3. Fusarium oxysporum f. spcubense
Yellowing of the lower most leaves starting from
margin to midrib of the leaves.
Yellowing extends upwards and finally heart leaf alone
remains green for some time and it is also affected.
The leaves break near the base and hang down around
pseudostem.
Longitudinal splitting of pseudostem. Discolouration
of vascular vessels as red or brown streaks. The fungus
spreads through use of infected rhizomes Continuous
cultivation results in build up of inoculum.
4. Pathogen
Mycelium is septate, hyaline and branched. Fungus
produces micro, macro conidia and also
chlamydospores.
Micro conidia - Single celled or rarely one septate
hyaline elliptical or oval.
Macro conidia - Sickle shaped hyaline, 3-5 septate and
tapering at both ends.
Chalamydospores - Thick walled, spherical to oval,
hyaline to slightly yellowish in colour.
5. Mode of spread and survival
The pathogen is soil borne.
It survives in soil as chlamydospores for longer periods.
The primary spread of the disease is through infected
rhizomes and secondary spread is through irrigation
water.
6. Management
Avoid growing of susceptible cultivars viz., Rasthali,
Monthan, Red banana and Virupakshi.
Grow resistant cultivar Poovan.
Corm injection of 3 ml of 2% Carbendezim injected in
the corm by making a hole to a depth of 10cm with 45
angle on 5 and 7 month a smentioned earlier.
Soil drench with 0.1% carbendazim or 0.01% Vapam
8. Pseudomonas solanacearum /Ralstonia/ Burkholderia
solanacearum
Leaves become yellow and progress upwards. The
petiole breaks and leaves hang.
When it is cut open discolouration in vascular region
with pale yellow to dark brown colour.
Thediscolouration is in the central portion of the
corm.
Internal rot of fruits with dark brown discoloration.
When the pseudostem is cut transversely bacterial
ooze can be seen
9. Pathogen /Disease cycle
Moko disease is caused by race 2 of Ralstonia
solanacearum which infects Musa and Heliconia.
Cells of bacterium are rod shaped and motile by 1-4
flagella.
They are Gram negative
P.I: Through diseased plant suckers used for planting.
➢ S.I: Through irrigation water, implements and by
insects.
10. Management
Grow resistant varieties like poovan and monthan.
➢ Adopt strict plant quarantine and phytosanitary measures
➢ Use of healthy planting material.
➢ Disinfestation of tools with formaldehyde diluted with water in 1:3
ratio.
➢ Crop rotation (3 years rotation with sugarcane or rice) & providing
good drainage
➢ Allow fallow period or flooding during off-season
➢ Fumigation of infected site with Methyl Bromide or chloropicrin.
➢ Spray systemic insecticide to prevent transmission of disease to
healthy plants.
➢ Biocontrol with Pseudomonas fluorescens
11. Bunchy top / Curly top / cabbage
top /strangle disease
12. Bunchy top virus or Banana virus - 1 or Musa virus - 1
Symptoms
Prominent dark green streaks on the petioles and midrib along
the leaf veins
➢ Green streaks range from a series of dark green dots to a
continuous dark green line (Morse code)
➢ Marginal chlorosis and curling of leaves
➢ Petioles fail to elongate
➢ Leaves are reduced in size, chlorotic, stand upright and
become brittle and are crowded at the top (Bunchy top) and shoe
dark green streaks with ‘J hook’ shape near the midrib.
➢ Flowers display mottled and streaked discolouration
➢ Plants show marked stunting
13. Pathogen/Disease cycle
The virus belong to genus nanovirus and family
Nanoviridae.
The virus is isometric and ssDNA with multipartite.
P. I. Through infected plant suckers.
S. I. By Banana aphid, Pentalonia nigronervosa
14. Management
Eradication of all infected suckers by spraying with
kerosene or by injecting herbicide, 2, 4-D
➢ Use of only certified banana suckers for planting
The new crop should be regularly inspected and the
diseased plants destroyed as soon as noticed.
➢ Vector control with systemic insecticides, Viz.,
Phosphomidon @ 1ml/lt or Methyl demeton @ 2 ml/lt
16. Mycosphaerella musicola (Cercospora musae)
Mycosphaerella fijiensis
On leaves small light yellow or brownish green narrow
streaks appear.
They enlarge in size becomes linear, oblong, brown to
black spots with dark brown brand and yellow halo.
Black specks of fungal fruitification appear in the
affected leaves.
Rapid drying and defoliation of the leaves
17. Survival and spread
Survives on dry infected leaves on the field soil and primary
infection takes place through ascospores in the infected
plant debris.
Secondary spread through wind borne conidia and
ascospores
Infection takes place through stomata on the lower surface
of young leaves.
Surface moisture is necessary for release of both conidia
and ascospores. Hence the disease is severe in moist
weather
18. Management
Removal and destruction of affected leaves followed by
spraying with BM (1%) + linseed oil (2%)
Prevent water accumulation around the plant and go for
periodical weeding.
Spray zineb@0.25% or copper oxy chloride@0.3%
suspended in mineral oil .
Spray chlorothalonil@0.2% or carbendazim or thiophanate
methyl@0.1% or mancozeb@0.25% along with spreading
agent.
Wetting agent such as teepol or sandovit added at the rate
of 1ml/lit of water.