It is a matter of astonishment to many that the luscious mango, Mangifera indica L., one of the most celebrated of tropical fruits, is a member of the family Anacardiaceae–notorious for embracing a number of highly poisonous plants. The extent to which the mango tree shares some of the characteristics of its relatives will be explained further on. The universality of its renown is attested by the wide usage of the name, mango in English and Spanish and, with only slight variations in French (mangot, mangue, manguier), Portuguese (manga, mangueira), and Dutch (manja). In some parts, of Africa, it is called mangou, or mangoro. There are dissimilar terms only in certain tribal dialects.
The mango tree is erect, 30 to 100 ft (roughly 10-30 m) high, with a broad, rounded canopy which may, with age, attain 100 to 125 ft (30-38 m) in width, or a more upright, oval, relatively slender crown. In deep soil, the taproot descends to a depth of 20 ft (6 in), the profuse, wide-spreading, feeder root system also sends down many anchor roots which penetrate for several feet. The tree is long-lived, some specimens being known to be 300 years old and still fruiting. Nearly evergreen, alternate leaves are borne mainly in rosettes at the tips of the branches and numerous twigs from which they droop like ribbons on slender petioles 1 to 4 in (2.5-10 cm) long. The new leaves, appearing periodically and irregularly on a few branches at a time, are yellowish, pink, deep-rose or wine-red, becoming dark-green and glossy above, lighter beneath. The midrib is pale and conspicuous and the many horizontal veins distinct. Full-grown leaves may be 4 to 12.5 in (10-32 cm) long and 3/4 to 2 1/8 in (2-5.4 cm) wide. Hundreds and even as many as 3,000 to 4,000 small, yellowish or reddish flowers, 25% to 98% male, the rest hermaphroditic, are borne in profuse, showy, erect, pyramidal, branched clusters 2 1/2 to 15 1/2 in (6-40 cm) high. There is great variation in the form, size, color and quality of the fruits. They may be nearly round, oval, ovoid-oblong, or somewhat kidney-shaped, often with a break at the apex, and are usually more or less lop-sided. They range from 2 1/2 to 10 in (6.25-25 cm) in length and from a few ounces to 4 to 5 lbs (1.8-2.26 kg). The skin is leathery, waxy, smooth, fairly thick, aromatic and ranges from light-or dark-green to clear yellow, yellow-orange, yellow and reddish-pink, or more or less blushed with bright-or dark-red or purple-red, with fine yellow, greenish or reddish dots, and thin or thick whitish, gray or purplish bloom, when fully ripe. Some have a “turpentine” odor and flavor, while others are richly and pleasantly fragrant. The flesh ranges from pale-yellow to deep-orange. It is essentially peach-like but much more fibrous (in some seedlings excessively so-actually “stringy”); is extremely juicy, with a flavor range from very sweet to subacid to tart. There is a single, longitudinally ribbed, pale yellowish-white, somewhat woody stone, flattened, oval or kidney-shaped, sometimes rather elongated. It may have along one side a beard of short or long fibers clinging to the flesh cavity, or it may be nearly fiberless and free. Within the stone is the starchy seed, monoembryonic (usually single-sprouting) or polyembryonic (usually producing more than one seedling).
Origin and Distribution
Native to southern Asia, especially eastern India, Burma, and the Andaman Islands, the mango has been cultivated, praised and even revered in its homeland since Ancient times. Buddhist monks are believed to have taken the mango on voyages to Malaya and eastern Asia in the 4th and 5th Centuries B.C. The Persians are said to have carried it to East Africa about the 10th Century A.D. It was commonly grown in the East Indies before the earliest visits of the Portuguese who apparently introduced it to West Africa early in the 16th Century and also into Brazil. After becoming established in Brazil, the mango was carried to the West Indies, being first planted in Barbados about 1742 and later in the Dominican Republic. It reached Jamaica about 1782 and, early in the 19th Century, reached Mexico from the Philippines and the West Indies. In 1833, Dr. Henry Perrine shipped seedling mango plants from Yucatan to Cape Sable at the southern tip of mainland Florida but these died after he was killed by Indians. Seeds were imported into Miami from the West Indies by a Dr. Fletcher in 1862 or 1863. From these, two trees grew to large size and one was still fruiting in 1910 and is believed to have been the parent of the ‘No. 11’ which was commonly planted for many years thereafter. In 1868 or 1869, seeds were planted south of Coconut Grove and the resultant trees prospered at least until 1909, producing the so-called ‘Peach’ or ‘Turpentine’ mango which became fairly common. In 1872, a seedling of ‘No. 11’ from Cuba was planted in Bradenton. In 1877 and 1879, W.P. Neeld made successful plantings on the west coast but these and most others north of Ft. Myers were killed in the January freeze of 1886. In 1885, seeds of the excellent ‘Bombay’ mango of India were brought from Key West to Miami and resulted in two trees which flourished until 1909. Plants of grafted varieties were brought in from India by a west coast resident, Rev. D.G. Watt, in 1885 but only two survived the trip and they were soon frozen in a cold spell. Another unsuccessful importation of inarched trees from Calcutta was made in 1888. Of six grafted trees that arrived from Bombay in 1889, through the efforts of the United States Department of Agriculture, only one lived to fruit nine years later. The tree shipped is believed to have been a ‘Mulgoa’ (erroneously labeled ‘Mulgoba’, a name unknown in India except as originating in Florida). However, the fruit produced did not correspond to ‘Mulgoa’ descriptions. It was beautiful, crimson-blushed, just under 1 lb (454 g) with golden-yellow flesh. No Indian visitor has recognized it as matching any Indian variety. Some suggest that it was the fruit of the rootstock if the scion had been frozen in the freeze of 1894-95. At any rate, it continued to be known as ‘Mulgoba’, and it fostered many off-spring along the southeastern coast of the State and in Cuba and Puerto Rico, though it proved to be very susceptible to the disease, anthracnose, in this climate. Seeds from this tree were obtained and planted by a Captain Haden in Miami. The trees fruited some years after his death and his widow gave the name ‘Haden’ to the tree that bore the best fruit. This variety was regarded as the standard of excellence locally for many decades thereafter and was popular for shipping because of its tough skin. George B. Cellon started extensive vegetative propagation (patch-budding) of the ‘Haden’ in 1900 and shipped the fruits to northern markets. P.J. Wester conducted many experiments in budding, grafting and inarching from 1904 to 1908 with less success. Shield-budding on a commercial scale was achieved by Mr. Orange Pound of Coconut Grove in 1909 and this was a pioneer breakthrough which gave strong impetus to mango growing, breeding, and dissemination. Enthusiastic introduction of other varieties by the U.S. Department