This document summarizes mango malformation, a disease caused by the fungus Fusarium moniliforme var. subglutinans that affects mango production. It describes the two types of malformation - vegetative and floral. Vegetative malformation disrupts apical growth resulting in stunted seedlings. Floral malformation causes thickened panicles with numerous unopened male flowers. Susceptibility varies by cultivar and is influenced by temperature, plant age, and time of year. Low temperatures during flowering increase incidence. Management strategies discussed include use of plant growth regulators, deblossoming, pruning, and fungicides or biocontrol agents like Trichoderma.

1. Ningappa Kirasur
2014-12-129
Dept. of Olericulture
COH, Vellanikkara 1

2. Mango
o Mangifera indica L.
o Anacardaceae
o 2n=4x=40
o South East Asia
o Occupies a pre-eminent place among fruit crops in India
o It is ‘King of fruits’ in the country
o Malformation is the most threatening malady
o Causes 50-80% yield loss
2

3. Mango Malformation
o Fusarium moniliforme var. subglutinans
o It was first reported by Watt in 1891 Darbhanga
district of Bihar
Types of malformation
o Vegetative Malformation
o Floral Malformation
3

4. Vegetative Malformation
o Is more commonly found on young seedlings
o It is characterised by disrupting of apical growth
resulting in several small flushes
o Quite short internodes at the apical ends of various
branches
o These shoots bear small leafy structures
4

5. Contd…
o The multi-branching of shoot apex with scaly leaves
is known as “Bunchy Top” or “Witche’s Broom”
o The malformed seedlings, becomes remain stunted
and die
5

6. Symptoms of Vegetative malformation
Contd…
6

7. Floral Malformation
o The primary, secondary and tertiary rachises become
short, thickened and hypertrophied
o Such panicles are greener and heavier with
increased crowded branches
o These panicles have numerous flowers that remain
unopened and are predominantly male flowers
7

8. Symptoms of floral malformation
Contd…
8

9. Cultivar susceptibility
o The susceptibility to malformation in mango varieties is
variable
o Is governed by the different factors like temperature, age of
the tree, time
o Amrapalli was found highly susceptible to mango
malformation
9

10. Contd…
o The 60% diseased panicles in cv. Neelum during the
flowering of February-March
o whereas the same plant had only 4-5%
malformation during off season flowering in June
o Incidence of disease is more in young plants than in
older ones
o About 91% incidence in 4-8 years plants 9.6% in
older plants was reported
10

11. Abiotic factors
Temperature:
o The low temperature at the time of flowering was
correlated with the intensity of malformation
o The incidence of disease is most severe in north-
west region of India
o where mean temperature during flowering remains
between 10-15°C
o It is mild where corresponding temperature is
15-20°C, sporadic at 20-25°C
11

12. Nutritional aspects
Micronutrient:
o The micronutrient deficiency, particularly iron and
zinc and copper has been associated with the cause
of malformation
12

13. Ethylene
 As some of the symptoms of mango malformation
resemble with those of ethylene effects
 The role for ethylene in mango malformation
Significantly higher level
13

14. Other Factors
Malformin:
o The presence of malformin- like substances in fully
grown malformed panicles has been reported
o The stem and root of malformed vegetative seedlings
contain higher level of malformin as compared to
healthy seedlings
14

15. Mangiferin
o Mangiferin is either absent or present. only in traces
in healthy mango panicles but in malformed ones
contains higher concentration
15

16. MANAGEMENT
Plant Growth regulators:
o The application of NAA 100-200 ppm, at flower bud
differentiation stage reduce the malformation
o Spraying of 500 ppm ethrel in February was highly
effective in reducing floral malformation
16

17. Contd…
o Spraying 1000 ppm placlobutrazol prior to FBD,
during the first week of October
o GA3 @ 30ppm reduced incidence of malformation
when sprayed at pre bloom stage
17

18. Deblossoming
o Deblossoming at bud burst stage, spraying of 200
ppm NAA was reported to be very effective in
controlling malformation
o Application of cyclohexamide at 250 ppm was very
effective in deblossoming the panicles
18

19. Pruning
o Prune the malformed branches
o Pruning followed by spraying with the mixture of
fungicide (Captan 0.1%), helps in controlling the
spread of the disease
19

20. Insecticides and fungicides
o Pruning followed by a spray of insecticides follidol or
metasystox as a control measure was recommended
o The control of malformation with spray of Carbendazim
0.1% at 10, 15 and 30 days interval (Oct. to Feb.) during
the flower bud differentiation stage
20

21. Management through bio-pesticides
o Trichoderma viridae, T. virens and
T. harzianum were used against the malformation
o The best result was obtained from Trichoderma
harzianum followed by T. virens and T. viridae
21

22. 22