POST HARVEST DISEASES OF BANANA, APPLE AND FIG

Ataulla ChapparabandID. No. : 6916Dept. of plant pathology

Anthracnose: Colletotrichum musarum

• Symptoms • The disease is variously known as

anthracnose, black rot, blakened rot, ripe rot.(Smoot et al.,1971)

• Small, black, circular specks on the skin of fruits. Later the spots become sunken & coalesce to form large spots.

• Bright salmon-coloured conidial mass appears on the spots.

• Severely infected fruits become dark due to blemishes.

• Acervuli also develop on the skin and the pulp becomes partially soft.

• latent infection usually starts during or after the harvest of bunches in small peel wounds and it continues to develop without a dormant period. (Chakraborty 1957)

Dark brown patches on immature fruits

Fruit turns black and shrivel

Contd..

• The presence of large areas on the ripe or ripening fruits is the main charecteristic symptom of this disease (Sohi 1975)

• Manly latent infections at the time of harvest, show large number of appressoria on the surface of the peel.

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

• Temp. 30 to 35°C and RH- 85.7 -100 %• Light brown depressed lesion, Coalesce and

cover the whole fruit and in Severe case pink spore masses on fruit surface will appear.

Whole bunch turns black

Management• Storing the fruits at 14.50 C with wax coating

(sadashivam et al., 1971)• cultural practices like clean and careful handling of fruits,

clean packing sheds proper washing before storage minimizes the storage losses. (Burdon et al.,1969)

• Post harvest dipping of fruits in • Carbendazim 400 ppm.• Benomyl (0.1%) for 5 Sec (Long 1970) • Aureofungin sol 100 ppm.• TBZ (400 ppm) (Phillips 1970)

CROWN ROT: Fusarium roseum, Lasidiplodia theobromae, Deightonialla torulosa

• Symptoms• Darkening of the hand and the adjacent

peduncle. The discoloured area covers almost one fourth of the fruit if the conditions are favourable.

• Loss of ability of hand to support fruits.• Main stalk decay rapidly, Tissue become

blackened and Emit pineapple odour.• Wind blown bunches develop severe spotting

on the fingers in rainy weather. Temp.23.9o C • Occurrence of black tip – fruit piercing moth,

helps in direct penetration of fungus.• The conidia are usually 3 to 5 septate. The

conidia are spread by air.

Initial Symptom

Darkening of peduncle

• Management• Control of crown rot starts in the field with the

regular removal of leaf trash.• Proper field sanitation can greatly reduce the

number of crown rot fungi spores present. (Ogawa et all., 1963)

• Do not keep rotting fruits or plant waste materials near the packing station.

• Maintain clean washing water in the delatexing baths and change the water frequently to stop it becoming heavily contaminated with spores.

• Dehanding should be done carefully with a sharp knife so as to avoid leaving a ragged cut. Finally, post-harvest treatment of fruits with an effective fungicide should be done.

• Johanson (et all., 1989) reported that highly absorbant cellulose pad coated with TBZ is effective for its control.

Fungus

Cigar-end rot: Verticillium theobromae

• First reported in Madhya Pradesh. • Srivastava & tandon (1971) reported Verticillium

theobromae as the cousal agent• Symptoms:  distal end of the fruits rots and which

on drying gives appearance of lightened cigar• Infection starts from tip of immature fruit and

spreads upward.• Ashy conidia and conidiophores cover the rotted

portion.• Imparting burnt ashy cigar-end appearance with a

dark border.• Decay may extend up to one-third of the fruit but

internal tissues develop a dry rot.• The fungus – plant debris – microsclerotia. Infected plant parts – irrigation water –

implements.• Conidia are hyaline, oblong to cylindrical, borne at

the ends of tapering phialides, aggregated into rounded, mucilaginous translucent heads.

Blackening at the tip

Management• The principal method of control is frequent manual removal and

burning of dead flower parts and infected fruits.• Use of fungicide to control the disease is also recommended. • Use of TBZ (400 ppm) as waxing is also effective (shillingford

(1977)• Use of tridemorph and triforin were also effective to check the

disease.• In the pack house, care should be taken to cull infected fruits to

avoid contaminating the washing water with spores.• Cigar-end rot is effectively controlled by covering the flower

(immediately after emergence) with a polyethylene bag before the hands emerge.