of Agriculture’s Bureau of Plant Industry, by nurserymen, and other individuals followed, and the mango grew steadily in popularity and importance. The Reasoner Brothers Nursery, on the west coast, imported many mango varieties and was largely responsible for the ultimate establishment of the mango in that area, together with a Mr. J.W. Barney of Palma Sola who had a large collection of varieties and had worked out a feasible technique of propagation which he called “slot grafting”. Dr. Wilson Popenoe, one of the early Plant Explorers of the U.S. Department of Agriculture, became Director of the Escuela Agricola Panamericana, Tegucigalpa, Honduras. For more than a quarter of a century, he was a leader in the introduction and propagation of outstanding mangos from India and the East Indies, had them planted at the school and at the Lancetilla Experiment Station at Tela, Honduras, and distributed around tropical America. In time, the mango became one of the most familiar domesticated trees in dooryards or in small or large commercial plantings throughout the humid and semi-arid lowlands of the tropical world and in certain areas of the near-tropics such as the Mediterranean area (Madeira and the Canary Islands), Egypt, southern Africa, and southern Florida. Local markets throughout its range are heaped high with the fragrant fruits in season and large quantities are exported to non-producing countries. Altogether, the U.S. Department of Agriculture made 528 introductions from India, the Philippines, the West Indies and other sources from 1899 to 1937. Selection, naming and propagation of new varieties by government agencies and individual growers has been going on ever since. The Mango Form was created in 1938 through the joint efforts of the Broward County Home Demonstration Office of the University of Florida’s Cooperative Extension Service and the Fort Lauderdale Garden Club, with encouragement and direction from the University of Florida’s Subtropical Experiment Station (now the Agricultural Research and Education Center) in Homestead, and Mrs. William J. Krome, a pioneer tropical fruit grower. Meetings were held annually, whenever possible, for the exhibiting and judging of promising seedlings, and exchanging and publication of descriptions and cultural information. Meanwhile, a reverse flow of varieties was going on. Improved mangos developed in Florida have been of great value in upgrading the mango industry in tropical America and elsewhere. With such intense interest in this crop, mango acreage advanced in Florida despite occasional setbacks from cold spells and hurricanes. But with the expanding population, increased land values and cost and shortage of agricultural labor after World War II, a number of large groves were subdivided into real estate developments given names such as “Mango Heights” and “Mango Terrace”. There were estimated to be 7,000 acres (2,917 ha) in 27 Florida counties in 1954, over half in commercial groves. There were 4,000 acres (1,619 ha) in 1961. Today, mango production in Florida, on approximately 1,700 acres (688 ha), is about 8,818 tons (8,000 MT) annually in “good” years, and valued at $3 million. Fruits are shipped not only to northern markets but also to the United Kingdom, Netherlands, France and Saudi Arabia. In advance of the local season, quantities are imported into the USA from Haiti and the Dominican Republic, and, throughout the summer, Mexican sources supply mangos to the Pacific Coast consumer. Supplies also come in from India and Taiwan. A mango seed from Guatemala was planted in California about 1880 and a few trees have borne fruit in the warmest locations of that state, with careful protection when extremely low temperatures occur. Mangos have been grown in Puerto Rico since about 1750 but mostly of indifferent quality. A program of mango improvement began in 1948 with the introduction and testing of over 150 superior cultivars by the University of Puerto Rico. The south coast of the island, having a dry atmosphere, is best suited for mango culture and substantial quantities of mangos are produced there without the need to spray for anthracnose control. The fruits are plentiful on local markets and shipments are made to New York City where there are many Puerto Rican residents. A study of 16 cultivars was undertaken in 1960 to determine those best suited to more intense commercial production. Productivity evaluations started in 1965 and continued to 1972. The earliest record of the mango in Hawaii is the introduction of several small plants from Manila in 1824. Three plants were brought from Chile in 1825. In 1899, grafted trees of a number of Indian varieties, including ‘Pairi’, were imported. Seedlings became widely distributed over the six major islands. In 1930, the ‘Haden’ was introduced from Florida and became established in commercial plantations. The local industry began to develop seriously after the importation of a series of monoembryonic cultivars from Florida. But Hawaiian mangos are prohibited from entry into mainland USA, Australia, Japan and some other countries, because of the prevalence of the mango seed weevil in the islands. In Brazil, most mangos are produced in the state of Minas, Gerais where the crop amounts to 243,018 tons (22,000 MT) annually on 24,710 acres (10,000 ha). These are mainly seedlings, as are those of the other states with major mango crops–Ceará, Paraibá, Goias, Pernambuco, and Maranhao. Sao Paulo raises about 63,382 tons (57,500 MT) per year on 9,884 acres (4,000 ha). The bulk of the crop is for domestic consumption. In 1973, Brazil exported 47.4 tons (43 MT) of mangos to Europe. Mango growing began with the earliest settlers in North Queensland, Australia, with seeds brought casually from India, Ceylon, the East Indies and the Philippines. In 1875, 40 varieties from India were set out in a single plantation. Over the years, selections have been made for commercial production and culture has extended to subtropical Western Australia. There is no record of the introduction of the mango into South Africa but a plantation was set out in Durban about 1860. Production today probably has reached about 16,535 tons (15,000 MT) annually, and South Africa exports fresh mangos by air to Europe. Kenya exports mature mangos to France and Germany and both mature and immature to the United Kingdom, the latter for chutney-making. Egypt produces 110,230 tons (100,000 MT) of mangos annually and exports moderate amounts to 20 countries in the Near East and Europe. Mango culture in the Sudan occupies about 24,710 acres (10,000 ha) producing a total of 66,138 tons (60,000 MT) per year. India, with 2,471,000 acres (1,000,000 ha) of mangos (70% of its fruit-growing area) produces 65% of the world’s mango crop–9,920,700 tons (9,000,000 MT). In 1985, mango growers around Hyderabad sought government protection against terrorists who cut down mango orchards unless the owners paid ransom (50,000 rupees in one case). India far outranks all other countries as an exporter of processed mangos, shipping 2/3 of the total 22,046 tons (20,000 MT). Mango preserves go to the same countries receiving the fresh fruit and