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Esbern Friis-Hansen | 20 December 1999 | Seedling - December 1999

December 1999



Agricultural policies and a top-down approach to agricultural research and development over the last thirty years have marginalised farmers’ knowledge and the use of local landraces in Tanzania. This article outlines a participatory case study which set out to examine the state of farmer-based genetic resource management at the local level in an attempt to provide a better basis for enhancing collaboration between the informal and formal plant genetic resource management systems.


The Government of Tanzania has supported the development of formal plant genetic resource management institutions at the expense of farmers’ own local institutions and strategies. During the modernisation period of the 1970s and 1980s, Tanzanian agricultural policy actively discouraged farmers from being involved in local plant genetic resource management and from using local landraces. This policy was manifested in a number of ways, including pricing policies (subsidising prices of modern varieties of seed and corresponding inputs); credit policies (tying loans to purchase modern varieties); extension service promoting use of modern varieties; and a general crude belief among bureaucrats that anything modern (Western) is good while local traditions are backwards and conservative.

In spite of an effort to strengthen farmers’ collective voice through farming systems research, there has been a general lack of farmers’ participation in the agricultural research process and lack of accountability by state institutions to farmers. Plant collection missions have regarded farmers as potential sources of crop varieties, not as sources of knowledge regarding plant genetic resource management or partners in their conservation. Commodity plant breeding programs have primarily been based on on-station trials and have taken little notice of the results of farming system research. Seed regulations have been based on international standards, which are incompatible with farmers’ management practices. Finally, seed multiplication and distribution have been centrally organised without the involvement of farmers other than as customers.

The effects on agricultural development are varied and not easily assessable. Direct benefits for peasant farmers are likely to be quite limited, in particular for food crops and especially for farmers in semi-arid areas. A simple, and far from comprehensive, measurement of success is the adoption rate of modern varieties. In 1994, only 2% of the maize crop in Tanzania was planted with purchased certified seed of modern varieties. This is a very low level, even given that a considerably larger proportion of land is likely to be cultivated with retained seed of hybrid and composite maize varieties. The vast majority of land in Tanzania is planted with seed of landraces, developed and maintained by farmers themselves.

The agricultural policy of Tanzania has undergone further drastic changes in the 1990s as part of a structural adjustment programme. Impacts have included: (i) termination of parastatal crop marketing organisations and hand over to private traders, (ii) abolishment of price subsidies, (iii) withdrawal of direct state involvement in import and distribution of fertilisers and other chemical inputs, and (iv) the opening of the seed market to multinational private seed companies and scaling down of support for the parastatal seed company Tanseed. Agricultural research and extension are largely continuing with top-down non-participatory approaches.

Despite their lack of support, farmers’ local plant genetic resource management systems are responsible for providing seeds for the vast majority of food crops in Tanzania. The links and interactions between local plant genetic resource management systems and formal plant genetic resource institutions are limited and weak. To provide a better basis for enhancing collaboration between the informal and formal plant genetic resource management systems a participatory project was carried out to examine the social dynamics of farmers plant genetic resource management in two different Tanzanian communities. Mkulula is a poor village growing sorghum for subsistence situated in a marginal semi-arid area, while Nyelegete is a better off and more commercial village with traditionally irrigated rice as the dominant crop.

Sorghum cultivation in Ismani

Mkulula village is situated in the Ismani Division of the Southern Highlands of Tanzania. The area is now characterised as semi-arid, although only 50 years ago it was densely covered with natural forest. Large-scale forest clearing occurred in the 1950s and 1960s during which time slash and burn agriculture was practised with maize, sorghum and millet as the major crops. In the 1970s, as a result of the forced resettlement of the Tanzanian population into nuclear villages, maize became the main crop. But by the mid-1980s, as a result of deforestation, reduced soil fertility and a fall in rainfall, maize production was no longer viable. During the 1980s and 1990s sorghum gradually became the main crop: it now covers more than half the total cultivated area.

