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T. alwl On the face of it, it is surprising that tarwi (Lupinus mutabilis) has not been developed as an international crop. Its seeds contain more than 40 percent protein as much as or more than peas, beans, soybeans, and peanuts the world's premier protein crops. In addition, its seeds contain almost 20 percent oil as much as soybeans and several other oilseed crops. Tarwii thus would appear to be a ready source of protein for food and feed as well as a good source of vegetable oil for cooking, margarine, and other processed food prod- ucts. One of the most beautiful food crops, tarwi (pronounced tar-wee) could also qualify as an ornamental. Its brilliant blue blossoms bespangle the upland fields of the Indians of Peru, Bolivia, and Ecuador. Indeed, corn, potato, quinoa, and tarwi together form the basis of the highland Indian's diet. In Cuzco, the former Inca capital, baskets of the usually bone-white tarwi seeds are a customary sight in the markets. The seeds are most often served in soups. Tarwi seeds are outstandingly nutritious. The protein they contain is rich in lysine, the nutritionally vital amino acid. Mixing tarwi and cereals makes a food that, in its balance of amino acids, is almost ideal for humans. With its outstanding composition, tarwi might become another "soybean" in importance.2 Because of this possibility, re- searchers in countries as far-flung as Peru, Chile, Mexico, England, the Soviet Union, Poland, East and West Germany, South Africa, and Australia have initiated tarwi research. This "pioneer" species can be cultivated on marginal soils. Its strong taproot loosens soil and (because it is a legume) its surface roots collect nitrogen *om the air. Both of these abilities benefit the land in which it is grown. ~ Also widely known as "chocho." At a 1986 conference of the International Lupin Association, the name "Andean lupin" was proposed for international use. 2 This is not as improbable as it seems. Sixty years ago the soybean was hardly known outside Asia; today it is America's third largest crop and is a vital part of the economies of Brazil and several other non-Asian nations. Like tarwi it requires processing to rid its seeds of adverse components. 181
182 LOST CROPS OF THE INCAS Despite all its qualities, tarwi is almost unknown as a crop outside the Andes. It has been held back mainly because its seeds are bitter. However, this can be overcome. The bitter principles (alkaloids) are water soluble, and they are traditionally removed by soaking the seeds for several days in running water. Technology now has modernized the process to the point where it can be done in a matter of hours. Also, in another approach to removing the bitterness, geneticists in several countries have created "sweet" varieties whose seeds are almost free of bitterness and need little or no washing. These efforts would appear to pave the way for a future role for tarwi in world agriculture. PROSPECTS Andean Region. Tarwi is found from Venezuela to northern Chile and Argentina, and in this area it is already getting modern attention. Engineers in Peru and Chile have developed machinery to debitter tarwi seeds. Indeed, small industrial installations are now operating at Cuzco and Huancayo in Peru.3 Their product is being used to feed schoolchildren and to produce a line of cereals. Also, researchers in Chile and Bolivia have created varieties with only one-thousandth of the alkaloid levels found in bitter types. Given these advances, tarwi cultivation and use should expand in the Andes. This is significant because the crop is an important contributor to the nutritional well-being of many campesinos for whom meat is a luxury. The highland diet is low in protein and calories, and the quality protein and high oil content of tarwi seed provide a double nutritional benefit. Other Developing Areas. The lengthy process of washing the seeds has previously hindered tarwi's introduction to areas outside the Andes. However, the sweet types could make the plant into a major crop for tropical highlands and for a number of temperate regions. So far it is barely known outside of South America, but a hopeful sign is that in Chapingo, Mexico, tarwi has produced high yields of seed.4 3 These pilot plants are capable of processing 7,000 tons of seed per year into vegetable oil and plant protein. The German government organization GTZ (Deutsche Gesellschaft fur Technische Zusammenarbeit, Dag-Hammarskjold-Weg 1, D-6236 Eschborn 1) has spearheaded support for the investigation and development of tarwi. 4 Information from J. Etchevers.
