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Neglected Crops: 1492 from a Different Perspective. 1994. J.E. Hernándo Bermejo and J. León (eds.). Plant Production and Protection Series No. 26. FAO, Rome, Italy. p. 165–179.

Andean roots

The author of this chapter is J. Rea (La Paz, Bolivia).

(Lepidium meyenii)

Botanical name: Lepidium meyenii Walp.

Family: Brassicaceae (Cruciferae)

Common name. English: mace, pepper grass, pepper weed; Spanish: mace (Peru)

The mace is one of the Andean crops which occupy a very restricted area. It is found only on the central sierra of Peru in the departments of Junín and Pasco, in the puna agro-ecological zone above 4000 m where low temperatures and strong winds limit other crops.

Domestication of this plant appears to have started at least 2000 years ago, around the area of San Blas in the department of Junín. During his visit to the Junín area in 1549, the encomendero Juan Tello de Soto Mayor reportedly received mace "fruits" as a tribute and used them to improve the fertility of the livestock of Castile. It was also stated, during a visit to the area of Huánuco in 1572, that the Chinchaycochas had used the mace for bartering since the time of the Incas, as there was no other crop on their lands.

The mace is grown on small plots with a few rows and up to about 500 m2 in size, on peasant land in communities around Lake Junín (Yanacancha, Ingahuasi, Cerro de Pasco, Ninacaca and Vicco). It is a biennial herbaceous plant, whose subterranean part (hypocotyl) is edible and highly valued for its nutritional value, especially proteins and minerals. The rural community is firmly convinced that eating mace enables couples who think they are infertile to have children.

Uses and nutritional value

When the fresh hypocotyls have been harvested, the peasant usually roasts them in the field in the form of huatias (cooked between clods of red-hot peat) on pachamancas (cooked in contact with hot stones taken from a wood fire and covered with earth). However, most of the harvest is left to dry and can then be kept for several years.

For eating purposes, the dried hypocotyls are hydrated overnight and parboiled in water until they are soft. They can be liquefied to prepare juices, cocktails, porridges and jams. Nowadays the dry matter is being processed to prepare products in tabloid form which are in demand because of their nutritional value and because of the supposition that they stimulate sexual appetite and increase fertility.

The high calcium content (258 mg) and iron content (15.4 mg) per 100g are the main advantages of this Andean crop. It has a 14 percent protein and 78 percent carbohydrate content and is also rich in starch, glucosides, alkaloids and tannins. The protein content may vary between 10 and 14 percent depending on the fertility conditions of the soil and the variety.

Rats fed on mace produced some 25 percent more offspring than control rats, probably because development of the Graafian follicles is stimulated.

Botanical description

Lepidium meyenii is a herbaceous, perennial plant, growing 12 to 20 cm. Its has succulent roots and short and decumbent stems. Its leaves are rosulate, pinnatipartite and are continuously renewed from the centre of the rosette. The racemes are pauciflorous. The fruit is in siliculae, measures 4 to 5 mm and is dehiscent with two carinated valves, each containing a seed. The seeds are ovoid, 2 to 2.5 mm and reddish grey.

The hypocotyls, which are the edible part of the plant, vary between 2 and 5 cm in size and may be white or yellow, reddish and white, white and yellow. white and purple, light-lead grey, purple and lead grey or yellow, red and grey.

Figure 19. Andean roots: A) mace (Lepidium meyenii) A1) racemose inflorescence; A2) fruit in a silicula; A3) dried root; B) arracacha (Arracacia xanthorrhiza); B1) leaves; B2) umbel inflorescence; B3) fruit; B4) cross-section of the fruit

Ecology and phytogeography

Cultivation of the mace is limited to the puna agro-ecological zone of the central region of the Peruvian Andes, at altitudes between 4000 and 4400 m. The puna is characterized by periods of temperatures below 0°C, called frosts, even at the height of the crops' growing period. However, the mace tolerates these temperatures fairly well, just as the bitter potato does. When the mace was sown in other latitudes, such as in Berlin, Germany, (lat. 52°N) in 1990, it did not manage to form hypocotyls. This result appears to support the idea that the mace is a short-day plant.

