Mangoes in India
. . . . .
mildew, Anthracnose, Die back , Phoma blight , Bacterial canker,
Red rust , Sooty mould Postharvest
Mealy bug , Inflorescence midge, Fruitfly, Scale insects, Shoot borer,
Bark-eating caterpillar, Stem borer, Shoot gall psylla, Leaf webber,
malformation, Biennial bearing, Fruit drop,
Black tip, Clustering disorder in mango (‘Jhumka’)
| Home |Mango
Mango suffers from
several diseases at all stages of its life. All the parts of the plant,
namely, trunk, branch, twig, leaf, petiole, flower and fruit are attacked
by a number of pathogens including fungi, bacteria and algae. They cause
several kinds of rot, die back, anthracnose, scab, necrosis, blotch, spots,
mildew, etc. Some of these diseases like powdery mildew are of great
economic importance as they cause heavy losses in mango production. Major
diseases of mango and their control measures are discussed below.
a) Powdery mildew
(Oidium mangiferae Berthet) : Powdery mildew is one of the
most serious diseases of mango affecting almost all the varieties, It occurs
up to latitude of 40o North and South of the equator. It may
persist for longer period at an elevation of 600-1200 meters, in many African
countries, south of the Sahara, the middle East, Southern Asia and America
: from the Southern United States to Peru and Brazil.
The disease is reported to
cause approximately 20 per cent crop loss in Maharashtra state alone. Sometimes,
as high as 70-80 per cent crop loss has been recorded on individual plant
The characteristic symptom
of the disease is the white superficial powdery fungal growth on leaves,
stalks of panicles, flowers and young fruits. The affected flowers and
fruits drop pre-maturely reducing the crop load considerably or might even
preven the fruit set. Rains or mists accompanied by cooler nights during
flowering are congenial for the disease spread. The fungus parasitizes
young tissues of all parts of the inflorescence, leaves and fruits.
: Following three sprays of fungicides at 15 days interval recommended
for effective control of the disease :
Wettable sulphur 0.2 per cent (2 g Sulfex
/ lit. water).
Tridemorph 0.1 per cent ( 1 ml Calixin
/ lit. water).
Dinocap 0.1 per cent (1 ml / g Karathane
/ lit. water).
of Glomerella cingulata Ston, Spaull and Schrenk) : The anthracnose
disease is of widespread occurrence. The disease causes serious losses
to young shoots, flowers and fruits under favourable climatic conditions
of high humidity, frequent rains and a temperature of 24-32oC.
It is also affects fruits during storage. The disease produces leaf spot,
blossom blight, withertip, twig blight and fruit rot symptoms. Tender shoots
and foliage are easily affected which ultimately cause ‘die back’ of young
branches. Older twigs may also be infected through wounds which in severe
cases may be fatal.
Depending on the prevailing
weather conditions blossom blight may vary in severity from slight to a
heavy infection of the panicles. Black spots develop on panicles as well
as on fruits. Severe infection destroys the entire inflorescence resulting
in no setting of fruits. Young infected fruits develop black spots, shrivel
and drop off. Fruits infected at mature stage carry the fungus into storage
and cause considerable loss during storage, transit and marketing. The
fungus perpetuates on twigs and leaves of mango or other hosts. Varietal
differences in susceptibility have been noted in India. In Kerala, maximum
damage was observed on Neelum, whereas variety Edward was reported to be
resistant. Since the fungus has a long saprophytic survival ability on
dead twigs, the diseased twigs should be pruned and burnt along with fallen
leaves for reducing the inoculum potential.
Trees may be sprayed twice with Bavistin (0.1%) at 15 days interval during
flowering to control blossom infection. Spraying of copper fungicides (0.3%)
is recommended for the control of foliar infection.
back (Botryodiplodia theobromae Pat.) : Die back is one of
the serious diseases of mango. The disease is prevalent in Rajasthan, Delhi,
Tamil Nadu, Punjab, Haryana, Orissa, Gujrat, Maharashtra and Uttar Pradesh.
