Nature of Damage

• The nymphs and adults congregate under the outer base of the pseudostem

• Aphids always accompanied by ants, which act as dispersing agents of nymph

• Honey dew secretion appears on the plants which attracts the ants

• The aphids suck the sap of the plant and reduce the growth and vigour

• They also act as a vector of Banana Bunchy Top Virus (BBTV)

Identification of Pest

Nymph : Oval or slightly elongated, reddish brown with six segmented antennae
Adult : Small to medium sized aphids, shiny, reddish to dark brown or almost black. They have six segmented antennae and prominent dark veins
Adults start producing young one day after reaching maturity. They can give birth to 4 aphids per day with an average production of 14 offspring per female.

Control Measures

Cultural Control

• Ensure clean cultivation

• Use healthy and pest free suckers co check the pest incicence

• Rogue out the affected plants

• Ratoon and inter crops shoul not be taken up

• Collect planting material from healthy plants

• Immersing flowers and foliage in hot water at 49 degrees centigrade for 10 minutes kills banana aphids.

• Destruction of weeds and alternate hosts.

Chemical Control

• Spray soapy water or insecticidal soap  on plants thoroughly on petioles, furled leaves, whorls or on young suckers

• Spray Dimethoate (75ml/100lit) or Diazinon (1.5ml/lit) or Acephate (1.3g/lit) on infested plants and suckers

• Spray Methyl Demeton 25 EC 0.05%

Biological Control

• Introduction braconid wasps, Lysiphlebius testaceipes as parasitoid to parasitize the aphids

• Release predators such as lady bird beetles and lace wings in the field which are very active aphid feeders

• Apply bio control agents like entomopathognic fungus, Beauveria bassiana in the banana fields

Nature of damage

• Newly planted banana fields are easily susceptible to infestation

• Infestation begins at the base of the outermost leaf-sheath and in injured tissues at the lower part of the pseudostem.

• Initially the young grubs make several longitudinal tunnels in the surface tissue until they are able to penetrate to adjacent inner leaf-sheaths

• Then they bore into the pseudostem base and rhizome/corm, but also into the base of suckers and into roots.

• Larval tunnels may run for the entire length of fallen pseudostems.

• Infested plant shows yellowing and withering of leaves, slowed plant growth, root destruction, reduced fruit production

• Young infested suckers often wither and fail to develop.

• Plants are easily blown down by mild to strong winds.

• An economic threshold of 3 weevils per cut banana corm or pseudostem placed in the field overnight will trigger control action

Identification of Pest

Egg: elongate-oval, about 2 to 3 mm long and white in colour.
Eggs are laid singly in small cavities that are chewed out by the female in the base of the pseudostem just above ground level, in the upper part of the corm, in roots near the soil surface and at the end of cut stems (stumps).
Egg period is 4 to 36 days depending on temperature conditions.
Grub: creamy white legless grubs, stout and distinctly curved and swollen in the middle of the body.
The head is reddish-brown with strong mouthparts. Fully-grown grubs are about 12 mm long.
Grub period is 20 to 25 days
Pupa: white and about 12 mm long. Pupation takes place in holes bored by the grubs. Pupal period is 5 to 7 days 

Adult: 10 to 16 mm long weevils, hard-shelled, with a rather long curved snout. Newly emerged weevils are red brown, turning almost black after a few days.
They are free living, they are most commonly found between leaf sheaths, in the soil at the base of the mat or associated with crop residues.
Weevils may live for up to two years, and can live without food for six months, but are very sensitive to desiccation and will die within 48 hours if kept in a dry substrate. They are active at night.

Control Measures
Cultural Control

• Field sanitation

• Use clean planting material – This can be done by selecting vigourous healthy planting material

• Trimming the suckers

• Hot water treatment of corms at 52 to 55°C for 15 to 27 minutes

• Suckers should be pruned periodically and infested pseudostems must be removed from the field and destroyed. 

