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5.6.1 Inputs

Cassava being a subsistence crop is produced by small holder farmers under marginal lands. Among the inputs in the production of food crops which a household may be lacking is availability of farm land, hired labour and mechanization (COSCA Tanzania, 1996). In this case land has to be acquired by requesting land allocation from the village government or the community in which he/she is living, or be bought. Most subsistence farmers own at least a small piece of land where food crops such as maize, cassava, millet, etc., are grown.

In Tanzania households are headed by 80 percent men and 20 percent women. Gender influence the frequency of the use of purchased inputs, while the uses of hired labour and mechanized transportation are less frequent among fields of female headed households than among fields of male headed households (COSCA Tanzania, 1996). Farm mechanization such as seedbed preparation or farm transportation is less frequent among female owned fields than among male owned fields. The frequencies of use of other purchased inputs were about the same. Transport vehicles are operated by the male while carrying of farm produce by head load is mostly a female operation. In a few cases farmers (especially cattle owners) use ox-drawn implements for activities such as land preparation. Transportation of farm produce from the fields to their homes and cassava products to the markets after processing. The combination of all the above (i.e. hired/group labour, field to home transportation and land availability) may influence cassava land area expansion (COSCA Tanzania, 1996).

Food crop milling machines are available at the village level, to individual farmers on a custom basis. A farmer takes his food crops to the village square or to the market place to be milled for a fee. The milling machines are not crop specific; with different appliances the same machine is used to mill different crops or the same crops of different farmers whether wet or dry. Therefore, mechanized food processing although an important purchased input in the smallholder agriculture is a unique type of input and it is treated as a village level infrastructure.

5.6.2 Market accessibility

Ease of access to market centres, availability of cassava marketing middleperson, credit and unproved post-harvest handling facilities which would link the farmers to sources of demand for farm products and supply of farm inputs is called farmers' access to market (Nweke, 1996b). Information collected in Tanzania during the COSCA study on cassava market accessibility showed that means of access to the market was either by motor vehicles, foot or other means such as usage of bicycles, animal or boats (COSCA Tanzania, 1996). Proximity to market was grouped into categories above or below 10 km based on a subjective estimate of the distance a farmer can walk in a day with a head load of cassava products. Farmers in 50 percent of the villages surveyed attended markets on foot, over a distance of not more than 10 km (Table 13).

Availability of middleperson (traders and processors) facilitates the marketing process for farmers especially to distant markets. The farmers will spend more time on production activities rather than on marketing. Communication to the cassava producing areas in Tanzania is poor and very limited among the COSCA study countries, with the exception of Zaire, the relative number of villages that had paved road access to market centres was lowest while the relative number which used dirt roads was highest in Tanzania (Appendix 5).

Most roads from the district headquarters or towns close to the cassava producing villages are poor and some are impassable for three to six months in a year. This renders transportation of cassava and its products from the producing centres to the marketing centres difficult and very costly. Good road links expand the market demand for cassava because farmers can reach more consumers with their harvest (COSCA Tanzania, 1996). A fine example in Tanzania is the urban supply of fresh cassava roots in Dar-es-Salaam city where the market is flooded with fresh roots from Coast, Morogoro and Tanga regions which are connected to the city by the tarmac road. The southern zone is a big producer of cassava but cannot sell their bumper harvests to the needy regions like Dar-es-Salaam, Coast, Tanga and Morogoro. However, cassava produce in the southern zone finds its market, especially the dried product, through ships and boats which can load and off load at Mtwara port because of poor road infrastructures some roads to the southern zone are impassable for about six months of the year.

From the overall analysis, the level of investment in village-level road construction is low compared to other cassava producing countries.

Table 13. Percentage distribution of surveyed villages by indices of market access in Tanzania with other major producing countries (1990–1992)

MarketCôte d'lvoireGhanaNigeriaTanzaniaUgandaZaireweighted mean
Distance and means to market places motor vehicles, any distance       
Non-motor vehicles any distance footless284638273524
More than 10 Ian foot, 10 km and above       
Main cassava mot buyers:       
Credit institutions       
Money lenders       
Mot available 938389958885
Cooperative service       
Mot available747921188330
Trade loans       
Mot available728769891007480
Mechanized processing technologies       
Greeting machines       
Not available10175200015
Milling machines       
Not available1883553362138

Source: COSCA, 1996

5.6.3 Storage facilities

In ground storage of fresh cassava roots is practised in most of the cassava growing zones whereby roots are left in the ground and harvested in piecemeal when the family requires them. Harvested cassava roots may be stored in sacks on a short-term basis since deterioration starts two days after they are harvested. Recent efforts to introduce the low cost cassava fresh roots storage technology is meant to extend the shelf-life of the fresh roots of cassava soon after harvesting. The technology has long been used in various parts of the world and has been transferred, tested and validated in local Tanzania conditions. It has been found useful in extending cassava fresh roots supply from Kisarawe district, coast region, since 1995 (G. Ndunguru, 1997. Personal communication).

Traditional storage facilities are employed in the storage of cassava products especially the dried cassava pieces or chips called “makopa” and “udaga”. Storage in the form of flour is not preferred, in order to minimize flavour changes and insect infestation. Lack of storage facilities for flour products may be another setback. Dried pieces/chips are usually stored in sacks, large woven round baskets called “Whenge” on the floor in the house, in the attic, etc. When stored in the house on raised platforms heaped above the cooking place in the kitchen or in the attic, there is an additional advantage of getting the product smoked which preserves it further. Makopa can be stored for two to three months before insect damage but the smoked ones can be stored for one year. Dried cassava chips are easily marketed because traders find it easier for transportation and often the products fetch higher prices in the market (Wright et al., 1996).

In the local markets farmers sell dried chips to traders or middlepersons who in turn transport the products to big towns or the cities and sell them to retailers or market vendors. At national level, the National Milling Corporation (NMC) used to purchase dried chips which could either be stored in the sacks or heaped on the floor in the godowns. The NMC has of recent, stopped purchasing cassava chips where in some areas businesspersons have taken over the purchasing and exporting.

5.6.4 Processing infrastructure

The need for cassava processing is for ease of marketing, reducing bulkiness and perishability, extending shelf-life, removing cyanogens, reducing transportation costs and adding value to a unit weight. This applies to fresh cassava root because it contains between 62–65 percent water and starts deterioration within two days after harvest. Cassava processing methods include a combination of several procedures that are performed during specific time periods and in specific sequence. On average, 75 percent of the total cassava produced in Tanzania is processed and only 25 percent is used in fresh form (COSCA Tanzania, 1996). The proportion of total cassava processed is higher among farmers who grow bitter cassava than sweet varieties.

The main activities involved in traditional cassava processing include peeling, crushing, milling, slicing, sun or smoke drying, frying/roasting, fermenting by soaking or heaping, stacking or sedimentation, sieving, cooking, boiling or steaming (COSCA Tanzania, 1996). When carrying out these activities one can achieve the intermediate products which need further preparation for a meal or end products which can enter the marketing system directly.

Traditional processing methods and major processed products

The numerous technological pathways of cassava processing take advantage of locally available processing resources such as water for wet fermentation and sunlight for drying and firewood for frying, etc. These environmental factors are complemented with the availability of the processing equipment and available technologies. Labour for peeling, pounding/milling and roasting is the only processing resource constraint which no traditional technique has been able to address. Certain convenient cassava food products such as roasted or fried fresh root pieces, which are attractive to urban consumers are however made whenever market demand exists irrespective of whether the necessary processing resources such as charcoal or firewood for frying are available.

