Mango

Mangoes are generally harvested at physiological mature stage and ripened for optimum quality.

a) Maturity : The mango fruits should be harvested at green mature stage.The best way to observe maturity in mango is the colour of the pulp which turns cream to light yellow on maturity and hardening of the stone.

b) Harvesting : The harvesting in mango should be done in the morning hours and fruits should be collected in plastic trays and kept in shades. The fruits should not be allowed to fall on the ground as the injured fruits cause spoilage to other healthy fruits during packaging and storage. Fruits harvested with 8-10 mm long stalks appear better on ripening as undesired spots on skin caused by sap burn are prevented. Such fruits are less prone to stem-end rot and other storage diseases.

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.

  • 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.
  • 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.

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.

Embryo abortion, climatic factors, disturbed water relation, lack of nutrition, disease, pest and hormonal imbalances are the major factors that lead to fruit drop.

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.

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.

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.

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 :

  • Pruning of shoots bearing malformed panicles
  • Deblossoming of early emerged / infested panicles.

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 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.

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.

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.

The common diseases are the powdery mildew, anthracnose and dieback.

To control dieback of twigs and branches, cut the affected twigs below the infected region and apply Bordeaux paste to the cut ends.

In general, 40-45 years old mango trees exhibit decline in fruit yield because of dense and overcrowded canopy. The trees do not get proper sunlight resulting in decreased production of shoots. The population of insects and pests built up and the incidence of diseases increases in such orchards. These unproductive trees can be converted into productive ones by pruning.

Intermingling, diseased and dead branches are removed. Thereafter undesirable branches of unproductive trees are marked. At the end of December, these marked branches are beheaded at 1.5 to 2.0 meter from distal end and the cut portions are pasted with copper oxy chloride solution. During March-April, a number of new shoots emerge around cut portions of the pruned branches.

After two years of pruning new shoots comes and the yield of fruit increases gradually.

Due to wide spacing and developing root patterns, the large unutilized interspace can be exploited for growing inter and mixed crops successfully.

The soil fertility can also be maintained / enhanced by careful selection of intercrops and adequate management of the orchard. This enables the orchardists to raise extra income during the years when the main crop yields no / low returns.

Selection of intercrops depends on agroclimatic region, marketing facilities, levels of inputs and other local considerations.

Some fertility restoring crops like legumes and leguminous cover crops should be included into the intercropping patterns. The partial shade loving crops like pineapple, ginger, turmeric, etc. can be grown in fully grown orchards. Some of important crop rotations recommended are as follows :

  • Greengram -gram
  • Blackgram -gram
  • Cowpea-gram

Immediately after planting the mango, the weed problem may not exist, but it is advisable to break the crust with hand hoe each time after 10-15 irrigations. However, subsequent hoeing may be done depending on weed growth in the basin.

Interculture operations are equally important for the bearing mango orchards. First ploughing should be done before the onset of rains. This will help in checking run-off losses and facilitate maximum retention of water in the soil. Orchard may be ploughed again after the rainy season is over in order to suppress weed growth and to break capillaries. Third ploughing may be done in the last week of November or first week of December with a view to checking the population of mango mealy bugs.

Amount and frequency of irrigation depends upon the type of soil, prevailing climatic conditions, especially rainfall to be given, and its distribution and age of trees.. During the first year the plants are to be watered every 2-3 days in the dry season. Trees in the age group of 2-5 years should be irrigated at 4-5 days interval. The irrigation interval could be increased to 10-15 days for 5-8 years old plants during dry season. When trees are in full bearing stage, generally 2-3 irrigations are given after the fruit set. Profuse irrigation during 2-3 months proceeding the flowering season is not advisable. Irrigation should be given at 50 per cent field capacity.

Grow vegetables, horse gram, black gram, pineapple and banana as intercrop in young orchards. Carry out intercultural operations by ploughing or digging twice during the year in June October. For reducing fruit drop and to improve productivity, NAA at 10-30 ppm concentration may be sprayed to the entire inflorescence at the peak stage in the second week after fruit set.

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