The increased cultivation of sorghum has primarily been based on farmers’ use of indigenous landraces acquired through exchange with traditional sorghum growing farmers in neighbouring regions. Sixteen sorghum varieties, representing a diversity of crop traits and well adapted to local production conditions and household requirements, are cultivated in Mkulula. The people living in Mkulula village today have migrated from several different areas and have different ethnic backgrounds, which is continue to influence their cropping choices. People from the Gogo tribe, who originate from a traditional sorghum growing area in central Tanzania, use 11 sorghum varieties and have the greatest local knowledge about sorghum. People from the Bena and Hehe tribes, who migrated from areas with high rainfall in the Southern Highlands where there is a strong preference for maize, cultivate four sorghum varieties and have only recently shifted from maize to sorghum as their major crop. The Masai, who traditionally were pastoralists and only recently have taken up cultivation of crops on a large scale, also cultivate four sorghum varieties.

Diversity for diverse uses

The use characteristics of landraces in Mkulula satisfy multiple production goals (see Table 1):

(i) Household end-uses: preferences include a combined use of both grain and non-grain products, palatability in relation to subsistence consumption and cultural ceremonies, suitability for traditional methods of processing, and specialised end-uses, such as brewing of opaque beer. All the landraces of sorghum planted produce long-stalked plants for use as fodder for livestock and building materials.

(ii) Adaptation to the local environment: Terrain, soil fertility and water availability help determine farmers’ planting choices. Some sorghum varieties (PN3, Tegemeo, Sandala, Sanyagi and Msabe) outperform others on the loamy clay soils, while others (Serena, Madzi, Lugugu and Kasao) perform better on the poorer, sandy soils.

(iii) Performance under low external input conditions: Crop varieties are adapted to optimise performance when cultivated under resource constraints. All sorghum landraces have broad tolerance to pathogens and many diseases such as Loose Smuts are kept at low levels. Some landraces are particularly tolerant of drought stress. The landraces used cover a wide spectrum with regard to time to maturity.

Different social groups of farmers use different types of seed varieties. Resource- poor farmers, who do not own a team of oxen and a plough, have to wait until the better-off farmers have finished ploughing their fields to rent an ox-team. They grow a higher proportion of early-maturing varieties as their growing season is shorter. Earliness to maturity enables farmers to plant and subsequently harvest early, as well as to plant late and still harvest a mature crop. The disadvantage is that earliness to maturity is often inversely related to yield, and farmers compromise by selecting a range that matures at different times.

There are clear gender differences in local plant genetic resource management. Women play a dominant role in managing plant genetic resources as their responsibilities include reproduction as well as production. Women are local seed selectors for the range of end-use criteria relating to the household food requirements, e.g. palatability, taste, colour, smell, cooking time, etc. Women’s focus on the household economy provides a balance to market-oriented pressures that emphasise high yield and uniformity. In many households, women manage components of the farming system containing high levels of biodiversity - such as home gardens - and make extensive use of gathered species and tree products. Since women prepare the families’ meals, this influences on the variety of crops which they select for the home garden. Often, the home garden is used as an experimental plot where women tend indigenous and other species as they try them out and adapt them for use. Home gardens also serve as a refuge for less common species and varieties.

Seed selection is a complex and sometimes misunderstood process. Some farmers assess individual entire plant’s performance through the season when selecting seed, while other farmers select seed post-harvest from threshed crops in their storage. The latter method has been interpreted as an indication of farmers’ loss of interest in selection and development of their varieties. However, this seed selection procedure is common for sorghum and millet throughout Southern Africa, and although farmers are commonly not able to explain their practice in a rational or theoretical manner, the reasons for their method of selection can nevertheless be logical. Two possible explanations for farmers choosing to select post-harvest emerged after extensive discussions with farmers in Tanzania. The first is that such seed is likely to have good post-harvest storage qualities. The second is that such seed will have taken full advantage of the rainy season (which is often a limiting factor for crop production). Modern varieties of sorghum and millet are known to be highly susceptible to post-harvest pests, and the chosen method of selection reflects that protection against post-harvest pests is given higher priority by farmers than earliness to maturity.

Retention from a farmer’s own harvest is commonly the dominant source of seed of frequently used landraces for small-scale farmers, while new or less frequently used varieties are exchanged among neighbours, within the community, or even within regions. Community seed exchange fulfils four major functions: (i) as a back-up source of seed if, for some reason, a farmer fails to produce seed himself; (ii) as a point of access to varieties used in other communities; (iii) as an important diffusion mechanism within the community for new varieties (both landraces and modern varieties) which are often first tried out by the more innovative farmers; and (iv) it plays an important role as a source of seed for landraces in situations of rehabilitation following a poor harvest. The intra-species diversity of sorghum in Mkulula village has developed over the past 10-15 years and has largely been based on inter-community seed exchange.