TARWI 183 Field of tarwi high in the Peruvian Andes, near Chiara, Department of Cuzco. (D.W. Gade) Industrialized Regions. This adaptable plant will flower both in the short days of the tropics and in the long summer days of the temperate zones. As noted, it has already been grown experimentally in Europe, South Africa, and Australia. Current types mature late in temperate latitudes, but a diligent search of the native germplasm in the Andes will likely turn up quick-maturing forms. USES As has been mentioned, tarwi appears to be a ready source of vegetable protein and vegetable oil for both humans and animals. It is also suitable for processed food products, high-protein meal for food and feed, and margarine. In the Andes, the cooked seeds are popular in soups, stews, and salads, or are eaten as snacks, like peanuts or popcorn. The soft seed coat makes for easy cooking. Like other lupine (for example, the "lupini beans" of Italy and the white lupine of Eastern Europe), tarwi is an excellent green manure
184 LOST CROPS OF THE INCAS ~~. ~~. ~~. ~~ -~ ~~-~6s~>s~ ·sS) saws as so stress act ash s s s ~ · ~~ ,s~S'sss s~s~sy~s~s~s~sss~s~sssS~s~ ~s~s~s.~ss~s as s~s#~s~~sss~s~s~s~s~s~s~s~s ·s~sss~s~s~ss s~s~ss~ss.sS ~~ :l/!lI~!ll/~<': '~SS~SL ~~.~,~ ~~ ~~< ~~ ~~ ~~sss~S ~~i~i#~1~ (~---~s~.~,~ ~~ ... <~ ~~ ~~ |^~ ~~ ~~ ~ ~~ ~~ a Bows of washed Thai seeds are ~ common sigb1 in markers 1broupbout 1be Andes ARbougb unknown elsewbere, 1bese sheds brave ~ composhion roughly comp~fable 13 1ba1 of soybeans, one of 1he world's premier crops. (H. BrOchcr)
TARWI 185 crop, able to fix as much as 400 kg of nitrogen per hectare. Much of the nitrogenous product remains in the soil and becomes available to succeeding crops. With the high prices and shortages of this essential fertilizer element, tarwi could become increasingly important in crop- rotation systems.5 NUTRITION As noted, the seeds are exceptionally nutritious. Protein and oil make up more than half their weight. In a survey of seed from more than 300 different genotypes, protein content varied from 41 to 51 percent (average 46 percent); oil content varied in roughly inverse proportion from 24 to 14 percent (average 20 percent).6 Removing the seed coat and grinding the remaining kernel yields a flour that contains more than 50 percent protein. Tarwi protein has adequate amounts of the essential amino acids lysine and cystine, but has only 25-30 percent of the methionine required to support optimal growth in animals. The protein digestibility and nutritional value are reportedly equivalent to those of soybean.7 Tarwi oil is light colored and acceptable for kitchen use. It is roughly equivalent to peanut oil, and is relatively rich in unsaturated fatty acids, including the nutritionally essential linoleic acid. The seeds' fiber content is not excessive, and they are thought to be good sources of nutritionally important minerals.8 AGRONOMY Like most Andean crops, tarwi is hardy and adaptable. It is easily planted and tolerates frost, drought, a wide range of soils, and many pests. Its soft-skinned seeds germinate rapidly, producing vigorous, rapid-growing seedlings.9 Robust vegetative growth continues~through- out the growing season and the plants become masses of foliage topped by showy purplish-blue flowers.~° Most fields, however, remain under 1 m tall and at the end of the season bear many tiers of pods, held high above the leaves. Each pod contains the beanlike seeds that are white, speckled, mottled, or black. 5 For centuries, tarwi has been an important component in the traditional crop rotations of the Andes. It is likely that tarwi's alkaloids are a factor in controlling potato nematodes when the two crops are rotated. Information from M. Tapia. 6 Information from R. Gross. 7 Ortiz et al., 1975. ~ Pakendorf et al., 1973. 9 However, the young plant often remains in a state of suspended growth for several weeks, during which time it is very susceptible to pests. 'I On Taquile Island in Lake Titicaca, there is a variety with rose-colored flowers. Information from T. Plowman.
