Pachyrhizus ahipa

[3] The first mention of ahipa was in connection with the Indian cultures in the Andes, more precisely in the Salta and Jujuy provinces of Argentina.

[4] Indications of the Pachyrhizus species in general were also made at the southern coast of Peru, in the Nasca culture.

[2] The origin of the ahipa plants is most likely in the ceja de montañas Andean region.

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.

[5] The Andean bean is a perennial plant and can grow in erect, semierect or twining forms.

[2] The flowers, which grow on short stalks, are white blossoms or of a pale lavender colour.

[2] Generally, the flowers exhibit an internally curved stigma in close contact with the anthers.

P. ahipa is a short-day plant, so flowering takes place under decreasing day length.

The thousand grain weight is around 300 g.[2] Every plant shows a single swollen root, which thins out toward both ends.

In Bolivia, P. ahipa is normally sown between August and October, depending on the rainy season.

In determining the rate, preferred traits such as tuber size play an important role.

The average temperature in this region is 16–18 °C, although the climatic conditions are extremely dependent on the time of day.

[4] At the time of harvest, seeds show high nitrogen contents, but some remains in leaves, providing a nitrogen-rich straw which can be used for animal feeding or as fertilizer, if the plant material is incorporated into the soil.

The P. ahipa plant is therefore able to form an efficient symbiosis with nitrogen-fixing bacteria, such as Rhizobium and Bradyrhizobium, and is able to fix 58–80 kg nitrogen per hectare.

[2] 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 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.

Due to a high moisture content, the tubers may shrivel and lose condition during storage and transportation.

If damaged, they are susceptible to attacks by fungi, 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%).

[2] Its sometimes dwarf-like habit makes P. ahipa well suited for large-scale commercial cultivation.

The roots taste sweet and are crisp like an apple and are an attractive addition to green salads.

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

The European market is economically highly interested in the protein content, mostly as feed for cattle.

As an adaption to insect predators, ahipa plants accumulate canavanine in its seeds.

This is highly toxic to some insects and can pose a significant problem in livestock foraging, especially if ahipa plants escaped into wild vegetation.

[2] Pachyrhizus ahipa plants must be propagated sexually, because the reproductive rate by cloning from tubers is very low.

The traits of the Andean bean of most interest are tuber quality, growth habit, and early maturity.

The results of breeding between the different species showed especially good performing hybrid lines with regard to high tuber yield as well as wide adaptability.