The disease on the tree may be noticed at any time of the year but it is
most conspicuous during Oct.-Nov. The disease is characterized by drying
of twigs and branches followed by complete defoliation, which gives the
tree an appearance of scorching by fire. The onset of die back becomes
evident by discolouration and darkening of the bark. The dark area advances
and young green twigs start withering first at the base and then extending
outwards along the veins of leaf edges. The affected leaf turns brown and
its margins roll upwards. At this stage, the twig or branch dies, shrivels
and falls. This may be accompanied by exudation of gum. In old branches,
brown streaking of vascular tissue is seen on splitting it longitudinally.
The areas of cambium and phloem show brown discolouration and yellow gum
like substance is found in some of the cells.
: (i) Prune the diseased twigs and spray with copper oxychloride
(0.3%) on infected trees. Pruning should be done in such a way that the
twigs are removed 2-3 inches below the affected portion. (ii) In small
plants, pruning of twigs is followed by pasting of copper oxychloride.
blight (Phoma glomerata (Cords) Woll. Hochapf)
Phoma blight, a new disease of mango,
was first reported at Central Mango Research Station, Lucknow. The disease
was later detected in mango growing belt around Lucknow region. It is now
gaining economic importance.
The symptoms of the disease
are noticeable only on old leaves. Initially, the lesions are angular,
minute, irregular, yellow to light brown, scattered over leaf lamina. As
the lesions enlarge, their colour changes from brown to cinnamon and they
become almost irregular. Fully developed spots are characterized by dark
margins and dull grey necrotic centres. In case of severe infection such
spots coalesce forming patches measuring 3.5-13 cm in size, resulting in
complete withering and defoliation of infected leaves.
The disease could be kept under control by spray of copper oxychloride
(0.3%) just after the appearance of the disease and subsequent sprays at
20 day intervals.
canker (Xanthomonas campestris pv. mangiferaeindicae) :
Canker disease of mango, caused by a bacterium, is prevalent in Andhra
Pradesh, Maharashtra, Karnataka, Kerala, Tamil Nadu, U.P., Bihar, Delhi,
Haryana, Madhya Pradesh and probably in several other mango growing areas.
Besides being pathogenic on several varieties of mango, the organism is
capable of infecting wild mango, cashew nut and weeds as well. The disease
causes fruit drop (10-70%), yield loss (10-85%) and storage rot (5-100%).
Many commercial cultivars of mango including Langra, Dashehari, Amrapali,
Mallika, and Totapuri are susceptible to this disease.
The disease is found on leaves, petioles,
twigs, branches and fruits, initially producing water-soaked lesions and
later turning into typical cankers. The disease first appears as minute
water-soaked irregular lesions on any part of leaf or leaf lamina. The
lesions are light yellow in colour but with age, enlarge and turn dark
brown to black. They become angular, cankerous and raised, and are surrounded
by chlorotic halos. Several lesions coalesce to form irregular necrotic
cankerous patches. In severe infections the leaves turn yellow and drop
off. Cankerous lesions appear on petioles, twigs and young fruits. The
water soaked lesions also develop on fruits which later turn dark brown
to black. They often burst open, releasing a highly contagious gummy ooze
containg bacterial cells. The fresh lesions on branches and twigs are water
soaked which later become raised and dark brown in colour with longitudinal
cracks but without any ooze.
not wait for appearance of the disease. The key to success for full control
is to start application of fungicides before the infection has established.
Seedling certification, inspection and
Three sprays of streptocycline (100 ppm)
or Agrimycin-100 (100 ppm) after first visual symptom at 10-days intervals.
Monthly sprays of Bavistin (1000 ppm)
or copper oxychloride (3000 ppm)
were also found effective.
f) Red rust
( Cephaleuros virescens Kunze) : Red rust disease, caused
by an alga, has been observed in mango growing areas. The algal attack
causes reduction in photosynthetic activity and defoliation of leaves thereby
lowering vitality of the host plant.
The disease can easily be recognized
by the rusty red spots mainly on leaves and sometimes on petioles and bark
of young twigs and is epiphytic in nature. The spots are greenish grey
in colour and velvety in texture. Later, they turn reddish brown. The circular
and slightly elevated spots sometimes coalesce to form larger and irregular
The disease is more common in closely
planted orchards. Fruiting bodies of the alga are formed in humid atmosphere.
