''Pachyrhizus ahipa'', also called the ahipa or Andean yam bean, is a tuberous root-producing legume, which is mainly distributed in the Andean region.Sørensen, M., Gruneberg, W. J., Ørting, B., 1997. Ahipa (''Pachyrhizus ahipa'' (Wedd.) Parodi). In Andean roots and tubers: ahipa, arracacha, maca and yacon. Promoting the conservation and use of underutilized and neglected crops (M. Herman & J. Heller, eds.). International Plant Genetic Resources Institute, Rome, p. 13-73.

History

Archaeological evidence suggests ''P. ahipa'' was widely distributed about 2000 years ago.Popenoe, H., King, S.R., Léon, J., Kalinkowski, L.S., Vietmeyer, N.D., Dafforn, M., 1989. Lost crops of the Incas. Little known Plants of the Andes with Promise for Worldwide Cultivation. National Academy Press, Washington, p. 37-46 The first mention of ahipa was in connection with the Indian cultures in the Andes, more precisely in the

Salta Salta () is the capital and largest city in the Argentine province of the same name. With a population of 618,375 according to the 2010 census, it is also the 7th most-populous city in Argentina. The city serves as the cultural and economic ce ...

and

Jujuy San Salvador de Jujuy (), commonly known as Jujuy and locally often referred to as San Salvador, is the capital and largest city of Jujuy Province in northwest Argentina. Also, it is the seat of the Doctor Manuel Belgrano Department. It lies near ...

provinces of Argentina.Ørting, B., Grüneberg, J., Sørensen, M., 1996. Ahipa (''Pachyrhizus ahipa'' (Wedd.) Parodi) in Bolivia. Genetic Ressources and Crop Evolution, 43, p. 435-446 Indications of the ''Pachyrhizus'' species in general were also made at the southern coast of

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, in the Nasca culture. The origin of the ahipa plants is most likely in the ''ceja de montañas'' Andean region. Today, it is still in use in small native communities in

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

and northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. The crop was never widely distributed which could have to do with the very specific climatic adaptions it exhibits. Another reason could be the acquisition of Latin America by the Spanish and Portuguese conquest, which had the general policy to destroy the traditional Andean agricultural systems. The local marketing of the Andean bean during the religious festival ''Corpus Christi'' indicates a relationship with ancient religious uses. Today, the production is restricted to a few local villages and farmers.

Description

''Pachyrhizus ahipa'' is member of the

Fabaceae The Fabaceae or Leguminosae,International Code of Nomenc ...

and predominantly

self-pollinating Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to ...

.Leonel, M., Bortolucci Ferrari, T., Bruder, S., Sarmento, S., Alvares de Oliveira, M., 2005. Planting time, developmental stages and characteristics of roots and starch of Pachyrhizus ahipa. Scienta Agricola, 62 The Andean bean is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

plant and can grow in erect, semierect or twining forms. The erect species can grow to 15–40 cm tall, the semierect one about 30–60 cm, and the twining forms 60–200 cm long. These plants are herbaceous and lignified depending on the genotype. They do not show a lateral axis. The leaves are trifoliate with stipules or pinnately arranged leaflets with caduceus stipels. The flowers, which grow on short stalks, are white blossoms or of a pale lavender colour. They show a tubular calyx and a papilionaceous corolla. Generally, the flowers exhibit an internally curved stigma in close contact with the

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

. This habitus is very unfavourable in connection with the

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

behaviour of insects, as they are not able to pollinate the flowers very effectively. Additionally, the pollen fertility is often not very high. It varies between 45 and 100%. The flowering pattern is not consistent. Each season, 100 – 800 flowers per plant can be produced. ''P. ahipa'' is a

short-day plant Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light a ...

, so flowering takes place under decreasing day length. The pods are 13–17 cm long and up to 16 mm wide. The seeds are black, lilac, maroon, or black and white mottled. They are round, kidney-shaped, and about 0.8–1 cm long. Seed production differs from plant to plant and lies between 20 and 100 per plant. The thousand grain weight is around 300 g. Every plant shows a single swollen root, which thins out toward both ends. The roots are about 15 cm long and usually weight about 500-800 g. The yellow skin of the root encloses a white pulp, which is interwoven with a soft fiber.