also to Hong Kong, Iraq, Canada and the United States. Following India in volume of exports are Thailand, 774,365 tons (702,500 MT), Pakistan and Bangladesh, followed by Brazil. Mexico ranks 5th with about 100,800 acres (42,000 ha) and an annual yield of approximately 640,000 tons (580,000 MT). The Philippines have risen to 6th place. Tanzania is 7th, the Dominican Republic, 8th and Colombia, 9th. Leading exporters of fresh mangos are: the Philippines, shipping to Hong Kong, Singapore and Japan; Thailand, shipping to Singapore and Malaysia; Mexico, shipping mostly ‘Haden’ to the United States, 2,204 tons (2,000 MT), annually, also to Japan and Paris; India, shipping mainly ‘Alphonso’ and ‘Bombay’ to Europe, Malaya, Saudi Arabia and Kuwait; Indonesia, shipping to Hong Kong and Singapore; and South Africa shipping (60% ‘Haden’ and ‘Kent’) by air to Europe and London in mid-winter. Chief importers are England and France, absorbing 82% of all mango shipments. Mango consumers in England are mostly residents of Indian origin, or English people who formerly lived in India. The first International Symposium on Mango and Mango Culture, of the International Society for Horticultural Science, was held in New Delhi, India, in 1969 with a view to assembling a collection of germplasm from around the world and encouraging cooperative research on rootstocks and bearing behavior, hybridization, disease, storage and transport problems, and other areas of study.
The original wild mangos were small fruits with scant, fibrous flesh, and it is believed that natural hybridization has taken place between M. indica and M. sylvatica Roxb. in Southeast Asia. Selection for higher quality has been carried on for 4,000 to 6,000 years and vegetative propagation for 400 years. Over 500 named varieties (some say 1,000) have evolved and have been described in India. Perhaps some are duplicates by different names, but at least 350 are propagated in commercial nurseries. In 1949, K.C. Naik described 82 varieties grown in South India. L.B. and R.N. Singh presented and illustrated 150 in their monograph on the mangos of Uttar Pradesh (1956). In 1958, 24 were described as among the important commercial types in India as a whole, though in the various climatic zones other cultivars may be prominent locally. Of the 24, the majority are classed as early or mid-season:
Blooming and Pollination
Mango trees less than 10 years old may flower and fruit regularly every year. Thereafter, most mangos tend toward alternate, or biennial, bearing. A great deal of research has been done on this problem which may involve the entire tree or only a portion of the branches. Branches that fruit one year may rest the next, while branches on the other side of the tree will bear. Blooming is strongly affected by weather, dryness stimulating flowering and rainy weather discouraging it. In most of India, flowering occurs in December and January; in northern India, in January and February or as late as March. There are some varieties called “Baramasi” that flower and fruit irregularly throughout the year. The cultivar ‘Sam Ru Du’ of Thailand bears 3 crops a year–in January, June and October. In the drier islands of the Lesser Antilles, there are mango trees that flower and fruit more or less continuously all year around but never heavily at any time. Some of these are cultivars introduced from Florida where they flower and fruit only once a year. In southern Florida, mango trees begin to bloom in late November and continue until February or March, inasmuch as there are early, medium, and late varieties. During exceptionally warm winters, mango trees have been known to bloom 3 times in succession, each time setting and maturing fruit. In the Philippines, various methods are employed to promote flowering: smudging (smoking), exposing the roots, pruning, girdling, withholding nitrogen and irrigation, and even applying salt. In the West Indies, there is a common folk practice of slashing the trunk with a machete to make the tree bloom and bear in “off” years. Deblos-soming (removing half the flower clusters) in an “on” year will induce at least a small crop in the next “off” year. Almost any treatment or condition that retards vegetative growth will have this effect. Spraying with growth-retardant chemicals has been tried, with inconsistent results. Potassium nitrate has been effective in the Philippines. In India, the cultivar ‘Dasheri’, which is self incompatible, tends to begin blooming very early (December and January) when no other cultivars are in flower. And the early particles show a low percentage of hermaphrodite flowers and a high incidence of floral malformation. Furthermore, early blooms are often damaged by frost. It has been found that a single mechanical deblossoming in the first bud-burst stage, induces subsequent development of particles with less malformation, more hermaphrodite flowers, and, as a result, a much higher yield of fruits. There is one cultivar, ‘Neelum’, in South India that bears heavily every year, apparently because of its high rate (16%) of hermaphrodite flowers. (The average for ‘Alphonso’ is 10%.) However, Indian horticulturists report great tree-to-tree variation in seedlings of this cultivar; in some surveys as much as 84% of the trees were rated as poor bearers. Over 92% of ‘Bangalora’ seedlings have been found bearing light crops. Mango flowers are visited by fruit bats, flies, wasps, wild bees, butterflies, moths, beetles, ants and various bugs seeking the nectar and some transfer the pollen but a certain amount of self-pollination also occurs. Honeybees do not especially favor mango flowers and it has been found that effective pollination by honeybees would require 3 to 6 colonies per acre (6-12 per ha). Many of the unpollinated flowers are shed or fail to set fruit, or the fruit is set but is shed when very young. Heavy rains wash off pollen and thus prevent fruit setting. Some cultivars tend to produce a high percentage of small fruits without a fully developed seed because of unfavorable weather during the fruit-setting period. Shy-bearing cultivars of otherwise desirable characteristics are hybridized with heavy bearers in order to obtain better crops. For example: shy-bearing ‘Himayuddin’ ´ heavy-bearing ‘Neelum’. Breeders usually hand-pollinate all the flowers that are open in a cluster, remove the rest, and cover the inflorescence with a plastic bag. But researchers in India have found that there is very little chance of contamination and that omitting the covering gives as much as 3.85% fruit set in place of 0.23% to 1.57% when bagged. Thus large populations of hybrids may be raised for study. One of the latest techniques involves grafting the male and female parents onto a chosen tree, then covering the panicles with a polyethylene bag, and introducing house flies as pollinators. Indian scientists have found that pollen for crossbreeding can be stored at 32° F (0° C) for 10 hours. If not separated from the flowers, it remains viable for 50 hours in a humid atmosphere at 65° to 75° F (18.33° -23.09° C). The stigma is receptive 18 hours before full flower opening and, some say, for 72 hours after.