The major cassava product processed in Tanzania, chips/flour is known by various names such as chinyanya “makopa abutega kondowole, onnindyenge, udaga, chikondole, bada, dimwehe uhu, undule, mbule, makonga, obusanobwe or kivunde”. The products are made by a wide range of alternative traditional processing methods. These were grouped by COSCA under one major product namely cassava chips/flour. Elaborate notes on the processing techniques and cyanide levels of some processed products are presented in Appendix 6.

Processing equipment

The various techniques used in cassava processing at household level involve manual labour and in most cases traditional processing tools are employed as a means to obtain desirable end products. Traditional tools include knives for peeling and slicing, mats for sun-drying, big clay pots for fermentation and pestle and mortar for pounding, etc. Most of these tools are rudimentary hence limited in operational capacity, causing the labour input invested in the processing chain to be high. Available processing resources sometimes determine the type of cassava product to be processed. In Tanzania the bulk of cassava crop is processed during the dry season when there is strong sunshine for drying purpose.

Although chips being dried on a mat or in flat baskets may be moved to protect them from bad weather, those dried on rocks in the field, roadside, on the roof top, etc. are often not moved. If it rains, the chips get soaked and drying is started all over again (Mlingi, 1988). The wide range of drying surface possibilities and practices are such that the products can gather significant amounts of mould, dust and other dirt which influence the taste and colour of the end product.

5.6.5 Extension services

Organization of extension services for cassava crop in Tanzania starts at the ministry level where the responsible person for all the extension activities is the Assistant Commissioner for Extension and Agriculture. At this level a subject matter specialist is the implementer of all the activities. At the regional level three people are responsible for extension services. These are the Regional Agricultural and Livestock Development Officer, the Regional Extension Officer and the Subject Matter Specialist (RSMS). The next stage is at the district level where there is implementation of all the extension service. The DALDO, DSMS, DEO and DCO work together. The execution of all activities and setting of target is carried out while implementation is carried out by the Division Extension Officer (DIVEO) and Village Extension Officer (VEO).

The flow of research recommendations/information is channelled through different levels depending on the type of clients. As from 1989 there has been some strengthening of the farmer-research-extension linkages through the National Agricultural Livestock Rehabilitation Programme (NALERP) administered by the Ministry of Agriculture. Several bimonthly workshops have been conducted to train extension agents. In the bimonthly workshops researchers participate fully in the sessions.


Gender roles in cassava production do not differ very much from one area to the other. For example land preparation in the lake zone is done by both men and women, with the exception of ox-ploughing. Generally land preparation is done using hand hoes (Karlen, 1991).

Planting is also a shared activity in some regions Eke Mwanza, however, in general situations, this activity is mostly carried out by women. Weeding is carried out by both male and females, but with more labour input from female farmers (Rugimbana and Nyanga, 1995). Harvesting is mainly women's work with more labour input especially in transporting of crops to the homestead (Thro, 1994). In Tanzania women provide much of the labour for the staple crops such as maize, rice, cassava and sweet potato. Food processing, preservation and storage is a major responsibility of female farmers. COSCA studies in main cassava growing areas showed that about 75 percent of the arable fields were owned by men, 15 percent by women and about 10 percent by whole families (Table 14).

Table 14. Percentage distribution of crop fields by gender ownership

CropsNo. fieldsWhole familyMenWomenTotal
Sweet potato2119081100

Source: COSCA-Tanzania (1996)

Decisions pertaining to the sale of cassava products are made by the male head of the household where large proportions of the products are intended for sale. In such cases the man usually dictates on the use to be made of the cash earned. Small cassava sales are controlled by women and the money obtained is mostly used for small necessities such as soap, matches, salt, notebooks for school children, etc. (Thro, 1994).

As already noted women's labour input in cassava production and post-harvest handling is enormous. This is further aggravated by the use of traditional implements, which are in most cases limited in terms of operational capacity and also by the additional responsibilities that a woman has to fulfil.

A case study conducted in Kwimba district, in the lake zone, on gender role distribution in various activities indicated that involvement of women in agricultural production goes parallel to their involvement in domestic chores i.e. house and childcare, food preparation, water and fuelwood fetching etc. (Appendix 7).

In view of the above-mentioned analysis, the promotion of appropriate technologies to reduce women's workload is inevitable. Some efforts have already been directed towards addressing these issues but only in a limited way, hence further promotional activities are necessary.



The main objective of government intervention in the food crop marketing system in Tanzania has been to ensure food security. Several pricing mechanisms have been tried in order to provide incentives to producers while keeping consumer costs low. This has led to continuous reform of marketing systems in the country. The semi-controlled marketing system inherited from the colonial period, could not achieve the national objective. The system provided low producer prices, while charging high prices to the consumers. Lower producer prices discourage production of food crops, hence national food insecurity.

The state controlled marketing system ensured that producers are encouraged to produce more through provision of higher prices. However, before 1974, the system employed could not fulfil the objective. Producers were further penalized by the cooperative unions who incurred high costs which were transferred to producers through low prices. On the other hand, consumers paid relatively low prices. Pan-territorial pricing systems discouraged food crop production in accessible areas, while encouraging remote producers.

Trade liberalization has improved marketing of food crops because of easy access to markets such as local village markets 'magulio'. Also, it has increased competition which increases producer prices in accessible areas, hence encourages production of food crops. Tins has facilitated efficiency allocation of resources. However, more resources are allocated to the most profitable crops, while the less profitable food crops like cassava will be marginalized


Trends of production and consumption (estimates) of cassava in Tanzania between the 1980/81 and 1995/96 season are shown in Figure 5. Consumption of cassava includes quantities consumed within and outside the country. Local consumption was estimated based on expected population and consumption growth rates as explained by FAO (1986). However, quantities exported are underestimated as reliable data could not be obtained.

The results show that in recent years consumption of cassava has exceeded local production. Major reasons could be due to outbreak of cassava pests (mealybug) and diseases which have led to low production.

Figure 5. Cassava production and consumption trend from 1980–81 – 1995–96

Figure 5

Estimated domestic consumption and official consumer prices were used to estimate demand elasticity for cassava. The result indicated that consumption of cassava increases with consumer prices, having a demand elasticity of 0.15 implying that demand for cassava depends on population growth. Nevertheless, it should be noted that, the driving force behind an increased demand for cassava is due to low production levels of the preferred staples caused by drought and the increased demand for carbohydrate food crops (FAO, 1986).


The Government together with other donors have invested in the development of the cassava sector in Tanzania. Available data indicates that cassava research and other complementary services particularly marketing and extension have not been adequately funded. As such the impact of research at farm level has been minimal. Studies have shown that when farmers use recommended practices the net benefit per unit area and labour productivity are higher than when traditional practices are used (MDB, 1983; COSCA Tanzania, 1996). Since information on the rate of adoption was not available, return to investment on research was not quantified. However, enterprise analysis shows that investing in cassava research has high return when the recommended practices are adopted by farmers (Table 15). Moreover, cassava has contributed to the national economy as an export crop (Appendix 8) as well as a food security crop. It should however be noted that documentation and proper records of the exported dry cassava chips to European countries were not readily available. The current model on the trade liberalization actual records is not captured because of different informal channels by which cassava products are exported in foreign countries.

