Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
9 TAMARIND Tamarind (Tamarindus indica) is one of the great trees of the tropics. Its feathery foliage is common from Senegal to Singapore, Suriname to Samoa. Everywhere it grows, people enjoy the curiously sweet-sour pulp found inside its brittle, gray or cinnamon-brown pods. That pulp is sucked out as a refreshing treat, or mixed into myriad drinks and sauces. Its tang especially blends with the fire of chilies, a marriage lending many tropical dishes their distinctively tart, sweetly biting savor. The famous cuisines of South India (e.g., vindaloo) and Java (satay ayam) are good examples. Westerners recognize the tamarind taste mainly from the well-known WorcestershireÂ® sauce, Jamaicans from their world-famous PickapeppaÂ® sauce. It is also a common âsecretâ ingredient in barbeque sauces. History books often say this plant hails from India. The common name, too, derives from the Arabic tamar-uâl-Hind, or date of India. Even the scientific epithet âindicaâ reflects this old belief in its place of origin. But for all this literal association with India, tamarind is actually African. The wild version is a common savanna tree and can be found over a huge area stretching from the Atlantic to beyond the far edges of Central Africa. The capital of Senegal is named for this native favorite, which in the local Wolof language is called âdakar.â This tall legume has long been integral to African culture. For millennia, people have crushed the fruit pulp in water to form a paste, which they then employ for âsouringâ their bowls of sorghum or millet gruel. Women in the Sahel, for example, slip in some tamarind when making the gel-like porridge (normally called toh) that is a daily staple of millions. Although its main product may seem like a rather minor food, tamarind has been called a tree of life. In this regard, an important feature is that its fruits can be stored away and served laterâespecially during the dry season when fresh fruits are scarce or nonexistent. Fulani nomads, for example, preserve the sugar-rich tamarind pulp in the form of sun-dried cakes, which they rely on for sustenance while moving across the Sahara sands. Modern Africa has been far from backward in advancing this fruit. Already, tamarind-based soft drinks are favorites in many places. In Mali and Burkina Faso, for example, such drinks (both fresh and carbonated) rival the ubiquitous Coca-ColaÂ® in popularity. Among other things, they are 149
150 LOST CROPS OF AFRICA Wild tamarind, Cape Verde. This species is cultivated throughout the tropics, where it is appreciated for its shade as well as for the sweet-and-sour pulp found inside its brittle, gray-brown pods. What is not widely known is that tamarind is actually African. The original wild version can be found over an area stretching from these islands off Senegal to beyond the Central African Sahel. (Peter Longatti) featured in up-market restaurants. And Maliâs own concentrated tamarind syrup is said to sell better than fancy fruit syrups imported from France. The country is itself exporting tamarind drinks to Europe, where they can be seen selling well on the streets and even in the bars of Paris and Rome. Although the processed pulp has a notable commercial future in sauces, syrups, drinks, jams, and confections, there are also forms that can be enjoyed out of hand. These âalmost sweetâ types have their own separate future. However, in the short term they are unlikely to become large-scale international commodities because outside their traditional range, people just arenât accustomed to sucking a gummy dark-colored paste from a pod. The living tree has great value too. It withstands the assaults of city smog and, thanks to a deep and extensive root system, weathers violent storms. It also tolerates the salty air of coastal locales. Its crown of drooping branches bears graceful, feathery foliage, giving it a handsome appearance and making it outstandingly useful for beautifying parks, backyards, boulevards, markets, and country roads. It is a much-beloved shade tree, both on account of its evergreen foliage and its dense crown. In India, for instance, stately tamarinds throw shade over thousands of villages and millions of grateful travelers every day. For these reasons, alone, it holds much promise in tropical reforestation, especially for plantings in places where people live, work, congregate, and crave a spot of refreshing shade. And the living tree offers many more possible benefits. It is especially promising for reclaiming deforested and damaged lands and restoring them