• Banana stumps kept in the field after harvest must be removed and destroyed as they serve as weevil refuges and breeding sites

• Crop rotation with non host crops like paddy and sugarcane

• Use mechanical barriers in the field

• Ensure proper fertilization and free from weeds at all times

• Use mulch away from the banana stool leaving a clear ring about 60 cm from the base of the stool to keep the roots growing towards the surface and to avoid moist conditions near the stool, which will attract banana weevils

• Do not take regular crop in the same field to avoid initial infestation

• Removal of pseudo stems below ground level

• Avoid growing Robusta, Karpooruvally, Malbhog, Champa and Adukkar

• Grow less susceptible varieties like Poovan, Kadali, Kunnan, Poomkalli

Chemical Control

• Cut the banana plant after harvest at the ground level and treat it with carbaryl (1g/liter) or chlorpyriphos (2.5 ml/lit) at the cut surface.

• Application of Furadan 3G @ 20 gms or Phorate 10G @ 12 gms or Neem cake @ 1/2 Kg. per pit at planting.

• Before planting, the suckers should be dipped in 0.1 per cent quinalphos emulsion.

• Remove the pseudostem after harvest and treat it with Carboryl (1g/lit) or Chlorpyriphos (2.5ml/lit).

• Fumigation of banana plants using Celphos (aluminium phosphide tablets), especially during the vegetative phase is phytotoxic and should be discouraged.

• Apply castor cake 250g or carbaryl 50g dust or phorate 10g per pit before planting also prevents infestation

• Severe attack dimethoate, methyl demeton, or phosphamidon may be sprayed around the collar region.

Biological Control

• Natural enemies - Predatory ants such as the bigheaded ant (Pheidole megacephala) and Tetramorium spp  feed the eggs, grubs and pupae of weevils.

• Apply biocontrol agents like Beauveria bassiana and Metarhizium anisopliae,an entomopathogenic fungus, in the banana fields and it causes more than 90% mortality of the weevils

• Steinerma and Heterorhabditis sp of nematodes attack both adult and grubs in the field.

• Application of 60 to 100 g of neem seed powder or neem cake at planting and then at four months intervals significantly diminished pest damage and increased yields. Application of over 100 g or neem oil was phytotoxic (harmful to plants) and uneconomical.

Mechanical Control

• Use of pheromone trap @ 25 traps /ha to destroy the weevil populations.

• Disc-on-stump traps can be used for trapping weevils. Disc-on-stump traps consist of corm slices placed on top of harvested plants cut at the rhizome. Adult weevils are attracted to the cut stems or corms for shelter, to feed and to lay eggs. The weevils can be collected by hand and destroyed. The efficiency of the traps depends on their numbers and frequency of trapping.

• Keep the longitudinal split banana traps @ 100/ha.

Nature of Damage:

• Nematode causes reddish-brown to black,elongated lesions which are readily seen when the roots are split open. Roots eventually blacken and die.

• Attacks by nematodes, combined with the effects of secondary rot organisms, destroy or weaken much of the root system.

• Infested plants lack vigour and fruiting is poor.

• Such plants are readily blown over and the roots are exposed.

Identification of pathogen

The causal organism of nematode is Burrowing nematode (Radopholus similis), Root lesion nematode (Pratylenchus coffeae), Root knot nematode ( Meloidogyne incognita), Sprial nematode(Helicotylenchus multicinctus)

Meloidogyne spp. Are sedentary endoparasites. Second stage juveniles emerge from the eggs, move towards the roots and penetrate the roots either at the root tip or in regions of previous penetration or where minor wounds are present.The eggs are laid within a gelatinous matrix to form an external egg sac or egg mass. A single sac contains several hundred eggs. Complete life cycle within four to six weeks

Burrowing nematode – eggs are laid in the corms and roots.2 weeks are required for the life cycle to be completed. Female nematodes live 2 to 3 months  and lay more than 100 eggs each. Nematode survive in the soil in the absence of suitable hosts

Lesion nematode – Their life cycle takes less than 20 days when temperatures range from 25 degree C – 30 degree C

Spiral Nematodes  are robust with strong stylets. They live partially or completely within roots, feeding on the outer cortical cells.