Genetic diversity

The species L. meyenii was described by Gerhard Walpers in 1843. It has been suggested that the cultivated mace is not L. meyenii but a new species. L. peruvianum Chacón, based on various specimens collected since 1960 in the district of San Juan de la Jarpa, in Huancayo province. This assertion is based on comparative studies of the botanical characteristics, and in particular on the histochemical observations of the hypocotyl, which is the main distinguishing feature of this new species.

In the cultivation area, at least eight types of mace are differentiated according to the colouring of the plant and the hypocotyl. Although there is no gene bank for this species, the Agricultural University of La Molina and the University of Pasco have collected genetic material.

Cultivation practices

The mace is sown at the beginning of the rainy period (September-November) as the sole crop or combined with strips of bitter potato. According to the peasants in the area, this combination protects the potato from insect attack, since the mace contains repellent volatile substances.

It can be sown on freshly ploughed pasture land that has lain fallow (purun), or on ground under an annual rotation with another crop (kallpar) such as the bitter potato. Generally speaking, soil preparation is deficient and broadcast sowing is carried out without any fertilization or, at best, only a manure dressing. The seeds are buried using branches or are left to be trod on by sheep. Tillage is not usually carried out, except to make sure that the small plants are not trampled by animals. The mace is believed to deplete the soil; this probably occurs when the nutrients removed are not sufficiently replenished.

Harvesting begins in May or June. The fresh hypocotyls are exposed to the sun's rays for about four to six days until they are dry. They are then stored in a cool, dark place until they are eaten.

The yield is very variable: in fields where little care has been devoted to managing the crop, about 2 to 3 tonnes per hectare are obtained while, with appropriate row cultivation practices, fertilization and the prevention of pest attacks, it is possible to produce up to 15 to 16 tonnes per hectare.

Plants which produce the hypocotyl in the first year do not produce seed. The following practices are carried out to obtain seed: after selecting the biggest, soundly formed and suitably ripened hypocotyls, between 30 and 50 are placed in a hole which is 50 to 60 cm deep and of the same radius and which is covered with damp earth. The plantlets take 25 to 30 days to grow. To transfer them, a seed bed is prepared with soft earth and fertilized with farmyard manure. Care must be taken to ensure that there is adequate humidity for the vigorous development of the plants, which will produce seeds within six to seven months after transplanting.

Prospects for improvement

This crop offers excellent possibilities for improvement, in particular because there is a potential market for the hypocotyls as a stimulant (similar to ginseng).

With simple mass selection techniques, varieties can be bred which give a better yield and are more uniform, thus facilitating their processing. Current local ecotypes have to be conserved so as not to lose existing genetic variability.

Cultivation practices can also be improved: a system of cultivation combined with the bitter potato is suggested, this being another species suited to the ecological conditions of the puna.

The main limitation, which is being overcome, has been the scant attention that producers (basically livestock farmers from the puna area) have paid to this species. In order to encourage its cultivation, a yearly mace fair has been held since the Association of Maca Producers was established in the department of Pasco some years ago.

(Arracacia xanthorrhiza)

Botanical name: Arracacia xanthorrhiza Bancroft

Family: Apiaceae (Umbelliferae)

Common names. English: arracacha, white carrot, Peruvian parsnip; Aymara: lakachu, lekachu; Quechua: oqqe, huiasampilla, laqachu, raqacha, virraca, rikacha; Spanish: arracacha, racacha, zanahoria blanca, apio criollo, sonarca; Portuguese: batata baroa, mandioquinha, batata salsa, batata cenoura; French: arracacha, panème, pomme de terre-céleri

This is possibly one of the oldest cultivated Andean plants, its domestication having preceded that of the potato. There are no vestiges whereby its area of origin can be identified, although it could have been the northern part of South America, in view of the presence there of related wild species. Outside the Andes, it is grown in the Antilles, Central America, Africa, Sri Lanka and in large commercial areas in southern Brazil, where it is industrialized.