TAMARIND 151 to health and productivity. In Nigeria, for example, tamarind is used in anti-desertification programs because it has an ability to grow in arid climates and to resist savanna ground fires. In India also, strips of tamarind are planted among forest trees to act as firebreaks. And tamarind trees have notable promise for sequestering carbon from the atmosphere, because they typically stand for centuriesânot just because their physiology permits it, nor because they also resist droughts, fires, typhoons, and salt spray, but because people hate cutting down tamarind trees. PROSPECTS For all its widespread use, tamarind still remains largely unimproved and unappreciated as a horticultural crop. This is especially true across its African homeland. Indeed, although commercial tamarind plantings have sprung up in Thailand, the Philippines, Indonesia, Sri Lanka, Belize, Brazil, Guatemala, and elsewhere, only India exploits it in a nationally organized way. As a result, India now exports tamarind to the world. The species, however, has promise for vastly increased use in most parts of the tropics. A major portion of its future lies in a range of cultural situations, including subsistence farming, agroforestry, urban forestry, industrial plantations, and plantings established for humanitarian and environmental benefit. All in all, the tamarind is so superbly adapted to both dry savannas and monsoonal regions that it deserves greater research attention and extensive organized plantings in such locations. It is hardly a rocket-fast grower, but it is resilient, able to thrive in poor soils, and tolerant of abuse from people, pollutants, and powerful natural forces. The fact it meets two great needs of the tropicsâfood and shadeâendears it to the populace of the hot zones. That is why it has already spread so widely without formal help. Incidentally, it also means grateful growers will protect it almost with their lives. And that in turn means that plantings can be permanent and contribute to food security and human nutrition for decades or even centuries.1 Within Africa Long ago, tamarind marched beyond western Africa to find new homes across the continent. Further east, in Uganda for example, there is a broad tradition of mixing it into the local millet porridge known as ugali, and tamarind pulp is sold in almost every market. Still, when considered in Africa-wide perspective, tamarind is a much-neglected resource. 1 Many of these ideas, and much more about tamarind, are elaborated upon in a recent monograph, El-Siddig, K., H.P.M. Gunasena, B.A. Prasad, D.K.N.G. Pushpakumara, K.V.R. Ramana, P. Viyayanand, and J.T. Williams. 2006. Tamarind (Tamarindus indica L). Fruits for the Future 1 â Revised. International Centre for Underutilised Crops, Southampton, UK; see www.icuc-iwmi.org. Tamarind was also covered in our 1979 report, Tropical Legumes.
152 LOST CROPS OF AFRICA Mauritius. Although it may appear to be quite a minor food crop, tamarind has been called a tree of life because its sugar-rich fruits can be stored away without refrigeration and safely served weeks or months laterâespecially during the dry season when fresh foods are scarce or nonexistent. (Madeleine Philippe) Humid Areas Excellent prospects. Although considered a dryland species, the fact it thrives in places such as the Philippines, Indonesia, Singapore, Thailand, and Hawaii shows it can have high tolerance for humidity. It is indeed a tree of both parched zones and humid lowlands. Thus there are many parts of tropical Africa into which it could smoothly fit. Dry Areas Excellent prospects. Savannas are the plantâs original African habitat, so the tree is endowed with the potential to perform on seasonally dry, semi-arid sites. Of course, in such locations it grows more slowly than on better watered ones, but its deep taproot and natural ability to shed its leaves when stressed means that it survives even long droughts and lives on to thrive another day. Upland Areas Limited prospects. Tamarind requires tropical or near- tropical temperatures. Any promise for the highlands would likely be restricted to equatorial latitudes and elevations below, say, 1,500 m, where the climate never falls below freezing.