Control Measures:
Cultural Control

• The use of nematode-free planting material on uninfested land

• Trim the corm  tissue  until   all  black or discolored spots have been removed, leaving only clean white tissues

• Wash corms in running water, and allow them to dry before planting

• Submerge trimmed suckers for 20-25 minutes in hot water at 53-54°C.

• Grow nematode resistant varieties

• The planting tools should be cleaned before being used in the field

• Well decomposed manure should be used

• Crop rotation with non host crops

• Grow marigold in the inter space which serves as repellent and trap crop

• Covering the field for 6 to 8 weeks with plastic after tilling and watering raises the soil temperature

Chemical Control

• Application of Furadan 3G @ 20 gms or Phorate 10g @ 12 gms or neem cake @ 1/2 Kg. per pit at planting.
  

Nature of Damage

• Infestation of the weevil normally starts in 5 month old plants.

• Early symptoms of the infestation are the presence of small pinhead-sized holes on the stem

• Fibrous extrusions from bases of leaf petioles

• Adult weevils and exudation of a gummy substance from the holes on the pseudostem.

• During the advanced stages of infestation,  when split open the stem, exhibits extensive tunnelling both in the leaf sheath and in the pseudostem

• Rotting occurs due to secondary infection of pathogens and a foul odour is emitted. 

• When the true stem and peduncle are tunnelled after flowering, the fruits do not develop properly, presenting a dehydrated condition with premature ripening of the bunch itself.

Identification of Pest

Egg: Eggs are cream in colour and cylindrical in shape with rounded ends. The incubation period ranges from  3 to 8 days. 

Grub: The emerging larvae are fleshy, yellowish  white and apodous.  The larvae feed on tissues of the succulent sheath by tunnelling extensively and may reach as far as the true stem
Pupa: Pupate in cocoon by winding short pieces of fibrous materials of the sheath around its body. The pupa is exarate and present inside the cocoon.
Adult: The adult weevils are black-coloured and measure 23-39 mm. They often confine themselves within the pseudostem and in the decomposing tissues of harvested pseudostems. It  has a long life span and many adults live for  a year.

Control Measures
Cultural Control

• Uproot and burn infested plants.

• Planting material should be trimmed to reduce the number of eggs and grubs.

• After harvesting the bunch remove and destroy the pseudostem from ground level so as to avoid it serving as a breeding site for the pest.

• Avoid mattacking (leaving the plant after bunch harvest for recycling of nutrients) in weevil endemic areas.

• Prune the side suckers every month

• Use healthy and pest free suckers to check the incidence

• Do not dump infested materials into manure pit

• Apply mud slurry mixed with neem oil 5% on the pseudostem five month after planting in heavily infested areas to prevent oviposition
• Closely monitor the plants for the detection of oviposition punctureszxzsxz

Chemical Control

• Application of Furadan 3G @ 20 gms or Phorate 10g @ 12 gms or neem cake @ 1/2 Kg. per pit at planting.

• Treat the cut end of the leaf petiole with Chlorpyriphos (2.5ml/lit) + 1 ml sticking agent

• After harvesting of banana bunch cut the tree at base and treat it with 100ml Carbaryl (2g/lit) or apply 10g Beauveria bassiana

Biological Control

• Swab the cut surface of the longitudinal split traps with 20g of Beauveria bassiana fungus or Heterorhabditis indica nematode and the weevils die on their own due to infection

• Predatory ants such as big headed any and Tetramonrium spp. are important predators of the banana weevil.

• Dipping the suckers in 20% neem seed solution at planting

• Steinerma and Heterohabditis spp. attack both adults and grubs in the field.