Table 15. Cassava production costs and return to labour, for 1994–95: A case of Mtwara region, Southern Zone

Local Improved
Yield (tonnes/ha)4.08.0
Producer price (Tshs)25 00025 000
Realization (Tshs)100 000200 000
Labour input requirement (person-days) 
- Land preparation3030
- Planting1215
- Weeding (x 2)2121
- Plant protection03
- Harvesting1112
- Transport/marketing46
Total labour days7887
Operational costs (Tshs)  
- Land preparation  
(Ploughing & Ridging)18 00018 000
- Plant protection01 800
- Weeding (x 2)12 60012 600
- Planting7 2009 000
- Harvesting6 6007 200
- Transport/marketing10 00025 000
Total operational costs (TShs)54 40073 600
GROSS MARGIN45 600126 400
RETURN TO LABOUR (Tshs)584.601 452.90

US$1 = Tshs 580

When the crop is marketed as dry chips/flour (makopa) it does not fetch high prices due to competition with the preferred grain staples particularly in urban centres, but when marketed as fresh roots, its prices are high (Ndunguru et al, 1994). However this trend is not sustainable because of bulkiness and persistability of fresh roots. Ways to improve the processing techniques in order to come up with a good quality product which can compete well with gram staples need to be envisaged. The case study conducted by the Tanzania Food and Nutrition Centre (TFNC) in collaboration with the Natural Resource Institute (NRI) on the analysis of fresh cassava marketing costs and margins for cassava traded between Kisarawe (Coast Region) and Dar-es-Salaam market is shown in Table 16.

Table. 16. Cassava marketing costs and margins between Kisarawe (Coast region) and Dar-es-Salaam, 1994

Producer price (shs/bag)*2 000 
Uprooting and packing400 
Carrying to collection point in Kibuta200 
Village levy5 
Transport to DSM (Buguruni Markets)800 
Commission fee100 
Market levy10 
Security charge20 
Storage charge7 
Carrying to the retail selling point150 
Total costs (Tshs)4 092 
Retail selling price (Tshs)6 800 
Profit (Tshs)2 708 

* = One bag of cassava fresh roots weighs 80 kg
Source: Ndunguru et al., 1994
US$1 =TShs 580

An impact assessment study on the acceptance of introduced cassava products in the Lake Zone showed that cassava doughnuts and cakes were highly marketable in Mwanza and Mara regions which will increase the demand of cassava (Kapinga et al., 1996). The net benefit analysis of cassava doughnuts shows a profit margin of Tsh 597.65 when one kilogram of makopa is processed and sold as doughnut (Table 17). The findings do not imply that cassava products are superior over others, but it is an indication that even in places where cassava is grown at large, farmers could still earn cash income from selling the processed products. Tins could raise the status of cassava from being an emergency crop after others have failed, to a cash crop.

Table. 17. Cost-benefit analysis of cassava product diversification: A case of doughnuts

Revenue: (Tshs)
Output (doughnuts/kg)75 
Price (Tshs/ piece)30 
Gross margin (Tshs)2 250 
Processing Costs: (Tshs)
Dry cassava chips kg80 
Margarine 170 g112.5 
Baking powder 750 g750 
Sugar 75g46.9 
Cooking oil (610 ml)307.5 
Labour charges250 
Total Costs1 652.35 
Net benefit (Tshs)597.65 

Small-scale starch processing has been observed to have high returns to investment. However, this opportunity has not been utilized. A cost-benefit analysis was undertaken to assess financial benefits of scale cassava starch production in Dar-es-Salaam (Table 18). The result indicates that small-scale starch processing is a viable economic activity. Although the first round of operation has a higher negative balance, the second production has higher net benefit which off-sets investment costs.

Table 18. Economic analysis of small-scale cassava starch production in Dar-es-Salaam, 1996

Cassava starch (kg)
Price (Tshs/kg)
Gross Benefit
1st Prod.
270 000
And Prod.
2 700
Production costs (Tshs)  
Fresh cassava roots (tonnes)45 00045 000
Transportation1 5002 000
Grating6 1006 100
Filtering cloth8 0000
Sedimentation drums219 9600
Drying mats24 0000
Packaging (bags)4 5004 500
Labour costs12 00012 000
Total costs321 06069 100
Net benefit-133 215200 900

Note: Production is estimated at two operations per month. All production is undertaken in one month

Investment in the multiplication of cassava planting material is another venture where farmers can benefit as indicated in one of the case studies in at Ukiriguru Research Institute, lake zone (Table 19). The estimates of the operations have put into account only the basic requirements for the good quality planting material. The cassava multiplication plots are discarded after two cropping seasons to ensure production of good healthy planting material.

From different case studies analysed it is obvious that cassava can enter well into a commercial sector to realize its full potential. Efforts to add the value to cassava need to be strengthened.

Table 19. Benefit-cost analysis of multiplication of cassava planting material, in the Lake Zone

Benefit :Year 1Year 2
Planting material (number of plants/ha)15 00015 000
Price for planting material (Tshs ./plant)2020
Price for fresh roots (Tshs/ plant)020
Gross benefit (Tshs./ ha)300 000600 000
Operational Costs:  
Land hire20 0000
Labour costs:  
Land preparation18 0000
Planting9 0000
Thinning03 600
Weeding (x3)18 90026 838
Farm yard manure (lOt/ha)50 0000
Inorganic fertilizers55 00065 000
Plant protection (rouging)10 00014 200
Harvesting of planting material10 00014 200
Total costs (Tshs)170 000128 3838
Net benefit (Tshs)109 000476 162

US$1 = Tshs 580. Estimates are based on the experiences of Root/Tuber Research Programme at Ukiriguru Research Institute 1994/95–1995/96. The variety used is Liongo Kwimba.


In Tanzania, cassava is an important food security crop and its production is becoming more important throughout the country due to its drought resistant and storage (in ground) characteristics. The crop has more advantage over the major grain staples in dry areas. It is logical therefore, to invest in cassava production in such areas because, normally, the same areas have poor soils in which only crops with low resource requirement, such as cassava, can perform well. Some areas in Tanzania have been identified to have a comparative advantage in cassava production over other zones. These areas include: lake zone, eastern zone, southern zone and Zanzibar. However, lack of data make the quantitative analysis difficult in determining the comparative advantage. Nevertheless, proxies such as weather (rainfall) and soils are used in selection of areas (zones) with comparative advantage in cassava production.

To measure the comparative advantage of Tanzania in production of cassava and hence its economic efficiency from the national point of view, the Domestic Resource Cost (DRQ) was used (Table 20). The results show that DRC for improved and traditional production practices were 0.59 and 0.93, respectively. This implies that both cassava production practices, by comparison have comparative advantage, with DRCs less than one. However, traditional production practice is not as efficient as the improved one by having a higher DRC of 0.93.

Analysis of producer prices through PAM gave a Nominal Protection Coefficient (NPC of 0.78), which is lower than one, implying that prices paid by buyers to farmers were lower than the international parity prices for cassava. Tins means that cassava producers were taxed by the Government.