The basic causes of its marginalization should be sought in the socio-economic context of its growers. The current secondary causes are to be found in a few limiting factors of an agronomic nature. We may mention its photoperiod requirements, susceptibility to extreme temperatures, long growth cycle. susceptibility to pests and diseases and the difficulty of storing its roots. These are factors which can be modified if agronomic improvement work is carried out.

Uses and nutritional value

In the Andean region, potatoes are scarce in town markets during years of drought or frosts in the high areas. They are replaced by the arracacha, cassava, sweet potato , tannia (Xanthosoma sagittifolium), cocoyam or dasheen (Colocasia esculenta) and yam beans (Pachyrhizus spp.).

The roots are harvested as from the fourth month, depending on the cultivar and region. They are eaten boiled or as an ingredient in soups and stews, and also as a puree, roasted and fried in slices. The leaves are prepared in the same way as celery in raw or cooked salads, hence the name "Creole celery" which is given to it in Venezuela. After two to three months of storage, the sugar content in the roots increases through partial conversion of the starches.

The stump or crown of the roots—containing approximately 9 percent protein—is used to feed dairy livestock. The plant's stem and leaves are likewise used as animal fodder while the dried leaves can be used to prepare meal, which is also used as animal feed.

The arracacha's pleasant flavour and easy digestibility, which are universally acknowledged, result from the complex of starches, oils and mineral salts. The starch content ranges between 10 and 25 percent. The seeds are fine and similar to those of cassava. The arracacha is a good source of minerals and vitamins.

Botanical description

The plant consists of a short, cylindrical stem which grows to a height of 10 cm and a diameter of 10 cm, with numerous buds on the upper part. Each of these has leaves with long petioles, divided into three to seven very jagged folioles. The leaves are green or bronze-coloured depending on the variety. Two kinds of roots emerge from the stem: long and fine ones or tuberous and fusiform ones. The latter are the usable part. They are 5 to 25 cm long and up to 8 cm in diameter. The root is harvested before the end of the growing cycle; if it is left, floriferous buds sprout from the stem. The inflorescences are composite umbels, bearing many small, deep-purple flowers, a calyx and a corolla of five minute parts. The fruit is bicarpellar with an inferior ovary.

Ecology and phytogeography

Arracacia xanthorrhiza's minimum humidity requirement is 600 mm and the optimum 1000 to 1200 mm. It grows at an altitude of between 1500 and 3000 m, depending on the latitude, and its optimum temperature is 14 to 21 °C. Lower temperatures delay ripening of the roots and affect foliage growth. Higher temperatures, as in Maracay in Venezuela and Santa Marta in Colombia. and probably in the Amazon region, seem to reduce root size. A. xanthorrhiza grows in deep soils which have good organic matter, are fertile, well-drained and sandy, with a pH of 5 to 6. It does very well in fertile volcanic soils. Short days are required for good rooting.

The phytogeographical characteristics of the main cultivation regions are as follows:

In eastern Venezuela, better-quality arracachas, such as Amarilla, are produced at 1200 to 1400 m; in Barimitas, Santo Domingo, at 1500 to 1800 m. In Mérida, Venezuela, small crops of arracacha are found on the valley floors and on east-facing slopes. During dry periods, they are irrigated every two weeks. In Táchira, Venezuela, they are rotated with banana and plantains and are combined with maize through intercropping with maize and beans. In Colombia, A. xanthorrhiza occupies an important place in the production structure of departments, such as Ibaqué, that are above 1800 m; in Antioquía, Río Negro and Nariño, between 1200 and 2800 m; and in the basin of the Otengá River in Boyacá, up to 3200 m. On the coast, it grows in Santa Marta at 40 m. Under conditions of abundant humidity with irrigation, it is sown throughout the year and harvested at eight to 12 months.

