Mango physiological disorders A Lecture By Allah Dad Khan To FFS Trainee

2. Mango Physiological Disorders
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah DadKhan
Provincial Coordinator IPM KPK
MINFAL Pakistan

3. MANGO
Black tip
• Coal fumes of brick kilns containing sulphur
dioxide, ethylene and carbon monoxide are
• observed to be responsible for black tip. The
damage has been noticed in the mango
orchards
• located up to 200metres of distance from
brick kiln. It is characterised by depressed
spots of

4. Spongy tissue in fruit
• A non edible sour patch developed in the mesocarp of mango fruit is broadly termed
• spongy tissue. The malady has been reported only in Alphonso. The peculiarity of this malady is
• that external symptoms of the fruit affected by spongy tissue are not apparent at the time of
• picking or at the ripe stage. These can be detected only on cutting the ripe fruit. This malady
• renders the fruit unfit for human consumption. It is a physiological disorder in which fruit pulp
• remains unripe because of unhydrolyzed starch due to physiological and biochemical
• disturbances caused by heat in mature fruit at pre-and post-harvest stages. Single and double pre-
harvest dip of fruits in calcium solution significantly increased the calcium content in the ripe
• fruits, whereas there was no significant increase in calcium content by post harvest Ca dip
• treatment. The pre harvest dip significantly reduced the occurrence of spongy tissue in the ripe
• ‘Alphonso’ fruits. The use of wind-breaks for protecting the orchard from warm air during May,
• and use of proper precautions at post-harvest stage checks the disorder.

5. Malformation
• Among all the known diseases and insect pests of mango, malformation is
undoubtedly
• the most serious. Depending on the plant part affected, two categories of
the malformation,
• vegetative and floral, have been recognized. In vegetative malformation,
the vegetative buds in
• the leaf axils or at the apical meristem of the younger plants, on
activation, develop abnormally
• as compact rosette-like shootlets, bearing tiny leaf rudiments. Many such
shoots may arise to
• form a bunch, hence it is also sometimes known as bunchy top. The
problem is not serious in the
• grown-up trees. The affected new shoots on the old trees, however,
become thick, stunted, and
• develop a whorl of small leaves. Floral malformation, in contrast, is very
virulent and

6. • Fruit drop
• In mango, there is a heavy drop of
hermaphrodite flowers and young fruits
amounting to
• 99% or more. In general, in mango 0.1% or
less hermaphrodite flowers develop fruits to
• maturity. The maximum drop of fruits in
‘Langra’ and ‘Dashehari’ takes place in the
first three
• weeks of April and differs significantly from
the drops in the following weeks. Fruit drop
is to
• some extent associated with the variety, as
the variety ‘Langra’ is more prone to fruit
drop than
• ‘Dashehari’. Deficient nutrition of many
developing embryos
• may be the most important internal
• factor leading to post-fertilization drop in
mango. This results due to competition
among over-crowded fruitlets on panicle.
Degeneration of the embryo in the initial
stages of its development
• may yet be another cause of drop. This
occurs invariably, if the flowers are self-
pollinated. 2,4-D
• produced better results at concentrations
below 20ppm, because at higher
concentrations fruit
• and seed development is retarded. Single
spray of NAA or 2,4-D each at 20ppm or Alar
100ppm
• at pea stage of fruit gives promising results.

7. Nitrogen
Deficiency
Symptoms :
•
Yellow undersized leaves,
severe retardation of growth,
twigs become yellow in color.
Fruits smaller and mature
early. Leaves small with
general yellowing
• Correction Measure
:Application of recommended
nitrogenous fertilizers (80 kg
N/ha) or foliar application of
Urea 2-4% at fortnightly
intervals

8. Phosphorus
Deficiency Symptoms :
• Retarded growth premature
dropping of older leaves partial
die-back from the tip small green
younger leaves are borne at the
tips of the branches. Some
branches show die back. Leaf tip
necrosis and premature
abscission of leaves.
• Correction Measure :
• Soil application of single super
phosphate or foliar application of
ortho phosphoric acid 0.5
%thrice.
•

9. Potassium
Deficiency Symptoms :
• Darkening of leaves, reduced
growth and vigour. Appearance of
white, yellow or orange chlorotic
spots in older leaves and
distributed irregularly over both
under and upper leaf surfaces.
Necrotic areas develop along the
leaf margins. Poor growth of roots.
Die back with tip burn with small
leaves.
• Correction Measure :
• Foliar spray of KCl 2% at fortnightly
intervals.
•
•

10. Calcium
Deficiency Symptoms :
• Abnormal growth of young
leaves and growing points
resembling boron deficiency
severe deficiency leads to
death of the bud.
• Correction Measure :
• Application of gypsum at 50
kg/ha.
•

11. Magnesium
Deficiency Symptoms :
• Reduction in growth premature
defoliation yellowish brown
chlorosis featured by a green
wedge down the central part of
the leaf bronzing starting from
the edge of the leaf rounded
margin between each pair of
lateral veins.
• Correction Measure :
• Soil application of MgSO4 5-10
kg/ha a foliar spray of MgSO4 2%
at fortnightly intervals.
•

12. Sulphur
Deficiency Symptoms :
• Symptoms first appear on
young leaves with fading of
green colour. Growth is
stunted. Leaf tip remains
green and with severe
deficiency the whole leaf turns
yellow.
• Correction Measure :
• Soil application of sulphur
fertilizer
•

13. Boron
Deficiency Symptoms :
• Deficiency is common in high rain
fall areas, high temperature, soil
acidity and calcareous
soils. Fruits become brown in
colour. Flesh may become soft
and watery which cracks down to
the centre.
• Correction Measure :
• Application of 5-10 kg Borax / ha
a foliar spray of 0.25% Borax at 10
days interval or solubor at 300
gm/ 100litres of water.
•

14. Copper
Deficiency Symptoms :
• Shoots produced on long
drooping S-shaped branches
of previous growth are
weak lose foliage and die
back.
• Correction Measure :
• Foliar spray of Copper oxy
chloride 0.2% at fortnightly
intervals.
•

15. Manganese
Deficiency Symptoms :
• Deficiency appears on the middle of the
plant. Interveinal chlorosis of
leaves. Reduced growth leaf symptoms
appear very late leaves show a
yellowish green background with a fine
network of green veins on the upper
surface and disappearing after a few
weeks mature leaves thicker and
blunted. Specks of light grey to grayish
brown colour appear under mid
deficiency.
• Correction Measure :
• Foliar application of MnSO4 0.2% at
fortnightly intervals.
•

16. Zinc
Deficiency Symptoms :
• Leaf blade thickens leaf shape is
distorted leaf margin up or down the tip
may curve back interveinal areas leaves
are usually smaller thickened leaf blade
brittle spaced leaves show a rosette
appearance. Some twigs die back
flower panicles of trees showing little
leaf symptoms are usually small
irregular in shape drooping spikes.
• Correction Measure :
• Soil application of ZnSO4 10 kg/ha or
foliar spray of ZnSO4 0.5% or nitrozinc
at
150 ml /100litres of water.
•