The zoospores formed by the sporangia initiate fresh infections. Stem entry
is achieved by way of cracks. The affected areas crack and scale off. In
severe infection the bark becomes thickened, twigs get enlarged but remain
stunted and the foliage becomes sparse and finally dries up.
Two to three sprays of copper oxychloride (0.3%) is effective in controlling
g) Sooty mould
(Meliola mangiferae) : The disease is common in the orchards
where mealy bug, scale insect and hopper are not controlled efficiently.
The disease in the field is recognis by the presence of a black velvety
coating, i.e., sooty mould on the leaf surface. In severe cases the trees
turn completely black due to the presence of mould over the entire surface
of twigs and leaves. The severity of infection depends on the honey dew
secretion by the above said insects. Honey dew secretions from insects
sticks to the leaf surface and provide necessary medium for fungal growth.
The fungus is essentially saprophytic and is non-pathogenic because it
does not derive nutrients from the host tissues. Although no direct damage
is caused by the fungus, the photosynthetic activity of the leaf is adversely
affected due to blockage of stomata.
: The mango fruit is susceptible tomany postharvest diseases caused by
anthracnose (C. gloeosporioides) and stem end rot (L. theobromae)
during storage under ambient condtions or even at low temperature. Aspergillus
rot is another postharvest disease of mango.
Pruning of affected branches and their
prompt destruction prevents the spread of the disease.
Spraying of 2 per cent starch is found
It could also be controlled by spray of
Nottasul + Metacin + gumacasea (0.2% + 0.1% + 0.3%).
Control : Preharvest sprays of fungicides
could control the diseases caused by latents infection of these fungi.
Postharvest dip treatment of fruits with fungicides could also control
the diseases during storage. The following treatments are suggested.
(i) Three sprays
of carbendazim (0.1%) orthiophante-methyl (0.1%) at 15 days interval should
be done in such a way that the last spray falls 15 days prior to harvest.
dip treatment of fruits in carbendazim (0.1%) in hot water at 52+1oC
for 15 minutes.
More than 492 species of insects,
17 species of mites and 26 species of nematodes have been reported to be
infesting mango trees, about 45 per cent of which have been reported from
India. Almost a dozen of them have been found damaging the crop to a considerable
extent causing severe losses and, therefore, may be termed as major pests
of mango. These are hopper, mealy bug, inflorescence midge, fruitfly, scale
insect, shoot borer, leaf webber and stone weevil. Of these, insects infesting
the crop during flowering and fruiting periods cause more severe damage.
The insects other than those indicated above are considered as less injurious
to mango crop and are placed in the category of minor pests. A brief description
of the biology and control of major pests of mango is given below.
a) Hopper :
Of all the mango pests, hopper is considered as the most serious and widespread
pest throughout the country. Idioscopus clypealis Lethierry, Idioscopus
nitidulus (Walker)and Amritodus atkinsoni Lethierry are the
most common and destructive species of hoppers which cause heavy damage
to mango crop. Large number of nymphs and adult insects puncture and suck
the sap of tender parts, thereby reducing the vigour of the plants. Heavy
puncturing and continuos draining of the sap cause curling and drying of
the infested tissue. They also damage the crop by secreting a sweet sticky
substance which encourages the development of the fungus Maliola mangiferae,
known as sooty mould which affects adversely the photosynthetic activities
of the leaves. A low population of hoppers has been recorded in mango orchards
throughout the year but it shoots up during February-April and June-August.
Shade and high humidity conditions are favourable for their multiplication.
Such conditions usually prevail in old, neglected and closely planted orchards.
The female hoppers lay 100-200 eggs
on mid rib of tender leaves, buds and inflorescence. In summers the total
life cycle occupies 2-3 weeks.