Table 20. Policy Analysis Matrix (PAM) for cassava production (1991/92)

  Cost of production 
 Tradition ImprovedTradition ImprovedTradition ImprovedTradition Improved
Private Values15000 390000.0 0.022698 28192-7698 10808
Social Values19275 501150.0 0.017874 294461401 20669
Divergence-4275 – 111150.0 0.04824–1254-9097–9861

NPC= Both practices = 0.78
DRC: Traditional practices = -0.93
Improved practices = 0.59


The Tanzania economy is dependent on agricultural production which contributes to 55 percent of the Gross Domestic Product, 60 percent of the foreign exchange earnings and employs about 81 percent of the labour force (Wilson, 1994).

The present policy emphasis is to expand production of domestic food crops for ensuring food security and export crops for increased earnings. As a result of this policy, there has been a shift towards cassava particularly in the drought prone areas because of the need for more drought tolerant crops (MALDC, 1995). Successes and weaknesses of the current policy are summarized in Table 21.

Generally the research policy has succeeded in promoting cassava production by funding research, developing human resources, infrastructure and creating awareness on the importance of cassava to the farmers. The limitations have been low level of funding, lack of enough human resources and infrastructure, dependence on external funds for cassava research and limited motivation packages to research staff.


7.6.1 Germplasm development

The major objective of cassava breeding is improvement of genetic potential of the crop. Since its inception, the breeding programme has increased research efforts towards developing varieties adapted to targeted environments. Some varieties which have been released since the 1960s are still with the farmers in various agro-ecological zones. These include: Aipin Valenca, Lyongo (Liongo), Kigoma, Mzungu, Kibaha, Njema, Agriculture, Msitu Zanzibar and Kaniki (Table 22).

The breeders are aware that varieties released are subject to different criteria set by the consumers to ensure good adoption, even after release. A participatory research approach in which farmers are involved from the beginning in selecting the desirable varieties has recently been adopted by researchers. Strengthening of this approach in future is a must in order to minimize research costs and maximize selection efficiency.

Limitations of the breeding activities are that development of cassava varieties for targeted environments are very expensive because of the time required to complete a breeding cycle. Funds allocated are limited. At present the programme depends entirely on the external sources of funds. External funding is the only source for breeding activities. Sustainability of this activity is questionable, as once the external funding ceases, there is a chance that most promising activities will freeze. So the whole process of improving the cassava genetic potential will slow down.

Breakdown of resistant varieties due to diseases especially CBB, CBSD, ACMD and pest CGM CMD is prevalent in the country (Msabaha et al., 1988). This has slowed down the process of breeding and rapid diffusion of improved varieties to farmers. Susceptible varieties but with good root qualifies need to be addressed.

There is also limited utilization or acceptability of cassava varieties with high cyanide levels particularly in Zanzibar and coastal areas. Good varieties are rejected by some farmers because of high HCN content (COSCA Tanzania, 1996). Research towards addressing HCN has been initiated at the Tanzania Food and Nutrition Centre (TFNC) for processed cassava products Mlingi, 1995). However, there is a need to strengthen this activity, at the same time initiate studies on cyanide levels in fresh roots of cassava.

Table 21. Successes and limitations of the national agricultural policy

Government policy on agricultural food crops not very clearResearch on some food crops initiatedGovernment allocated land for research
- Little human resources devoted some time to food crop research
Research on food crops not given importance
- The emphasis on research was on cash crops.
Government policy needed on the status of food crops in the countryPolicy statement on importance of cassava as a food crop and emphasis on expansion of food cropsMore land allocated to research in various agro-ecological zones in the country
- Some funds allocated for cassava research 
- Human resources allocated for research of cassava
- Infrastructure developed for food crops research
- Low level of funds for cassava research
- Limited human resources development
- Limited development of cassava infrastructure.
Clear policy on Agricultural food production neededPolicy on agricultural food crops formed and emphasizes on the importance of drought tolerant crops and sensitizes people.- There has been a shift towards cassava particularly in drought prone areas.
- Cassava prioritized as a second Driority crop in crop research in the country, its status evaluated.
- Cassava considered as an emergency food crop when cereals fail.
  - Effort in human resources development increased: three M.Sc. and two Ph.D.s are still on training
- Short-term training undertaken
- Physical resources attained at a minimum requirement five vehicles nine motorcycles and 25 bicycles allocated to the programme.
- Government policy encouraged collaboration with other international and national institutions
- Staff morale is low due to lack of motivation by the Government - Funding levels still on the lower side
- Infrastructures still to be developed
- Research activities too dependent on funding from donors therefore sustainability for future research activities is questionable.
 Government support of production and control of pests/disease of cassava. Government policy on increased efficiency of its human resources.Some major pests and disease (cassava mealybug) have been controlled.
- Wide coverage of cassava research in the country has made it possible to conduct research throughout Tanzania.
- Retrenched some unskilled staff
Level of funding to support biocontrol activities.
- Few research staff on cassava, has made full attainment of research goals impossible. Retrenchment exercise has slowed down field activities tremendously.

Source: MALDC(1995)

Table 22. Successes and limitations of research interventions on cassava crop genetic potential improvement

Cassava varieties with low genetic potential in yield resistance to diseases/pests and undesirable quality characteristics- Develop and select cassava varieties with desirable characteristics
- Exchange and introduction of germplasm in the country.
- Research efforts increased towards developing varieties adopted to targeted environment
- Various good varieties released and are with the farmer, six varieties in the lake zone, five in the southern zone, four in the eastern zone and two in the southern highland
- Incorporation of various criteria set by consumer to ensure good adaptation of varieties even after release.
- Participatory approach in which farmers are involved from the beginning in selection of desirable varieties
- Some varieties with good resistance to diseases and with good quality released.
- Breeding/developing cassava varieties for targeted environments appears expensive because of a long breeding cycle of cassava
- Funds allocated to breeding are limited and also at present depend mainly on external funds. Sustainability of this approach in questionable, as once external funding ceases, promising activities will have to be frozen.
- Protocol involved in exchanging and introducing new germplasm from other countries is cumbersome, need for the Government to shorten the procedure.
- Prevalence of outbreak of important diseases (CMD CBB, CBSD) slows down the breeding process
Bitterness/toxicity of cassava varietiesResearch on HCN levels initiated at TFNC and SUA- HCN levels of cassava processed products determined-No research is being done on establishing cyanide levels of Tesh cassava roots
- Some good varieties rejected by farmers due to their high HEN content.

7.6.2 Adoption or non-adoption of varieties

There have been informal releases of cassava varieties to farmers. Varieties Aipin Valenca, Msitu Zanzibar, Amani 4763/16, Amani 46106/27 and agriculture are among the varieties with high yielding abilities still with farmers. However, it has been difficult to trace many varieties because they might have acquired local names. Appendix 9 shows the names of varieties selected from research institutions and still with farmers in different zones as observed from COSCA studies and key informants that worked in the past with the Amani Research Station. Studies to establish the distribution of improved varieties is needed, while molecular marker DNA finger printing techniques could help to characterize the same varieties that might have acquired different local names. This will remove uncertainties on the adoption of improved varieties at farm level. Also the underestimation or overestimation of the adopted varieties will be minimized.