Culture

Sowing

Before sowing, the soil must be loosened to a depth of 15–25 cm. Further, the soil has to be thoroughly cleaned from weeds and stones. In Bolivia, ''P. ahipa'' is normally sown between August and October, depending on the rainy season. The seeding rate is between 40 and 65 kg/ha. In determining the rate, preferred traits such as tuber size play an important role. Further,

soil fertility Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality.

and seed weight must be taken into account. The planting distance is 20–60 cm between rows and 6–25 cm between plants in the same row. Therefore, about six to 83 plants/m² are possible. It is planted on

ridges A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...

, when it is flood irrigated, which is mostly the case in the Andean region.

Cultivation

The cultivation period is between five and 10 months. The first flowers appear 87–140 days after sowing. Those flowers are removed manually, a process called reproductive pruning. This means the flowers, as well as the young pods, are removed. The tuberous roots remain the main sink for photosynthates and nutrients. The yield improves drastically. Reproductive pruning is very labour-intensive and must be done once or twice a season.Leidi, E.O., Rodríguez-Navarro, D.N., Fernández, M., Sarmiento, R., Semedo, J., Marques, N., Matos, A., Machado, A.P., Ørting, B, Sørensen, M., Matos, M.C., 2004. Factors affecting root and seed yield in ahipa (Pachyrhizus ahipa (Wedd.) Parodi), a multipurpose legume crop. European Journal of Agronomy, 20, p. 395-403 Mature pods normally appear from April through June. At about nine months, the roots are tuberized and the aerial part is completely dry. ''P. ahipa'' is normally sown in a pure culture, but can be intercropped with maize. In a crop rotation, it is sown prior to

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Unit ...

, maize/

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

, maize/ oca,

groundnut Groundnut may refer to: * Seeds that ripen underground, of the following plants, all in the Faboideae subfamily of the legumes: ** '' Best Basketball Player'', Obinna Udunni ** '' Arachis villosulicarpa'', a perennial peanut species ** ''Vigna sub ...

manioc ''Manihot esculenta'', commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively cultivated a ...

Environmental conditions

''Pachyrhizus ahipa'' can mainly be found in cool tropical and subtropical valleys, on sun-facing slopes, on the border between the warm and cold

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

. The average temperature in this region is 16-18 °C, although the climatic conditions are extremely dependent on the time of day. The precipitation is between 400 and 700 mm, occurring within 4–6 months, with the rest being the dry season. Therefore, the climate is

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

. ''P. ahipa'' grows to an elevation of 1800 – 3000 m above sea level. Cultivation is mainly carried out along loamy riverbanks. It can also be grown on loamy hillsides. It favours

soil pH Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the neg ...

levels of 6-8 and well-drained soil types. ''Pachyrhizus ahipa'' plants can tolerate long dry spells. Anyway, to increase tuber yield, an additional water supply is essential.

Nutrient needs

At the time of harvest, seeds show high

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

contents, but some remains in leaves, providing a nitrogen-rich straw which can be used for animal feeding or as

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

, if the plant material is incorporated into the soil. In one season, 67 kg N/ha were taken up by roots and seeds. This nitrogen is mainly provided by the

inoculation Inoculation is the act of implanting a pathogen or other microorganism. It may refer to methods of artificially inducing immunity against various infectious diseases, or it may be used to describe the spreading of disease, as in "self-inoculati ...

with efficient bacterial strains. The ''P. ahipa'' plant is therefore able to form an efficient

symbiosis Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

with nitrogen-fixing bacteria, such as ''

Rhizobium ''Rhizobium'' is a genus of Gram-negative soil bacteria that fix nitrogen. ''Rhizobium'' species form an endosymbiotic nitrogen-fixing association with roots of (primarily) legumes and other flowering plants. The bacteria colonize plant cells ...