TAMARIND 153 Beyond Africa The tamarind, a tree of many uses, has an especially attractive future for producing drinks, jams, and confections on an industrial scale. As noted, the tree adapts so well from dry savannas to well-drained monsoonal areas that greater plantings seem in order for much of the tropics. USES People both rural and urban utilize every part of this species: pulp, seeds, leaves, flowers, wood, and the whole tree itself. Among the wealth of tamarind products, the main ones are the following. Fruit As noted, the pulp is commonly eaten fresh. In addition, it is blended with sugar, and pressed into loaves, balls, or cakes. Even still on the tree this fruit is almost dry, and that alone endows it a long shelf life. Indeed, it may keep almost indefinitely. One preservation method involves pressing shelled fruit into rounded cakes and storing in a cool place. Another entails packing fruits into jars, using alternate layers of whole tamarinds and sugar. No matter whether fresh or preserved, tamarinds offer many culinary applications: They can be used to sweeten and season foods such as: â¢ Cereal productsâincluding Africaâs many types of porridges, gruels, and pablums (fufu, ugali, toh, ogi, kisra, pap, couscous, and the rest). â¢ Soups, sauces, chutneys, curries, fish. This is currently the main use for which European and North American countries import the pulp, especially to add to condiments such as steak and barbecue sauces. â¢ Confections, preserves, ice creams, syrups. Markets in tropical America often carry a sweetmeat of pressed tamarind and sugar. The fruits are also dipped in powdered sugar and eaten for dessert, like strawberry. â¢ Drinks. Shelled fruitsâcooked in syrup until soft and then put through a sieveâare made into refreshing drinks popular across the tropics. âTamarind-adesâ are enjoyed throughout much of Africa (for instance, Sudan, Egypt, West Africa, and coastal East Africa). Some are sold in cans and are even carbonated. Such tamarind beverages are also especially popular in Guatemala, Mexico, indeed most of the American tropics. Seeds Tamarind seeds are edible, usually roasted or boiled and eaten after shucking the seedcoat. In roasted form they are said to taste âbetter than peanuts.â In composition, they contain about 60 percent starch. In the form of a flour, they are added to cake- and bread mixes as well as other edible products. A purified pectinlike gum useful for stabilizing processed foods is made from them as well. In addition, an oil resembling peanut oil can also be extracted from the abundant seeds.
154 LOST CROPS OF AFRICA Other Foods Young leaves, flowers, and baby pods are all agreeably sour, and in some countries are used to season rice, fish, or meat in curries, soups, or stews. Immature pods are also used like common beans: roasted or boiled, and served as a vegetable, pickled, or added to salads. Fodder Tamarind is a vital fodder tree for arid and semiarid lands. Further, ground-up seeds make a palatable, high protein âconcentrateâ for livestock feed. Raw Materials The powder and concentrated juice from the fruitâs pulp are promising raw materials for the food-processing industry. Products from the seeds are promising industrial resources too. Purified seed-gum may be used for sizing textiles and paper products; it also has potential as filler for the adhesives used in making plywood. In addition, the seeds yield a semi- drying oil. This resembles linseed oil, and is said to be suitable for making paints and varnish. Wood The dark, purplish-brown tamarind heartwood is heavy and dense (weighing around 1,000 kg per cubic meter). Strong and termite-resistant, it takes a fine polish and makes excellent toys, tool handles, turnery products, furniture, and decorative paneling. It is very strong and stable and can be used for boatbuilding. It is widely employed in the camel-powered oil presses in remote rural areas such as Western Sudan. Although sold in North America under the name Madeira Mahogany, it is costly and hard to work, and the treeâs typically short bole limits its use as sawn timber. Fuel Tamarind wood is a valued fuel, and it gives off an intense heat. The heat output approaches 5,000 calories per kg. In India it is the fuel of choice for firing brick kilns. The charcoal can be of such high quality that it has long been used to make gunpowder, and it was also a major fuel for producer gas (âgasogenâ) units that powered many Indian vehicles during World War II. Ornamental Use One of the worldâs finest shade trees, tamarind is particularly valued in semiarid regions, where its huge dome of graceful foliage is all that enlivens many a dreary scene. To find this ornamental along a hot, dusty road or a public park is truly a joy. Miscellaneous Uses In Africa, tamarind is a host of one of the wild silkworms (Hypsoides vuillittii). It also is a good host plant for Kerria lacca, a shellac-providing insect. The flowers are reportedly a great source of honey. The trees make good firebreaks because the abundant leaf litter and deep shade beneath their dense canopies suppress most undergrowth. Some