The mango is naturally adapted to tropical lowlands between 25°N and 25°S of the Equator and up to elevations of 3,000 ft (915 m). It is grown as a dooryard tree at slightly cooler altitudes but is apt to suffer cold damage. The amount of rainfall is not as critical as when it occurs. The best climate for mango has rainfall of 30 to 100 in (75-250 cm) in the four summer months (June to September) followed by 8 months of dry season. This crop is well suited to irrigated regions bordering the desert frontier in Egypt. Nevertheless, the tree flourishes in southern Florida’s approximately 5 months of intermittent, scattered rains (October to February), 3 months of drought (usually March to May) and 4 months of frequently heavy rains (June to September). Rain, heavy dews or fog during the blooming season (November to March in Florida) are deleterious, stimulating tree growth but interfering with flower production and encouraging fungus diseases of the inflorescence and fruit. In Queensland, dry areas with rainfall of 40 in (100 cm), 75% of which occurs from January to March, are favored for mango growing because vegetative growth is inhibited and the fruits are well exposed to the sun from August to December, become well colored, and are relatively free of disease. Strong winds during the fruiting season cause many fruits to fall prematurely.
The mango tree is not too particular as to soil type, providing it has good drainage. Rich, deep loam certainly contributes to maximum growth, but if the soil is too rich and moist and too well fertilized, the tree will respond vegetatively but will be deficient in flowering and fruiting. The mango performs very well in sand, gravel, and even oolitic limestone (as in southern Florida and the Bahamas) A polyembryonic seedling, ‘No. 13-1’, introduced into Israel from Egypt in 1931, has been tested since the early 1960’s in various regions of the country for tolerance of calcareous soils and saline conditions. It has done so well in sand with a medium (15%) lime content and highly saline irrigation water (over 600 ppm) that it has been adopted as the standard rootstock in commercial plantings in salty, limestone districts of Israel. Where the lime content is above 30%, iron chelates are added.
Mango trees grow readily from seed. Germination rate and vigor of seedlings are highest when seeds are taken from fruits that are fully ripe, not still firm. Also, the seed should be fresh, not dried. If the seed cannot be planted within a few days after its removal from the fruit, it can be covered with moist earth, sand, or sawdust in a container until it can be planted, or kept in charcoal dust in a dessicator with 50% relative humidity. Seeds stored in the latter manner have shown 80% viability even after 70 days. High rates of germination are obtained if seeds are stored in polyethylene bags but the seedling behavior may be poor. Inclusion of sphagnum moss in the sack has no benefit and shows inferior rates of germination over 2- to 4-week periods, and none at all at 6 weeks. The flesh should be completely removed. Then the husk is opened by carefully paring around the convex edge with a sharp knife and taking care not to cut the kernel, which will readily slide out. Husk removal speeds germination and avoids cramping of roots, and also permits discovery and removal of the larva of the seed weevil in areas where this pest is prevalent. Finally, the husked kernels are treated with fungicide and planted without delay. The beds must have solid bottoms to prevent excessive taproot growth, otherwise the taproot will become 18 to 24 in (45-60 cm) long while the top will be only one third to a half as high, and the seedling will be difficult to transplant with any assurance of survival. The seed is placed on its ventral (concave) edge with 1/4 protruding above the sand. Sprouting occurs in 8 to 14 days in a warm, tropical climate; 3 weeks in cooler climates. Seedlings generally take 6 years to fruit and 15 years to attain optimum yield for evaluation. However, the fruits of seedlings may not resemble those of the parent tree. Most Indian mangos are monoembryonic; that is, the embryo usually produces a single sprout, a natural hybrid from accidental crossing, and the resulting fruit may be inferior, superior, or equal to that of the tree from which the seed came. Mangos of Southeast Asia are mostly polyembryonic. In these, generally, one of the embryos in the seed is a hybrid; the others (up to 4) are vegetative growths which faithfully reproduce the characteristics of the parent. The distinction is not absolute, and occasionally a seed supposedly of one class may behave like the other. Seeds of polyembryonic mangos are most convenient for local and international distribution of desirable varieties. However, in order to reproduce and share the superior monoembryonic selections, vegetative propagation is necessary. Inarching and approach-grafting are traditional in India. Tongue-, saddle-, and root-grafting (stooling) are also common Indian practices. Shield- and patch-grafting have given up to 70% success but the Forkert system of budding has been found even more practical. After many systems were tried, veneer grafting was adopted in Florida in the mid-1950’s. Choice of rootstock is important. Use of seedlings of unknown parentage has resulted in great variability in a single cultivar. Some have believed that polyembryonic rootstocks are better than monoembryonic, but this is not necessarily so. In trials at Tamil Nadu Agricultural University, 10-year-old trees of ‘Neelum’ grafted on polyembryonic ‘Bapakkai’ showed vigor and spread of tree and productivity far superior to those grafted on ‘Olour’ which is also polyembryonic. Those grafted on monoembryonic rootstock also showed better growth and yield than those on ‘Olour’. In 1981, experimenters at Lucknow, India, reported the economic advantage of “stone-grafting”, which requires less space in the nursery and results in greater uniformity. Scions from the spring flush of selected cultivars are defoliated and, after a 10-day delay, are cleft-grafted on 5-day-old seedlings which must thereafter be kept in the shade and protected from drastic changes in the weather. Old trees of inferior types are top-worked to better cultivars by either side-grafting or crown-grafting the beheaded trunk or beheaded main branches. Such trees need protection from sunburn until the graft affords shade. In South Africa, the trunks are whitewashed and bunches of dry grass are tied onto cut branch ends. The trees will bear in 2 to 3 years. Attempts to grow 3 or 4 varieties on one rootstock may appear to succeed for a while but the strongest always outgrows the others. Cuttings, even when treated with growth regulators, are only 40% successful. Best results are obtained with cuttings of mature trees, ringed 40 days before detachment, treated, and rooted under mist. But neither cuttings nor air layers develop good root systems and are not practical for establishing plantations. Clonal propagation through tissue culture is in the experimental stage. In spite of vegetative propagation, mutations arise in the form of bud sports. The fruit may differ radically from the others on a grafted tree-perhaps larger and superior-and the foliage on the branch may be quite unlike that on other branches.