7.6.3 Improvement of cropping systems with cassava

Improvement of cassava agronomic practices has been to some extent addressed by research (Table 23). Poor soil fertility under continuous cropping of cassava is an issue which requires attention. Integration of the legumes in continuous cassava cultivation seems to improve solution for soil fertility. However the system has not been tested on-farm and therefore recommendation of this practise to farmers is yet to be done; and socioeconomic implications of this practise has to be determined before popularizing this practise (Roots and Tubers Annual Report; 1994).

Other studies so far have been location specific calling for attention to other zones. Some research recommendations have been adopted while others are yet to be adopted. Research efforts towards addressing this issue are still at an infancy stage.

Limitation to this activity is that multiplication of planting materials is a very expensive exercise particularly in dry areas because biomass production is low in comparison to moist areas (Table 24). Also the multiplication rate of cassava is low relative to food grains. Training of farmers in multiplication and off-season storage of planting materials could sustain this exercise.

Absence of facilities for rapid multiplication of vegetatively propagated crops complicates management of root and tuber crops and slows release of new disease and pest tolerant cultivars (Wilson, 1994). Facilities for this activity need to be in place, for easy execution of the whole exercise. For the initial stages the external funding support for multiplication of planting materials is required urgently. For sustainability however, farmers and all key players should participate fully in the process.

7.6.4 Reduction of pests/disease incidences

Vulnerability of cassava to devastating diseases and pests are causes for concern (Wilson, 1994). ACMD which has become a devastating disease along the coast regions, Zanzibar and the Lake Zone. Recently another strain namely East African Cassava Mosaic Disease was reported along the coastal belt of the Indian Ocean and North Western parts of Lake Victoria. However, there are hopes that devastation can be substantially reduced by some improved cassava varieties (Wilson, 1994). Research successes and limitations towards addressing this problem are summarized in Table 25.

These cultivars are at present in research stations and surrounding villages but their release, multiplication and distribution are still at the infancy stage due to financial constraints and the country is yet to benefit from them. The same trend has been observed in Cassava Brown Streak Disease (CBSD) observed mainly along the coastal regions stretching down to Mtwara region. Cassava mealybugs and cassava green mites are major potentially devastating pests in major growing areas of cassava; particularly in the semi-arid areas. It is very obvious that food shortages being experienced in some of the drier areas of northern Tanzania are partly due to cassava mealybug attacks. This also slows down the process of multiplication of cassava planting material in these areas. Biological control through the predatory wasp E. lopezi has been introduced in the country but has had mixed success (Wilson, 1994). Some areas have reported successful control while others have reported no significant change and sometimes very little establishment of the wasps. Monitoring of the pest by researchers has been difficult because of lack of resources. These together with lack of commitment by the Government on containing this problem have led to increased pest attacks at farm level. Unless new measures of combating these devastating pests are taken, the increased production of cassava per unit area at farm level, particularly in the dry areas, remains doubtful.

Table 23. Successes and limitations of research interventions on the improvement of cassava agronomic practices

Poor soil fertility maintenance at farm level.Use of organic and inorganic fertilizers
- Integration of tree legumes in continuous cassava cultivation
- Rotation studies.
- Fertilizer packages for sole crop identified.
- Alley cropping with the legumes recommended.
- Recommended packages for rotation with cassava identified.
- Inorganic use of fertilizer not economical to subsistence farmers because of high price of fertilizers versus low market value of cassava.
- Use of farm yard manure limited to livestock owned only.
- Alley cropping technique not yet on-farm and therefore socioeconomic implications not determined.
- Rotation packages recommended for only one zone WCGA, not tested anywhere else.
Management practises on cassava fields very poor- Weeding regime studies
- Spacing studies on cassava - Plant density studies
- Consequences of plucking leaves.
Weeding regimes identified and recommended
- Appropriate densities recommended for various zones
- Effects of plucking leaves noted and yield loss determined - Regimes of plucking leaves identified.
- Farmers not weeding appropriately
- Plant densities of cassava depend on importance of cassava by the farmers.
Time needed between harvesting leaves recommended for one zone only.
Lack of indigenous knowledge on the cassava field management practises.Baseline studies by COSCA Project undertaken- Existing Agronomic practises at farm level identified and documented.
- Farmers distinguish between a major and a minor crop in recropping. Aggregate output main reason for intercropping.
- Plant density of cassava in farmers' fields identified. Age of harvest identified Fallow system identified, diseases/pests, levels in cassava intercrops established.
- Need to incorporate existing agronomic practises into agronomy research.
- Cassava densities low in farmers' fields. Fallow systems practised is very limited due to shortage of land.
- Diseases/pests pressure in intercrops not significantly different from cassava monocrop.

Table 24. Successes and limitations of the research interventions on cassava multiplication and distribution of planting materials

Problem(s)Intervention (s)SuccessesLimitations
Critical shortage of clean healthy planting materials at farm levelEstablishment of multiplication plots of cassava planting materials at research institutions and nearby villagesCassava varieties Liongo Kwinba, Msitu Zanzibar, Aipin valenca and Liongo Control, Kibaha and Kigoma Red distributed in their targeted areas.Multiplication of planting material in dry areas is a very major constraints
Lack of well-defined mechanisms at national level on the multiplication and distribution of cassava planting material.Training of extensionists and farmers on rapid multiplication techniquesGeneration of income/revenue through sale of planting material and roots to support research.Multiplication rate of cassava is low compared to other crops such as grains propagated seeds.
Timely availability of cassava planting material of superior varieties developed by research institutions.Organization of farmer field days and demonstrations.Awareness by farmers on the new techniques on storage and multiplication of planting material at level attained.Bulkiness and perishability of the crop.
 Contracting farmers in multiplying the planting material.Contribution towards rehabilitation of food production in Ngara district (refugee hit area) achieved.Regular attack by pests and diseases.
  Involvement of NGOs and other special projects in the exercise achievement.Multiplication and distribution is an expensive exercise
   Low level of trained farmers and extensionists in multiplication techniques

Table 25. Successes and limitations of research interventions on the reduction of pests and disease incidences

1970 to 1980Outbreak of cassava green mites (CGM)Establishment of economic threshold for the pest Investigation of resistant varietiesEconomic threshold for CGH was established Varieties with good levels of resistance were identifiedThe identified varieties were not accepted by farmers due to poor yielding ability and their flowering ability made improvement impossible
 Sporadic appearance of Cassava Bacterial Blight (CBB)Studies on the rate of spread of the diseases.Distribution and extent of severity of CBB was established in the Lake zone. Some control strategies were identified.Economic threshold was established Awareness of the disease at farm level not created.
1981 to 1990Termite attack in cassava fields.Use of chemical control strategy.A chemical called Alandrin was identified.Residual effects of the chemical were not analysed. Economic analysis of the use of chemical and implications at farm level not assessed. The testing of generated technology not carried out. Less costly and safe control method not identified.
 High incidences of CMD in major cassava growing areas.Establishment of the distribution and economic threshold. Identification of control strategies. Selection of varieties with good level ofCultural control measures were identified. Distribution of the disease was established. Several varieties were earmarked for good level of resistance to ACMD.Economic threshold not determined because of difficulties in obtaining the disease free materials for establishment of the trial. Rate of spread of the disease through vector infection was high even in the assumed clean plants (disease free plots) making it

7.6.5 Improvement of cassava post-harvest handling techniques and product diversification

Various studies conducted by different key players in the cassava sector identified a critical problem of poor and rudimentary ways of cassava post-harvest handling (processing, storage and utilization). The range of cassava food products was narrow, cassava was transformed predominantly into inconvenient food products which could not compete effectively with food grains on the market; and therefore did not have as much market opportunities as cassava food products made in other countries, especially in West or Central Africa (Msabaha, el al., 1996; FAO, 1986, Wilson, 1994 and COSCA Tanzania, 1996).