Three sprays of 0.15 per cent Carbaryl or 0.04 per cent Monocrotophos or
0.05 per cent Phosphomidon or 0.05 per cent Methyl Parathion have been
found very useful in controlling the pest population. First spray should
be given at the early stage of panicle formation. The second spray at full
length stage of panicles but before full bloom and the third spray after
the fruits are set and have attained pea stage are recommended.
: Biological control agents such as the predators Mallada boninensis
Chrysopa lacciperda, the egg parasite Polynema sp. and a preparation
of the fungus Beauveria bassiana are the important useful bioagents
to control this pest.
Integrated Pest Management (IPM)
The continuous use of pesticides though
control the pests but pose some other serious problems like killing of
and natural enemies, development of resistance to insecticides and residues
which are on fruits hazardous to human population. Besides, the high cost
of pesticides, labour and maintenance of equipments are other limiting
factors in pest control. Integrated pest management is gaining momentum
to take care of these problems. To manage mango hopper pest, avoid dense
planting and keep the orchard clean by regular ploughing and removal of
weeds. Pruning of overcrowding and over lapping branches should be done
in the month of December. Chemical spray is to be minimized necessary.
Neem products may be included in the management schedule of the pest. The
use of insect growth regulator Buprofezin (0.0125 %) is also suggested
as one of the sprays.
Mealy bug :
It is another major pest of mango in India and is widely distributed all
along the Indo-gangetic plain. Drosicha mangiferae Green is the
most common mealy bug and causes severe damage to mango crop throughout
the country. Nymphs and adults suck the plant sap and reduce the vigour
of the plant. Excessive and continuous draining of plant sap causes wilting
and finally drying of infested tissue. They also secrete honey dew, a sticky
substance, which encourages the development of a fungus Maliola mangiferae,
as sooty mould.
The adult male is winged and small,
female is bigger and wingless. The female, after copulation, crawl down
the tree in the month of April-May and enter in the cracks in the soil
for laying eggs in large numbers encased in white egg sacs. The eggs lie
in diapause state in the soil till the return of the favourable conditions
in the month of November - December. Just after hatching, the minute newly
hatched pink to brown coloured nymphs crawl up the tree. After climbing
up the tree they start sucking the sap of tender plant parts. They are
considered more important because they infest the crop during the flowering
season and if the control measures are not taken timely , the crop may
be destroyed completely.
: Polythene (400 gauge) bands of 25 cm width fastened around the
tree trunk have been found effective barrier to stop the ascent of nymphs
to the trees. The band should be fastened well in advance before the hatching
of eggs, i.e., around November - December.
: Application of 250 g per tree of Methyl Parathion dust 2 per cent
or Aldrin dust 10 per cent in the soil around the trunk kills the newly
hatched nymphs which come in contact with the chemical.
Spraying of 0.05 per cent Monocrotophos
or 0.2 per cent Carbaryl or 0.05 per cent Methyl Parathion have been found
useful in controlling early instar nymphs of the mealy bug.
: Menochilus sexmaculatus, Rodolia fumida and Sumnius
renardi are important predators in controlling the nymphs. The entomogenous
fungus Beauveria bassiana is found to be an effective bioagent in
controlling the nymphs of the mealy bug.
Pest Management (IPM) : The IPM schedule of mealy bug is very important
and useful if timely operations are done. Flooding of orchards with water
in the month of October kills the eggs. Ploughing the orchards in the month
of November exposes the eggs to sun’s heat. In the middle of December,
400 gauge alkathene sheet of 25 cm width may be fastened to the tree trunk
besides raking the soil around the tree trunk and mixing of 2 per cent
Methyl Parathion dust. The dust may also be sprinkled below the atkathene
band on the tree. The congregated nymphs below the band may be killed by
any of the suggested insecticides. The above IPM schedule holds promise
to control the mealy bug but spraying of neem product and the spores of
the fungus Beauveria bassiana will further ensure the reduction
of the pest population.
midge : The mango inflorescence midge, Erosomyia
indica Grover Diptera : cecidomyiidae) is another major pest of mango.
Recently, this pest has become very serious in certain pockets of Uttar
Pradesh causing serious damage to mango crop by attacking both the inflorescence
and the small fruits. The adult midge are harmless minute flies which are
short lived and die within 24 hours of emergence after copulation and oviposition.