Reduction in the size of mango trees would be a most desirable goal for the commercial and private planter. It would greatly assist harvesting and also would make it possible for the homeowner to maintain trees of different fruiting seasons in limited space. In India, double-grafting has been found to dwarf mango trees and induce early fruiting. Naturally dwarf hybrids such as ‘Julie’ have been developed. The polyembryonic Indian cultivars, ‘Olour’ and ‘Vellai Colamban’, when used as rootstocks, have a dwarfing effect; so has the polyembryonic ‘Sabre’ in experiments in Israel and South Africa. In Peru, the polyembryonic ‘Manzo de Ica’, is used as rootstock; in Colombia, ‘Hilaza’ and ‘Puerco’. ‘Kaew’ is utilized in Thailand.
About 6 weeks before transplanting either a seedling or a grafted tree, the taproot should be cut back to about 12 in (30 cm). This encourages feeder-root development in the field. For a week before setting out, the plants should be exposed to full morning sun. Inasmuch as mango trees vary in lateral dimensions, spacing depends on the habit of the cultivar and the type of soil, and may vary from 34 to 60 ft (10.5-18 m) between trees. Closer planting will ultimately reduce the crop. A spacing of 34 x 34 ft (10.5 x l0.5 m) allows 35 trees per acre (86 per ha); 50 x 50 ft (15.2 x l5.2 m) allows only 18 trees per acre (44.5 per ha). In Florida’s limestone, one commercial grower maintains 100 trees per acre (247 per ha), controlling size by hedging and topping. The young trees should be placed in prepared and enriched holes at least 2 ft (60 cm) deep and wide, and 3/4 of the top should be cut off. In commercial groves in southern Florida, the trees are set at the intersection of cross trenches mechanically cut through the limestone. Mangos require high nitrogen fertilization in the early years but after they begin to bear, the fertilizer should be higher in phosphate and potash. A 5-8-10 fertilizer mix is recommended and applied 2 or 3, or possibly even 4, times a year at the rate of 1 lb (454 g) per year of age at each dressing, Fertilizer formulas will vary with the type of soil. In sandy acid soils, excess nitrogen contributes to “soft nose” breakdown of the fruits. This can be counteracted by adding calcium. On organic soils (muck and peat), nitrogen may be omitted entirely. In India, fertilizer is applied at an increasing rate until the tree is rather old, and then it is discontinued. Ground fertilizers are supplemented by foliar nutrients including zinc, manganese and copper. Iron deficiency is corrected by small applications of chelated iron. Indian growers generally irrigate the trees only the first 3 or 4 years while the taproot is developing and before it has reached the water table. However, in commercial plantations, irrigation of bearing trees is withheld only for the 2 or 3 months prior to flowering. When the blooms appear, the tree is given a heavy watering and this is repeated monthly until the rains begin. In Florida groves, irrigation is by means of overhead sprinklers which also provide frost protection when needed. Usually no pruning is done until the 4th year, and then only to improve the form and this is done right after the fruiting season. If topping is practiced, the trees are cut at 14 ft (4.25 m) to facilitate both spraying and harvesting. Grafted mangos may set fruit within a year or two from planting. The trees are then too weak to bear a full crop and the fruits should be thinned or completely removed.
Mangos normally reach maturity in 4 to 5 months from flowering. Fruits of “smudged” trees ripen several months before those of untreated trees. Experts in the Philippines have demonstrated that ‘Carabao’ mangos sprayed with ethephon (200 ppm) 54 days after full bloom can be harvested 2 weeks later at recommended minimum maturity. The fruits will be larger and heavier even though harvested 2 weeks before untreated fruits. If sprayed at 68 days after full bloom and harvested 2 weeks after spraying, there will be an improvement in quality in regard to soluble solids and titratable acidity. When the mango is full-grown and ready for picking, the stem will snap easily with a slight pull. If a strong pull is necessary, the fruit is still somewhat immature and should not be harvested. In the more or less red types of mangos, an additional indication of maturity is the development of a purplish-red blush at the base of the fruit. A long-poled picking bag which holds no more than 4 fruits is commonly used by pickers. Falling causes bruising and later spoiling. When low fruits are harvested with clippers, it is desirable to leave a 4-inch (10 cm) stem to avoid the spurt of milky/resinous sap that exudes if the stem is initially cut close. Before packing, the stem is cut off 1/4 in (6 mm) from the base of the fruit. In Queensland, after final clipping of the stem, the fruits are placed stem-end-down to drain. In a sophisticated Florida operation, harvested fruits are put into tubs of water on trucks in order to wash off the sap that exudes from the stem end. At the packing house, the fruits are transferred from the tubs to bins, graded and sized and packed in cartons (“lugs”) of 8 to 20 each depending on size. The cartons are made mechanically at the packing house and hold 14 lbs (6.35 kg) of fruit. The filled cartons are stacked on pallets and fork-lifted into refrigerated trucks with temperature set at no less than 55° F (12.78° C) for transport to distribution centers in major cities throughout the USA and Canada.
