Banana freckle leaf spot disease

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
BANANA FRECKLE LEAF SPOT DISEASE
STUDENT COURSE TEACHER
ARVINTH. S Dr. PARTHASARATHY. S
2015021016 Asst.Prof., (Plant Pathology)

2. Disease Name:
Banana Freckle leaf spot disease
Pathogen Name:
Teleomorph : Guignardia musae
Anamorph : Phyllosticta musarum
Common Name:
Banana freckle

3. Systematic Position
Kingdom : Fungi
Phylum : Ascomycota
Class : Dothediomycetes
Subclass : Incertaesedis
Order : Botryosphaeriales
Family : Botryosphaeriaceae
Genus : Guignardia
Species : G. musae

4. Occurrence
History and Diversity
In the absence of disease management, there is
an estimated 78% yield loss. Although the fruit is still
edible when affected by the disease, market value is
reduced. This causes problems for the exporting
business in Taiwan and the Philippines.

5.  Banana Freckle was first identified in Hawaii in 1917
and then soon after in the Philippines.
 The disease is most common in Hawaii, Indonesia,
Thailand, Taiwan, and New Guinea. This devastating
fungal disease can infect the leaves during any stage
of the plant’s life cycle.
 It is believed that the pathogen is mutating rapidly
and needs to be closely monitored. Further testing
and quarantine notices have been placed on infected
areas to prevent movement of disease.

6. Pathogen description
• Spores land on Banana plant or fruit by rain splash or
movement of infected tissue and fruit.
• The spores that landed on the plant germinate grow on
the outside of the host into masses known
as mycelium, they also form appressoria in order to
penetrate the host cells.
• After entering, the hyphae form a haustorium which
allows them to absorb nutrients through the plasma
membrane of the host cell.

7. • Asexually it produces fruiting body called as
pycnidium in which conidia are borne.
• Sexually the hyphae of opposite mating types
undergo karyogamy and meiosis to produce
ascocarp with asci.

8. Symptoms
• Symptoms typically appear after 2–4 weeks after
the banana cluster has opened, and seem to be
primarily localized on older leaves.
• Infected tissues may also yellow with age, and
eventually senesce in the most severe case of
symptoms. Even in the cases of minor infection,
the fungus renders the banana fruit unmarketable at
the loss of the grower.

9. • Major macroscopic diagnostic signs include
small brown to dark brown specks on leaves
and fruits, which indicate the presence of
fungal spores protruding through the infected
tissues.
• This gives leaf a sooty appearance and rough
texture and these spots cover the entire surface.
• Microscopically, these dark spots, or freckles,
can range from 1 mm in diameter to 4 mm.

10. Symptoms
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11. © http://www.pestnet.org/fact_sheets/banana_freckle_124.htm

12. © http://www.pestnet.org/fact_sheets/banana_freckle_124.htm

13. Spread of disease
Mode of spread :
Spores land on Banana plant or fruit by rain
splash or movement of infected tissue and fruit.
Favorable conditions
The fungus develops in wet weather and in heavy
rainfall.

14. Management
Physical control
• Bag bunches as soon as possible after the male bud
has been removed to help prevent fruit infection.
Cultural control
• Cut out diseased patches on leaves.
• Growing resistant varieties such as Cavendish
AAA banana.

15. Chemical control
In severe cases, spray Bordeaux mixture 1%
or Mancozeb 0.3% (3g/L) along with stickers.
Copper oxy chloride (Oleop) @ 0.2-0.4%
(2-4g/L) is also recommended.