In Ecuador, crops are found between 1500 and 3000 m along the inter-Andean passage, although there are fewer of them on the western and eastern sides of the range. At higher altitudes, it is cultivated sporadically; production cycles exceed one year, with greater development of the stump or crown in relation to the roots. The greatest concentration of cultivars is in Azuay and Loja.

In Peru, it is cultivated almost throughout the country trom 1200 to 3200 m, where there is humidity. The two major centres of diversity are found in the northern sierra (Cajamarca) and southeastern sierra (Cuzco).

In Bolivia, the greatest concentration of crops is in the yungas of La Paz and Cochabamba, between 1000 and 1800 m. In the valleys of La Paz, cultivation is very sporadic, and is carried out at 3500 m, with irrigation during dry years.

In Brazil, it has spread from São Paulo to Santa Catarina, where it is intensively cultivated from 700 to 2000 m.

Genetic diversity

Among more than 60 specimens collected in the Andean countries, there are numerous cultivars which are differentiated by foliage colour and the external colour of the root: white or yellow, both with purple pigmentations.

Germplasm collections in South America

ICTA established a gene bank between 1965 and 1967. with 50 accessions from Colombia, Bolivia. Ecuador and Peru. The collection was kept in San Mateo in Lima but at 3050 m but, because of the termination of the Andean Crops Programme, this material was transferred in 1967 and 1968 to various institutions in Andean countries and Brazil.

There are a great many varieties in Colombia: Paliverde is the most common (90 percent), Paliamarilla occurs to a lesser extent and Palirrusia or Palirroja are uncommon. Paliverde can attain yields of 10 to 15 tonnes per hectare of roots and 4 to 7 tonnes per hectare of stumps.

Considerable variability has been found among arracachas, particularly insofar as foliage and root characteristics are concerned. The most notable types are the bronze-foliaged ones originating from Colombia. In these, no correlation is observed between the presence of anthocyanin in the leaves and roots, since the latter had a white epidermis and also a white phloem and xylem. The types with yellow roots, both on the surface and on the internal part, have a pale bronze foliage, with anthocyanins restricted to the lower section of the leaves. Consequently, there is no clear correlation between foliage colour and root colouring.

The congeners closest to the cultivated species are: A. sequatorialis, A. andina, A. elata and A. moschata. Other species have also been found, such as A. pennelli Constance in Bogota, A. tolucensis H.B.K. var. multiflora in Colombia and Mexico; A. wigginessi Constance in the south of Cuenca, Equador; A. incisa Wolf in La Oroya; and A. peruviana Wolf in Ayacucho, Peru.

Cultivation practices

The description of the traditional cultivation technique is based on experiments and visits made to peasants in Colombia and Peru.

The arracacha is reproduced by colinos (in Colombia), suckers or pashincas (in Peru), which are short ramifications or shoots which emerge from a madre in Colombia and a buque in Peru. In Colombia, approximately 400 kg per hectare of colinos are required which are planted out and then earthed up. When rooting has developed, three or four earthings can be done at the same time as weeding, although some farmers say that if earthing up is done repeatedly the plant produces only foliage. The growing period is variable; in the highest and coldest areas it can be eight months while, in the savannah, it can be as long as a year. This species prefers cloudy areas with a constant humidity.

In some areas, the arracacha is included in a rotation. It generally follows potatoes and vegetables or is combined with maize (five furrows of maize and one of arracacha) and also with coffee (in Manizales, Colombia). The sowing time coincides with the beginning of ripening of the maize and it is then left in the field for up to two years.

Prospects for improvement

The following may be mentioned as agronomic limitations of A. xanthorrhiza: its long production cycle compared with potatoes and other tubers; the lignification of its roots on maturity; the deterioration in the quality of stored roots; pests and diseases, such as one unidentified mite which attacks the roots; rotting caused by Pseudomonas sp., which begins at five or six months in the root and foliage; Alternaria sp., Erwinia spp. and Rhyzoctonia crocorum; and lesions from nematodes, such as Pratylenchus penetrans which cause root necrosis.