The yield varies with the cultivar and the age of the tree. At 10 to 20 years, a good annual crop may be 200 to 300 fruits per tree. At twice that age and over, the crop will be doubled. In Java,, old trees have been known to bear 1,000 to 1,500 fruits in a season. Some cultivars in India bear 800 to 3,000 fruits in “on” years and, with good cultural attention, yields of 5,000 fruits have been reported. There is a famous mango, ‘Pane Ka Aam’ of Maharashtra and Khamgaon, India, with “paper-thin” skin and fiberless flesh. One of the oldest of these trees, well over 100 years of age, bears heavily 5 years out of 10 with 2 years of low yield. Average annual yield is 6,500 fruits; the highest record is 29,000. . Average mango yield in Florida is said to be about 30,000 lbs/acre. One leading commercial grower has reported his annual crop as 22,000 to 27,500 lbs/acre. One grower who has hedged and topped trees close-planted at the rate of 100 per acre (41/ha) averages 14,000 to 19.000 lbs/acre.
In India, mangos are picked quite green to avoid bird damage and the dealers layer them with rice straw in ventilated storage rooms over a period of one week. Quality is improved by controlled temperatures between 60° and 70° F (15° -21° C). In ripening trials in Puerto Rico, the ‘Edward’ mango was harvested while deep-green, dipped in hot water at 124° F (51° C) to control anthracnose, sorted as to size, then stored for 15 days at 70° F (21° C) with relative humidity of 85% to 90%. Those picked when more than 3 in (7.5 cm) in diameter ripened satisfactorily and were of excellent quality. Ethylene treatment causes green mangos to develop full color in 7 to 10 days depending on the degree of maturity, whereas untreated fruits require 10 to 15 days. One of the advantages is that there can be fewer pickings and the fruit color after treatment is more uniform. Therefore, ethylene treatment is a common practice in Israel for ripening fruits for the local market. Some growers in Florida depend on ethylene treatment. Generally, 24 hours of exposure is sufficient if the fruits are picked at the proper stage. It has been determined that mangos have been picked prematurely if they require more than 48 hours of ethylene treatment and are not fit for market.
Keeping Quality and Storage
Washing the fruits immediately after harvest is essential, as the sap which leaks from the stem bums the skin of the fruit making black lesions which lead to rotting. Some cultivars, especially ‘Bangalora’, ‘Alphonso’, and ‘Neelum’ in India, have much better keeping quality than others. In Bombay, ‘Alphonso’ has kept well for 4 weeks at 52° F (11.11° C); 6 to 7 weeks at 45° F (7.22° C). Storage at lower temperatures is detrimental inasmuch as mangos are very susceptible to chilling injury. Any temperature below 55.4° F (13° C) is damaging to ‘Kent’. In Florida, this is regarded as the optimum for 2 to 3 weeks storage. The best ripening temperatures are 70° to 75° F (21.11°-23.89° C). Experiments in Florida have demonstrated that ‘Irwin’, ‘Tommy Atkins’ and ‘Kent’ mangos, held for 3 weeks at storage temperature of 55.4° F (13° C), 98% to 100% relative humidity and atmospheric pressure of 76 or 152 mmHg, ripened thereafter with less decay at 69.8° F (21° C) under normal atmospheric pressure, as compared with fruits stored at the same temperature with normal atmospheric pressure. Those stored at 152 mmHg took 3 to 5 days longer to ripen than those stored at 76 mmHg. Decay rates were 20% for ‘Tommy Atkins’ and 40% for ‘Irwin’. Spoilage from anthracnose has been reduced by immersion for 15 min in water at 125° F (51.67° C) or for 5 min at 132° F (55.56° C). Dipping in 500 ppm maleic hydrazide for 1 min and storing at 89.6° F (32° C) also retards decay but not loss of moisture. In South Africa, mangos are submerged immediately after picking in a suspension of benomyl for 5 min at 131° F (55° C) to control soft brown rot. In Australia, mature-green ‘Kensington Pride’ mangos have been dipped in a 4% solution of calcium chloride under reduced pressure (250 mm Hg) and then stored in containers at 77° F (25° C) in ethylene-free atmosphere. Ripening was retarded by a week; that is, the treated fruits ripened in 20 to 22 days whereas controls ripened in 12 to 14 days. Eating quality was equal except that the calcium-treated fruits were found slightly higher in ascorbic acid. Wrapping fruits individually in heat-shrinkable plastic film has not retarded decay in storage. The only benefit has been 3% less weight loss. Coating with paraffin wax or fungicidal wax and storing at 68° to 89.6° F (20° -32° C) delays ripening 1 to 2 weeks and prevents shriveling but interferes with full development of color. Gamma irradiation (30 Krad) causes ripening delay of 7 days in mangos stored at room temperature. The irradiated fruits ripen normally and show no adverse effect on quality. Irradiation has not yet been approved for this purpose. In India, large quantities of mangos are transported to distant markets by rail. To avoid excessive heat buildup and consequent spoilage, the fruits, padded with paper shavings, are packed in ventilated wooden crates and loaded into ventilated wooden boxcars. Relative humidity varies from 24% to 85% and temperature from 88° to 115° F (31.6°-46.6° C). These improved conditions have proved superior to the conventional packing of the fruits in Phoenix-palm-midrib or bamboo, or the newer pigeonpea-stem, baskets padded with rice straw and mango leaves and transported in steel boxcars, which has resulted in 20% to 30% losses from shriveling, unshapeliness and spoilage. Green seedling mangos, harvested in India for commercial preparation of chutneys and pickles as well as for table use, are stored for as long as 40 days at 42° to 45° F (5.56°-7.22° C) with relative humidity of 85% to 99%. Some of these may be diverted for table use after a 2-week ripening period at 62° to 65° F (16.67° -18.13° C).