Only one modern variety, PN3, is planted to any large extent in the community. Its introduction raises some interesting questions about long-term food security and the erosion of the sorghum gene pool (see box).

Modern Varieties - Blessing or curse?

As a response to the 1991/1992 drought in Southern Africa, which also affected Ismani, an international NGO distributed 40 tons of a modern sorghum variety by way of emergency seed supply to Ismani. The NGO had no knowledge about the performance of the modern variety, PN3, which was purchased in Zimbabwe. PN3 was developed by ICRISAT (International Crop Research Institute for the Semi Arid Tropics) with the participatory involvement of farmers in the breeding process. PN3 has been successful in Mkulula village for the following reasons: (i) it has a short time to maturity and yet a yield level similar or slightly higher than the local long-season landraces; (ii) it is white and farmers are content with its palatability as food as well as for local beer; and (iii) it is easier to process than the local landraces.

While the introduction of PN3 was highly successful, it resulted in widespread genetic erosion among the local landraces. After its introduction and cultivation on a small scale in the 1992/93 season, the PN3 variety expanded to cover almost half of the sorghum area in the 1993/94 season. During the 1994/95 season the PN3 variety was cultivated on between 75% and 90% of the farmers’ sorghum fields and only 11 out of the 16 local varieties were still present in the village and confined to the remaining area. Several of the remaining landraces were cultivated in such small quantities that they were threatened by extinction.

While farmers’ adoption of PN3 has had an immediate positive impact on farmers’ household food production and security, the long-term effects of the farmers’ increased dependency on one variety is unclear. It is likely that most of the remaining sorghum varieties will be abandoned and the community will be highly vulnerable in the event that PN3 falls victim to a disease, pest or unfavourable climatic conditions. In 1995 some farmers in Mkulula reported that the PN3 had begun to change certain characteristics (such as increasing its length to maturity as a result of cross-pollination with local sorghum varieties). The absence of access to ‘pure’ PN3 seed (the Tanzanian seed authorities do not recognise the PN3 variety and it is therefore not produced and sold as certified seed) will increasingly create problems for farmers who have become dependent on the PN3 for their subsistence.

One of the most productive farmers in Mkulula village has become engaged in seed multiplication and distribution of PN3. Because of access to oxen, ploughs and casual labour, good husbandry practices, and the particular farmer’s isolated location outside the village, the seed of PN3 produced by him is more ‘true to type’ than that produced by most other farmers. More than 50 other farmers visit his farm every year to ask for pure PN3 seed.


Rice cultivation in Usangu Plains

Nyelegete village is located in the Usangu Plains, another semi-arid area in the Southern Highlands of Tanzania. Usangu Plains has experienced a dynamic demographic change over a 30 year period with a rapidly increasing population resulting from immigration from surrounding areas. Commercialisation has transformed the area from a traditional pastoral society to an intensive, irrigated, rice-based economy with broad social differentiation and a well-developed labour market closely linked to cultivation of rice for marketing. For some labour tasks only women are hired as casual labourers because of particular plant genetic resource management skills, including seed selection and transplanting.

Rice cultivation was introduced to the Usangu plains by immigrants from India as early as the 1930s. It expanded dramatically after the construction of a main irrigation canal in 1964 and farmers’ subsequent construction of additional informal irrigation canals. Farmers on the Usangu Plains have cultivated a number of rice varieties over the past three decades. However, none of the varieties introduced over the past 15 years have been adopted by farmers and rice cultivation is still dominated by three varieties previously in use. Kilombero is a landrace with a medium maturity and medium water requirement, medium yielding potential, a high market demand and price and with good taste and cooking qualities; Fiya is a modern variety with late maturity, high potential yield, high water demand and medium market demand and price and with average taste; Supa Mati is a early maturing modern variety with high yield potential and medium market demand and price and with average taste.

Seed of rice varieties are harvested, processed and stored separately, while the grain is often harvested and sold/consumed in variety mixtures. Although each household cultivates seed to satisfy its own requirements, seed exchange and sales between farmers are common. Selection is made in the field between the time of maturity and harvest. Seeds are selected from fields with good levelling, which have received sufficient water and have a mature homogeneous plant population. While each household commonly selects sufficient seeds to meet the requirements of the following season, some degree of specialisation does exist. Some farmers, mostly women, are known to be skilled as seed selectors, and farmers in need of good-quality seed of a specific variety approach these specialists. The commercialisation of rice production is gradually transforming the traditional seed exchange system into a family-based seed production system leading to increased specialisation within the community.