186 LOST CROPS OF THE INCAS Reportedly, the green-matter production considerably exceeds that of the commercial European lupin species (Lupinus albus and L. Iuteus). In experiments in the Soviet Union, the plant produced 50 tons per hectare of green matter containing 1.75 tons of protein per hectare. ~ ~ Many forms of the plant resist the lupinosis fungus, which sometimes kills livestock that feed on the foliage of other lupin species. Also, many ecotypes are resistant to lupin mildews and rots.~3 HARVESTING AND HANDLING Unlike many lupin species, tarwi pods do not split and shed their seed on the ground. Ancient Indian cultivators probably selected plants that held their seed until they could be harvested. As noted, the water-soluble alkaloids must be washed out before the seeds can be eaten. LIMITATIONS As already stated, tarwi's most serious known liability is the alkaloids in its seeds. Apart from that, its long vegetative cycle during and after flowering is a major limitation. Because there has been little agronomic improvement of tarwi, the available cultivars are primitive. Most have indeterminate growth and produce multiple tiers of flowers. Unless drought or cold causes the plants to "dry down," they keep on flowering endlessly. Continuous flowering boosts yields and can be a good thing for a small farmer because it means a continuing source of food. However, it also means that pods ripen at different times, and for a large-scale farmer this greatly hinders harvesting, especially if machinery is used. Also, current tarwi cultivars require a growing season as long as 5- 11 months to fully ripen their seeds. In temperate zones, this means that the seeds do not always ripen before the onset of winter. In the Andean highlands, the drought season starts as the plants begin ripening, thus bringing the flowering to a natural end. Compared with other commercial lupin crops (for example, Lupinus angustifolius or L. Iuteus), tarwi has a lower leaf to stem ratio, so that it produces fewer seeds than would be expected from such a mass of vegetation. " Brucher, 1968. |2 Van Jaarsveld and Knox-Davies, 1974. |3 These ecotypes are not yet in intensive cultivation, however. Information from K.W. Pakendorf.
TARWI 187 Tarwi cross-pollinates so readily (the percentage of outcrossing may exceed 10 percent) that to preserve specific cultigens, such as low- alkaloid types, may require a special system of seed production and distribution. This factor particularly limits the increase of "sweet" tarwi in the Andes because of the recessive inheritance of the genes for low-alkaloid types and because bitter types are always nearby. Elsewhere (for example, in parts of North America), wild lupinesi4 may be a source of pollen pollution. Current types are particularly sensitive to alternaria, a fungal disease that destroyed a large area of the crop in Peru in one recent year. RESEARCH NEEDS Eliminating problems caused by the bitter alkaloids would help tarwi advance as a world crop. Research is needed into improving the technology of debittering the seeds on a large scale. Also, the nonbitter varieties should be advanced to commercialization. From the research already completed, it seems that strains with almost no alkaloids are available in nature or can be created artificially. The challenge now is to make them stable, so that the low alkaloid content is inherited uniformly by succeeding generations. Also, the initial low-alkaloid strains have been proven highly susceptible to insect attack. Breeding programs should seek plants that have alkaloids in the leaves but not in the seeds.'7 Research to boost yield is also needed. Today, many flowers fail to set seed. Studies of pollination and fertility could point the way to helping the plant to approach its potential. (The failure to set seed is a characteristic of all lupine, and research on other species may also benefit tarwi.) In any breeding program, high priority should be given to selecting early-maturing varieties for areas where growing seasons are short (for example, temperate latitudes and semiarid areas with short rainy seasons). Early-maturing types may also suffer less damage from pests |4 "Lupine" is the standard American spelling; "lupin" is standard elswhere. We suggest that the former be reserved~for undomesticated species and the latter for the domesticated species. 15 However, it may not be vital. Several staple foods require elaborate processing before they are safe to eat. Cassava is an example. '6 This has been achieved by E. von Baer (see Research Contacts). The stable, sweet line, called "inti," has been created through successive breeding that has reduced the alkaloid content to a level below 0.003 percent while maintaining 51 percent protein and 16 percent oil. The seeds are small, however, and the yields lower than normal. Both problems seem likely to be overcome soon. '7 A method that uses specially prepared reagent paper to screen for the presence of alkaloids is already available. Information from E. Nowacki.