TAMARIND 155 parts of the tree supposedly have curative properties, including fungicidal and antibacterial agents reportedly found in various tamarind products. Concentrated doses of the raw pulp are also used as a gentle laxative, and when boiled into a drink is considered good for inflammations. It is also mixed with salt and used to polish brass, copper, and silver. The seed testa can be used in tanning leather, while the seed husks have been found to make effective fish poisons. NUTRITION Up to half the pod weight consists of pulp, which contains both sugars and tart organic acids. Though reputedly richer in sugar than any other fruit (30-40 percent), the pulp usually tastes quite tangy. The acidity is largely due to tartaric acid, whose levels sometimes approach 12 percent of the pulp. However, there is much variability among different trees; some fruits are almost acid free, others so sour as to pucker the mouth. Notably sweet cultivars have been selected in Thailand, and these are highly prized. As the pod ripens its acidity hardly decreases, but sugar levels increase until they more or less match the sourness. Hence tamarind is said to be simultaneously the most acidic and most sweet of fruits. The dry pulp also consists of about 4 percent protein, and 1 percent fat. Though it contains negligible provitamin A, it is a good source of the B vitamins thiamin, niacin, and riboflavin. While the high acidity might suggest a good antiscorbutic, numerous tests have found that neither the ripe nor the green stages contain significant quantities of vitamin C. As to minerals, the calcium valueâsometimes above 0.1 percentâis reportedly the highest for any fruit. The phosphorus and potassium contents are also unusually high, averaging respectively about 165 and 900 mg per 100 g dry weight. Pods can also be high in iron, averaging about 4 mg per 100 g dry weight. This could make them useful in countering anemia. The leaves, with a protein content of 3-4 percent, make a vegetable of modest nutritional merit. They are supposedly, however, a good source of provitamin A, calcium, and phosphorus. The seeds are about as high in food value as maize or wheat. They contain about 60 percent starch, 15 percent protein, 5 percent oil, and small amounts of sugar. The protein is high in essential amino acids. HORTICULTURE The tree is easily propagated via direct seeding or transplantation from nurseries. Handled carefully, seeds remain viable for years and germinate rapidly after being scarified or soaked in warm water overnight. These treatments break the dormancy, with good germination occurring in about a week. However, seedlings are inherently slow growers, taking a year or so to become big enough for planting out. Fruiting then begins in 7-8 years.
156 LOST CROPS OF AFRICA Outstanding mother trees are propagated asexually, a process providing many advantages. Vegetatively propagated specimens come into bearing within 3-4 years. They produce more fruits as well as more-uniform fruits than seed propagation. Trees also seem to remain smallerâmaking them easier to harvest and handle. Shield and patch budding and cleft grafting are fast, reliable vegetative-propagation methods used on a commercial scale in the Philippines. Trees can also be started from branch cuttings, and superior clones can also be grafted onto seed-propagated rootstock. Globally speaking, tamarind trees receive minimal care, and tend to get very large. But in Thailandâs central delta they are intensively cropped and kept to convenient size by planting them close together (about 500 trees per ha) and by pruning (which also rejuvenates the fruiting wood). Even though tamarind is something of a âblue-collar crop,â Thai orchardists treat it with as much respect as their mango, pumelo, durian, and other quality fruits. They pamper their valuable tamarinds with such âwhite-collarâ treatments as irrigation, heavy manuring, and thorough pest and disease protection. Tamarind is shade intolerant and does not appear to regenerate beneath its own canopy. Although slow to mature, the trees are long lived. On average they continue fruiting 60 years, but individual specimens may remain productive 150 years or even much longer. HARVESTING AND HANDLING Average annual yields vary tremendously, depending on conditions, the inherent quality of the tree, and the care it is given. One review gives average yields from adult trees as 10 to 50 kg per year.2 Another reports 150 to 200 kg, or about 12 to 16 ton per hectare.3 A third refers to average yields between 500 and 800 kg for domesticated trees in India.4 And there are also claims of well-grown trees producing up to 2,000 kg of fruits per year. If whole pods are for market, they are best harvested by clipping, which avoids damaging the podâs shell. Fully ripe tamarind fruit can reputedly be left on the tree up to 6 months without loss of quality. Eventually, though, they abscise naturally, or are lost to pests, especially various beetles. The mature fruit has exceptional keeping qualities and is often soldâ unshelled but without other protectionâin village markets frequently notable for dirt, filth, and flies. Even when the shells have cracked or broken open, the sugary pulp can remain edible several months. Pulp destined for processing is separated from shell, seeds, and fiber before being compressed and packed (commonly in palm leaf mats) for storage, shipment, and sale. 2 Forestry Fuelwood Research and Development Project (F/FRED). 1992. Growing multipurpose trees on small farms. Winrock International, Bangkok. 3 Information supplied by the Royal Tropical Institute, Amsterdam. 4 International Centre for Research in Agroforestry (ICRAF). 1992. A Selection of Useful Trees and Shrubs for Kenya: Notes on Their Identification, Propagation and Management for Use by Farming and Pastoral Communities. ICRAF, Nairobi.
