Characterised existing sweetpotato seed system actors, identified efficient seed distribution channels and market preferred varieties in Bukombe and Butiama districts, Tanzania

Tanzania is a major sweetpotato producer in sub-Saharan Africa. The area under sweetpotato
has been rising steadily relative to main food staples. However, the yields have stagnated at
around 4 t/ha compared with the potential yield of above 20 t/ha, partly due to limited access
to quality seeds. Most farmers in SSA recycle seed from the previous crop or source from
neighbours. This increases the probability of accumulating viruses, which may reduce the
sweetpotato yield by over 50%.
Studies have shown that farmers are willing to pay a premium for quality seeds. Therefore,
an efficient seed distribution channel that ensures seeds move from the breeding stage to the
multiplication stage without any disconnections between the nodes can provide farmers with
better access to quality seed at an affordable price. However, there are disconnections in the
current seed distribution channels, particularly between the public and private sectors. In
addition, most farmers do not often replenish planting materials once they buy quality
planting materials.
There are hardly any exclusive seed multipliers in the seed value chain due to a lack of
understanding about potential business opportunities. Identifying a sustainable and
profitable business model for seed multipliers is important in ensuring that farmers are
constantly supplied with quality planting materials when they need them. This needs greater
efforts to demonstrate the benefits of using quality planting materials, establish delivery seed
distribution channels to reach a large number of end-users, and strengthen farmer seed
management capacities and farmer seed networks.
A study was conducted in Mara and Geita regions to identify market preferred and the main
sources of the sweetpotato roots. The survey on the root producers were carried to
understand the acquisition and provision of the market-preferred varieties and the
connections between the nodes in the existing seed distribution channels. The study also
conducted key informant interviews with other key stakeholders such as the public sector
(i.e., Tanzania Agricultural Research Institute-TARI). The team will propose a sustainable
business model that can link formal and informal seed sectors for consistent supply of quality
and market preferred planting materials to root producers.
The study utilized “the structure, conduct, and performance (SCP)” tool to establish
relationships in the sweetpotato seed market. The SCP paradigm postulates a causal
relationship where the structure influences the conduct, and in turn, the conduct influences
the performance. The structure refers to the type of market, pricing strategy, the degree of
concentration of buyers and sellers, the level of product differentiation, and condition of
entry in the market. The conduct is the behavior of buyers and sellers and how they react to
each other strategy. The performance of the seed market considers indicators such as profit
of the seed and root producers and seed security indicators. The study also mapped the
linkages of the existing nodes of sweetpotato seed channels by looking at the seed acquisition
and provision transactions.
A total of 45 traders participated in the survey in Bukombe, Butiama, Ilemela and
Nyamagana districts. Most of the traders were male, and the average age was between 37-
44 years in the four districts. Most traders are members of trader’s associations, some
traders were in cooperatives, and a few were in digital platforms. The traders benefited
from the association through access to credit, access to market information, facilitating joint
marketing, and saving cash.
The markets were mainly rural (Bukombe and Butiama) and urban markets (Ilemela and
Nyamagana). The type of traders in these markets were either wholesalers or middlemen
(aggregators), with most markets operating the whole day, where the contract between sellers
and buyers is largely oral. The high season when the supply of sweetpotato roots is high in the
market ran from February to June, while the low season runs from July to November.
Overall, Polista (62%), Mage (40%), and Ukimwi (28%) were the three most traded in the
market, but there were district differentials in the traded varieties. For instance, Ukerewe
(56%) was the most traded variety in Butiama. The common attributes liked about these
varieties include high dry matter, big root size, good taste for Polista, high dry matter, good
color and high market demand for Ukimwi, long shelf life, high market demand, and good
color of the flesh for Mage. The three most disliked attributes in Polista were late maturing,
short storage life, and susceptibility to pests and diseases. In Ukimwi susceptible to pests and
diseases, limited supply of planting material, and small size of the root. Low dry matter, late
maturing, and high-water content were the three most disliked attributes of Mage variety.