There is room for improvement in the present production system of peasant agriculture. An analysis of cultivation practices from sowing up to harvesting should be the basis for implementing future research depending on specific local situations.

In every country and in the regions with the greatest concentration of cultivations and germplasm. it would be of socio-economic, cultural and educational benefit to organize communal centres of action, where specific projects are put into operation as part of an integral concept whose economic feasibility is tested with the farmers themselves and neighbouring communities. For example, the operation of a processing unit would be linked with production, postharvest marketing and the industrial process. At the same time, school and community canteens could be run on the basis of educational and nutritional criteria. Any surpluses achieved during a project would reflect the satisfactory result and would make extension to other regions easier. Shared research on a wide scale needs to be planned with farmers on smallholdings. Covering a large area with multiple ecologies, projects would benefit from the contribution of many people. The positive aspects of existing farming practices would be reappraised and specific problems solved.

This genuinely revolutionary methodology is being tested in some Andean countries, where peasant communities are responsible for its administration. The real promoters, i.e. expert peasant farmers who share out the benefits, therefore participate in its operation.

This proposal is a departure from the schemes based on traditional technical standards and values and suggests a change in the logic and rationality of approaches. The theory seems to tie in with practice, as was the case for the Aymaras and other Andean peoples who constantly carried out practices and trials each year and for each crop, on one and on many smallholdings, thereby ensuring the survival of the population.

Potential areas for introduction and cultivation

The result of the research will make it possible to extend the current restricted frontiers of arracacha cultivation. For example, in Cajamarca in Peru and Anaime in Colombia, which are regions with an Andean ecology, it would be possible to step up cultivation with a view to industrialization, as is happening in southern Brazil.

Lines of research

Under INIAP's Andean Crops Programme (in Ecuador), the following strategies of action have been drawn up:

Mauka, Chago
(Mirabilis expansa)

Botanical name: Mirabilis expansa Ruíz & Pavón

Family: Nyctaginaceae

Common names. Spanish: mauka (Bolivia), chago, arricón, yuca, inca, cushipe, chaco (Peru), miso, taso, pega pega (Ecuador)

The cultivation of Mirabilis expansa was first described 25 years ago in La Paz, Bolivia. Some 15 years later it was found to the north of Quito, Ecuador. and later in Cajamarca, Peru, where there seems to be the biggest area of production. It is an interesting case of a practically unknown crop with a wide geographical distribution—it is known from Venezuela to Chile.

The crop is maintained in small vegetable gardens and in a marginal way. It is greatly valued in the communities of temperate valleys at around 2800 m for human consumption and animal teed. It occurs alone or combined with maize, cucurbits or other plants. and remains in the field for several years as a result of the transplanting of vegetative parts.

Uses and nutritional value

The roots and leaves are used for human consumption. It is prepared in the same way as sweet potato or cassava: shortly after harvesting, the root is parboiled and peeled, and it can also be an ingredient of soups and stews; the leaves are used in salads and chili sauces. In Ecuador, it is eaten as a savoury or as a sweet. For the latter preparation. it is buried for approximately one week in pits dug in the soil, where layers of barley straw and mauka are alternated so as to concentrate the sugars. In both cases, it can be accompanied by coarse sugar honey.

In Bolivia, the stems and swollen roots, which are yellow, are left to ripen in order to eliminate certain astringent constituents which might the affect the tongue and lips. They are then cut and cooked, preferably adding corn molasses, cane molasses or sugar to make them more agreeable. The cooking water is served as a soft drink.

The whole plant is used as animal feed and pigs, cavies, sheep and cattle are very partial to it. For pig feeding, the raw underground parts are mixed with the foliage, wild vegetation or maize while cavies are fed the green foliage or hay. Its degree of conversion is higher than that of other agricultural by-products.

Dietary analyses of Bolivian maukas showed a 7 percent protein content, 2760 mg of calcium and 590 mg of phosphorus (in dry matter) in the underground parts and a 17 percent protein content in the foliage.