APPLE

Blue mould: Penicillium expansum

• Most destructive disease of apple in transit and in storage condition most prevalent in India (Singh 1941)

• Symptoms:  it Mainly originate usually from wounds, stem and invasions of core rot. Late in the season , when the fruit is weak, infection through lenticels may accure.

• the rot may develop around any minor injury as softish, water soaked, small pale to yellowish brown spots , initially shallow but subsequently deep and wide.

• Affected rind of the fruits become watery.• Watery spot increases in size and then entire

fruit rots and emits bad smell• Blue fungal growth is seen on the surface of

the fruits. (Ilag 1972)

Fruit rind become Watery

Fruit rot

Affected fruits

Management:

• avoide skin injuries .•Use of Benzimidazole fungicides in combination adequately controls the disease.(Rosenberger &Meyer, 1985)• Pre storage dip in TBZ (500ppm) for 2-3 minutes.• Benlate and Topsin M (0.05% - 0.1%) are effective when sprayed 15 days before harvest.(Borecka 1977)• Treating the friuts with benomyl, thiophanate-methyl • 2% bleaching powder – 5 minutes and 0.2% flit 406 – 10 minutes• TBZ – 0.1% incorporated in waxol-0-120 –under refrigeration

White rot: Botryosphaeria dothidea

White rot

Dark brown spot

Symptoms:One type - rot the fruit from the inside outward.Entire apple becomes soft but retains its shape and takes on a light brown color.Second type - white rot is small, brown, circular spots on the fruit, similar to bitter rot. The spots are softer than black rot and more cupped-shaped than bitter rot

Management:•Eliminating dead wood, including current season's fire blighted twigs, and avoiding stub cuts is important for disease prevention.•Pre harvest spray of carbendazim2-3 times starting six weeks before harves control the disesae. (Gupta 1989)

Alternaria rot: Alternaria alternata• Symptoms:• Disease is more in december to april and more in refrigerated fruits

than the fresh fruits.•  Typical rot symptoms of this disease are, spots of nearly round, brown

to black lesions, often centred around a skin resulting in breaking or weakening the tissue.

• Thees spots enlarge with ivory black center .• The spots are firm, dry and shallow.• The surface of spots becomes dark brown to black and in the advanced

stages, the rotted tissues become spongy and the affected flesh turns black.

Rounded brown spot

Enlarged brown spotRotted tissues Internel rotten tissue

Management:• Practice orchard sanitation and “soft

handling” of fruit.• Harvest fruit at proper maturity.• Careful handling during picking, washing, and

packing• Store fruits at temperatures of 0° to 4 °C.• Storing bins should be disinfected with chlorin

or steam.(Spott, 1990)• Washing of fruits with captofol (10 or 100

ppm) for 3-10 min. (Ballinger ,1983)

Green mould rot: Penicillium italicum• Symptoms:  It occurs on fruits during

storage and transit.• Affected of the fruits become watery.• Watery spot increases and then

entire fruit rots and emits bad smell• Green fungal growth is seen on the

surface of the fruits• Spores of the pathogen are air-borne• It entry through the stylar-end or

lenticels was selective and in frequent

Internal watery tissue

Increased watery spots

Management:

• Benomyl, Thiophanate-methyl • 2% bleaching powder – 5 minutes and 0.2% flit

406 – 10 minutes• storage at 2-40C.• TBZ – 0.1% incorporated in waxol-0-12 – under

refrigeration (Subramanian et al., 1973)• Pre storage dip in TBZ (500ppm) for 2-3 minutes.• Boric acid at 4% and Imazil

Apple scab: Venturia inaequalis• Symptoms:    Small, rough, black, circular

lesions of about 1-4mm in diameter on their skin after keeping in cold storage. Such syndrom is called as pin point scab

• These spots in storage enlarge in to sunken areas affected with secondory wet rot fungi cousing to fruits (Gupta 1992)

• low temperatures of 4 and 8°C favours for the development of disease.

• Ascus is slightly spatulate in shape• Ascospores are 2-celled, yellowish with

the upper cell shorter and sowewhat wider than the lower cell, oval shaped

Black circular lesions on skin

Enlarge spotsAscospores

Management:

• Infected spurs and cankers should be pruned during summer.