TAMARIND 157 Tamarind promises to boost rural development in most parts of the tropics. The sour-sweet pulp is very versatile, mixing easily into sauces and drinks. Its tang blends well with the fire of chilies, lending many tropical dishes their distinctively tart, sweetly biting flavor. (Glenn Kopp, Missouri Botanical Garden) LIMITATIONS There are conflicting claims about the need for a long dry spell around harvest time. Some contributorsâbasing their conclusions on African experienceâdeclare this is a necessity for growing tamarind as a fruit. In humid areas of Southeast Asia, however, orchards receiving more than 1,500 mm of rainfall annually are possibly the most productive anywhere. For the first few years of life, the young tree needs protection from grazing animals such as goats. Harvesting the fruit is difficult because the stem connecting the pod to the tree stays tough even when the fruit is ripe. Although a legume, the tamarind apparently fixes no nitrogen. Nodule- like lumps are often seen on the roots, but active nitrogen fixation has yet to be detected, despite many attempts. Insect pests can attack the pods, especially any left on the tree for some time. Seeds are prone to insect attack as well. Beetles and weevils are the worst antagonists. Ripe seeds should always be kept in airtight containers. Most African countries lack the marketing channels and information to develop substantial operations, but those could be quickly instituted. Not everyone loves this fruit at first sight. In fact, some take a long time getting used to its lowly looks. The pulp is not colorful or immediately
158 LOST CROPS OF AFRICA attractive but usually a rather sticky, somewhat fibrous mush, a sight that is not alluring to those who have yet to learn the secret of its flavor. NEXT STEPS There is a broad spectrum of focused actions that could help the world take better advantage of the tamarind.5 Below are just a few examples. Basic Studies Filipino researcher R.E. Coronel wrote us: âThe much- appreciated qualities of the tamarind and its adaptability to different soils and climates enabled it to conquer the tropics in the remote past; the tree and its fruit are still highly prized today. It is therefore all the more surprising that so little is known about tree phenology, floral biology, husbandry, yield, and genetic diversity....â6 The list could be expanded; there is much to learn. Selection Few of the tamarinds now growing throughout the tropics result from horticultural selectionâthey derive from seeds picked up perhaps at random. There is therefore excellent potential for markedly improving the crop. Much variation in fruit characteristicsâsuch as yield, sweetness, acidity, and the size and shape of the fruitâexists in nature and in millions of casual plantings. Some trees bear exceptionally large pods well filled with pulp; others are so lacking in acid they are referred to as âsweet.â Superior types such as these should be sought out and vegetatively propagated. In addition, budsports are common in tamarind. These isolated branches bear fruits different from those on the rest of the tree. Once identified, budsports can be readily propagated asexually to advance the crop. Germplasm Collections The greatest diversity of tamarind occurs in the African savannas stretching from Senegal into Sudan. There, specimens can be found exhibiting tolerance to waterlogging, persistent drought, extreme soils, high and low pH, and heavy grazing. These unique individuals need to be identified, tested, shared, and generally made available for use. There are also foreign tamarind collections that offer great possibilities. The Institute of Plant Breeding in the Philippines maintains a large number of accessions. In addition, India, Thailand, and other Southeast Asian countries have recorded many interesting types. The University of Florida has a collection near Homestead. From these, outstanding plants with fast growth, large fruits, and sweeter and juicier pulp are also likely to arise and help transform world appreciation for this overlooked crop. Windbreaks The tamarind is one of the few fruit treesâbecause its branches are so strong and pliantâthat can be grown in locations subject to 5 A full range of examples is in El-Siddig, et al. 2006, op. cit. 6 Information from R.E. Coronel.