Analysis of three cultivars of chago (mauka) from Cajamarca in Peru gives between 4 and 5 percent protein. The calcium content is very variable with a minimum of 157 mg and a maximum of 461 ma. The phosphorus content is 117 mg per 100 g. It is low in sodium and iron. The protein, calcium and phosphorus content of the chago is higher than other roots and tubers grown in the same agro-ecological area. This is an important advantage if we consider that the diet of the high Andes is frequently deficient in calcium and phosphorus. Because of its low sodium content, the chago could be promising in low-sodium diets.

Botanical description

A low, compact plant, M. expansa grows up to 1 m in height. The swelling of the edible part of the collar would tally with a perennial plant. The aerial part is formed by the branching of basal shoots from which dense groups of leaves arise.

The stems are cylindrical and are divided by nodes, from which pairs of opposite leaves arise. The leaves are ovulate or cordate, 3 to 8 cm long. 2 cm wide and somewhat coriaceous. The nervures and edges have reddish areas. The inflorescences are on long, slender terminal branches, are 3 to 6 cm in length and are covered with hairs which frequently have small insects stuck to them.

The usable parts are the stems and tuberous roots. The stems are salmon-pink in colour when they are below ground. They are generally smooth and fleshy, up to 50 cm long and 5 cm wide. The swelling process of the stems and the accumulation of nutritive substances are typical of Nyctaginaceae; they are the result of cambium activity creating irregular peripheral tissues around the external part of the stem. Towards the centre. several elliptical rows of isolated xylem vessels may be seen. The basic tissue is parenchymatous with an abundance of water, many starch grains and some cream-coloured fibre.

Figure 20. Andean roots: A) mauka, chago (Mirabilis expansa); B) leafcup (Polymnia sonchifolia); B1) roots

Ecology and phytogeography

The only information available on M. expansa's environmental requirements relates to Cajamarca in Peru, where the most evident ecological area for the crop would appear to be the semi-humid quechua (2300 to 3500 m), with a mean annual temperature of 13°C and with maxima of 25°C and minima of 5°C; deep soils with abundant organic matter and an annual precipitation of 680 mm.

Explorations and collections carried out to locate cultivated forms and wild relatives of the mauka reflect its geographical distribution.

In Bolivia, the mesothermal valleys of La Paz up to the point where they join the yungas: the province of Camacho, the cantons of Italaque and Mocomoco, the Yokarguaya communities towards Muñecas, Saavedra and Larecaja; the yungas of the north and south; Inquisivi towards Cochabamba; and, in the case of M. postrata in La Paz, Achumani, at 3500 m (Cota Cota National Herbarium, La Paz).

In Ecuador, Cayambe and Mojanda in Pichincha, with two morphotypes. In Ibambura, San Pablo. In Cuvinche-La Esperanza, a native species with a yellow root and white flowers can be cooked quickly. Another introduced species with a white root and magenta flowers is collected from June to November. At 3100 m in Cañar, Ingapirca, M. postrata and Moradilla or Pega Pega occur, with white and purple flowers.

In Colombia, Beteitivá, the basin of the Otengá River towards the wild barren plain of Las Puentes in Boyacá, there are wild forms at 3100m.

In Peru, Cajamarca is the centre of the widest diversity thus far described, with specimens collected from five provinces and 15 districts—the provinces of Celendín, Chota and Cajamarca being the most prominent; three provinces and 28 additional districts are indicated. The mauka also exists in other departments: La Libertad, Ancash, Amazonas and possibly to the south of Ayacucho as far as Cuzco and Puno. Wild specimens have been found in Huarochirí in Lima.

Genetic diversity

No definite cultivars exist, but the plants are differentiated by root colour, with White, Yellow and Light Orange being distinguishable.

At present, three collections of germplasm are available in the case of the cultivated species in Peru and Ecuador, where characterization has taken place and material is stored in live banks. In Cajamarca, there are 32 accessions at the Baños del Inca experimental station (INIAA) and three at the Faculty of Agronomy of the Technical University of Cajamarca. In Ecuador, there are three accessions at the Santa Catalina experimental station (INIAP).