'' and ''

Bradyrhizobium ''Bradyrhizobium'' is a genus of Gram-negative soil bacteria, many of which fix nitrogen. Nitrogen fixation is an important part of the nitrogen cycle. Plants cannot use atmospheric nitrogen (N2); they must use nitrogen compounds such as nitrat ...

'', and is able to fix 58–80 kg nitrogen per hectare. No further supply of nitrogen fertilizer is needed. If the vegetative aboveground parts are left in the field, a substantial amount of the fixed nitrogen is returned to the soil, about 12–80 kg N/ha. The enrichment is very important if a sustainable land-use system is desired. During nodulation, an increased

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

supply is advantageous, because nodulation can be improved. Further, it promotes the root and seed yield in ''P. ahipa'' plants. The final recipients of P are the pod shells, as well as the seeds. In total, about 7-9.6 kg P/ha were extracted from the soil. At harvest, the highest

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

contents can be found in pod shells and the roots. The removal of K at harvest was about 20.2 kg K/ha.Leidi, E.O., Vidueira, J.M., Cobo, J., de Castro, A., Rodríguez-Navarro, D.N., 2004. Nutrient Requirements of Ahipa, Tuberous-Root Crop. Journal of Plant Nutrition, 27, p. 931-945

Disease

''Pachyrhizus ahipa'' plants are not very susceptible to pests.

Nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

s such as ''

Meloidogyne Root-knot nematodes are plant-parasitic nematodes from the genus ''Meloidogyne''. They exist in soil in areas with hot climates or short winters. About 2000 plants worldwide are susceptible to infection by root-knot nematodes and they cause appro ...

'' sp. can pose a serious problem. Further, some of the bean weevil species can be harmful. The most serious viral disease is the bean common mosaic virus (BCMV). Yields can be reduced up to 30% if infected by this virus. If a general irrigation management is lacking, rot is also likely to appear.

Harvest

The tubers of ''P. ahipa'' are harvested as soon as the tubers show a marketable weight, depending on consumer’s preferences. Mostly the preferred weight is minimally about 0.4 kg.

Harvest Harvesting is the process of gathering a ripe crop from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper. On smaller farms with minimal mechanization, harvesting is the most labor-i ...

duration lasts between 10 and 30 days. The vegetative top is often left on the field to later incorporate it into the fields. If the tubers are not needed at the moment, they can even be left in the soil until needed. Only the plant tops have to be cut off. The yields of the different organs are about 28-53 tonnes/ha for the tuberous roots, 18-36 tonnes/ha for the fruits, and 1.3-2.7 tonnes/ha for the dry seeds.

After harvest

The optimal storage temperature for tubers is 12.5 to 17.5 °C. Storage, though, changes the ratio of starch and sugar in the direction of sweeter tubers. This characteristic is valued by most consumers. Some farmers leave their tubers in a sunny place before marketing them. Due to a high moisture content, the tubers may shrivel and lose condition during storage and

transportation Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, ...

. Another solution to shrivelling could be a thicker epidermis. It is important to avoid a damage to the tubers while harvesting. If damaged, they are susceptible to attacks by

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

, mainly by ''Rhizobus stolonifer'', ''Cladosporium'' sp., and ''Penicillium'' sp. An attack of one of those fungi leads to textural changes, decay, and internal browning when stored at low temperatures and high relative humidity (>80%). Seed storage is problematic. Under humid conditions, germination rapidly decreases. This is challenging, because the climate in tropics is very humid in the rainy season.

Commercial aspects

Its sometimes dwarf-like habit makes ''P. ahipa'' well suited for large-scale commercial cultivation. No international trade in ''P. ahipa'' occurs.

Nutrition

Roots

The carbohydrate-rich roots can be eaten raw and provide calories and

vitamin K Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...

and

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...