Three main selection criteria identified by farmers were productivity, household requirements and market demand.

(i) Productivity: Farmers seek to maximise their total household rice production by using a range of varieties which together enable them to optimise their resource base. If a farmer’s fields, for example, have early access to water (located up-stream in the local hierarchy of water distribution canals), the farmer may select varieties with longer time to maturity and a higher water requirement (which commonly means higher yield potential). The balance between access to land and availability of labour also influences farmers’ choices of varieties: large land owners tend to sow late maturing rice varieties by broad casting after early tractor ploughing, while farmers with limited land transplant early maturing varieties following ox-ploughing or hand hoeing.

Farmers perceive that there has been a gradually decline in availability of water for irrigation in Njelegete village. Diversions and increased use by upstream farmers is seen as the cause. Some farmers have responded to the reduced access to water by increasing their use of drought-tolerant and short-season rice varieties, which require less water and access to water over a shorter period. In practice this means reducing the use of Fiya, which requires more water and is less drought tolerant than Kilombero. It has also result in an increased use of Supa Mati, because of its early maturity.

(ii) Household uses: These remain important selection criteria, although their importance has been reduced with the increasing commercialisation of rice production. Local landraces such as "shinga ya mwali" (neck of a young unmarried women), which farmers describe as having "good appearance, taste and smell, but low yield," are close to becoming extinct locally, having been replaced by higher-yielding but less palatable modern varieties.

(iii) Market demand: this is increasingly becoming the most important selection criterion. In the 1970s, the Mbeya Primary Co-operative Union (the state-controlled monopoly marketing organisation) encouraged the purchase of modern varieties. This resulted in the loss of several local landraces. During the 1980s the blanket price policy of the Mbeya Primary Co-operative Union resulted in the increased use of high yielding but relatively poor tasting varieties. Trade liberalisation which occurred in 1988 had a dramatic impact on farmers’ selection of rice varieties. The co-operative was replaced by private traders, who were driven by consumer preferences. This led to the emergence of variety-specific demands and price differentiation according to variety. Because of this change, the demand for several high yielding but poorly tasting rice varieties has almost totally disappeared and a trade-off between price and volume determines the mixture of varieties that farmers plant.


Although they continue to be ignored by the formal plant genetic resource management system, farmers’ knowledge and management skills are alive and well at the local level. In both the villages studied, farmers continue to play a key role in the selection and maintenance of varieties for food resources. Their skills in selecting for different characteristics to meet environmental, household and consumer needs are evident and well-developed. Nevertheless, this study indicates that these farmers could also use some help. While some benefits have been gleaned by farmers from the introduction of modern varieties, particularly in better-off, market-led economies, a price has been paid by the gene pool. New varieties have had a dramatic impact on genetic erosion in both areas, and in Mkulula the spread of a single variety has reached a point where community food security is under threat. The lack of support for farmers traditional management practices and their use of locally-adapted landraces can partly be blamed for this situation and there is an urgent need for national policies to shift in support of farmers knowledge and expertise.

Esbern Friis-Hansen is a social scientist working for the Centre for Development Research in Copenhagen, Denmark. This article has been edited from a longer report (see below)


Main Sources:

• PB Eyzaguirre & M Iwanaga (Eds) (1996), Participatory Plant Breeding, International Plant Genetic Resource Institute, Rome, Italy.

• FAO (1996), The State of the World’s Plant Genetic Resources for Food and Agriculture. International Technical Conference on Plant Genetic Resources, Leipzig, Germany, 17-23 June 1996, FAO, Rome.

• E Friis-Hansen & L Guarino (1995), "Collecting plant genetic resources and documenting associated indigenous knowledge in the field: a participatory approach." In Guarino, Rao & Reid (eds) Collecting Plant Genetic Diversity. Technical Guidelines. Wallingford: CAB International, pp 345-367.

• E Friis-Hansen (1999), The socio-economic dynamics of farmers management of local plant genetic resources - A framework for analysis with examples from a Tanzanian case study. CDR Working Paper 99.3. Copies from: Centre for Development Research, Gammel Kongevej 5, DK-1610 Copenhagen V, Denmark. Fax: (45-33) 25 81 10. Email: Internet:

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