In the specimens evaluated in Cajamarca, root and foliage development is greater because of the more abundant precipitation compared with the Andean south. The astringency of the newly harvested roots should be pointed out in the Bolivian specimens compared with those from Ecuador' which are sweeter. A more detailed characterization is needed within the various collections. It may be added that, in rural areas, women have valuable information on the characteristics of cultivars.

Cultivation practices

Little is known about the cultivation of M. expansa, which is reputed to be hardy and is grown under peasant farming systems. The details given below come to a great extent from information obtained on germplasm collection trips.

Vegetative propagation is the technique normally used: basal shoots, pieces of stem or suckers. It is also reproduced by seed. Plants which have developed from basal shoots are harvested at the end of one year. This period can be longer if suckers are used. They are planted in furrows in holes measuring 1 x 1 m. Because of the frailness of the plants, earthing up must be done carefully.

The production cycle generally lasts about seven to nine months. In Ecuador, it is planted from July to August, intercropped with maize, which allows a better soil structure for root development by preventing the proliferation of slugs and attacks by a certain dipteron which bores into the plant's underground parts.

Phenology of the crop.


There are no official statistics on production, area under cultivation or yields.

Prospects for improvement

The mauka is a crop which has been reduced to family vegetable gardens and its conservation is mainly due to the interest of the peasants who value its production and appreciate its taste.

Its reproduction is cheap because of the ease of propagation from cuttings. However, it competes with other roots, since soil availability is limited in the agro-ecological area in which it is cultivated.

With an adequate selection of varieties and the development of a more appropriate cultivation technology, its production and marketing could be increased in some areas.

There is an interest among the peasant communities which are providing genetic material so that M. expansa can continue to be produced and consumed.

The National University of Cajamarca has set up a tissue culture laboratory and is able to experiment with germplasm stored in vitro.

Lines of research

Expansion of M. expansa, both within and outside its habitat, must be founded on basic applied research. There is still much to be learned about its botanical. biochemical, physiological, phenological and agronomic aspects that will allow more information to be obtained on cultivation practices. environmental photoperiod and thermoperiod requirements, humidity, soils, pests and diseases.

(Polymnia sonchifolia)

Botanical name: Polymnia sonchifolia Poeppig & Endlicher

Family: Compositae

Common names. English: leafcup, yacón; Spanish: yacón, yacuma, jícama (Ecuador, Bolivia), arboloco (Colombia), jícama ( Peru )

Originating in the Andes, Polymnia sonchifolia is grown from Venezuela to northeastern Argentina. on the slopes of the range with subtropical and tropical climates at around 2000 m. The wild forms were found by Bukasov on the Cundinamarca plateau in Colombia. It is a typically peasant crop. Its production increased during the widespread drought which laid waste the Andean region in 1982-1983, when potato production (which was seriously affected) was replaced by that of the leafcup with good results.

Its marginalization is connected with the absence of an intensive production technique which can be traced to the fact that this species is not customarily eaten in urban areas.

Uses and nutritional value

The pleasant-tasting sweet roots are eaten raw after they have been exposed to the sun for several days until the peel shrivels. Because it is easy to digest, it is used in invalids' diets in the usual areas of cultivation. Cattle and pigs also eat the roots together with the foliage.

In Ecuador, ten clones were evaluated during the one-year productive cycle, with the following yields: raw root, 41 tonnes per hectare and peeled root, 34 tonnes per hectare. The dry matter content of the roots is 15 percent.

The average sugar content increases as it becomes concentrated in the roots which are exposed to the sun for two weeks: fructose, 2 to 22 g per 100 g in fresh roots; alpha-glucose, from 2 to 7 g; beta-glucose, from 2 to 6 g, and sucrose, from 2 to 4 g. The sugars are similar to inulin. As in the case of sugar cane, the sugars can be concentrated to obtain sugar or molasses. There is also agro-industrial potential for converting these sugars into alcohol.