Mechanical Control

• Use Longitudinal Split Pseudostem Traps (LPST) – This traps (45cm long) are made from the pseudostem pieces cut longitudinally in two halves. Such traps are laid randomly in the field @ 25 traps per acre.

• Disc -on-stump traps and old pseudostems can be used for trapping weevils. Disc-on-stump traps consist of corn slices placed on top of harvested plants cut at the rhizome.

Nature of damage:

• The early symptoms appear as water-soaked smoky areas where the colonies congregate to feed and oviposit between touching or adjacent fruit. These areas then develop the typical rusty-red to dark brown-black discolouration.

• Further rusty growth of the fruit and yellowing of leaves.

• While the taste and texture of the fruit within these peels remains unaffected, the exterior discoloration reduces the marketability of affected fruit. 

• In severe cases the skin develops longitudinal cracks and sometimes fruit may split

Identification of pest:

Egg: Eggs are not visible to the naked eye. Eggs are laid just below the fruit or pseudostem surface. In summer, eggs hatch in about eight days
Larva: The wingless creamy white larvae are smaller but have the same shape as the adult. The larval period lasts about 8-10 days.
Pupa: Pupae are white, 1 mm in length, similar to the larvae and can crawl. The pupal stage lasts 7-10 days
Adult: The adult is slender, 1.5 mm long, creamy yellow to golden brown with delicate feathery wings. The front margin of the wings is made up of a fringe of black hairs and, when at rest, these give the adult thrips a characteristic longitudinal black stripe down the middle of the abdomen. Two eye-like dark patches at the base of the wings are characteristic of adult rust thrips. These patches can be used to distinguish from the smaller males of the banana flower thrips.

Management:
Cultural method:

• Use thrips-free planting material or tissue-cultured bananas and, if possible, hot water treatment  prior to planting.

• Destroy all the volunteer plants and that could act as a source of thrips to spread to other plantings.

• Bunch covers (which cover the full length of the bunch) do provide some protection if applied very early.

• Regular checking of fruit under the bunch covers is essential to ensure that damage is not occurring.

Biological method:

• Field release coccinelid predators such as lacewings and ladybird beetles exert some control over rust thrips on the plant, and ants may be effective in removing some of the pupae in the soil.

Chemical method:

• Bunches, pseudostem and the suckers should be sprayed chlorpyriphos

• Soil application with Fipronil and Bifenthrin

Nature of damage

• The fungus attacks the young banana fruits usually at the distal end

• At the initial stage, small, circular, black spots develop on the affected fruits. Then these spots enlarge in size, turn to brown colour  

• The skin of the fruit turns black and shrivels and becomes covered with characteristic pink acervuli. Finally the whole finger is affected. Later the disease spreads and affects the whole bunch.

• The disease results in premature ripening and shriveling of the fruits which are covered with pink spore masses.

• Occurrence if black lesions on the pedicel causes withering of the pedicel and dropping of the fingers from the hands

• Sometimes the main stalk of the bunch may become diseased. Infected fruits become black and rotten

Identification of pathogen

• Acervuli  are usually rounded or sometimes elongated, erumpent.

• Conidiophores are cylindrical, tapered towards the apex, hyaline, septate, branched and sub-hyaline towards the base, each with a single terminal phialidic aperture

• Conidia are hyaline, aseptate, oval to elliptical or straight cylindrical, obtuse apices or flattened at base and obtuse at the apex, guttulate.

• The spread of the disease is by air-borne conidia and numerous insects which frequently visit banana flowers also spread the disease 

• The disease is favoured by high atmospheric temperature and humidity, wounds and brusies caused in the fruit and susceptibility of the variety

Control Measures
Cultural Control

• Burn the infected materials

• Proper field sanitation

• Practice crop rotation with paddy or sugarcane

• Keep the field free of weeds and provide good drainage

• Fruit should be free from infection and as possible before it is transported, stored and ripened

• Banana bunches should be harvested at correct stage of maturity.