TAMARIND 159 the full blast of tropical storms. Its very extensive root system also seems to contribute equally to its unusual resistance to horrific winds. The need here is not so much for research but for demonstrations, nurseries, and programs to educate people and initiate planting projects. Commercial Development Tamarindâs commercial promise may merit plantation expansion throughout the tropics. As long as quality varieties are planted, it should prove to be a profitable crop that, once established, can require little care and provide benefits for centuries. Husbandry Tamarind horticulture deserves special attention. Very little is known, for instance, about growth rhythms in various parts of the tropics. Pruning and other manipulations could create, for example, low-growing specimens, manageable in normal orchard practice and reachable from ladders. In such ways, tamarind might produce on a more intensive scale. Reforestation Every person concerned with the greening of the tropics should consider tamarind. The tree is magnificent for bordering streets and highways, for shading backyards, for farm and village boundaries, and for reforesting denuded slopes. Global Cooling As a tree to combat any greenhouse effect, this evergreen has the advantage that it may grow (and accumulate carbon) for two or more centuries. Unlike many tropical trees, it normally reaches a ripe old age: people resist cutting it because it provides food to eat and products to sell. Moreover, they are grateful because it turns hot, baking streets into shady, cool boulevards. Whole cities and hundreds of thousands of kilometers of roadsides could be planted with tamarinds. Individuals wishing to help an overheating world could hardly find a better tool among the trees. Harvesting It seems unlikely that plantings of tamarind orchards will increase in any major way until better methods of harvesting are found or developed. For example, pods today are often just knocked off with sticks. Other This brief chapter can only touch on the myriad things that could make a difference with a crop as versatile as tamarind. An international website could stimulate further developments and keep the world informed of progress. Beyond food, there are medicinal uses as well as industrial and other applications that could appeal to specialists.7 Documentation of indigenous knowledgeâwith local participationâon uses and conservation should be undertaken throughout tamarindâs distribution. Specific technical aspects deserving research include genetic resources, breeding, agronomy, harvesting methods, postharvest practice, and processing. There are, too, the economics of production and marketing to be explored. 7 These too are discussed in the Fruit for the Future monograph previously quoted.
160 LOST CROPS OF AFRICA SPECIES INFORMATION Botanical Name Tamarindus indica L. Family Leguminosae (Caesalpinioideae) Common Names Afrikaans: tamarinde, suurdadelboom Arabic: tamar-uâl-Hind Bambara: tomÃ, tombi Bantu: omukooge (tree), enkooge (fruits) Burkina Faso: bu pugubu Arabic: tamr hindi Dutch: Tamarinde, Tamarindeboom English: tamarind, Indian date Ethiopia: hemor, homor, humar, komar, tommar (Am), aradeb (T), b/roka, rucahu, dareho, dindie, ghroma, gianko, omar (G/O) French: tamarin, tamarinier, tamarindier Fulani: jtatami Hausa: tsamiya Kanouri: tamsugu Kenya: mkwaju (Swahili), ol-masamburai (Masai), epedur (Turkana), roka (Bor), chuzaa, chua (Luo), kinthumula (Ka), muthithi (Meru), orn (Poko), arwo (Tugen), Loisichoi (Njemps) Malawi: ukwaju, bwemba (Ch), mkwesu (Y), nkwesu (Nk) Niger: bossÃ©, bossaye (Djerma), djatube (Peuhl) Nigeria: Icheku oyibo (Ibo), ajagbon (Yoruba) Peul: dabe, ngatabbi, nâjabi, nâjame, yammere Portuguese: tamarindo Senegal: dakar (Wolof) Somalia: hamar (Som) Sonrai: BÃ³sso Spanish: tamarindo Sudan: aradeib, tamri hindi (Arabic), shekere, kuashi, danufi (Nuba) Swahili: mkwaju Tamachek: basoro, bassasu, bochocko, tchimic Tanzania: mkwaju (Swa) Uganda: esukuru, esuguguru (leaves, Ts); fruit: e/apeduru (Buk/Kmj/Ts), iti (Bar/Md), chwa (A), cwa/o (Ach/Lng), pitei (Kk/Ach) Zambia: mushishi (B), mwemba (Ny), b/musiika (To)