In urban areas where there is an assured market, cassava is mainly consumed in a fresh form. Fresh roots are very susceptible to biodegradation hence can be kept for a few days after harvest. Although some techniques are being developed to extend this period (Table 26), it is still insufficient to permit transport and sale to distant markets. The technologies being developed by TFNC on low cost storage of fresh roots have some limitations in their adoptability because of insufficient resources for farmers to secure raw materials required. For instance, securing the wax for treating the fresh roots might not be economical to farmers and traders who have to transport fresh roots to the city.

The issue of hydrocyanic acid in the fresh roots is another limitation on the use of cassava in a fresh form. This may be so high in some varieties as to make it safe after processing (FAO, 1986). TFNC is working currently on the quality aspects of the processed products, the HCN content in fresh roots commonly traded is yet to be dealt with. Interventions on the introduction of new processing techniques particularly grated products 'gari' appear to be promising (Table 26). However the use of fuelwood in one of the processing steps which limits its adoptability particularly in drier areas. This technology is contrary to the government policy on the rehabilitation of the natural environment through afforestation. In this way it is enough to introduce the technology with complementary technology on fuel saving techniques. Alternatively, directly sundrying the cassava mash instead of roasting, the product obtained will be different. On the use of the latter option the HCN levels in the dried cassava mash should be determined firstly to produce the safe product for human consumption.

Table 26. Successes and limitations of research interventions on improvement of cassava post-harvest handling practices and utilization

1984–1990Traditional processing methods were considered to be poor and could not meet the nutritional needs.Improvement of traditional processing methods and development of cassava weaning foods.. Studies and documentation of traditional processing methods done for Masasi and Tarime districts.Issues on traditional storage facilities for dried cassava products have never been addressed.
   . Development of cassava weaning food recipes in Mtwara region under CSPD programme.Weaning foods for other cassava growing zones not yet developed.
   Method for cyanogen analysis in cassava was established. 
   .Cyanogen levels in cassava products from Masasi and Tarime were determined and reported.Dissemination of findings on health problems associated with consumption of insufficiently processed cassava was not carried out in communities which were not affected.
    Socioeconomic studies associated with cassava processing and consumption were not carried out.
1990–1994Narrow range of products derived from cassava.Product development and diversification of secondary productsIntroduction of diversified cassava products to some areas within lake and eastern zones was carried out. Preliminary observations show that there is potential market opportunities for cassava secondary products.Convenient cassava products not yet introduced in other cassava growing areas.
 Improved cassava post-harvest handling practices were not known.Introduction of cassava post-harvest handling practices.Advice given to farmers on hygienic conditions in traditional cassava processing e.g. peeling and sundrying. Limited efforts were made to introduce cassava graters for gariprocessing.Gender issues, in cassava processing not addressed at all. The product was acceptable but the technique has not yet been adopted, because of laborious equipment and lack of resources.
  Staff trainingRoot/Tuber Programme staff were sensitized on cassava post-harvest handling techniques.Human resources not sufficiently developed e.g. training for post-graduate diploma/degrees..
 The role of cassava in urban and rural food supply system not known.Need assessment studies conducted for Non-Grain Starch Staples (NGSS) (cassava, sweet potato and banana).. Market demand for fresh cassava roots in Dar-es-Salaam was established. Low cost fresh cassava root storage technology introduced in a few villages in Dares-Salaam and coast regions.Market losses in fresh cassava roots not yet investigated. Technology not yet replicated in other cassava growing zones. Follow up on the adoption of the technology not yet done.
1995o dateImproved cassava processing and developing diversified cassava products was inadequate.Introduction of cassava post-harvest handling techniques.A member of extensionists, farmers processors and small entrepreneurs received training in cassava post-harvest handling practices especially in product development. Six hundred (600) clients trained in product development and diversification adopted the technology.Only two zones were involved hence a need to cover more zones. Only one dissemination model was employed i.e. training demonstrations other models (e.g.) recipe books need to be considered. Failure to achieve 100 percent adoption may have been due to poor follow-up, poor quality flour, lack of resources and facilities.
 Limited and inefficient cassava processing methods, equipment used and products processed.Introduction of convenient cash products and improvement of cassava processing methods. Introduction of graters, teaching and demonstrating processing of different products. Intensive resource requirement hinders improvement of traditional processing methods. Very little labour saving technologies have been introduced.
   Recent introduction of local village markets has improved cassava marketing, market accessibility trading and volume traded.There is poor market accessibility in the country (poor transport facilities, location, active middleperson, etc.)
    . Traditional storage facilities lave never been given attention (investigations, expansion, improvement, etc.). Issues on traditional cassava processing infrastructure have not been designed.


Cassava is well integrated into the Tanzanian crop production systems. It plays an important role as a food security crop and provides useful opportunities for extending labour use and exploiting price peaks in the food market. There is a marked potential for cassava secondary products to compete well with other products from other crops such as wheat. Also return to labour investment on the use of improved varieties against local varieties appears to be significant and rewarding. The involvement of farmers/beneficiaries from initial stages to testing of developed technologies by researchers to suit the local conditions appears a breakthrough to slow adoption rate of disseminated technologies experienced in the past.

Changes in models of marketing food crops to open markets might help the producers, however caution should be taken when exercising tins because of the uncontrolled prices which might not favour the consumers. Cassava production at farm level is still low because of various problems as outlined below.


Since cassava is largely produced by family labour, development possibilities are constrained by the amount the family can produce (FAO, 1986). The farmer is then obliged either to hire additional labour capable of increasing productivity, with the tins trend, wealthier farmers are favoured and the less wealthy disadvantaged. Farming with family labour, in an economy with a strong subsistence bias, affords equitable access to land and the rewards of production. More heavily capitalized production, with the inevitable tendency to commercialization, holds out the prospects of greater efficiency, but with uneven allocation of production.


Although climate and sods limit the level of yields obtained from cassava in Tanzania, it is obvious that varieties with good tolerance to important pests and diseases would be more productive. Yield advantages could also be derived from the use of varieties with better adaptation to local conditions. Research advances to date appear promising, but one wonders with the current level of funding from the Government how sustainable this system will be. The number of research staff currently undertaking these activities is inadequate. Higher numbers of elite varieties/clones at most of the institutions cannot be tested due to limited irrigation capability.

The current research work on cropping systems is justified on the grounds that optimum levels for the various practices are location specific. If this is so, the inadequate cover in other stations where cassava crop is of importance would limit the application of findings. Therefore, it appears that the programme requires resources in terms of personnel, finance and physical facilities:

Special resources should be provided to support the biological control project for cassava mealybug and this should be extended to include control of cassava green mites. The rearing facilities may need expansion and more scientists should be supported for training at the biological control unit at IITA Ibadan, Nigeria:

Therefore, the recommendation is to establish facilities for propagation and distributing clean healthy planting material from the varieties of resistance to pests and diseases.

