Mango malformation

Mango malformation causes severe yield loss in India

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

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

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

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

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

6. Symptoms of Vegetative m alformation Contd … 6

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

8. Symptoms of floral m alformation Contd … 8

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

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

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

12. Nutritional aspects Micronutrient: 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 : The presence of malformin- like substances in fully grown malformed panicles has been reported The stem and root of malformed vegetative seedlings contain higher level of malformin as compared to healthy seedlings 14

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

17. Contd … Spraying 1000 ppm placlobutrazol prior to FBD, during the first week of October GA 3 @ 30ppm reduced incidence of malformation when sprayed at pre bloom stage 17

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

19. Pruning Prune the malformed branches 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 Pruning followed by a spray of insecticides follidol or metasystox as a control measure was recommended 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 Trichoderma viridae , T. virens and T. harzianum were used against the malformation The best result was obtained from Trichoderma harzianum followed by T. virens and T. viridae 21

22. Thank you 22