Up to beginning of the present decade, the department of Cochabamba did not appear in the official statistics of agricultural production as bitter potato producer; the work of AGRUCO caused that this information deficiency was reviewed. In general, Rea (1991) estimates that 15% of the total potato production in Bolivia corresponds to bitter and semiamargos cultivars, which demonstrates its importance in the economy and the local and national feeding.

The diet that characterizes the feeding in our country, particularly in the Andean region with consumption of potato–is calculated per capita consumption of 100 annual kg - it shows the great importance that they have the bitter potatoes consumed mainly in the form of black chuño, white chuño, or tunta and other preparations.

With regard to research carried out previously, an aspect in which a good advances is available refers to the botanical and taxonomic characterization of the potatoes cultivated, basically by the scientific interest in knowing the genetic potential for these materials. On the other hand, the same impetus was not available in order to study the economic, social and cultural importance of this biodiversity for the communities and the local consumers.

The community where the study was conducted has the typical characteristics of an original socioterritorial organization, that is that it keeps features important of the precolonial time, so much in the social organization, territorial and technological.

Its geographical location corresponds to the foothills of the Royal or Eastern mountain range of the Andes, in the sector corresponding to the Central Altiplano. It presents a predominantly rugged topography forming many basins and microcuencas, to an altitude among the 3800 to 4500 m.s.n.m. The climate is cold and semiarid, with an annual mean temperature of 8°C, with presence of frosts in seven months of year and with an average rain of 400 mm.

The economic activity concentrates on the agriculture and livestock basically. The use of the territory for these activities is sectoral, through the "aynokas." The entire community territory is divided in 13 sectors or aynokas, of which is cultivated annually three sectors; the first one always with potato, is the aynoka with more years of rest; the second sector is cultivated with grains (quinoa, cañahua, barley) in rotation with potato, and in the third sector or aynoka is cultivated forage (barley, oats) in rotation with the grains, then this aynoka enters in rest-grazing during 10 years. It is in the aynoka of potato where the parcels of bitter potatoes are located together with the other species of potatoes that are cultivated in the community.

Through different studies there was done a study of the species and varieties of potato cultivated by the families and the community; there was also analyzed the characteristics of its culture in accordance with the varieties and its relation to the ecological environment. In complementary form there was determined the use and destination of the varieties of bitter potatoes.

The utilized methodology was based on the approach to revalorizadora participatory research, on which the criteria and standpoints of the campesino are considered fundamental for the execution of research. For rendering operational research different methods and techniques were used such as being: case studies, family attendance, participating observation, establishment, and monitoring of parcels of observation, surveys semiestructuradas, discussion groups.

In the area two species of bitter potatoes and a semiamarga species have been identified. Among the first they are available the Solanum juzepczukii (2n = 36 cr.) with 10 varieties, and the Solanum curtilobum (2n = 60 cr.) with three varieties. The semiamarga species corresponds to the Solanum ajanhuiri (2n=24 cr.) with six varieties. In total they have been possible to identify 19 bitter and semiamargas varieties.

Among some morphological differences that were observed in the three species we can point out the following ones: The varieties of the species S. juzepczukii have the foliage with the arrosetado habit, with the lower sheets affixed to the soil, on the other hand the floral peduncles with short and as soon as stand out the foliage. The varieties of S. curtilobum, on the other hand, have the semierecto habit and with the floral peduncles long, large flowers that stand out clearly the foliage of the plant. With regard to the varieties of the species S. ajanhuiri, its principal differential characteristics are the profuse flowering of almost all the varieties, existing a variety, the Wila ajahuiri that has a very poor and mimetizada flowering in the foliage of the plant. On the other hand, these varieties have the long tubers, similar to the oca.

In the agronomic aspect, the most important difference is based on its resistance or tolerance at the low temperatures, the varieties of S. juzepczukii are more resistant existing some that can support temperature of–5°C, on the other hand the other two species are less resistant being able to support only around–2°C.

These species, by the characteristics of resistance to the frozen, particularly the belonging to S. juzepczukii, there are cultivated in those parcels that have greater risk for the frosts, that is in those that are found located in plains or in depressions where "settles the cold air", while the other varieties should be planted on the slopes where the cold air causes less harm // .

The culture of bitter potatoes in the area of study is very important, around 70% of the production of potato it corresponds to the bitter and semiamargas varieties, the rest this cover by semisoft and sweet varieties that belong to the species Solanum tuberosum spp. indigenous to the Andes and Solanum stenotonum. Around 80% of the production of bitter potatoes it is destined to the preparation of chuño, the rest is for seed, reciprocity and consumption in fresh. Of the total of the prepared chuño, approximately 70% is destined to personal consumption and 20% to the sale, that is that the bitter potatoes become an important component of the food diet in the community.

