WELCOMEWELCOMETO TO

Diseases of Fruit Diseases of Fruit CropsCrops

K. M. Golam DastogeerLecturerDepartment of Plant PathologyBangladesh Agricultural universityMmensingh-2202

DISEASES OF FRUIT CROPS

THE MANGOES

Anthracnose, sooty mould, leaf blight, die back,

powdery milddew, and a bacterial leaf spot

Anthracnose of mango On leaves, lesions start as small, angular, brown to

black spots that can enlarge to form extensive dead areas.

on panicles small black or dark-brown spots, which can enlarge, coalesce, and kill the flowers before fruits are produced.

Ripe fruits develop sunken, prominent, dark brown to black decay spots before or after picking.

sometimes “tear stain” symptom and cracking

• Spray Carbendazirn (Bavistin 0.1%) during flowering to controls blossom infection.

• Spraying copper fungicides (0.3%) to control of foliar infection.

• Dip treatment of fruits in Bavistin (0.1%) in hot water at 52 C for 15 minutes to control post harvest

Stem end rot of mango

In fruits, the pericarp darkens near the

base of the pedicel.

The affected area enlarges to form a

circular, black patch which under humid

atmosphere extends rapidly and turns

the whole fruit completely black within

two or three days.

The pulp becomes brown and softer• Avoid harvesting immature fruit• Careful handling to minimize

mechanical injuries. • Postharvest dip of fruits in

Carbendazirn (0.1%) in hot water at 52 ± 1°C for 15 minutes controls the disease in storage and transit.

White superficial powdery fungal growth on leaves, stalk of panicles, flowers and young fruits.

Affected flowers and fruits drop pre-maturely

Powdery Mildew

Control : Following three sprays of fungicides at 15 days interval recommended for effective control of the disease :

• Wettable sulphur 0.2 % (2 g Sulfex / lit.

water).

• Tridemorph 0.1 %( 1 ml Calixin / lit.

water).

• Dinocap 0.1 % (1 ml / g Karathane / lit.

water).

Misshapen shoots with short internodes

and brittle leaves.

Leaves are signiicantly smaller than

those of healthy plants and re-curve

towards the stem giving a bunchy-top

appearance.

Malformation

• Compact and clustery appearance

• Flower bud transform into vegetative

• Drying of twigs and branches followed by complete defoliation

• Gives the tree an appearance of • scorching by fire. • Initially it is evident by discoloration and

darkening of the bark. The dark area • advances and extends outward along

the veins of leaves. • The affected leaf turns brown and its • margins roll upwards. • Exudation of yellowish brown gum

Die Back

1. Pruning of the diseased twigs 2-3 inches below the affected portion and spraying Copper

2. Oxychloride (0.3%) on infected trees controls the disease. The cut ends of the pruned twigs are pasted

3. with Copper Oxychloride (0.3%).

• Black sooty mould on the leaf surface• Trees turn completely black• Mealy bug, scale insect, hoppers-honey

dew-fungal growth-photosynthesis impaired

Pruning of affected branches and their prompt destruction prevents the spread of the disease.

Spraying of 2 per cent starch is found effective.

It could also be controlled by spray of Nottasul + Metacin + gumacasea (0.2% + 0.1% + 0.3%).

• Red Rust• Rusty red spots mainly on leaves and

sometimes on petioles and bark of young

twigs

• Spots are greenish grey in colour and velvety

in texture. Later, they turn reddish brown.

• Circular and slightly elevated spots sometimes

coalesce to form larger and irregular spots. 

Control : Two to three sprays of copper oxychloride (0.3%) is effective in controlling the disease

Bacterial Leaf Spot

Anthracnose of Banana

• Infection appears as small, black, circular specks on the mature & immature fruits.

• The specks increase, become sunken and coalesce to form large spots of black in color.

• In case of severs infection, fruits may be covered with dark blemishes.

• Immature or young fruits ripen prematurely and turn black. The skin shriveled and often cracked. Spraying of Chlorothanlonil (0.2%) and

Bavistin (1 %) four times at 15 days interval is recommended. Minimising bruising; proper sanitation of handling and prompt cooling to 14°C are essential in minimising the disease in cold storage

Sigatoka/leaf spot of banana• First appears as small, light yellow spots

parallel to the side veins of leaves.

• Spindle shaped spots with grayish to

ash colored sunken centers surrounded

by dark brown margin and yellowish

haloes.

• several spots may run together to form

large patches, causing the leaf blade to

dry up from the edge-inwards.

• Rapid drying and defoliation of mature

leaves is the characteristic feature of

this disease.

Spray Dithane M-45 WP or Tilt 50 EC @ 0.3% at 10 days intervals.

Anthracnose of guava

• Symptoms appear in both green and ripe fruits.

• Small, pin-head sized spots appear on the unripe fruits.

• Spots enlarge to form sunken and circular and dark brown to black

• Minute black stromata appear in the centre

• Spots coalesce

• Infected area of the unripe fruits becomes

harder and corky.

• Scab or canker type symptoms can appear

on young and mature fruits.

• Infected fruits may be malformed and drop

off.

Die-back of guava

Young twigs are attacked

Flowers shade before opening and the

twigs become dark.

Gradually spreads downward resulting die-

back of the young twigs and small

branches

Ultimately whole branches die.

