Physiological Disorders and their Management Strategies in Mango
Authors: Pankaj Kumar, K.Usha and Nayan Deepak G
Div. of F & HT, ICAR-IARI, New Delhi


  • I. Alternate Bearing
  • Alternate Bearing or 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) is one of the most burning problems of mango cultivation.
  • Most of the commercial varieties of north India, namely, Dashehari, Langra and Chausa are alternate bearers, while south Indian varieties like Totapuri Red Small, Bangalora, and Neelum are regular in nature but they are unable to produce quality fruits under north Indian condition.
  • C/N (carbohydrate/nitrogen) ratio and nutritional and hormonal imbalance play vital role to cause alteration in bearing in mango.
Management Strategy

Use of paclobutrazol (cultar PPP333) was recommended for the first time in India from IARI, New Delhi. Application of paclobutrazol (PP 333) @ 22.5 ml/10 L of water at pea stage of mango fruit was found to induce new shoot growth in 65% of the fruited shoots which accounted for fruiting in the next season.

  • II. Leaf scorching
  • The characteristic symptom is scorching of old leaves at the tips or margins. The leaves fall down and consequently, the tree vigour and yield is reduced.
  • It is mainly due to excess of chloride ions which render potash unavailable.
  • This disorder is more common in saline soils or where brackish water is available for irrigation or where muriate of potash is used as a fertilizer to meet the potash requirement of the plants.
Management Strategy

  • It can be checked by 4-5 foliar applications of 2 % potassium sulphate on newly emerged flushes at fortnightly intervals

  • III. Mango Malformation
  • Mango malformation first reported in 1861 from Dharbanga in Bihar is now a serious threat to mango growers in Punjab, Delhi and Uttar Pradesh in India where more than 50% of the trees suffer from this malady and to some extent in Gujarat, Maharashtra, Bihar, West Bengal and Orissa. Southern India is virtually free from this threat.
  • Almost all the commercial mango cultivars like Bombay Green, Dashehari, Lucknow Safeda and Chausa show huge susceptibility to this malady.
  • Vegetative malformation is more common in nursery plants while it is floral malformed panicles that cause yield losses since effected panicles remain unproductive and are characterized by a compact mass of male flowers, greenish in colour and stunted in growth.
  • The complexity of the disorder is attributed to cultural, pathological and hormonal imbalance etc with temperature range of 25-28 0C (max.) and relative humidity >65% most conducive for the growth of the Fusarium mangiferae, resulting in severe incidence of malformation on newly emerged mango buds. 50-70% trees were attacked in North-Western, North-Eastern and North-Southern India. In Jammu, 21-45% floral malformation was recorded. There was an increase in incidence of malformation in Telangana and Andhra Pradesh and more than 50% damage was recorded in Punjab. Losses are as high as 86% in UP terrain. The yield losses in affected trees vary from 50-80% and in severe cases the loss may be almost total.
Management Strategies

  • It can be improved by a single spray of NAA (200 ppm) in the first week of October followed by deblossoming once at the bud burst stage during January. It has become the most widely accepted control measure for floral malformation.
  • Due to the airborne nature of spore dissemination and infection of buds, foliar spray with brewed tea prepared from datura, calotropis and neem plant extracts along with cow manure once before flowering and then again at flower bud initiation reduces the extent of mango malformation. Brewed tea is also rich in macro and micronutrients which help in fruit retention (3).
Conclusion

Physiological disorders associated with mango crop are not due to a single factor, but are due to amalgamation of pathological, genetical, environmental and physiological factors. Poor cultural and management practices followed in the orchards also aggravate the disorders resulting in poor yields and economic returns to the growers.

Impact on mango growers

The extent of damage to mango crop can be reduced by following recommended cultural and management practices at right time and in right dose. The estimated yield and economic returns earned by the mango growers when the crop is affected by the physiological disorders and after following the recommended management strategies is shown the following Table 1.


Table: Estimated yield (q/ha) and economic returns from mango trees effected with physiological disorder and after using control measures

i. Estimated yield (q/ha), economic returns from mango trees effected with disorders
Age of tree (yr) 6 7 8 9 10 11 12 13 14 15th onwards
Estimated yield (q/ha) 12 17 25 30 35 40 45 50 55 60
Economic returns @ Rs.10 / kg/ha 12000 17000 25000 30000 35000 40000 45000 50000 55000 60000
Total returns in North India (1,012,450 ha area) In Billion rupees 12.149 17.211 25.311 30.373 35.435 40.498 45.560 50.622 55.684 60.747
ii. Estimated yield (q/ha), economic returns using control measures
Age of tree (yr) 6 7 8 9 10 11 12 13 14 15th onwards
Estimated yield (q/ha) 25 35 50 60 70 80 90 100 110 120
Economic returns @ Rs.10 / kg/ha 25000 35000 50000 60000 70000 80000 90000 100000 110000 120000
Total returns in North India (1,012,450 ha area) In Billion rupees 25.311 35.435 50.622 60.747 70.871 80.996 91.120 101.24 111.37 121.49


References:


1. P.K. Majumder, D.V. Diware, 1989. Studies on horticultural aspects of mango malformation.ISHS Acta Horticulturae 231: ii International Symposium on Mango.10.17660/actahortic.1989.231.52.

2. Usha, K et al. (2009). Antifungal activity of Datura stramonium, Calotropis gigantea and Azadirachta indica against Fusarium mangiferae and floral malformation in mango. European Journal of Plant Pathology. 124, 637-657.



About Author / Additional Info:
Principal Scientist, Division of Fruits & Horticultural Technology, ICAR-IARI, New Delhi