Pests and Diseases
The fruit flies, Dacus ferrugineus and D. zonatus, attack the mango in India; D. tryoni (now Strumeta tryoni) in Queensland, and D. dorsalis in the Philippines; Pardalaspis cosyra in Kenya; and the fruit fly is the greatest enemy of the mango in Central America. Because of the presence of the Caribbean fruit fly, Anastrepha suspensa, in Florida, all Florida mangos for interstate shipment or for export must be fumigated or immersed in hot water at 115° F (46.11° C) for 65 minutes. In India, South Africa and Hawaii, mango seed weevils, Sternochetus (Cryptorhynchus) mangiferae and S. gravis, are major pests, undetectable until the larvae tunnel their way out. The leading predators of the tree in India are jassid hoppers (Idiocerus spp.) variously attacking trunk and branches or foliage and flowers, and causing shedding of young fruits. The honeydew they excrete on leaves and flowers gives rise to sooty mold. The mango-leaf webber, or “tent caterpillar”, Orthaga euadrusalis, has become a major problem in North India, especially in old, crowded orchards where there is excessive shade. Around Lucknow, ‘Dashehari’ is heavily infested by this pest; ‘Samarbehist’ (‘Chausa’) less. In South Africa, 11 species of scales have been recorded on the fruits. Coccus mangiferae and C. acuminatus are the most common scale insects giving rise to the sooty mold that grows on the honeydew excreted by the pests. In some areas, there are occasional outbreaks of the scales, Pulvinaria psidii, P. polygonata, Aulacaspis cinnamoni, A. tubercularis, Aspidiotus destructor and Leucaspis indica. In Florida, pyriform scale, Protopulvinaria Pyrformis, and Florida wax scale, Ceroplastes floridensis, are common, and the lesser snow scale, Pinnaspis strachani, infests the trunks of small trees and lower branches of large trees. Heavy attacks may result in cracking of the bark and oozing of sap. The citrus thrips, Scirtothrips aurantii, blemishes the fruit in some mango-growing areas. The red-banded thrips, Selenothrips rubrocinctus, at times heavily infests mango foliage in Florida, killing young leaves and causing shedding of mature leaves. Mealybugs, Phenacoccus citri and P. mangiferae, and Drosicha stebbingi and D. mangiferae may infest young leaves, shoots and fruits. The mango stem borer, Batocera rufomaculata invades the trunk. Leaves and shoots are preyed on by the caterpillars of Parasa lepida, Chlumetia transversa and Orthaga exvinacea. Mites feed on mango leaves, flowers and young fruits. In Florida, the most common is the avocado red mite, Paratetranychus yothersii. Mistletoe (Loranthus and Viscum spp.) parasitizes and kills mango branches in India and tropical America. Dr. B. Reddy, Regional Plant Production and Protection Officer, FAO, Bangkok, compiled an extensive roster of insects, mites, nematodes, other pests, fungi, bacteria and phanerogamic parasites in Southeast Asia and the Pacific Region (1975). One of the most serious diseases of the mango is powdery mildew (Oidium mangiferae), which is common in most growing areas of India, occurs mostly in March and April in Florida. The fungus affects the flowers and causes young fruits to dehydrate and fall, and 20% of the crop may be lost. It is controllable by regular spraying. In humid climates, anthracnose caused by Colletotrichum gloeosporioides (Glomerella cingulata) affects flowers, leaves, twigs, fruits, both young and mature. The latter show black spots externally and the corresponding flesh area is affected. Control measures must be taken in advance of flowering and regularly during dry spells. In Florida, mango growers apply up to 20 sprayings up to the cut-off point before harvesting. The black spots are similar to those produced by AIternaria sp. often associated with anthracnose in cold storage in India. Inside the fruits attacked by AIternaria there are corresponding areas of hard, corky, spongy lesions. Inasmuch as the fungus enters the stem-end of the fruit, it is combatted by applying Fungicopper paste in linseed oil to the cut stem and also by sterilizing the storage compartment with Formalin 1:20. A pre-harvest dry stem-end rot was first noticed on ‘Tommy Atkins’ in Mexico in 1973, and it has spread to all Mexican plantings of this cultivar causing losses of 10-80% especially in wet weather. Fusarium, Alternaria and Cladosporium spp. were prominent among associated fungi. Malformation of inflorescence and vegetative buds is attributed to the combined action of Fusarium moniliforme and any of the mites, Aceria mangifera, Eriophyes sp., Tyrophagus castellanii, or Typhlodromus asiaticus. This grave problem occurs in Pakistan, India, South Africa and Egypt, El Salvador, Nicaragua, Mexico, Brazil and Venezuela, but not as yet in the Philippines. It is on the increase in India. Removing and burning the inflorescence has been the only remedy, but it has been found that malformation can be reduced by a single spray of NAA (200 mg in 50 ml alcohol with water added to make 1 liter) in October, and deblooming in early January. There are 14 types of mango galls in India, 12 occurring on the leaves. The most serious is the axillary bud gall caused by Apsylla cistellata of the family Psyllidae. In Florida, leaf spot is caused by Pestalotia mangiferae, Phyllosticta mortoni, and Septoria sp.; algal leaf spot, or green scurf by Cephaleuros virescens. In 1983, a new disease, crusty leaf spot, caused by the fungus, Zimmermaniella trispora, was reported as common on neglected mango trees in Malaya. Twig dieback and dieback are from infection by Phomopsis sp., Physalospora abdita, and P. rhodina. Wilt is caused by Verticillium alboatrum; brown felt by Septobasidium pilosum and S. pseudopedicellatum; wood rot, by Polyporus sanguineus; and scab by Elsinoe mangiferae (Sphaceloma mangiferae). Cercospora mangiferae attacks the fruits in the Congo. A number of organisms in India cause white sap, heart rot, gray blight, leaf blight, white pocket rot, white spongy rot, sap rot, black bark and red rust. In South Africa, Asbergillus attacks young shoots and fruit rot is caused by A. niger. Gloeosporium mangiferae