Banana: Diseases and their Management

April 21, 2023 no responses

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Banana crops in India are susceptible to a variety of Disease of Banana that can impair development and productivity. Panama disease, Fusarium wilt, Sigatoka leaf spot, Anthracnose, and Bunchy top virus are all frequent banana diseases in India. Pathogens including fungi, bacteria, and viruses cause these disease of Banana.

1. Sigatoka Leaf Spot Disease

Yellow Sigatoka is found all around the world.
First observed in Java in 1902; epidemic in Sigatoka Valley, Fiji, in 1913.
Yellow Sigatoka is a severe danger to banana crops in the Indian states of Assam, Tamil Nadu, Karnataka, and Andhra Pradesh.

Causal Organism:

Yellow Sigatoka – Mycosphaerella musicola
Black sigatoka or black leaf streak – Mycosphaerella fijiensis

Favourable Conditions:

High humidity, dew, and rainy weather with a temperature above 21°C
Prolonged periods of leaf wetness
Poor drainage and low soil fertility, especially in terms of potassium
Grand Naine, Dwarf Cavendish, and Giant Cavendish are susceptible cultivars.

Symptoms:

Early symptoms emerge on the lower leaves. Initially, little reddish-brown specks appear on the leaves towards the tip or margin of the lamina.
Specks may also appear at the midrib. The specks grow in size and shape into spindle-shaped spots with a reddish-brown edge and a grey centre encircled by a yellow halo.
Spots that appear around the midrib grow and extend to the lamina’s border.

Management:

Applying the correct potassium fertiliser dose.
Spraying mancozeb or chlorothalonil at a concentration of 0.2% in mineral (paraffin) oil.
In the pre-monsoon period, spray chlorothalonil 0.2% with non-ionic adhesive, and in the rainy period, spray propiconazole 0.1% interspersed with trimorph 0.1% at 20-day intervals.

2. Panama Wilt of Banana

The first report came from Australia in 1874.
The popular variety Gros Michel, which was largely grown for export quality fruits, was the most susceptible and had to be replaced by Cavendish bananas, which were resistant in Latin American countries. Rasthali (Amrutapani), Gros Michel, and Karpooravalli cultivars are susceptible.

Causal Organism: Fungus; Fusarium oxysporum f.sp. cubense

Favourable Conditions:

Saturated poorly drained heavy soils
Cultivation of susceptible cultivars like Amritapani

Symptoms:

2-3 months old plants are also killed under highly favourable conditions
Symptoms initially seen in older plants in a mat
The earliest symptoms are faint yellow streaks on the petiole of the oldest, lowermost leaves
Affected leaves show progressive yellowing, break at the petiole and hang down along the pseudostem
Longitudinal splitting of pseudostem is very common
The fungus grows and blocks the vascular system resulting in wilting of the plant

Management:

Application of lime (1-2 kg/ pit) to the infected pits after chopping off the plants parts
Dipping of suckers in carbendazim (0.1%) solution before planting
Neem cake + Trichoderma viride should be applied in planting pits
Soil drench with 0.2% carbendazim or rhizome injection with 0.2% carbendazim Growing resistant Cavendish varieties, viz., Basrai (Vamanakeli or Dwarf cavendish), Poovan (Karpura chakkarakeli) etc.

3. Moko Disease or Bacterial Wilt of Banana

First recorded in Guyana in 1840 in Moko plantain Reductions in yield due to Moko of up to 74% have been reported in Guyana.
A disease outbreak in Trinidad in the late 1890s caused severe losses of Moko cooking bananas.

Causal Organism: Bacteria; Ralstonia solenacearum

Symptoms:

Discolouration of vascular strands, wilting, and blackening of suckers are all symptoms.
Vascular discoloration (pale yellow to dark brown or bluish-black) is localised at the core of the pseudostem and becomes less noticeable towards the periphery.
When the infected plant’s pseudostem is cut transversely, greyish brown bacterial slime is visible.
The fruits of infected plants have a firm brown dry rot.

Management:

Fumigation of the infected site with Methyl Bromide or chloropicrin.
Drenching soil in infected pockets with bleaching powder solution (1.5%) and Bordeaux mixture 1% + streptocycline (0.02%).
Biocontrol with Pseudomonas fluorescens.

4. Rhizome Rot or Soft Rot or Tip Over Disease of Banana

First recorded in Honduras on Gros Michel in 1949.
Reductions in yield due to Tip-over of up to 93% have been reported in Guatemala.
In India, the incidence is up to 70% in Karnataka

Causal Organism: Bacteria; Erwinia caratovora sub. sp. caratovora and Erwinia chrysanthemii

Management:

Drenching the plant’s base with Pseudomonas fluorescens @1-2 Byplont (50g/1t water at 0, 2, 4, 4, and 6 months after planting)

5. Bunchy Top or Curly Top or Cabbage Top or Strangles Disease of Banana

First reported from Fiji in 1889 in Cavendish varieties.
Around 1940, introduced to India from Srilanka through the cyclone.

Causal Organism: Banana Bunchy Top Virus

Vector: Aphid (Pentalonia nigronervosa)

Symptoms:

Dark green streaks appear on the midrib, petiole and veins of the lamina.
Marginal chlorosis in the leaf lamina resembles an iron deficiency symptom.

Management:

Use of certified virus-indexed tissue culture plants
Only plant disease-free suckers. Spray systemic insecticides to suppress vectors, which aids in disease prevention.
Plant only certified banana suckers or tissue culture plants.
Rouging diseased plants with all suckers in the mat by rouging or killing by injecting herbicide, 2,4-D, on a regular basis.

6. Banana Bract Mosaic Virus (BBMV) or Konkan Disease

First reported from Mindanao, Philippines in 1979
In India, this virus disease was first reported in Kerala as Kokkan disease
Very rapidly spreading in all the banana-growing states of India in the absence of regulation on the movement of suckers

Causal Organism: Banana Bract Mosaic Virus

Vector: Aphid

Symptoms:

Flattening at the top of the plants (crown) with leaves arranged as in travellers palm is common in cooking banana cultivars
Unclasping of leaf sheaths from the pseudostem is a feature of the disease
Pseudostems of infected plants bow or curve at an angle rendering them prone to break even at moderate wind speeds
Infected plants generally do not flower or flower very late and produce a small bunch with elongated and brittle peduncle

Management:

Vector control with Methyl demeton or dimethoate@ 0.2% at 3 – 4 weeks interval

7. Banana Streak Virus (BSV)

Banana streak virus (BSV) is a serious Musa disease that reduces the output of both bananas and plantains.
This has been reported in practically every country where this crop is produced, including Mauritius, India, and several African countries.

Causal Organism: Banana streak virus (BSV)

Vector: Mealybug