On the other hand, the chuño is for the rural family a strategic product, since not only it represents the basis of its feeding, but they also become the product, that through the barter, becomes a diversity of other food products as: bread, fruits, vegetables and others. It is also important in the changes that the rural families carry out in the valleys when they carry out their interecológicos trips, where they exchange chuño with corn or wheat. Finally the chuño, by its special characteristics of storage, is kept during several years as a strategic product of reserve, that can be utilized when they occur years of poor harvests or when some unforeseen need is available.

Concerning the rural management of the seeds, particularly as soon as it refers to the bitter and semiamargas potatoes, there exist different sources of supply, among the principal we have the following: by heredity, is the modality by which all the families of the community have agreed to her first seeds, many of them maintain those varieties for several years–10 or 20 years - thus they answer when he asks itself to them from when they have one determined variety. By purchase, it is another modality to which most of the families go either in order to renew a given variety or in order to introduce a new. These purchases carries them out mainly in the annual or regional fairs. Another form is through the barter, that is the exchange of an own product by seed of potato, this practice is carried it out in the local fairs and also to level interfamiliar in the communities. Through the harvest of k’ipas, that is of parcels where previous year was cultivated potatoes, there always remain tubers without collecting which give rise to voluntary plants of potato in the midst of the culture of rotation–quinoa, cañahua, barley or another one - From 2 February, celebration of Candelaria, is proceeded with the harvest of k’ipas of all the parcels that can, being given rise to the collection of a great diversity of potatoes, a part of which is utilized as seed. Some social practices of the work as the mink’a and the company, also give the opportunity to obtain seed, either through the payment by the assistance in the harvest of potato, or also by the participation "accompanied by the" culture of a given parcel of potato. Finally, with the incursion in the rural area of support institutions, these also become a seed provision environment of potato.

The principal levels in which the potato seed flow takes place are the following ones: at the interfamiliar level either in the same community or between communities within the same region. Here the dissemination of introduced varieties or the exchange of local varieties occurs between families. Another scenario is the regional, particularly when there are visited communities remote in other districts or departments, or when the annual fairs are visited in different regions; in these places one usually proceeds with the purchase, with the barter, or with the payment in potato by some carried out work. Something important that the comunarios consider when they are going to purchase seed of potato is that this comes from one cold place, with similar conditions to which are available in the community of origin.

These seeds normally undergo a process of adaptation when they arrive in the community, in the first place they are planted in canchones or protected places both with the adverse environmental condition and of the possible harm by the animals, this phase it is basically of multiplication of the seed. The following stage is the seeding in parcels, mixed with other varieties, here there is observed comparatively the behavior of the varieties introduced with the sites. Then the evaluation is done by quality for consumption, storage, performance, and tolerance to the different climatic condition as well as to the diseases and pests that affect the culture in the area.

In addition, there also have become some observations preliminary with respect to the chuño, that is the dehydrated product applying local technology through the frozen pressed-peeled and dried of the bitter potatoes. It has been confirmed that the ones missing from weight that undergo the potatoes by this process are different in accordance with the varieties in question; have registered losses of fresh potato weight to chuño that range between 74 and 80%, that is that the different varieties would have a performance in chuño of 4:1 to 5:1

With regard to the quality of the chuño, the campesinos recognize the quality considering basically the rapidity of the soaked for its culinary preparation, as well as by the taste and the texture of the same. In accordance with it is qualification, they have chuños for sale and for personal consumption, thus for example the chuños for personal consumption are those which soak rapidly and have excellent culinary quality, in addition recognize that these chuños come from potatoes that lose weight notably in the process of transformation.

As a result of some bromatologic analyses of the chuño of different local varieties of potatoes bitter, se it has to the content of proteins ranges between 6 and 7%; on the other hand the content in phosphorus is relatively high, 150 mgr/100 gr. of M.S., as well as a moderate content of calcium and iron, between 14 and 18 mg/100 gr. of M.S. These data show that in addition to being the chuño an energy food par excellence, also contains other elements important for the health and human nutrition.

The culture of the bitter potatoes in the area of Highland of the Prov. Tapacarí it is of great importance, not only because it represents the basis of the food security of its inhabitants, but because they are found to be adapted to that ecological condition in a relation of balance with nature.

The campesinos have the capacity to characterize its cultures considering botanical as well as agronomic aspects, although they deepen especially the environmental conditions ecological where there are developed as well as they prioritize the different uses that have and its characteristics of conservation.

There exist a series of strategies that makes it possible for them to energize its cultivated diversity of potatoes through the natural circuits that have succeeded in forming; however it is also notable that the social and cultural breakdown to that are seen submitted, distorts in diverse degree the vitality of these circuits, that at any rate become the fundamental basis of the maintenance of its biodiversity.

The chuño from the bitter potatoes, not only represents the basic dietary energy source for the rural inhabitant, but also is important source of as important elements as proteins, phosphorus, calcium, and iron; for this reason its consumption not only has increased at the level of the urban area but it should have the corresponding support.