TAMARIND 161 Description Tamarind is a massive, slow-growing, long-lived tree with dark-gray bark and strong supple branches that droop gracefully at the end. It may reach 25 m in height. The trunk can exceed 7 m in diameter but is usually short even in old trees. However, in the wet tropics trees seem to grow taller and can produce a fairly long clear bole. The bark is strongly fissured and scaly on the trunk and smooth on the branches. It exudes a blood-red gum. In most growing areas tamarind is evergreen; however, severe drought causes massive leaf drop. At flowering, the trees burst with showy clusters of pale-yellow, pink-veined blossoms. These are cross-pollinated, probably by insects (such as, in India, the honeybee relative Apis dorsata) and wind, although the flower structure does not exclude the possibility of selfing. The tree produces heavy crops of fruits, typically every other year. Trees are known still producing fruits at a reputed age of 200 years. Fruits are long, flattish, gray or rusty colored, bean-like pods, usually irregularly curved, sometimes with constrictions in the spaces between the seeds. They contain 2-10 seeds embedded in sticky pulp. At maturity, the shell turns brittle and is easily cracked open to expose the dark-brown, pasty pulp that surrounds hard, shiny, brown seeds, each in a parchment-like âenvelope.â Distribution This species is a native of the dry savannas of western Africa but it now reaches the southern limit of its range in Mozambique and Natal, where it has become naturalized around Durban. Tamarind performs so well in semi-arid and humid monsoonal climates that it is already truly pantropical. It is found across South Asia, where traders or travelers introduced it centuries ago. It is also common throughout the American tropics, especially the Caribbean. In Puerto Rico, as one example, it is fairly common along roadsides, around houses, and on hillsides in the dry, coastal regions. Horticultural Varieties Many different types exist depending on the form and quality of the fruits. But at present there are few standard varieties. Thai orchards grow cultivars of a sweet type (makahm wahn) named âMuen Chongâ, âNazi Zaâ, and âSi Chompooâ. âManila Sweetâ is a similar cultivar from the Philippines. Environmental Requirements In their native African habitat, wild tamarind trees mostly grow alone, rarely in small groups, sometimes along rivers (which may be seasonally dry) or lakes, as well as in often rocky, lowland-woodland. The species is a
162 LOST CROPS OF AFRICA light demander, very sensitive to frost, and withstands drought. Although happy on plains and stream banks subject to frequent flash flooding, it cannot withstand long-term inundation or stagnant waters. Rainfall In Africa tamarind thrives where annual rainfall drops as low as 750 mm and sometimes below 500 mm. It also can thrive in areas of Southeast Asia receiving more than 1,500 mm. Generally speaking, it seems to avoid regions exceeding 1,900 mm. Altitude By and large, it is found between sea level and 1,500 m elevation. In the Machakos district in Kenya, for instance, it can be seen growing well at about 1,200 m above sea level. Low Temperature Tamarind cannot tolerate persistent cold; even brief frost can cause severe damage or death. Anywhere mean annual minimum temperatures fall below about 7Â°C is too cold to cultivate tamarind reliably. High Temperature This tree seems undaunted where mean annual maximum temperatures can exceed a blistering 50Â°C. Soil Some writers claim tamarind prefers slightly acid (pH 5-5) soil. In Fiji, though, successful growth has been reported in highly acid (pH 4.5) to highly alkaline (pH 8.7) soils. In India, the tree also grows in alkaline soils (pH 8.5). Truth is, this species (or its genotypes) tolerates a diversity of substrates. Although growing best where soils are deep and well drained, it can flourish in poor soils and even rocky terrain. It is also frequently found beside termite mounds or in sands near the seashore. In the Sahelian zone, it commonly grows in association with baobab (see Chapter 2).