Also the establishment of multiplication plots at locations where the materials are to be used ensures good adaptability of the introduced varieties to local conditions. This exercise is however expensive, hence the need for external support cannot be over emphasized.


Therefore if cassava is to find a niche in the urban supply system it is imperative to transform it into a durable and ready to use form. Some efforts already initiated by the National Root/Tubers Programme in collaboration with TFNC, NGOs and other key players should be strengthened. A likely product suggested by FAO could be granular with roasted particles to obtain “gari”. Such material is readily packaged and stored.

A self-contained project should be prepared to select and evaluate the market potential for an improved cassava based food product. If successful this should be followed with pilot-scale production and a food education programme to establish the selected product.

This goes along with the promotion of cassava as a component since the information on these aspects was scanty, there is a need for further investigation to study the potential role of cassava in the industrial sector.


Changes in the marketing models did not influence marketing of cassava. Competitive products were not available, so prices remained low. The open market is the major marketing channel in existence. However, quantities marketed through this channel are not documented. Cassava production campaigns did not go hand in hand with the efficient marketing information system.

There has been no credit policy geared towards the development of the cassava sector compared with the cereals. To make this a reality, rewards to agriculture, in terms of the price paid to the farmers, should reflect this contribution to the economy. There is a clear need for a pricing policy which not only encourages production but provides sufficient income to provide a margin for investment. Consistent with this would be the improvement in the availability production inputs.


There is very little, if any, intervention which can be affected from the research side apart from advising the policy-makers on the priority given to improving the condition of roads at village levels. This could enhance the marketing of the crop:

Care should be taken when exercising the latter approach in order to strike a balance of research issues on both technology development and technology development and technology dissemination.

Lesson learned from the past experience indicate that it is very obvious that support to cassava research and development in Tanzania cannot be overemphasized. Therefore to address this, external assistance in the form of human, physical and financial resources is urgently required. Appendix 10 summarizes the protocols for the identified areas that need support from external funding.


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Cassava production trend per zone from 1986–87 – 1995–96

Source: Planning and Marketing Division, Ministry of Agriculture and Department of Statistics, Zanzibar


Major food crops production in Tanzania from 1981–82 – 1995–96

Source: Planning and Marketing Division, Ministry of Agriculture 1983–84 – 1992–93


Tanzania food imports (tonnes) 1975–76 – 1993–94

YearMaizeRiceWheat grain
1975/7610 70021 000Na
1976/741 6005 00061000
1977/7834 30049 000342 000
1978/79na41 00041 000
1979/80322 50055 000782 000
1990/81274 60063 200332 000
1981/82234 60070 20048 700
1982/83123 400292 40083 100
1983/84194 30057 10029 400
1984/851 282 50036 100461 300
1985/866 10032 90033 300
1986/8793 80083 50021 800
1987/88na52 30053 500
1988/89na19 500331 700
1989/902 2085 02028 800
1990/9116513 6003 300
1991/9224 50044 00019 000
1992/93nana40 000
1993/9424 900507 500Na

Source: National Milling Corporation, 1991/92 and Customs Department, Tanzania, 1994/95


Major food crops purchased by NMC from 1973–74 – 1990–91

Source: Marketing Development Bureau, Ministry of Agriculture and Cooperatives.


Percentage distribution of representative villages by nature of farmers access road to main market by country

Nature of roadCôte d'lvoireGhanaNigeriaTanzaniaUganda
Foot path1223290

Source: (COSCA Tanzania, 1996)


Summarized notes on the processing techniques of cassava in Tanzania

Processing of cassava is expected to reduce hydrogen cyanide (HCN) levels to negligible levels but for cassava chips/flour processed by direct sundrying of peeled roots, traces of residual cyanide levels are sometimes left. It has been reported that samples of cassava flour from Morogoro, Tanga and Dar-es-Salaam contained cyanide levels that varied from 38.2 mg/kg of dried white flour to 71.2 mg/kg of dry dark flour (Mwang'onda, 1980). A product with less than 50 mg/kg level of cyanide is considered safe when ingested (Bolhuis, 1954). A recommended level is still under development by TBS and TFNC. The method for direct sundrying peeled roots is used for processing non-bitter (sweet) cassava varieties. The other alternative method of making cassava chips/involves fermentation by heaping prior to sun or smoke drying. Chips made in any of the foregoing increases reliance on cassava both as a source of local food security in time of drought and as a source of steady real income for rural households. In areas where water is available for only a few months of the year, the possibility of relying on piece-meal harvesting and processing of cassava to even out seasonal variation in income and food supply may be significantly reduced (Berry, 1993). Traditional methods are converted into flour by milling.

Making of chips/flour is most efficient in dry climates. The products are made in areas remote from the market centres; because as dry products they are not bulky and they have long shelf-life hence relatively inexpensive to transport over long distances. In contrast to chips/flour, fresh root is the main cassava product in peri-urban centres such as those adjacent to Dar-es-Salaam. In such areas cassava genotypes low in cyanogens, are grown for sale to urban working class to whom fried cassava roots are convenient snacks at lunch break.

One of the cooked pastes reported is known as “mbute” in the Lake zone area or (“lowe”) in the western zone. This is processed by immersing whole roots in water for three to five days for them to soften and ferment. After that they are peeled, fibres removed and the pulp heaped on a rack for further fermentation or can be covered with leaves and pressed with heavy objects to drain off excessive liquid. The pulp is grounded or pounded and the fine pulp is wrapped firmly in leaves and steamed. These products are ready to eat as part of a meal without further cooking. The making of cooked pastes is expensive and labour intensive. The high production costs and the strong flavour of the product has restricted the production and consumption of the product to limited areas.

However processing is dependent on availability of water and the importance of water for processing is potentially serious

In 3.33 percent of the villages visited during the COSCA studies, plate and hammer mills were available. However, such mills are used for converting chips into flour and are also used for milling grains, beans and peas. Mechanization of cassava processing appears to be driven by market forces and the mechanization of various cassava processing steps is more common among villages which sell large proportions of their total cassava production. It is more common among villages which have good market access infrastructure.


Participation of men and women in selected activities: Kwimba district

ActivityPercentage contribution per activity
1. Ox- ploughing955
2. Harvesting3862
3. Weeding3862
4. Hand hoeing4852
5. Crop transportation2872
6. Processing and preservation1882
7. Firewood collection0100
8. Water collection595
9. Household chores0100
10. Land preparation5545

Source: Female farmers as clients for agricultural technology


Quantities of food crops exported in Tanzania (tonnes) from 1982–83 – 1994–95

1983/849 120nanana
1984/8511 000nanana,
1985/8617 384nanana.
1986/8715 215nanana,
1987/888 59190 800na8 732
1988/8913 77218711na14 729
1989/9036 99730 348na3 422
1990/9167 12157 0392 588na
1991/92213707 000451233
1992/9335 8784 141505na
1993/943 93716 1401439na
1994/959 0002 5256 191na

Source: National Miffing Corporation, 1991/92; Customs Department 1994/95; and Regional Agricultural and Livestock Development Office, Mtwara


Cassava varieties currently grown by farmers in four zones with an origin from the research institutions

Name of varieties per zone
MahizaAipin ValencaKigomaKigoma
Kiguu chaningaNj emuAgriculture 
Tingisha ndevu   
Msitu Zanzi -bar   

Source: COSCA Tanzania, 1996 and key informant from Amani Research Station, Tanga. Februaryl997


Identification of cassava research and development projects

•   Justification:

Synthesis of cassava status in Tanzania has shown that cassava is very well integrated into the Tanzania farming and food systems. It plays an important role as a food security crop as well as a provision of useful opportunities for return to labour investment. Also the crop has a good chance to stand as a cash crop in exploiting price peaks in the food market. This was noted in the various case studies on the comparative advantages for investing in cassava under different sectors.

