Mango is well adapted to tropical and sub-tropical climates. It thrives well in almost all the regions of the country from sea level to an altitude of about 1,400 m, provided there is no high humidity, rain or frost during flowering period. It may not be desirable to grow mango commercially in areas above 600 m above MSL in subtropics. It cannot stand severe frost, especially when plants are young. Though the best mango growing regions of the world have the annual mean temperature ranging from 21 to 27 °C, it can tolerate a temperature range of 5 to 44°C. Mango thrives well in places with annual rainfall in the range of 75 to 375 cm. Heavy rainfall prior to flowering induces excessive vegetative growth at the expense of flowering. Frequent rains and high humidity (about 80%) during flowering and fruit set are conducive to the incidence of pests and diseases and impair pollination and fruit set. In general, places with well distributed rainfall and dry summer are ideal for mango cultivation. Light rains during fruit development are good. It is better to avoid areas with heavy winds and cyclones.
Mango comes up well on a wide range of soils which are deep (minimum 6 feet) and well drained except clay, extremely sandy, rocky, calcareous, alkaline and water logged soils. Mango prefers slightly acidic soils though it can tolerate pH range of 5.5 to 7.5 and can also tolerate salinity up to 4.5 dSm-1. Slightly acidic to neutral, well drained and aerated loamy or alluvial deep soils rich in organic matter are ideal for mango cultivation.
Mango being highly heterozygous and cross pollinated, vegetative propagation is a must for getting true to type plant material. Only in the case of polyembryonic varieties, seed propagation can be adopted, but such trees will take longer period for bearing. Nucellar seedlings from polyembryonic varieties can be used to get clonal rootstocks, which impart uniformity. The polyembryonic variety Olour was found to be a dwarfing rootstock for Himsagar and Langra in North India and Vellaikulamban for Alphonso in South India. Bappakkai and Olour as rootstocks are moderately tolerant to salt (5.0 dSm-1) in irrigation water.
Till a few years back, inarching was the most common method of propagation. However, veneer grafting has given good results both under North as well as South Indian conditions. More recently, epicotyl grafting and softwood grafting by cleft and wedge method have become more popular being easier and economical. The latter three have the advantage that grafts can be prepared at places away from the mother plant with transported scion sticks but the scion has to be pre-cured for good success. High humidity is essential for good success of epicotyl and softwood grafting. In arid regions where field establishment of grafts is problematic, in situ softwood or veneer grafting could be useful.
The spacing varies according to fertility level of soil and prevailing growing conditions. Conventional spacing varies from 10m X 10m in the dry zones and poor soils where growth is less to 12m X 12m in heavy rainfall areas and rich soils where abundant vegetative growth occurs in case of vigorous varieties. New dwarf hybrids like Amrapali and Arka Aruna can be planted at closer spacing in the northern plains and the peninsular plateau, but not under humid tropical climate such as the coastal ecosystem where Amrapali tends to be vigorous. High density planting is advocated for increasing the productivity per unit land area by use of dwarfing rootstock, application of growth retardants like paclobutrazol and pruning, apart from using low vigour scion varieties. Rectangular and hedgerow planting for increasing planting density is also suitable. Higher planting densities with spacing such as 6m X 4m or 4m X 3m could be attempted for higher productivity, especially during the early orchard years, which needs more intensive care and management practices compared to conventional spacing to contain the tree size within the restricted space without causing overcrowding or over-shading during the later years.
Planting is usually done during July - August in rain-fed areas and during February - March in irrigated areas. In case of heavy rainfall zones, planting is taken up at the end of rainy season. Prior to planting, the land should be prepared by deep ploughing followed by harrowing and leveling with a gentle slope to facilitate good drainage. Pits of about one cubic meter size are dug at the desired spacing during dry summer months and after exposing them to sun for about 2 to 4 weeks, are refilled before rainy season with the original soil mixed with 20 - 25 kg well rotten FYM, 2.5 kg super phosphate and 1 kg muriate of potash. In areas having termite problem, soil drenching with Chlorpyriphos (0.2%) can be done.
The grafts for planting should be obtained from reliable sources and care should be taken that the polythene strip used for grafting is properly removed and that the plants have not become pot-bound. One-year-old healthy grafts are recommended for planting. The graft with its ball of earth intact is placed at the centre of the pit using a planting board by excavating as much soil as needed to accommodate the root-ball. Care should be taken that the roots are not exposed after planting and that the graft union is above the ground level. The moist soil of the pit is then pressed all round the ball of earth. Small basins should be formed around the plants and the plants should be irrigated immediately after planting.
