Pests
The important pests of mango are hoppers, stem borers, shoot midges, leaf feeding insects, fruit flies and psyllids.
- To control mango hopper, spray malathion 0.1 % at the time of flowering.
To control shoot midge, which causes the drying of tender shoots, or dimethoate 0.05%. Apply wettable sulphur for the control of powdery mildew and anthracnose.
To control mango stem borer, apply paste made of crude carbolic acid (130 ml), soft soap (1 kg) and hot water (3.7 litres) to holes in the bark and plug the holes. A To control fruit fly, spray malathion 0.1 % emulsion / suspension containing 2% sugar. Collect and destroy attacked fruits that rot and drop down. Fruit flies can be effectively managed by keeping Ocimum trap @ 4 / tree And collection and destruction of fallen fruits by taking deep pits having at least 60 cm depth, Setting up of pheromone trap (methyl eugenol trap) @ 1 trap per 15 cents, swabing the tree trunk with jaggery 10% containing malathion 0.1% @ 1 litre/ tree during fruiting season at fortnightly intervals, soil application of B. bassiana formulation @ 10 litre solution/ 40 m2 under tree canopy (20 g/ litre) during fruiting season and post-harvest treatment of harvested fruits with lukewarm water @ 480C containing 1% salt for 15 minutes is recommended.
The common diseases are the powdery mildew, anthracnose and dieback.
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To control dieback of twigs and branches, cut the affected twigs below the infected region and apply Bordeaux paste to the cut ends.
Disorders
Mango malformation : Malformation is widely prevalent in northern India. The malformed panicles remain unproductive and are characterised by a compact mass of male flowers, greenish in colour and stunted in growth. Some remedial measures are recommended as follows :
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Pruning of shoots bearing malformed panicles
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Deblossoming of early emerged / infested panicles.
Biennial 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. The problem has been attributed to the causes like genetical, physiological, environmental and nutritional factors.
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For overcoming biennial bearing, de-blossoming is recommended to reduce the crop load in the ‘On’ year such that it is balanced in in the ‘Off’ year.
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Soil application of Paclobutrazol (PP333) or @ 4 - 5 g per tree(amount varies with the age of trees) 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
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.
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Embryo abortion, climatic factors, disturbed water relation, lack of nutrition, disease, pest and hormonal imbalances are the major factors that lead to fruit drop.
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. Black tip disorder has generally been detected in orchards located in the vicinity of brick kilns.
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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.
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Spraying borax (1%) or other alkaline solutions like caustic (0.8%) or washing soda (0.5%) is also effective. The first spray of borax should be done positively at pea stage followed by two more sprays at 15 days interval.