Papaya mosaic

top young leaves are much reduced in size

Show blister like patches of dark green

tissue alternating with yellowish green lamina

and puckering

Often the leaves are severely curled giving

tendril like appearance.

stage

Management2-3 foliar sprays of Phosphamidon (0.05%) at an interval of 10 days starting from 15-20 days after sowing effectively checks the population of aphids

Leaf curl of papaya

characterized by severe curling, crinkling, and distortion of leaves accompanied by vein-clearing and reduction in size

Leaves become leathery and brittle

The most prominent symptom is the rolling of leaves downward and inward in the form of an inverted cup and thickening of veins.

ControlSpray insecticides dimethoate @ 0.02% for vector control with 2-3 sprays at the interval of 8 days.

Papaya Ring Spot

yellowing and vein-clearing of the young leaves.

conspicuous yellow mottling of the leaves and sometimes severe blistering and leaf distortion.

Dark-green streaks and rings also appear in the leafstalks and stems.

concentric rings and spots or C-shaped markings, a darker green than the background-green fruit color.

on ripe fruit darker orange-brown rings appear

ControlAphids can be controlled by 2-3 foliar sprays of Phosphamidon (0.05%) at an interval of 10 days starting from 15-20 days after sowing.

Anthracnose of Papaya

• Brown to black depressed spots on the fruits.

• Centers of these spots later turn black and then pink when the fungus produces spores.

• The flesh beneath the spots becomes soft and watery,

• Small, irregular-shaped water-soaked spots on leaves.

• These spots eventually turn brown. ControlSpay Copper Oxychloride 0.3% or Carbendazim 0.1% at 15 days interval

Stem rot / Foot rot

Water soaked spot in the stem at the ground level which enlarge and griddle the stem.

The diseased area turns brown or black and rot. 

Terminal leaves turn yellow droop off. 

The entire plant topples over and dies. 

Control•Seed treatment with Thiram or Captan 4 g/kg or Chlorothalonil. •Drenching with Copper Oxychloride 0.25 % or Metalaxyl 0.1%

Grey leaf spot of coconut/Leaf spot of coconut

Dark brown to grayish white oval spots appear scatteredly all over the leaf lamina. Margins of the spots are dark brown with grayish centre surrounded by yellowish haloes. In severely infected trees, hundreds of spots may be found on a leaf blade, causing blight and withering of the leaves.

Pale yellowish discoloration of the heart leaf.

Basal tissues of this leaf become rotten and this leaf can

easily be pulled out from the bud.

With the progress of the disease, brown lesions develop

at the base of all the young leaves.

Dead leaves drop off till the whole crown is lost and a

mere stem is left standing.

The soft, infected portion rots, degenerates to a slimy

mass and emits a foul smell.

Young nuts fail to develop and fall. Brown rotten area is

seen at the base of the young nuts.

Apply fytolan @ 0.5% to young leaves of affected and nearby healthy plants.

Bud rot of coconut

Scab of citrus

Irregular, corky spots on the leaves, twigs and fruits.

They become warty, erupted with cracks and scabby.

On the leaves, the spots are found more often on the lower surface than on the upper.

On the fruits, the warty growths are surrounded by yellowish or chlorotic haloes. The color of the spot turns from yellow to orange brown and finally black.

Several spots run together to form large patches of corky outgrowths. The leaves sometimes crinkle due to the occurrence of several spots on them.

• Lesions appear as yellowish spots on leaves, twigs, petioles, branches, fruit stalks, fruits and other parts including thorns.

• The spots enlarge gradually raised, rough and corky and are surrounded by yellow halo.

• The lesion on fruit looks similar to those on leaves except the yellow halo is usually absent and crater-like appearance is more noticeable.

Citrus canker

Die back of citrus

In the early stages, symptoms are restricted to one or two limbs but ultimately the whole tree is involved. The symptoms begin with die-back of small branches and twigs, yellowing of leaves and heavy bearing of' small fruits. Midrib and lateral veins of old, mature leaves turn yellow with interveinal areas along the veins showing diffuse yellowing. As the disease progresses, the symptoms intensify, resulting in severe chlorosis and mottling, reduction in leaf size and number, and wilting. Leaves may fall with onset of summer or autumn and the die-back of twigs commences up to down. This is followed by secondary growth consisting of short, upright, small, weak shoots showing a variety of discoloration of leaves. Minute dot like structures (called acervuli) are produced on the discolored tissues of the twigs. Often the small leaves have green veins or green blotches. Occasionally, small, circular, green spots appear on yellow tissues in younger most leaves. The die-back of weak shoot continues. ']'here is extesive and premature flowering. The fruits show conspicuous sun blotching. The cropping declines, foliage reduces, die-back of twigs extends, secondary fungal wood rot advances and finally the tree is completely destroyed.When the roots of such plants are examined, the feeder roots are also observed to be dead, the bark of the larger roots, distorted and brittle, and dry rot symptoms are seen, in many lateral roots. After 7 or 8 years the plants may die, by which time, there may be no leaf formation, the branches get dried up and the plants appears wilted almost completely. When the trunk root is affected most of tile altered roots are involved in a severe dry rot and the feeder roots are also dead.

Jacfruit Diseases

Diseases of importance include pink disease, Pelliculana (Corticium) salmonicolor, stem rot, fruit rot and male inflorescence rot caused by Rhizopus artocarpi; and leafspot due to Phomopsis artocarpina, Colletotrichum lagenarium, Septoria artocarpi, and other fungi. Gray blight, Pestalotia elasticola, charcoal rot,Ustilana zonata, collar rot, Rosellinia arcuata, and rust, Uredo artocarpi, occur on jackfruit in some regions.

THANKS TO ALL