The United Republic of Tanzania

Tanzania Agricultural Research Institute

TARI Ukiriguru

TARI Ukiriguru has the mandate to do research in United Republic of Tanzania the following crops:-


Cotton is an annual crop belongs to the family Malvaceae, order Malvales of the genus Gossypium (Gh, AD1 genome). The genus Gossypium included about 50 species of which 45 are diploid (2n = 2x = 26) and 5 are allotetraploid (2n = 4x= 52). Out of these only four species are cultivated, two old world species (G. arboretum L. and G. herbaceum L.) and two New World species (G. hirsutum L. and G. barbadense L.) (Percival et al., 1999; Ulloa et al., 2005; 2006) with the former being common to most countries including Tanzania (Iqbal et al., 2001)

Cotton is a lifeline of about 40% of the entire population of about 55 million. On average 400,000 hectares are sown to cotton by approximately 350,000 to 500,000 smallholder farmers and its contribution to the national export earnings is about US$ 92 million, which is about15% of the total national exchange earnings (TCB, 2010). Cotton production in Tanzania is limited by biotic and abiotic factors (Lukonge et al., 2007). .The cotton crop is 100% rain-fed yielding an average 300 kilograms of seed-cotton per acre.

Cotton is grown in 42 districts of 13 regions out of 127 districts and 21 regions, respectively. During the 2005/2006 financial year cotton was the first forex earner among agricultural commodities. Sustainable cotton farming has therefore, the potential to significantly contribute to poverty eradication and socio-economic development in Tanzania. Cotton is an annual crop that requires a substantial investment in pesticides and fertilizer to achieve profitable yields. The major constraints that face the cotton farmers in production include soil fertility exhaustion, insect’s pest like Jassids and thrips infestation, weeds and recently the diseases like fusarium wilt. The cost of inputs is often beyond the purchasing power of the average cotton smallholder; as a result Tanzanian cotton yields on average are less than one third of the globe average.

TARI Ukiriguru centre have a mandate to do research to develop varieties with characteristics by addressing the needs of four stakeholders farmers, ginners, spinners and cotton seed oil industries, Thus the developed variety must have the following characteristics: - High yielding (seed cotton and fibre), High ginning outturn (GOT) equal or above 40 %, Resistant/Tolerant to insect pests (Jassids, Thrips, Lygus and worms as well as diseases (Fusarium wilt, Bacterial Blight and Alternaria), Good fibre qualities needed by the World cotton industry further more we evaluates genotype for adaptability of the growing areas


Cassava (Manihot esculenta Crantz), originally from South America, is the fourth most important source of dietary energy in the developing world after the cereal’s wheat, maize, and rice, feeding an estimated 800 million people worldwide (FAO, 2013). Its ability to stay in the ground for up to three years makes it an excellent food security crop (Nweke et al., 2002). Other desirable attributes include drought tolerance, provision of reasonable yields in poor soils and weed suppression when the canopy is fully developed. Cassava is the second most important source of starch in the world (FAO, 2013). The high starch content (20–40%) makes cassava a desirable energy source for both human and industrial usage. Moreover, cassava has been projected to be highly resilient to future climatic changes compared with other major staples such as maize, sorghum and millet, which could provide Africa with options for adaptation (Jarvis et al., 2012). For these reasons, cassava has been recognized as a powerful tool in fighting/alleviating poverty both through food security and commercialization (FAO, 2013).

In Tanzania, cassava is one of the major food and cash crops. It ranks second to maize in most parts of the country as a source of energy contributing approximately19-21% of the total energy requirement (FAO, 2004). It has been considered as a food security crops over decades (Jarvis et al., 2012) but it is increasingly becoming a commercial crop because the potential for sale of fresh roots and leaves, processed products and planting materials is increasing. In Tanzania, out of the 7 main agro-ecologies, cassava is grown in mainly four, namely: a) lowland warm sub-humid (includes all the coastal areas), b) Mid-altitude semi-arid (includes central --- Dodoma, Singida, parts of Manyara), (c) mid-altitude sub-humid (Mwanza, Kigoma; Mara; Kagera, Kigoma. The crop is increasingly being recognized as a raw material for industrialization in starch, high quality cassava flour, dried chips for starch and Nudo industries, breweries among others.

The average cassava production in Tanzania is about 5.5 t/ha lower than the African average production of 8.4 t/ha (FAOSTAT, 2016). This is mainly caused by susceptibility of commonly growing farmer-preferred varieties to major diseases including cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Tanzania is a country where Cassava Brown Streak Disease (CBSD) was first reported in 1930’s (Storey, 1936) and has since expanded territory to affect cassava production in the entire country and beyond (Ntawuruhunga and Legg, 2007). Resistance Breeding strategies are being taken in Tanzania to combine resistance to CMD and CBSD in order to come up with varieties that have due resistance to both viral diseases.

In Tanzania the mandate to generate new cassava varieties that are resistant to important pests and diseases, high dry matter yield per unit area, good root characteristics and acceptability by consumers and processors is vested into Root and Tuber Crops Research Program under Tanzania Agricultural Research Institute (TARI). Research on tuber and root crops are coordinated countrywide from TARI Ukiriguru. In November 2019 Tanzania Agricultural Research Institute (TARI) officially released nine varieties with dual resistance and/or tolerance to CMD and CBSD with support from BEST CASSAVA and NEXTGEN CASSAVA projects.


Sweet potato (Ipomoea batata) is one of the most important root crops ranks the third after cassava and round potato. Tanzania is the fourth producer worldwide and third after Malawi and Nigeria in Africa with total annual production of 3,834,779 tonnes (FAOstat 2018). The crop is grown at varied altitude on all kind of soil and in areas where rainfall vary from 800 to 1400mm per year (Low et al. 2009, Clark et al. 2012) and thus it is virtually grown in all regions of Tanzania. However, high production is on the Lake, Lake zone produces about 25% of sweet potato produced in the country, other regions include Eastern and Southern zone and Zanzibar. Its adaptation to marginal land makes the crop affordable for most small scales farmers in Africa, requiring low input and labour.

Nutritionally I. batata  are rich in protein, starch, vitamin A, B, B6, C, mineral salts and fiber (Woolfe 1992). The most important, orange fleshed sweet potato are rich in beta carotenes, precursor of vitamin A important dietary component to children and pregnant woman (Chassy et al. 2008, Rose and Vasanthakaalam 2011). Sweet potato plasticity to environment stresses and high yield potential make the best for food and nutrition security. Currently, the crop is commercially grown and shipped to various urban areas including Mwanza, Dodoma, Morogoro and Dar es Salaam.