In the root and seed producers survey, a total of 110 households from the Bukombe and
Butiama district participated in the rapid seed system assessment survey after being
identified as a major source to sweetpotato markets in the region. The proportion of root
producers who also produced seeds was higher in Bukombe (72%) than Butiama (42%), where
the majority of the seed producers were not trained. Most producers produce seeds for their
own use. However, the neighbor farmers play a dominant role in both seed acquisition and
seed provision. The existing root buyers include wholesalers, commission agents/aggregators,
retailers, and NGOs. Most farmers sell the roots to wholesale traders, followed by commission
agents and retailers.
The median size for sweetpotato root plots was 0.8 hectares in both districts, while the
average size for sweetpotato seed plots was 0.2 hectares in Bukombe and 0.32 hectares in
Butiama. The average root yield was 2,461 kg/acre in Bukombe and 2060kg/acre in Butiama.
The average seed yield was 5,695kg/acre in Bukombe and 3,140 kg/acre in Butiama.
Overall, the three most preferred varieties are Polista, Ukimwi, and Mage, but varied with the
district. Polista variety was liked because of its high dry matter content, better taste, and high
market demand. The traits that farmers disliked include matures late, has low yield and is not
resistant to SPW. Ukimwi was preferred because it matures early, has high market demand,
high dry matter. The traits producers disliked were less resistant to SPVD, not stress-tolerant,
short shelf life, and limited access to planting material. The preferred attributes in Mage
include high market demand, good flesh color, early maturing, and high root yield. However,
the variety is late maturing, has low dry matter content, has a shorter shelf life, and less
resistant to stress (drought and poor soils).
About 90% of producers sell/share sweetpotato roots. The roots are mostly sold to wholesale
traders, followed by commission agents, retailers, and NGOs. The average quantity sold by
the respondents in the last year was about 8924 kg in Bukombe and 4850kg in Butiama. Only
26% and 53% of respondents sold seeds in Butiama and Bukombe, respectively. The most
common varieties provided were Ukimwi (33%), Pisi tatu (27%), Uso wa mchina (20%) in
Bukombe. Polista (57%) and Ukerewe (29%) were the most common varieties in Butiama.
Farmers predominantly sold to sweetpotato producers in both Butiama (86%) and Bukombe
(97%). Other seed buyers were international organizations, and local NGOs. Respondents sold
to producers mainly because they were friends and relatives without expectations but sold to
local NGOs, international organizations because they give higher prices.
About 47% in Bukombe and 28% Butiama acquired seed from elsewhere. Ukimwi was the
most dominant variety in Bukombe, while most respondents in Butiama received Polista and
Ukerewe. At least half of the respondents chose these varieties because they were market
preferred. The seeds were mainly sourced from sweetpotato producers because of close
relationships (relatives and friends).
TARI produced Kabode, Kakamega, NASPOT 12, and Mataya varieties through rapid
multiplication in screen houses and conventional methods in open field plots. The three most
preferred varieties were Kabode, NASPOT 12, and Mataya. All of them are early maturing,
high yielding, with better nutritional benefits. Kabode and NASPOT 12 are also tolerant to
SPVD and SPW. TARI has regular contact with about 20 decentralized vine multipliers and 30
farmers. In the last one year, TARI provided 5 types of varieties
The five types of varieties that TARI provided were Kabode, Kakamega, NASPOT 12, Mataya,
and Ejumula, where the seed class was basic. TARI provided a total of 1257 bundles to local
NGOs in February at TSH 2500 for each bundle of 100 cuttings of 30cm size.

Citation: Rajendran, S., Ochenje, I., Ogero, K., McEwan, M., Wanjohi, L., Mafuru, J., Mussa, H., and Motts, N. (2021). Characterised existing sweetpotato seed system actors, identified efficient seed distribution channels and market preferred varieties in Bukombe and Butiama districts, Tanzania (report). Lima, Peru: International Potato Center. 70 pp