• Proper fertilization prevents the infection

Chemical Control

• Protective spraying when the fruit is still young with Bordeaux mixture 1%

• Pre-harvest spray with Prochloroz 0.2% or Carbendazim 0.1% or Chlorothalonil 0.2% four times at fortnightly interval is highly effective

• Post harvest dipping of fruits in mycostatin 440 ppm or Aureofunginsol 100 ppm or Carbendazim 400 ppm or Benomyl 1000 ppm

Mechanical Control

• The distal bud should be removed when all the hands opened to prevent infection

• After harvest, the bunches should be transported to the store house without causing any bruises to them.  The transported bunches should be stored carefully at 7 to 10 degree c.

• Avoid contamination in collecting places, during transport and in ripening rooms

Nature of damage

• The disease is characterized by the presence of spindle shaped pinkish to reddish streaks on pseudostem, midrib and peduncle

• Typical mosaic and spindle shaped mild mosaic streaks on bracts, peduncle and fingers also observed

• Suckers exhibit unusual reddish brown streaks at emergence and separation of leaf sheath from central axis

• Clustering of leaves at crown with a travelers palm appearance, elongated peduncle and half filled hands are its characteristic symptom

Identification of pathogen

• The disease is caused by a virus belonging to potyvirus group. The virions are flexuous filamentous

• The virus is transmitted through aphid vectors such as Aphis goosypii, Pentolonia nigronervasa and Rhopalosiphum maidis. In field the disease spread mainly through suckers

Control measures
Cultural Control

• The diseased plants should be removed as and when noticed to avoid the spread of the disease

• Disease free planting materials should be used for new planting

• The banana gardens should be kept free from weeds

• Weeds in the nearby areas should be removed as the virus survives in them in off-season

• Early detection by regular inspection of planting and eradication of diseased plants from the field as soon as they are noticed

Nature of Damage

• Initially, dark green streaks appears in the veins of lower portion of the leaf midrib and the leaf stem

• Dark green, hook-like extensions of the leaf lamina veins can be seen in the narrow, light-green zone between the midrib and the lamina.

• On mature plants infected with BBTV, new leaves emerge with difficulty, are narrower than normal, are wavy rather than flat, and have yellow (chlorotic) leaf margins.

• They appear to be “bunched” at the top of the plant, the symptom for which this disease is named.

• Severely infected banana plants usually will not fruit, but if fruit is produced, the banana hands and fingers are likely to be distorted and twisted. 

Identification of Pathogen

• The virus is an isometric particle measure 20nm in diameter.

• It is ssDNA virus belonging to Nanoviridae family and babu virus genus.

• The virus has multi component genome

• There are six circular single stranded genomes known to be established

• The virus concentration is more present in phloem

• It is transmitted by infected suckers and banana aphid

Control Measures
Cultural Control

• Use virus free planting materials

• Remove and rouging of infected banana plants

• Chop,dry and bury the infected plants

• Maintain clean, weed free field for early detection of infested suckers

• Avoid banana cultivation in sugarcane and cucurbitaceous areas as sugarcane mosaic virus or cucurbit mosaic virus can easily spread to banana

Chemical Control

• The diseased trees should be injected with 4 ml of Fernoxone  solution(50g in 400 ml of water)

• Insertion of Fernoxone capsules (containing 200 to 400 mg of chemical per capsule) into the pseudostem by using the banana injector or capsule applicator

Nature of Damage

• The pathogen affects even the immature fruits. The upper portion of the peduncle is exposed to the hot sun, when the bunch emergence occurs during summer months and due to reduced functional leaves reduced 

• The infection, which occurs in perianth, spreads to fingers causing blackening of the skin, shrinkage and folding of the tissues.

• The affected tissues are corrugated and covered with fungus conidiophores and powdery grey conidia resembling ash on a cigar end.

• Dry rot also occurs in the pulp and the affected tissues become dry and fibrous.

• Warm and moist conditions favour the disease occurrence and the disease spread is high in old and badly maintained plantations.