From the report and the previous missions by FAO, it is very clear that current cassava productivity is near the lower end of internationally reported yields. These are considerably lower than the rhetorical potential for the crop. Emphasis on improvement of cassava genetic potential through cassava germplasm development and priority on improvement of production practices could result in better returns for labour and material inputs. Improvements in farming practices could raise soil fertility, reduce the risk of declining productivity of the land resources and minimize the vulnerability of cassava crop to major pests and diseases. While improving the production practises for maximum yields, the issue of phytosanitation should not be overlooked. Since cassava is vegetatively propagated, the risk of accidental introduction of pests and disease with imported clones is high. Emphasis on the use of tissue culture materials and true seeds during the introduction would minimize such risk. Hence there is a great need to strengthen the plant quarantine services.

Various missions have noted the discrepancies on the national agricultural statistics offices and FAO estimates of cassava production. The report notes the inefficiency in the data collection mainly due to lack or little formal marketing of the crop. The yields at farm level both from different case studies and on-farm trials, contradict greatly with the national agricultural statistics and that of FAO. The knowledge use of improved varieties and the impact of these varieties at farm level is lacking. This in turn underestimates the impact of research in cassava despite its long history as noted in this report. One major factor has been the confusion existing on the identification of varieties because many have acquired local names. According to key informants in Amani, Tanga where the research of cassava began in the country, there is a very big chance of tracing the distribution of the improved varieties; in so doing the impact and all relevant information on cassava production could be determined.

A shortage of cassava planting material at farm level has been identified as one of the limiting factors in cassava production. For a sustainable solution, propagation centres of elite materials need to be established. Along with this, farmers and all key players need to be trained in the techniques of multiplication and management. The proposed propagation centres would serve to provide initial stock of planting material which could be distributed to pilot farmers and NGOs working directly with stakeholders. It is believed that at a certain stage farmers will be in a position to take over the responsibility of multiplying and storing their own planting material for future use.

A durable and convenient way to use cassava food is likely to increase the competitiveness of cassava with respect to cereals. In addition, emphasis on the improvement of existing rudimentary processing techniques would reduce the health hazards caused by insufficiently processed products. As noted in the report, cassava products are readily acceptable on the food markets, more so when their producer prices are more profitable.

From this background, it is very obvious that while the needs for root crop development are extensive, a project to meet all the requirements would be expensive and possibly unsustainable by Tanzania after the support grant has ceased. Therefore, recommendations put forward by the FAO missions (Wilson, 1994) and FAO, still hold. The recommendation is for a project that emphasizes the propagation of nucleus materials; processing and storage; impact assessment of improved cassava varieties and updating of the national cassava statistics; and an integrated approach of cassava production systems.

The project could be set for seven years for full realization of the achieved outputs per activity. Below is the outline of protocol for the proposed projects.


Cassava planting material propagation and distribution

Counterpart agency:Ministry of Agriculture and Cooperatives (Departments of Research and Training and Extension)
Objective:To multiply and distribute clean healthy initial stock of cassava planting material of elite varieties
Duration:Three years
ActivitiesTrain specialists in the techniques through study tours, in:
- service training short courses;
- establishing propagation nurseries;
- selecting suitable sites;
- establishing infrastructure and acquiring irrigation equipment;
- recruiting local staff;
- acquiring 7 tonne lorry and 4WD vehicles;
- propagating material of elite lines with best techniques available;
- distributing clean elite fines to farmers through extension.
Donor contribution:Personnel short-term consultancy on irrigation.
-International travel
Government contribution:Counterpart personnel
-Field staff, labour
Outputs:Trained specialists
-Propagation nurseries established
-Clean planting material distributed


Improved processing and storage techniques for cassava and extending the range and competitiveness of cassava based foods

Objectives:To introduce new processing techniques
To diversify the products of cassava with new technologies
To introduce new storing techniques
To commercialize cassava products.
Counterpart agencies:Ministry of Agriculture and Cooperatives (Department of Research and Training) and Tanzania Food and Nutrition Centre
Activities:Train specialists in processing techniques
-Establish infrastructure
-Recruit local staff
-Advertise and launch campaigns for processing and storage
-Demonstrate the techniques
-Disseminate the techniques through leaflets, etc.
-Seek commercial agents for cassava products
-Monitor sale and use of cassava products
-Encourage private entities to manufacture cassava products.
Duration:18 person-months
Donor contribution:Short-term consultancy on the training aspect
-Procurement and operational costs
Government contribution:Counterpart personnel
 Post-harvest team
Outputs:Increased opportunities for cassava production and use through introduction of new processing techniques
 New storing techniques
 New commercial cassava products


Institutional strengthening on cassava research and development

Objectives:To improve the capability of the research programme to generate extension messages capable of improving cassava production with special emphasis on:
 Germplasm, development
Soil fertility maintenance
IPM packages on pest and disease control
 To improve the general capability of the quarantine services to ensure the safe importation of cassava material. To acquire a capacity to receive and multiply in vitro cassava planting material

Counterpart agencies: Ministry of Agriculture and Cooperatives (Department of Research and Training and Tropical Products Research Institute and Plant Protection Division):

Duration:Seven years
Activities:Establish cassava breeding and agronomy trials
 Field experimentation
 Farmers field demonstrations and technology verification trials
 Train in plant quarantine methods and in handling in vitro material
 Rehabilitate the laboratory facilities for tissue culture
 Test and disseminate improved production technologies
Donor contribution:Short-term consultancy on plant quarantine
 Counterpart training in tissue culture and plant quarantine
 Laboratory and material
 International travel
Government contribution:Land, personnel
 Existing programmes
 Office accommodation
 Laboratory space materials
Output(s):Improved production packages of cassava identified and disseminated
 Improved plant protection services


Impact assessment of improved cassava varieties in cassava growing areas of Tanzania

Objectives:To assess the rate of adoption of improved cassava varieties and agronomic packages
 To assess the impact of improved cassava varieties in the production of cassava at farm level
 To identify the factors that determine the adoption of research packages by farmers
 To update the cassava production statistics at farm level for future follow-up
Counterpart agencies:Ministry of Agriculture and Cooperatives (Departments of Research and Training and Planning and Marketing Division) Tanzania Bureau of Statistics Department.
Duration:Eight person months
Activities:Design of the study
 Development and testing of the questionnaire
 Training of enumerators site selection
 Conducting the survey
 Data collection from key informants
 Data processing and report writing
 Feedback seminars to farmers and policy-makers.
Donor contribution:Short-term consultancy on designing and development of the questionnaire
 Financial support
Government contribution:Counterpart personnel
 Survey teams
 Data processing
 Preparing reports
Outputs:Number of improved varieties adopted
 Impact on production and potential role in household food security and cash income
 Future strategies to suit farmers' needs identified
 National statistics updated

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