The flies lay eggs singly on floral parts like tender inflorescence axis,
newly set fruit or tender leaves encircling the inflorescence. The eggs
hatch within 2-3 days. Upon hatching, the minute maggots penetrate the
tender parts on which the eggs have been laid and feed on them. The floral
parts finally dry up and are shed. The larval period varies from 7-10 days.
The mature larvae drop down into the soil for pupation. The pupal period
varies from 5-7 days. There are 3-4 overlapping generations of the pest
spread over the period from January-March. Thereafter, as the weather conditions
turn unfavourable, the mature larvae undergo diapause in the soil instead
of pupating. They break diapause on the arrival of favourable conditions
in following January.
The midge infests and damages the
crop in three different stages. The first attack is at the floral bud burst
stage. The eggs are laid on newly emerging inflorescence, the larvae tunnel
the axis and thus destroy the inflorescence completely. The mature larvae
make small exit holes in the axis of the inflorescence and slip down into
the soil for pupation. The second attack of the midge takes place at fruit
set. The eggs are laid on the newly set fruits and the young maggots bore
into these tender fruits, which slowly turn yellow and finally drop. The
third attack is on tender new leaves encircling the inflorescence. The
most damaging one is the first attack in which the entire inflorescence
is destroyed even before flowering and fruiting. The inflorescence shows
stunted growth and its axis bends at the entrance point of the larvae.
It finally dries up before flowering and fruit setting.
In addition to the inflorescence midge,
indica, two other gall-midges Dasineura amramanjarae Grover
and Procystiphora mangiferae Felt have been found damaging the mango
inflorescence. They infest and damage the floral buds of the inflorescence.
The mature larvae of D. amramanjarae are red, whereas those of P.
mangiferae are orange in colour. The larvae of the former species pupate
in buds itself. The infested buds of D. amramanjarae
have red coloured
petals and hence can be identified easily. The infested buds of P. mangiferae
and look bigger than normal buds. The control measures used for
were also found effective against these midges.
As the larvae pupate in the soil, ploughing
of the orchards expose pupating as well as diapausing larvae to sun’s heat
which kills them.
Soil application of Methyl Parathion also
kills pupating as well as diapausing larvae in the soil. The insecticide
in the soil should be applied after monitoring larval population on white
sheet below the tree.
Spraying of 0.05 per cent Fenetrothion
or 0.045 per cent Dimethoate or 0.04 per cent Diazinon at the bud burst
stage of the inflorescence has been found effective in controlling the
: The oriental fruitfly is one of the most serious pests of mango in the
country which has created problem in the export of fresh fruits. Daccus
dorsalis, D. zonatus and D. correctus are the most common fruitflies
which cause serious damage to mature mango fruits. The adult flies are
dark brown in colour and measure 7 mm in length and 4 mm across the wings.
The females have tapering abdomen which ends in an ovipositor. The female
punctures the outer wall of the mature fruits with the help of its pointed
ovipositor and insert eggs in small clusters inside the mesocarp of mature
fruits. After hatching, the larva feeds on the pulp of fruit which appears
normal from outside, but drops down finally. The mature maggots fall down
into the soil for pupation. The emergence of fruitfly starts from April
onwards and the maximum population is recorded during May-July which coincides
with fruit maturity. The population declines slowly from August to September
after which it is non-existent up to March.
: The adult fruitflies can be controlled by bait sprays of carbaryl
(0.2%) + protein hydrolysate (0.1%) or molasses starting at pre-oviposition
stage (first week of April), repeated once after 21 days. Another method
to control these flies is to hang traps containing a 100 ml water emulsion
of methyl euginol (0.1%) + Malathion (0.1%) during fruiting (April to June).
About 10 such traps are sufficient for one hectare of orchard.
pest management (IPM)
Collection and proper disposal of
the infested and dropped fruits.