causes black spotting of fruits. Erwinia mangiferae and Pseudomonas mangiferaeindicae are sources of bacterial black spot in South Africa and Queensland. Bacterium carotovorus is a source of soft rot. Stem-end rot is a major problem in India and Puerto Rico from infection by Physalospora rhodina (Diplodia natalensis). Soft brown rot develops during prolonged cold storage in South Africa. Leaf tip burn may be a sign of excess chlorides. Manganese deficiency is indicated by paleness and limpness of foliage followed by yellowing, with distinct green veins and midrib, fine brown spots and browning of leaf tips. Inadequate zinc is evident in less noticeable paleness of foliage, distortion of new shoots, small leaves, necrosis, and stunting of the tree and its roots. In boron deficiency, there is reduced size and distortion of new leaves and browning of the midrib. Copper deficiency is seen in paleness of foliage and severe tip-bum with gray-brown patches on old leaves; abnormally large leaves; also die-back of terminal shoots; sometimes gummosis of twigs and branches. Magnesium is needed when young trees are stunted and pale, new leaves have yellow-white areas between the main veins and prominent yellow specks on both sides of the midrib. There may also be browning of the leaf tips and margins. Lack of iron produces chlorosis in young trees. Fig. 61: Low-fiber mangoes are easily prepared for the table by first cutting off the “cheeks” which can then be served for eating by spooning the flesh from the “shell”.
The Mango should always be washed to remove any sap residue, before handling. Some seedling mangos are so fibrous that they cannot be sliced; instead, they are massaged, the stem-end is cut off, and the juice squeezed from the fruit into the mouth. Non-fibrous mangos may be cut in half to the stone, the two halves twisted in opposite directions to free the stone which is then removed, and the halves served for eating as appetizers or dessert. Or the two “cheeks” may be cut off, following the contour of the stone, for similar use; then the remaining side “fingers” of flesh are cut off for use in fruit cups, etc. Most people enjoy eating the residual flesh from the seed and this is done most neatly by piercing the stem-end of the seed with the long central tine of a mango fork, commonly sold in Mexico, and holding the seed upright like a lollypop. Small mangos can be peeled and mounted on the fork and eaten in the same manner. If the fruit is slightly fibrous especially near the stone, it is best to peel and slice the flesh and serve it as dessert, in fruit salad, on dry cereal, or in gelatin or custards, or on ice cream. The ripe flesh may be spiced and preserved in jars. Surplus ripe mangos are peeled, sliced and canned in sirup, or made into jam, marmalade, jelly or nectar. The extracted pulpy juice of fibrous types is used for making mango halva and mango leather. Sometimes corn flour and tamarind seed jellose are mixed in. Mango juice may be spray-dried and powdered and used in infant and invalid foods, or reconstituted and drunk as a beverage. The dried juice, blended with wheat flour has been made into “cereal” flakes, A dehydrated mango custard powder has also been developed in India, especially for use in baby foods. Ripe mangos may be frozen whole or peeled, sliced and packed in sugar (1 part sugar to 10 parts mango by weight) and quick-frozen in moisture-proof containers. The diced flesh of ripe mangos, bathed in sweetened or unsweetened lime juice, to prevent discoloration, can be quick-frozen, as can sweetened ripe or green mango puree. Immature mangos are often blown down by spring winds. Half-ripe or green mangos are peeled and sliced as filling for pie, used for jelly, or made into sauce which, with added milk and egg whites, can be converted into mango sherbet. Green mangos are peeled, sliced, parboiled, then combined with sugar, salt, various spices and cooked, sometimes with raisins or other fruits, to make chutney; or they may be salted, sun-dried and kept for use in chutney and pickles. Thin slices, seasoned with turmeric, are dried, and sometimes powdered, and used to impart an acid flavor to chutneys, vegetables and soup. Green or ripe mangos may be used to make relish. Fig. 62: The long center tine of the mango fork is designed for piercing the base of the center section and right through the seed. With the strip of peel removed, the most flavorful flesh around the seed can be enjoyed like a lollipop. In Thailand, green-skinned mangos of a class called “keo”, with sweet, nearly fiberless flesh and very commonly grown and inexpensive on the market, are soaked whole for 15 days in salted water before peeling, slicing and serving with sugar. Processing of mangos for export is of great importance in Hawaii in view of the restrictions on exporting the fresh fruits. Hawaiian technologists have developed methods for steam- and lye-peeling, also devices for removing peel from unpeeled fruits in the preparation of nectar. Choice of suitable cultivars is an essential factor in processing mangos for different purposes. The Food Research Institute of the Canada Department of Agriculture has developed methods of preserving ripe or green mango slices by osmotic dehydration, The fresh kernel of the mango seed (stone) constitutes 13% of the weight of the fruit, 55% to 65% of the weight of the stone. The kernel is a major by-product of the mango-processing industry. In times of food scarcity in India, the kernels are roasted or boiled and eaten. After soaking to dispel the astringency (tannins), the kernels are dried and ground to flour which is mixed with wheat or rice flour to make bread and it is also used in puddings. The fat extracted from the kernel is white, solid like cocoa butter and tallow, edible, and has been proposed as a substitute for cocoa butter in chocolate. The peel constitutes 20% to 25% of the total weight of the fruit. Researchers in India have shown that the peel can be utilized as a source of pectin. Average yield on a dry-weight basis is 13%. Immature mango leaves are cooked and eaten in Indonesia and the Philippines.