Identification of Pathogen

• Conidiophores are solitary or in small groups.

• Conidia are hyaline, oblong to cylindrical. They are borne at the ends of tapering phialides, aggregated into rounded, mucilaginous translucent heads.

Control Measures
Cultural Control

• Young bunches should be opened up to the light and air and the bracts which remain attached to the bunch should be removed especially during wet weather

• The plantations should have enough aeration by avoiding overcrowding of plants

• Improved sanitation helps in the reduction of the disesase

• By placing polythene sleeves over the stems before hands emerge

Chemical Control

• The bunches may be sprayed with Copper oxychloride 0.25 per cent solution along with a wetting agent @ 0.5 to 1.0 ml per litre of spray fluid

• Spraying of the peduncle with Carbendazim at 0.1% or Dithane M-45 at 0.1% after shoot emergence

Mechanical Method

• Removal of pistil and perianth by hand immediately after the fruits are formed.

• Pistils should be removed 8 to 11 days after bunch emergence.

Nature of Damage

• This disease is more pronounced on young suckers leading to rotting and emitting of foul odour

• Roting of collar region is a commonest symptom followed by epinasty of leaves, which dry out suddenly

• If affected plants are pulled out it comes out from the collar region leaving the corm with their roots in the soil

• Splitting of pseudostem is common in late stage of infection in cultivars Robusta, Grand Naine and Thella Chakkerakeli

• When affected plants are cut open at collar region yellowish to reddish ooze is seen

• In early stage of infection dark brown or yellow water soaked areas are more in the cortex area

• In advance stage the interiror lesions may decay to such extent that cavities surrounded by dark spongy tissues are formed

• This soft rotting may spread radially towards growing point through the cortical tissues. The rotten corm emits foul smell

Identification of Pathogen

• The pathogen is a Gram-negative bacterium with peritrichous flagella and it is a rod shaped bacterium that lives alone or aggregates into pairs and chains

• The pathogen is soil borne and enters through wounds and also through leaf sheath of suckers

• The disease can be spread by infected plant debris, plant wounds and injuries. Hot and damp weather with plenty  of rainfall  trigger the disease to occur. Water is required for the bacteria to invade into the plant

Control Measures
Cultural Control

• Good drainage and soil conditioning can control the disease to some extent.

• Plant disease free suckers.

• Remove infected plants immediately.

• Remove plant residues after harvest.

• Practice crop rotation by using crops that are not susceptible to the bacterial rot disease like soyabean, forage legumes and small grains. Banana should not be grown along with onion and other vegetables. 

• Control nematodes and other insect pests that serve as  vectors of the bacteria to invade the plant tissues.

• Use of rhizomes with dead central buds and active lateral buds prevents the appearance of the disease.

• Avoid planting during rainy season and use of bigger suckers (more than 500g) for planting.

Chemical Control

• Drench with Methoxy Ethyl Mercuric Chloride (Emisan-6) 0.1 / or Sodium hypochlorite 10% or Bleaching powder 20g /litre/tree.

• Drench suckers 2% bleaching powder to control the disease in field at planting followed by another drenching the soil after 3rd month of planting to control the pathogen.

Nature of damage

• The disease is characterized by the presence of typical mosaic-like or discontinuous linear streaking in bands extending from margin to midrib.

• Rolling of leaf margins, twisting and bunching of leaves at the crown and a rigid erectness in newly emerged leaves

• The presence of dead or drying suckers is noticed in advanced cases referred as heart rot resulting from rotting of heart leaf and central portion of pseudostem

• Primarily infected banana plants develop severe mosaic symptoms in young growth showing broadly streaked chlorotic or yellowish green bands and patches or chlorotic mottling distributed in patches over the leaf lamina

• The leaves are narrower and smaller than normal and the infected plants are dwarf and lag behind in growth. Such plants do not produce bunches but as a virus reservoir