Scale insects were not considered serious pest on mango in any part of
the country till recently, but of late, they have assumed the status of
serious pest in certain parts of the country. Pulvinaria polygonata,
Aspidiatus destructor, Ceroplastis sp. and Rastococus sp. are
some of the most common scale insects infesting mango crop. The nymphs
and adult scales suck the sap of the leaves and other tender parts and
reduce the vigour of the plants. They also secrete honeydew which encourages
the development of sooty mould on leaves and other tender parts of the
mango plant. In case of severe scale infestation, growth and fruit bearing
capacity of the tree is affected adversely. Among the above scale insects,
polygonata is posing a serious threat to mango industry of western
Ploughing the orchards and exposing the
diapausing pupae to sun’s heat. Releasing of parasite and predator during
December to February are helpful in reducing the pest population.
Monitoring and destruction of emerging
adult with methyl euginol traps.
Early harvesting of mature fruits.
Selective and need based bait spray.
Hot water treatment or vapour heat treatment
(VHT) of fruits before storage and ripening for killing the larvae.
Pruning of the heavily infested plant parts and their immediate destruction
followed by two sprays of Monocrotophos (0.04 %) or Diazinon (0.04 %) or
Dimethoate (0.06 %) at an interval of 20 days have been found very effective
in controlling the scale population.
f) Shoot borer
(Chlumetia transversa) : This pest
is found all over the country. Larvae of this moth bore into the young
shoot resulting in dropping of leaves and wilting of shoots. Larvae also
bore into the inflorescence stalk. The adult moths are shining grey in
colour and measure about 17.5 mm with expanded wings. Hind wings are light
in colour. Female moths lay eggs on tender leaves. After hatching, young
larvae enter the midrib of leaves and then enter into young shoots through
the growing points by tunnelling downwards. The full grown larva is dark
pink in colour with dirty spots and measures about 22 mm in length. There
are four overlapping generations of the pest in a year and it overwinters
in pupal stage.
The attacked shoots may be clipped off and destroyed. Spraying of Carbaryl
(0.2%) or Quinalphos (0.05%) or Monocrotophos (0.04%) at fortnightly intervals
from the commencement of new flush gives effective control of the pest.
A total of 2-3 sprays may be done depending on the intensity of infestation.
caterpillar (Ludarbella quadrinotata) : This pest is found
damaging a variety of plants including a number of fruit trees, forest
trees and ornamentals all over India. The old, shady and neglected orchards
are more prone to attack by this pest. Larvae of this moth feed on the
bark and weaken the tree. The moth is light grey in colour with dark brown
dots and measures about 35-40 mm with expanded wings. A single female lays
about 300-400 eggs in batches on the bark. The full grown caterpillar is
dirty brown in colour and is about 35-45 mm in length. The caterpillar
spins brown silken web on the tree which consists of their excreta and
wood particles. Larvae also make shelter tunnels inside the stem in which
they rest. Larvae actually feed from April to December. There is only one
generation in a year.
Remove the webs from tree trunks and put emulsion of Monocrotophos (0.05%)
or DDVP (0.05%) in each hole and plug them with mud.
Stem borer is widely distributed
in India and attacks a variety of fruit trees including mango. Damage is
caused by the grub of this beetle as it feeds inside the stems boring upward
resulting in drying of branches and in severe cases attained stem also
dies. Adult beetles, 35-50 mm in size, are stout and greyish brown in colour
with dark brown and black spots. Eggs are laid either in the slits of tree
trunk or in the cavities in main branches and stems covered with a viscous
fluid. Full grown grubs are cream coloured with dark brown head and 90
x 20 mm in size. Pupation takes place within the stem. Beetle emerges in
July-August. There is only one generation of the pest in a year.
The pest can be effectively controlled by following the recommendations
given for the control of bark eating caterpillar.
Shoot gall psylla
(Apsylla cistellata) : It is a very serious pest of mango
in many parts of India, particularly in Terai region of U.P., north Bihar
and West Bengal. This pest creates green conical galls in leaf axis. The
activity of the pest starts from August. The galls dry out after emergence
of psyllid adults in March. The females lay eggs in the midribs as well
as in lateral axis of new leaves. Nymphs emerge from eggs during August-September
and crawl to the adjacent buds to suck cell sap. As a result of feeding,
the buds develop into hard conical green galls. The galls are usually seen
during September-October. Consequently, there is no fruit set.
