User talk:Bonvinc

The Ahipa (pronounced a-hee-pa) is one of the five species composing the genus Pachyrhizus (Patchy=thick, Rhizus=roots) within the legume family of the Fabaceae. Along with its two relatives (Pachyrhizus erosus known better as jicama or the yam bean and P. tuberosus) P. Ahipa is cultivated for its edible tuberous roots. Despite a certain agronomic potential- Ahipa is one of few tuber crops capable of biological nitrogen fixation - it is an unfamiliar crop that is hardly cultivated today. Its cultivation is restricted to remote regions of the andean valleys in Bolivia and Peru between 1500 and 3000 meters. The tuber is mainly consumed raw in various dishes, specially appreciated in salads for its freshness and crispiness.

=Description=

Ahipa is an erect/semi erect perennial herbaceous plant that can grow from 30-200 cm depending on the genotype. Its trifoliate leaves have asymmetrical and entire leaflets, which are wider than long. It usually has few to no lateral axis(0-6) with only 2 to 6 flowers per lateral axis. All genotypes have short inflorescences, 5-9 cm. The wing and keel petals are usually glabrous, and curve outwards following anthesis. The seeds are round(0.8-1.1cm) usually black but can be black and white, they grow into 8-11cm pods. In most Ahipa genotypes, a single root differentiates to become a tuber root, which is swollen at the top end, comparable to an oversized radish. Its length can vary between 13-17 cm long and 11-16 mm wide, almost circular in the cross-section.

Biological nitrogen fixation
Like other members of the legume family, Ahipa has the ability to enter in symbiosis with N-fixing bacteria (Rhizobium and Bradyrhizobium). While the above ground biomass of most  grain legumes is removed from the field, biomass of Ahipa remains on the field and can be an essential N-source for following crops in N-depleted soils. This interesting feature could enable Ahipa to become a promising alternative culture in crop rotations of low input Agro-ecosystems.

Nutrient content
The tuber of Ahipa is both nutritious and healthy. The protein content ranges between 8-18 %, of the total dry weight. Carbohydrates are present in large proportions: the starch content is between 45-55 % and the sugars between 8-24%. Lipids are present in less than 1% of the tubers dry weight. Compared to other traditional root crops Ahipa has an intermediate nutritional value because when consumed fresh it has a high moisture content lowering therefore the protein and energy concentration.

=Uses= Ahipa tubers are principally consumed fresh and raw. Locally it is considered being a fruit rather than a vegetable because of its sweet and fresh taste. It is specially appreciated in vegetable and fruit salads in summer. In Bolivia it is common that the tubers are used for medical purposes. The tubers are considered to have a cleansing effect upon the body. The tuber is considered to have beneficial effect on the lungs and is used as medicine to heal coughs.

Production areas and retailing
There are no major productions areas for Ahipa, which is entirely cultivated by small scale farmers for home consumption mostly. Ahipa can be found on local markets in major cities of Bolivia Peru and Ecuador. However only a small fraction might reach the cities (perhaps less than 50%) as it is first sold at the nearest village markets. No international trade takes place for Ahipa. Though the farmers earn less per unit area compared to commercial root and tuber crops (cassava and potato), the price at the local markets is similar to such crops. As a short season crop, Ahipa does not provide a continuous cash flow throughout the area as cassava or potato do.

=Agronomy=

Plant propagation
Ahipa can either be propagated by seeds or by small tuber parts which have the advantage to reduce the growing period. In general it is more common for farmers to buy the seeds on local markets. To ensure quality seed production plants with desirable agronomic traits are not reproductively pruned as the others. Seeds from these plants are collected and sowed the next season. Seeding rates range from 40-65 kg/ha depending on factors such as soil fertility anddesired tuber size.

Pests and Diseases
Bean Common Mosaic Virus (BCMV) affects all three cultivated species of the Pachyrhizus family. No insect pests attacking the vegetative parts have been reported by the farmers in Bolivia. Though when introduced into other environments, most insect pests will attack Ahipa. Although the seed contains the highest concentration of Rotenone insect pests such as the bean weevil infest Ahipa seeds. Nematodes may also be a problem. It has been reported that the nematode Meloidogyne sp. destroyed tubers of entire field experiments in Ecuador.

Harvest and post harvest handling
In Bolivia tubers are harvested by hand using a hoe. The tubers are harvested once they have reached the desirable size, which is when sold on the markets rarely  under 0.4 kg. The tubers are generally harvested after 7-9 months. Though in some genotypes marketable tubers were produced after only 4 months. Ahipa tubers seem to be sensitive to cool temperatures as cool storage temperatures have been found to reduce storage life. The optimal storage temperature ranges from 12.5° to 17°. Prolonged storage modifies the starch/sugar ratio, increasing the sucrose and decreasing the starch content. Indeed some producers in Bolivia leave their tubers out in the sun for two weeks prior to selling to obtain a sweeter tuber.

Yield
In Bolivia yields have been recorded between 8-30 T/ha ( cassava =10t/ha) independently of the size of the tubers. Higher yields- 29 to 50 T/ ha- were reached on field experiments in Mexico and Portugal. --Bonvinc (talk) 11:43, 20 April 2011 (UTC)bonvinc

=References=