This document discusses papaya fruit rot caused by various fungal pathogens. It provides details on the causal organisms (Rhizopus stolonifer, Ascochyta caricae, Lasiodiplodia theobromae, Colletotrichum gleosporioides), symptoms, disease cycle, taxonomy, and integrated disease management strategies for the major pathogens that cause papaya fruit rot. Environmental conditions like high humidity and frequent rains favor disease development. The disease spreads via airborne spores and through wounds during harvesting and storage. Control involves cultural practices like pruning, hot water treatment, and fungicide applications.

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
( (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
PAPAYA FRUIT ROT
SUBMITTED BY, COURSE TEACHER
KEERTHANA.R Dr. PARTHASARATHY.S
2015021062. Asst. Prof., PLANT PATHOLOGY

2. CAUSAL ORGANISM
• Rhizopus stolonifer – Rhizopus fruit rot
• Ascochyta caricae – Phomopsis fruit rot
• Lasiodiplodia theobromae – Stem end rot or surface fruit rot
• Colletotrichum gleosporioides - Anthracnose

3. OCCURENCE
• Papaya fruit rot is a serious and widespread in almost all the
chief Papaya growing parts of Assam.
• It was observed at the Burnihat Fruit Research Station in July,
1944 and has since recurred every year in a severe form during
rains.

4. DISTRIBUTION
• It is world wide in distribution. It is distributed in Malaysia,
Hawaii, Australia, Brazil, Spain, Taiwan, Fiji, Samoa and
Tonga.
• In India, it is distributed in Assam, Maharastra, Karnataka,
Tamil Nadu, Bihar, U. P, Kerala.
LOSSES
A survey of the Cachar district and in the North Cachar hills
showed 10 – 15% of the fruits to be affected on the trees.

5. SYMPTOMS OF RHIZOPUS ROT
• Irregular and the water-soaked
lesions which then gradually
enlarge and get covered by
white and dark brown fungal
growth and sporangiophores.
• The fruits become watery and
emit a foul odour.
TNAU Agritech portal

6. SYMPTOMS OF PHOMOPSIS ROT
• Affected fruit develops a water-
soaked spot which increases and
skin becomes soft .
• The rotten area turns dark brown to
black and get depressed and cracks
at a later stage.
TNAU Agritech portal

7. SYMPTOMS OF STEM END ROT
• The rot begins as dark
green, water-soaked spots.
• Later, the affected portion
becomes shriveled and turns
dark brown.
www.agritech.tnau.ac.in

8. SYMPTOMS OF ANTHRACNOSE
• Brownish superficial discolouration on skin of the fruit,
which develops circular, slightly sunken areas.
• Lesions gradually coalesce and sparse mycelia growth appears
on the margin of the spots.
• Finally results in mummification and deformation.

9. SYMPTOM
hiveminer.com

10. TAXONOMIC CLASSIFICATION OF RHIZOPUS
ROT
Kingdom: Fungi
Phylum : Zygomycota
Order : Mucorales
Family : Mucoraceae
Genus : Rhizopus
Species : R.stolonifer

11. PATHOGEN CHARACTERS
• It is a saprophytic species and spread by means of stolons.
• Stolons provide aerial growth of mycelium
• It produces germ shaped sporiangiospore which is short,
unbranched, stiff with single columellate sporangium and
sexually produces zygospores

12. SPORANGIOSPORE OF Rhizopus stolonifer
www2.andog.ac.kr
en.wikipedia.org

13. TAXONOMY OF PHOMOPSIS ROT
Kingdom: Fungi
Phylum: Ascomycota
Class: Dothideomycetes
Subclass: Dothideomycetidae
Order: Incertae sedis
Family: Incertae sedis
Genus: Ascochyta
Species: A. caricae

14. PATHOGEN CHARACTERS
• Mycelium is white, branched and septate which then produces
pycnidia
• Conidia are hyaline, fusiform, unicellular produced in
pycnidia

15. TAXONOMY OF STEM END ROT
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Botryosphaeriales
Family: Botryosphaeriaceae
Genus: Lasiodiplodia
Species: L. theobromae

16. PATHOGEN CHARACTERS
• Erumpent pycnidia formed in stromata
• Conidia are initially hyaline and unicellular, subovoid to
ellipsoidal.
• Mature conidia are two celled, cinnamon to light brown in
colour with striations.

17. TAXONOMY OF PAPAYA ANTHRACNOSE
Kingdom: Fungi
Division: Ascomycota
Class: Sordariomycetes
Order: Glomerellales
Family: Glomerellaceae
Genus: Colletotrichum
Species: C. gloeosporioides

18. PATHOGEN CHARACTERS
• Pathogen is hemibiotroph, survives in soil without host and
when lands upon the host produces appresorium.
• Fungus produces hyaline, one celled, ovoid to oblong, slightly
curved or dumbbell shaped conidia.
• Waxy acervuli that are produced in infected tissues are
subepidermal, typically with setae, simple, short, erect
conidiophores.

19. DISEASE CYCLE
Online Biology Notes

20. FAVOURABLE CONDITIONS
 High humidity
 Temperature of 25°C during storage.
 Frequent rains.
 Moist conditions favours the development of the disease .

21. MODE OF SPREAD
 Primary spread
Primarily spreads through air borne conidia and by the
rain splashes.
 Secondary spread
Secondary spead by means of wounds and injuries in the
fruit .

22. INTEGRATED DISEASE MANAGEMENT
• Cuts should be made at an angle to allow water to drain from
the wood surfaces.
• Avoid injuries during the harvesting of fruits.
• Prune early in the season when spore production is low or late
in the season when wounds are less susceptible and heal more
rapidly.
• Hot water treatment 49°C for 20 minutes for effective control.

23. • Post harvest treatment with Benzimidazole may reduce fruit
loss.
• Borax, captan, difolatan and dithane M-45 are effective.
• The disease can be controlled by dipping the fruits with DCNA
(2,6 – dichloro – 4 nitroaniline) at 1000-2000 ppm.
• Spray the fruits with Bordeaux mixture @ 5g in 1 litre of
water at an intervals.

24. REFERENCES
• https://www.appsnet.org/Publications/potm/pdf/Oct08.pdf
• http://agritech.tnau.ac.in/crop protection/crop pdf/papaya.pdf
• Thind T.S, Disease of fruits and vegetables and their
management, 2016, Kalyani publishers, New Delhi, pg.no 136
– 137.
• Chaube H.S, Crop disease and their management, 2015, PHL
learning publishers, New Delhi, pg.no 636 – 637.