchains,ovalandbeanshaped
with3-5transversesepta.

14. Survivalandspread:
•Primary spread : Through Ascospores.
•Secondary spread : Wind borne conidia.
Favourable conditions:
•Relativehumidityabove70%withwarmweather
(12-25ºCtemp.)andintermittentrainsfavours
disease.

15. Symptoms:
•Smallyellowishspotsfirstappearalongtheleaf
margins,whichgraduallyenlargeandturninto
brownishpatcheswithconcentricrings.
•Severeinfectionleadstodryinganddefoliation.
•Darkbrown-purplishpatchesappearontheinfected
fruitsandrachisjustbelowitsattachmentwiththe
shoots.

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17. Management:
•Sprayingofthiophenytemethyl0.2%or
pyraclostrobin+metiram0.1%.

18. Disease Name:
Cylindrocladium leaf spot
Causal agent:
Cylindrocladiumcolhounii

19. Systematic Position:
•Kingdom : Fungi
•Phylum : Ascomycota
•Class : Sordariomycetes
•Subclass : Hypocreomycetidae
•Order : Hypocreales
•Family : Nectriaceae
•Genus : Cylindrocladium
•Species :C. colhounii

20. Symptoms:
•Darkpurplespotsdevelopfirstontheshouldersof
thefruitandthenspreaddownthesides.
•Spotsenlargeandthenlaterdryoutandcrack.

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22. Management:
•Spraying of carbendazim 0.1%.
•Spraying of tebuconozole + mancozeb 0.1%.

23. Disease Name:
Diplodia rot
Causal agent:
Botryodiplodiatheobromae

24. Systematic Position:
•Kingdom:Fungi
•Division:Ascomycota
•Class:Sordariomycetes
•Order:Diaporthales
•Family:Incertaesedis
•Genus:Botryodiplodia
•Species:B.theobromae

25. Pathogen:
•Pycnidialfungiproducehyalinethinwalled
pycnidiosporeswhichbecomebrown,thickwalled,
twocelledwithlongitudinalstriations.

26. Favourablecondition:
•Optimumtemperatureis25.9°Cto31.5°Cand
relativehumidityis80%.
Survivalandspread:
•Thepathogenpersistsininfectedplantpartswhich
serveassourceofinoculums.

27. Symptoms:
•Purplishtoblackspotsorblotchesconfinedtothesurface
ofthefruitandeventuallycoveredwithwhitemyceliaand
blackpycnidia.
•Diplodiarotisdistinguishedbyitsdarkinternal
discolourationandtheextensivecorkyrottingproduces.
•Thepenetratedflesheventuallysoftensorhardensand
cracks,dependingonthepresenceofsecondarymicrobes.

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29. Management:
•Spraying of carbendazim 0.1%.
•Spraying of tebuconozole 0.1%.
•Spraying of trifloxystrobin 0.1% or zineb 0.2%.

30. Disease Name:
Black canker
Causal agent:
Phomopsis annonacearum

31. Systematic Position:
•Kingdom:Fungi
•Division:Ascomycota
•Class:Sordariomycetes
•Order:Diaporthales
•Family:Valsaceae
•Genus:Phomopsis
•Species:P.annonacearum

32. Pathogen:
•Myceliumisseptate,palebrowncolour.
•Conidiaisoblongandovalshaped.

33. Favourableconditions:
•Thediseaseisfavouredbyextremelywetweather
andcooltomoderatetemperatures(15ºCto20ºC).
Survivalandspread:
•Primary:Soilbornechlamydosporesanddormant
myceliumfromplantdebris.
•Secondary:Windborneconidia.

34. Symptoms:
•Irregularlyshapedspotsrangingfromsmallspecksto
largeblotches.
•Spotshaveanindistinctfeatherededge.
•Tissuedamageunderthespotsisnomorethan10
mmdeep.

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36. Management:
•Spraying of tricyclazole 0.1%.
•Spraying of pyrocostrobin 0.1%.