Eggs are white while nymphs are flat
and of pale yellow in colour. Adults are 3-4 mm long with black head and
thorax and light brown abdomen. Female lays approx. 150 eggs during March-April
and nymphs pass the winter inside the galls. There is only one generation
of the pest in a year.
The galls with nymphs inside should be collected and destroyed to prevent
carryover of the pest. The pest can effectively be controlled by spraying
Monocrotophos (0.05%) or Dimethoate (0.06%) or Quinalphos (0.05 %) at 2
week intervals starting from the middle of August. The use of same chemical
for every spray should be avoided.
j) Leaf webber
(Orthaga euadrusalis): The pest is
attaining serious proportions. Its infestation starts from the month of
April and goes up to December. Eggs are laid singly or in clusters within
silken webbings on leaves. Upon hatching, the caterpillars feed on leaf
surface by scrapping. Later, they make web of tender shoots and leaves
together and feed within. Generally, 1-9 larvae are found in a single web.
Pupation takes place inside the webs in silken cocoons. However, the last
generation (December-January) pupates in the soil. The adult moths are
medium sized and sombre coloured. Fully grown caterpillar measures 2.5
to 3 cm. They are brownish in colour with brown spots and whitish striation
on the dorsal surface. The pupae diapause for about five to six months.
The infestation is severe in shady conditions. Old orchards with lesser
space between tree canopy have more infestation than open orchards.
Pruning of infested shoots and their burning in the month of April to July
is found effective. Raking of the soil around the base of the trees in
January, after the last generation has pupated, helps in checking the pest
population. Three sprays starting from the last week of July at 15 days
interval with Carbaryl (0.2%) or Monocrotophos (0.05%)) or Quinalphos (0.05%)
have been found effective in controlling the pest.
(Sternochetus mangiferae) : This insect is widely
distributed in tropics. It is a common pest of mango in southern India.
Another species, S. frigidus,of the pest is found in Assam and Bengal.
Sweeter varieties such as Alphonso, Bangalora, Neelum, etc. are
more prone to attack by this pest.
Female lays eggs on the epicarp of
partially developed fruits or under the rind of ripening fruits. Newly
emerged grubs bore through the pulp, feed on seed coat and later cause
damage to cotyledons. Pupation takes place inside the seed. Discolouration
of the pulp adjacent to the affected portion has been observed.
Eggs are minute and white in colour.
Adult weevils are 5 to 8 mm long, stout and dark brown in colour. Life-cycle
is completed in 40 to 50 days during June-July. Adults hibernate until
the next fruiting season. There is only one generation in a year.
Destroying the affected fruits and exposing
the hibernating weevils by digging the soil
Spraying the trees with Fenthion (0.01%)
a) Mango malformation
: Malformation is widely prevalent in northern India, particularly
in the states of Punjab, Delhi and western U.P. where more than 50 per
cent of the trees suffer from this malady. The malformed panicles remain
unproductive and are characterised by a compact mass of male flowers, greenish
in colour and stunted in growth. The main and secondary rachis are thick
and short and bear flowers with relatively larger bracts, sepals and petals
as compared to normal flowers. The malformed panicles remain intact on
the trees for a considerable period. Though research efforto made hitherts
have not been able to ascertain its etiology, the complexity of the disorder
is attributed cultural practices, nutritional, to many factors like, mites,
fungal, viral, etc. hormonal imbalance. The exact cause and control of
the malady is yet to be established. However, some remedial measures are
recommended as follows :
bearing : The term biennial, alternate or irregular bearing generally
signifies the tendency of mango trees to bear a heavy crop in one year
(On year) and very little or no crop in the succeeding year (Off year).