Identification of pathogen

• The casual agent of this disease is Cucumber mosaic virus(CMV). The virus is isometic, linear positive sense and single stranded RNA. The RNA is surrounded by a protein coat consisting of 32 copies  of single structural protein which form isometric particles

• The primary transmission is through use of infected daughter suckers from diseased palnts and the secondary spread of the disease is through melon aphid, Aphis gossypii  and Aphids maidis

Control Measures  
Cultural Control

• The banana gardens should be kept free from weeds

• Infected suckers should not be used for planting

• Weeds in the nearby areas should be removed as the virus survives in them in off-season

• Growing pumpkin, cucumber and other cucurbits between the rows of banana crop should be avoided

• Dry heat treatment of suckers at 40 degree C for one day inactivated the virus

• Early detection by regular inspection of planting and eradication of diseased plants from the field as soon as they are noticed

• Use of high input crop management of system comprising of 10 kg farm yard manure at the time of planting and subsequently at an interval of 3 months. 1 kg neem cake, 200 gm nitrogen, 40 gm phosphorus, 200 gm potassium per plant, 4 weeding at 2 months interval up to 8 months stage

Chemical Control

• Spraying Methyl Demeton 0.03 per cent (0.3 ml/lit of water) at 3 to 4 weeks interval controls the vector and reduces the spread of the disease

• Foliar spray of micronutrient (0.2% CuSo4(2ml/lit), 0.2% FeSo4(2ml/lit), 0.5% ZnSo4(5 ml/lit) and 0.1% H3Bo3(1 ml/lit of water) at 3,5 and 7th month after planting and spraying Glyphosate 2Kg per hectare to control weeds

• Control of insect vector by spraying Phosphomidon at 1 ml per litre or methyl demeton at 2 ml per litre

Nature of Damage

• Externally, the first obvious signs of disease in most varieties are wilting and a light yellow colouring of the lower leaves, most prominent around the margins. They eventually turn a bright yellow colour with dead leaf  margins.

• In the advanced stages of disease, affected plants may have a spiky appearance due to prominent upright apical leaves in contrast to the skirt of dead lower leaves.

• Internally, symptoms first become obvious in the xylem (water conducting) vessels of the roots and the rhizome. These turn a reddish-brown to maroon colour as the fungus grows through the tissues.

• When a cross-section is cut, the discolouration appears in a circular pattern around the centre of the rhizome where the infection concentrates due to the arrangement of the vessels. As symptoms progress into the pseudo-stem, continuous lines of discolouration are evident when the plant is cut longitudinally

Identification of Pathogen

• The casual organism is Fusarium oxysporum f.sp.cubense.

• This pathogen contains colonies of white to purple pigemented mycelium. Hyphae are septate and hyaline.  Conidiaphores are short and simple and having macroconidia and microconidia

• Macroconidia usually produced abundantly, slightly sickle-shaped, thin-walled, with an attenuated apical cell and a foot-shaped basal cell. They are three to 5-septate measuring 23-54 x 3-4.5 µm.

• Microconidia are abundant, mostly non-septate, ellipsoidal to cylindrical, slightly curved or straight, 5-12 x 2.3-3.5 µm occurring in false heads  from short monophialides.

• The disease is soil borne and the fungus enters the roots through the fine laterals. The disease incidence

• The incidence is high in acid alluvial soils.

• The pathogen is easily spread by infected rhizomes or suckers, farm implements or vehicles, irrigation water

Control Measures
Cultural Control

• Practice proper crop rotation with paddy/sugarcane once or twice followed by banana for 2-3 cylces

• Plant wilt resistant cultivars  such as Poovan and Nendran in endemic areas

• Avoid susceptible varieties such as Rasthali, Monthan, Karpuravalli, Kadali, Rasakadali, Pachanadan etc.

• Remove and destroy infested plant material after harvest

• When only 1-3 plants are infected, kill and chop up the diseased plants and stew all the material in water at a temperature of at least 70 deg C for 30 minutes.