• Affected fruits whether on trees or fallen on the ground should be collected and buried in the soil.

• Diseased mummies should be ploughed into the soil.

• spray of mancozeb, phenyle mercuric chloride, bitertenol,benomyl 15-20 day before harvest.

Grey mould: Botrytis cinererea• Symptoms:  second most important post harvest

disease of apple.• The pathogen grows more rapidly in cold storage

and can infect the adjacent fruits.• The rot appears as firm brown areas on the fruits • It May have ash grey powdery spore mass.• The fungus advances into the inner flesh resulting

in a soft, watery mass of decayed tissue contained in a slightly intact, brown skin

• The pathogen sporulates on the surface of fruit and results in appears as the typical, powdery, grey mould stage. Fermented odour is also noticed

Watery mass

Brown spot

Grey mould

•The disease can spread by contact.

Management:• Managed by moving down the population of

weeds and grasses or with use of combination of Benzimidazol fungicedes.

• Sodium bisulphate which releases SO2 when in contact with moist air can be used with packing material.

• Dibromotetrachloroethane, sodium-o-phenyl phenate, 2-acetyl-3-hydroxyfuran (Eckert and Sommer, 1967).

• Grey mould can be controlled by prompt cooling (Rycall &Penzer, 1982)

Black rot: Botryosphaeria obtusa• Recorded from USA (Helser 1916)• Symptoms: it appears as a single firm brown spot on the

friut surface.•  Rot first appears on the calyx end of the fruit as a firm,

black, metallic-like spot with concentric rings.• Typical decay spots are circular and medium brown in

colour.• Reddish border spots appear anywhere on the apple

surface.• The entire inner flesh very slowly becomes brown to

black but devoid of any bad odour Black concentric rings

Decayed brown spotsReddish borde

Management:

• Treatment of fruits with linseed oil or mustard oil or castor oil.

• Treatment with capton (Fedorova 1980)

Bitter rot: Glomerella cingulata• Symptoms: Small, brown, circular

spots appears on the skin of fruits.• Later become sunken, forming a

saucer-shaped depression.• Wet weather conditions results in

the production of pink fruiting bodies of the fungus in the centre of the rotten area.

• Rot penetrates deeply into the flesh of fruit.

• 68°F favors the development of disease.

Bitter rot

Management:

• Three sprays of Bordeaux or Zn-Cu lime mixture at 20 days interval. (Liu et all., 1981)

• Spray Mancozeb 0.25 % in field.• Treatment with Mancozeb and capton @0.25

% to check the disease in storage.(Sutton 1990)

• Besides this proper sanitation is required, i.e all mummified fruits canckerd wood must be removed and burnt(Ryall &Pentzer, 1982)

Brown rot: Monilinia fructicola• Symptoms: • Enlarged spots of rotting appears and they are

soft but not mushy.• Circular and medium brown during the early

and medium stages of development.• Decayed area enlarges, small black spots

about 1/8 inch across gradually develop at the lenticels

• Entire fruit is decayed and under warm conditions turns black and develops a velvety sheen.

• In warm, moist conditions gray to tan fungal tufts develop, either in varying size patches or scattered over the decayed surfaces and fruit remain firm but hard and rubbery.

• Finally such infected fruits become grooved and indented and turn in to a sclerotoid mass and the flesh becomes permeated

Circular and medium brown fruit

Decayed fruits

Management:

• Control of brown rot begins with sanitation.• All twigs with brown rot cankers need to be

pruned and removed from the area or destroyed.

• Effective control can be achieved with use of benzimidazoles, triadimefon, fenarimol. (Motte et all., 1983)

FIG

Anthracnose

• The spots on the fruit initially appears as, small sunken and discolored areas. Later, these areas increase in size and pink masses of spores become visible on the surface of the discolored parts

• Fallen and diseased fruit should be gathered and. destroyed. Dried and diseased fruit should not be allowed to remain on the tree, as these harbor the fungus which will give rise to new in- . festations.

management

REFERENCES

• Post harvest diseases of horticultural perishables

by: Neeta Sharma & M. Mashkoor Alam• Post harvest pathology of perishables by: M.K. Dasgupta and N.C. Manda

http://agritech.tnau.ac.in/crop_protection/crop_diseases_postharvest_apple_8.html