Most of the commercial varieties of north India, namely, Dashehari, Langra
and Chausa are biennial bearers, while south Indian varieties like Totapuri,
Red Small, Neelum and Bangalora are known to be regular bearers. When a
tree produces heavy crop in one season, it gets exhausted nutritionally
and is unable to put forth new flush thereby failing to yield in the following
season. The problem has been attributed to the causes like genetical, physiological,
environmental and nutritional factors. For overcoming biennial bearing,
deblossoming is recommended to reduce the crop load in the ‘On’ year such
that it is balanced in in the ‘Off’ year. Proper maintenance of orchard
by way of effectively controlling pests and diseases and regular cultural
operations may also result in better performance of the tree every year.
Soil application of Paclobutrazol (PP333) or @ 4 - 5 g per tree
in the month of September resulted in early flowering with higher fruit
set and yield. It may be applied every year for regular fruiting, particularly
in young trees. The time of application may vary according to fruit bud
Pruning of shoots bearing malformed panicles
Deblossoming of early emerged / infested
c) Fruit drop
Despite high fruit set initially, the ultimate retention is quite low in
mango. The intensity of fruit drop, varies from variety to variety. Among
the commercially grown varieties, Langra is more susceptible to drop while
Dashehari is the least. The fruit drop is more or less a continuous process
and can be classified into three groups : (i) Pinhead drop, (ii) Post-setting
drop and (iii) May-month drop. The fruit drop in first two groups are insignificant
compared to the third group which affects the final yield significantly
and needs more attention. Embryo abortion, climatic factors, disturbed
water relation, lack of nutrition, disease, pest and hormonal imbalances
are the major factors that lead to fruit drop. The foliar application of
Alary (B-nine) @ 100 ppm or NAA 20 ppm at pea stage of fruit was found
effective in controlling fruit drop in mango.
d) Black tip
: Black tip is a serious disorder, particularly in the cultivar Dashehari.
The affected fruits become unmarketable and reduce the yield to a considerable
extent. The damage to the fruit gets initiated right at marble stage with
a characteristic yellowing of tissues at distal end. Gradually, the colour
intensifies into brown and finally black. At this stage, further growth
and development of the fruit is retarded and black ring at the tip extends
towards the upper part of the fruit. Black tip disorder has generally been
detected in orchards located in the vicinity of brick kilns. It has been
reported that the gases like carbon monoxide, sulphur dioxide and ethylene
constituting the fumes of brick kiln are known to damage growing tip of
fruits and give rise to the symptoms of black tip. Apart from these factors,
irrigation, condition of the tree and management practices also play important
role in deciding the severity of the disorder.
Planting of mango orchards in North-South
direction and 5 to 6 km away from the brick kilns may reduce incidence
of black tip to a greater extent.
The incidence of black tip can also
be minimised by the spray of borax (1%) or other alkaline solutions like
caustic (0.8%) or washing (0.5%) soda. The first spray of borax
should be done positively at pea stage followed by two more sprays at 15
disorder in mango (‘Jhumka’)
: A fruiting disorder, locallly known as ‘Jhumka’, is characterised
by the development of fruitlets in clusters at the tip of the panicles.
Such fruits do not grow beyond pea or marble stage and drop down after
a month or so of fruit set. These fruits do not contain seeds when they
are cut open. The disorder seems to be due to lack of pollination / fertilization
which may be attributed to many reasons. Among them, absence of sufficient
population of pollinators in the orchards is the major reason. Surveys
conducted in the mango belt of Lucknow revealed that the more problem is
area in Malihabad and Dashehari is the most affected cultivar. The other
reasons causing the disorder are old and overcrowding of trees, indiscriminate
spraying against pests and diseases, use of synthetic pyrethroids for spraying,
monoculture of Dashehari, and bad weather during flowering. Some of the
remedial measures are suggested below :
Insecticides should not be sprayed at
full bloom to avoid killing of pollinators.
Pests and diseases should be controlled
in time by spraying the recommended pesticides only.
Introduction of beehives in the orchards
during flowering season for increasing the number of pollinators.
The practice of monoculture of a particular
variety may be avoided. In case of Dashehari, 5-6 per cent of other varieties
should be planted in new plantations. In old orchards, where monoculture
of a particular variety like Dashehari is followed, a few branches may
be top worked with pollinizing varieties.
Pruning of old trees may be done to open
Spraying of 300 ppm NAA may be done during