From the foregoing, the great agronomic potential of P. sonchifolia may be appreciated. It is also used as a soil protector because of its ability to maintain itself as a perennial species, especially in dry agro-ecological areas.

Botanical description

P. sonchifolia is a perennial plant which forms a densely ramified root system from which cylindrical stems grow to about 1.5 m in height. The leaves vary in shape. being pinnatifid at the base of the stems and triangular on the apical part. The flowers appear on terminal branches and have five pointed, green, triangular bracts. The outer flowers have long ligules which are 10 to 15 mm long. yellow or orange in colour and denticulate at the apex. while the central ones are tubular and about 8 mm in length.

The roots are irregular or fusiform and develop ram)fied masses at the base of the plant. They are purple on the outside, while the inner part is fleshy and orange-coloured. It is propagated from shoots taken from the collar of the plant.

Ecology and phytogeography

Little information exists regarding the environmental requirements of P. sonchifolia. However, according to field observations, they are as follows:

Photoperiod. The plant develops under both short-day and long-day conditions.

Humidity. Because of its growth habits. it requires humidity in the first stages, but afterwards can tolerate periods of drought.

Altitude. P. sonchifolia is grown at sea level in Peru. New Zealand and the United States. although there is no information on the production of usable roots, except in New Zealand where it is grown commercially. Its upper limit appears to be 2 000 m.

Temperature. It tolerates high temperatures and minimum temperatures of 4 to 5°C.

Soil. It shows wide adaptation for foliage production. However, to produce edible roots it requires deep. rich and well-drained soils.

Geographical distribution

In Colombia, it is grown on the tableland of Cundinamarca, Boyacá and Nariño, from 2600 to 3000 m on the high, bleak plateaus.

In Ecuador, it is grown from 2400 to 3000 m sporadically between maize fields and in vegetable gardens in the inter-Andean corridor in the following order of importance: in Loja, Azuay, Cañar, the lakeside area of San Pablo in Imbabura and in Bolívar province.

In Peru, cultivated varieties are found from 1300 to 3500 m, with the greatest concentration in the north and southeastern sierra, between 2000 and 3000 m.

In Bolivia, it is grown around 2500 m, at a maximum altitude of 3600 m at the head of the valley to the north of La Paz (the provinces of Larecaja, Camacho, Muñecas, Bautista Saavedra): in Cochabamba de Pocona towards the south, Chuquisaca and the mesothermal valleys of Santa Cruz.

In Argentina, it grows to the northeast of Jujuy and Salta.

Genetic diversity

The IICA began leafcup collections in 1963. Since then, 88 collections have been obtained in Peru, especially from Cajamarca.

In Ecuador, 24 collections have been gathered and a wild form has been found (the best time for collecting is from June to August). A preliminary evaluation has been made of the sugar content in ten clones.

The best-known cultivars in each country—White, Purple and Yellow—coincide insofar as the colour of the edible part of the roots is concerned: Yellow is the most sought after.

Cultivation practices

Traditional cultivation begins with the preparation of ploughed maize or potato fields, where the shoots are planted in furrows. Sowing can be done throughout the year provided there is moisture in the soil. Earthing up is done just once. The plants reach maturity at approximately seven months in low areas and in one year in the highest areas such as the heads of valleys.

The roots break easily and must be harvested with care and then separated from the central stem which is then used for livestock feed. They are stored in dark, dry places where they are kept tor months and become sweeter because of starch conversion. The sun's action accelerates this process. In intensive crops, yields of up to 40 tonnes per hectare can be obtained.

Prospects for improvement

The fresh root of P. sonchifolia has a high water content, hence its food value is low.

In the Andean region, there is a potential demand. In other subtropical and tropical regions of the world it could be developed as an industrial crop for inulin production. The leafcup could also acquire importance as a perennial fodder and cover crop in arid conditions. In this connection, it would appear as a component of multiple complementary crops.

Lines of research

The leafcup needs to be "rediscovered" through the following measures if its cultivation is to be extended:


last update Thursday, May 14, 1998 by aw