• Grow healthy plants with proper fertilization, irrigation, weed control

• Provide good drainage especially during rainy season

• Soil application of rice chaffy grain or dried banana leaf formulation or well decomposed compost around the plants 

Chemical Control

• Application of 2 per cent of Carbendazim as injection of Carbendazim 50 ml capsule application

• Paring (pralinge removal of roots and outer skin of corm) and dipping of the suckers in a solution containing 0.2 per cent Carbendazim + 14 ml of per litre of water. Instead of Monoctophos the suckers may be dipped in clay slurry and sprinkled with Carbofuran granules at 40g/corm

• Soil drenching of Carbendazim 0.2 per cent solution alternated with Propiconozole 0.1% around the pseudostem at bimonthly intervals starting from five months after planting

• Application of urea + sugarcane trash (250g/pit) followed by lime (1Kg/pit) and neem cake (1-2Kg/pit)

• Application of neem cake @ 250 Kg/ha was most effecgtive in controlling Fusarium wilt in Rasthali cultivar

Biological Control

• Application Pseudomonas fluorescens a bactericide can also be applied along with farmyard manure and neem cake.

• About 60 mg of Pseudomonas (in a capsule) can be applied in a 10 cm deep hole made in the corm.

• Application of bio control agents like Trichoderma viride @ 25 g for 4 times once at the time of planting in the planting pit and remaining doses at third, fifth and seventh month after planting

• Application of T.harzianum Th-10, as dried banana leaf formulation @ 10g/platn in basal + top dressing on 2,4,and 6 months after planting

• Dipping the planting materials in spore suspension of P.fluorescens at 10g per plant at 3,5 and 7 months after planting

Mechanical Control

• Machinery and equipment should be treated with a  sanitary solution such as Farmcleanse®

• Footwear, which may have contacted banana plants or soil around banana plants elsewhere, should not be worn on the farm.

• No agricultural vehicles, tools (including shovels, knives and ladders) or equipment should be removed from, or brought on to, the farm without prior approval from management.

• Provide mechanical barriers in and around the infected plants

Nature of Damage

• Initially, appearance of pale yellow or greenish streaks parallel to the veins on the upper surface of the leaves

• Then these streaks darken and become more or less elliptical brown spots.

• Later on, the centre of these spots turns to light grey colour surrounded by yellow halo

• The spots often coalesce to form large irregular patches of dried tissue

• Rapid drying and defoliation of leaves are the characteristic feature of this disease

• Normally 15-18 leaves are necessary at the time of shooting for bunch development, but due to Sigatoka leaf spot it is difficult to maintain 15 leaves

• In severe cases, immature bunches fail to fill out 

• The fingers of bunch in affected plants tend to remain undersized and angular but pulp starts ripening

Identification of Pathogen

• This disease is caused by Mycospharella musicola fungus by the characteristics of the conidia and conidiophores

• The conidiophores are bottle shaped and bear conidia. Conidia are narrow and multiseptate 

• Perithecia are dark brown to balck, amphiceous, erumpent, ostiolate

• Asci are oblong, clavate. Ascopores are one septate, hyaline, obtuse-ellipsoid with upper cell slightly broader

• The conidia of the fungus are carried by wind ,rain water and old dried infected leaves and they help to spread the disease 

Control Measures  
Cultural Control

• Removal and destruction of affected leaves.

• Keep the banana field as weed free and remove the suckers timely.

• Avoid planting at close spacing.

• Provide proper drainage and avoid water logging in the fields which favours infection.

Chemical Control

• Spray Bordeaux mixture 1 per cent + linseed oil 2 per cent on the plants.

• Spray Copper oxychloride or Zineb with gas oil or mobile oil or white oil.

• Spray  3 times with Carbendazim 0.1 per cent or Propicanozole 0.1 % or Mancozeb 0.25% or Calixin 0.1%  and teepol (sticking agent) at 10-15 days interval, as the disease starting from initial appearance of leaf specks in lower side of the leaf.