188 LOST CROPS OF THE INCAS and diseases. In addition, selection for mutants with a single short flowering period is needed. (Such determinate types have been located in southern Peru and Bolivia and probably can also be found elsewhere in the Andes. Synchronous ripening would be particularly useful in many locations dependent on mechanical harvesting. Adaptability trials should be conducted in different parts of the world. Other cultivated lupine are fairly specific in their temperature and soil requirements; tarwi, too, might prove to have limited adapt- ability. Practical tests of the seeds in food products should be undertaken. This is likely to generate a demand that will stimulate commercial production, especially in the high Andes. SPECIES INFORMATION Botanical Name Lupinus mutabilis Sweet Family Leguminosae (Fabaceae) Common Names Quechua: tarwi Aymara: tauri Spanish: altramuz (Spain), chocho (Ecuador and northern Peru), tarhui (southern Peru and Bolivia), chuchus muti (Bolivia) English: tarwi, pearl lupin, Andean lupin Origin. Pre-Inca people domesticated this lupin more than 1,500 years ago, and it became a significant protein contributor to the region's food supply. It provides a common motif on both ancient and modern . . ceramics ant weavings. Description. Tarwi is an erect annual, growing 1-2.5 m tall, with a hollow, highly branched stem and short taproot. The showy, multi- colored purple to blue Howers (each with a yellowish spot) are held high above the digitate leaves. To attract pollinating insects, the flowers exude a honeylike aroma. The hairy, 5-10 cm long pods are Hattened, about 2 cm across, and contain 2-6 (or more) ovoid seeds 0.6-1.0 cm across. Horticultural Varieties. Many ecotypes and landraces exist throughout the central Andes. As mentioned, South American re- searchers have begun selecting for higher, more uniform yields and less bitter seeds. However, standardized varieties are not yet available. ~8 Information from E. von Baer.
TARWI 189 Germplasm collections are maintained at the Universidad del Cuzco in Peru; at the Estacion Gorbea in Chile; at the Institute of Plant Genetics in Poznan, Poland; in East Germany; and in the U.S.S.R. Environmental Requirements. The plant is native to tropical latitudes (from 1°N to 22°S) but occurs mainly in cool valleys and basins at high altitudes. Thus it is a crop for cool climates (tropical highlands and temperate regions), not for the humid or arid tropics. Daylength. Apparently neutral. Tarwi will flower and set seed both in the short (12-hour) tropical days and in the longer summer days in temperate zones. Rainfall. The limits are unknown, but tarwi withstands exceptional levels of drought. Altitude. From Colombia to Bolivia this species grows in the Andes at altitudes from 800 m to well over 3,000 m. In Australia, Europe, and California, it has been grown at or near sea level. Low Temperature. Tarwi is semihardy. Mature plants are frost resistant; young plants are frost sensitive. High Temperature. Unknown. Soil Type. The plant is tolerant of sandy and acid soils, but in acid soils the production of rhizobium is very poor. Related Species. The genus Lupinus is very diverse, with more than 100 different species in the New World and a smaller number in the Mediterranean region. Other than tarwi, all agriculturally important lupine derive from Mediterranean species. These, too, have important global promise. The seed of Mediterranean lupine were rendered free of toxic alkaloids in the late 1920s and 1930s by the German researcher R. von Sengbusch, who isolated low-alkaloid ("sweet") strains. These are now used as feed and fodder in Europe (especially the Soviet Union and Poland), the United States, Australia, and South Africa. Of particular note is the narrowleaf lupin (Lupinus angustifolius). Nonbitter types with soft seed coats were discovered in Germany in the 1920s. Through 20 years of dedicated selection, the Australian scientist John S. Gladstones developed an early-maturing, sweet- seeded, nonshattering type. It is now widely planted in Western Australia as livestock feed, and its grain is exported to Europe.