, as well as potassium.Leidi, E.O., Sarmiento, R., Rodríguez-Navarro, D.N., 2003. Ahipa (''Pachyrhizus ahipa'' edd.Parodi): an alternative legume crop for sustainable production of starch, oil and protein. Industrial crops and products, an international journal, 17, p. 27-37 Normally, it is eaten fresh, almost like a fruit. In some raw cases, it is also prepared as a juice. The roots taste sweet and are crisp like an apple and are an attractive addition to green salads. They can be boiled and even after cooking, they retain their crunchy texture. Ahipa tubers are even considered to have a cleansing effect on the body. It is supposed to cure infections of the throat and the air passage. Its dry matter ranges from 15-30%. Further, the tuber contains 48-54%

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

, which consists of 96-99.9%

amylopectin Amylopectin is a water-insoluble polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. Plants store starch within specialized organelles called amylopl ...

. This is a very high value and especially interesting for food processing, where low solubilisation and

retrogradation Retrogradation is the landward change in position of the front of a river delta with time. This occurs when the mass balance of sediment into the delta is such that the volume of incoming sediment is less than the volume of the delta that is lost ...

are important. Because of the high starch and amylopectin content, ahipa is a good material for the starch industry. Further, the suitability of the Andean bean depends on other factors such as extractability of the starch, the diameter of the starch granules or particles and their distribution. After nine months, the starch granules are very homogenously distributed in the tuber. There is a high percentage of granules, which show the same size of about 12-18 μm diameter. This indicates that the tuber growth is completed. ''P. ahipa'' can produce 19-28%

sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...

s in its root. The

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

content lies between 8 and 18%. The European market is economically highly interested in the protein content, mostly as feed for cattle. Protein content also may be interesting for the food industry, because about 80% of the protein is water-soluble and not extractable within a pH range of 2-10. The

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

content is very low, below 1%. Altogether, the tuber shows a very good nutritional composition. However, because the tuber contains a lot of water, the protein and energy concentration may be rated as being medium.

Seeds

The seeds of the Andean bean contain high protein concentrations. As an adaption to insect predators, ahipa plants accumulate

canavanine L-(+)-(''S'')-Canavanine is a non-proteinogenic amino acid found in certain leguminous plants. It is structurally related to the proteinogenic α-amino acid L- arginine, the sole difference being the replacement of a methylene bridge (-- unit) in ...

in its seeds. This is highly toxic to some insects and can pose a big problem in livestock foraging, especially if the ahipa plants escaped into the wild vegetation. The oil of the seeds has special properties such as high

palmitic acid Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...

and γ-tocopherol concentrations, as well as few

linolenic acid Linolenic acid is a type of naturally-occurring fatty acid. It can refer to either of two octadecatrienoic acids (i.e. with an 18-carbon chain and three double bonds, which are found in the '' cis'' configuration), or a mixture of the two. Lino ...

s. These aspects are of interest in the food industry.

Breeding

Several breeding goals are important in ''P. ahipa'', apart from it being used as a vegetable crop, a basic food crop, or a possible industrial crop. Those traits are mainly the reduction of the growth period and a reduced pod formation. This is especially important, if reproductive pruning could be avoided, saving time and money could be saved. ''Pachyrhizus ahipa'' plants must be propagated sexually, because the reproductive rate by

cloning Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, cl ...

from tubers is very low.

Propagation Propagation can refer to: * Chain propagation in a chemical reaction mechanism *Crack propagation, the growth of a crack during the fracture of materials * Propaganda, non-objective information used to further an agenda * Reproduction, and other fo ...

by seed is very advantageous, because transmission of

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es can be avoided and the storage of the propagation material is inexpensive. Several interspecific hybridization experiments have been conducted among all the ''Pachyrhizus'' species. The traits of the Andean bean, of most interest are tuber quality, growth habit, and early maturity. The results of the breeding between the different species showed especially good performing hybrid lines with regard to high tuber yield as well as wide adaptability. Nevertheless, negative secondary effects, such as reduced seed set and reduced germination rates, have been observed.

Prospects

''Pachyrhizus ahipa'' should be used by a wider range of farmers for several reasons: * It shows a very good adaptability to climatic and edaphic ranges * The nutrients protein and starch are very well balanced, additionally, the taste is good * It shows good postharvest and storage characteristics * Nitrogen fixation, demand as fuel wood, and food production are favourable for the environment

References

{{Taxonbar, from=Q492080 Phaseoleae Root vegetables