In the initial one or two years, provide stakes to make the plants grow straight. Training the plants in the initial stages is essential to give them proper shape. About 75 to 100 cm of the main stem from the base should be kept free from branching and the main branches can be allowed thereafter in such a way that they grow in different directions and are spaced at about 20 to 25 cm apart. The main stem may be headed back at a height of about 1.2 m to facilitate the development of scaffold branches. Any suckers coming from rootstock should be immediately clipped off. Branches which cross over and rub each other may be removed at pencil thickness and the centre of the trees may be kept open to facilitate infiltration of sunlight. Once proper frame work is established, minimal pruning may be needed for the removal of diseased, pest infested or dried shoots and overcrowding branches and those touching the ground annually, immediately after harvest of fruits.
Occasional centre opening of the canopy once in three or four years, concurrently with the annual pruning, in overcrowded and old trees helps in getting good flowering and fewer incidences of pest and disease. Annual pruning assumes more importance under high density planting, Tipping of primary, secondary and tertiary branches is also needed under high density planting during the initial years of orchard establishment to enhance branching and thereby fruiting terminals early and to give a compact shape to the trees.
In general, 73g N (170g Urea), 18g P2O5 (112g single super phosphate) and 68g K2O (114g muriate of potash) per plant per year of age from first to tenth years and thereafter 730g N, 180g P2O5 and 680g K2O per plant per year can be applied in two splits – half N + full P2O5 and K2O immediately after harvest of fruits in June - July and the other half of N in October, by broadcasting in the basins around the pants leaving about 30 cm from the tree trunk, followed by hoeing into a depth of 15 cm. Irrigation may be provided after fertilizer application if there are no rains. Well decomposed farm-yard manure may be applied every year. Application of FYM @ 25 t / ha is helpful in saline soils for mango plants to tolerate salt injury. Foliar spray of 3% urea is recommended before flowering in sandy soils. Precise fertilizer application has to be followed based on soil and leaf analysis. For nutritional diagnosis, 4 to 5 months old leaves from the middle of non-bearing shoots are used.
Among the micronutrients, zinc deficiency is the predominant one, which can be corrected by three sprays of 0.3% zinc sulphate in February, March and May. Spraying 0.5% magnesium sulphate in February and April and 0.3% ferrous sulphate are helpful to correct magnesium and iron deficiencies. Spraying 0.5% Borax twice at monthly interval after fruit set and 0.5% manganese sulphate after blossom is useful to correct boron and manganese deficiencies, respectively.
Irrigation has to be scheduled depending on the soil and climatic conditions prevailing and age of trees. For young plants, frequent watering is needed for proper establishment. During initial years, protective irrigation is to be provided to the newly planted grafts at an interval of about 2-3 days while trees of 3-4 years can be irrigated at 4-5 days interval in summer. No irrigation is needed in rainy season unless there are long spells of drought and frequency can be reduced during winter months. In grown up trees, irrigation at 10 to 15 days interval from fruit set to full maturity of fruits is beneficial for improving fruit size and reducing fruit drop. Irrigation is not advisable for 2 to 3 months prior to flowering, as it is likely to promote vegetative growth. Although basin irrigation was generally followed in mango orchards, drip irrigation is recommended for economizing the water use. About 50% replenishment of evaporation losses is generally recommended under drip irrigation and 75% of recommended dose of fertilizers can be supplied through drip irrigation using soluble fertilizers.
Mango fruits should be harvested at optimum stage of maturity as immature fruits have inferior quality and over mature fruits have poor shelf life. Mangoes should be harvested at mature green stage, which can be judged, by fully developed cheeks with outgrown shoulders, formation of a depression at the stalk end, visibility of lenticels, change in skin color from dark-green to light-green, change in pulp color from white to yellowish, when specific gravity of the fruit ranges between 1.01 and 1.02 or when one or two ripe fruits fall from the plant naturally. Mangoes should be harvested by hand with a certain length of the stalk. Also, mango harvesters having long pole with a cutting blade and a small bag beneath to catch the fruit should be used. Keep the harvested fruits in a cool place away from direct sunlight and heat to avoid accelerated metabolic activities and ripening that reduces the shelf life.
After harvest, latex should be allowed to drain away from the fruit by placing them in inverted position over bamboo or gunny thread netting for 20 to 30 minutes or until the sap flow is stopped, with the stalk clipped short (1 cm), while holding the fruit with stem end down. Fruits should not be allowed to come in contact with the soil at any stage as soil sticks to the latex and scratches the peel and microorganisms may enter from the soil through stalk or injuries. The fruits can be placed in plastic crates for handling and transportation and the use of bags, sacks and baskets should be avoided. Uniform ripening of mature mangoes could be hastened by exposure for 18-24 hours to ethylene gas, either direct from cylinders, ethylene generators or as liberated from ethephon/ethrel using alkali, in an air tight chamber or room. Optimum temperature for storage of mango is 13°C and 85 - 95% relative humidity, while that for ripening is 20° - 25°C.