Sweet potato (Ipomoea batatas( L.) Lam) is a major Root and tuber crops for direct human consumption in the world especially Africa, yet it is one of the least marketed. It is among the world’s most important, versatile, and under exploited food crops, with more than 133 million tonnes (FAOSTAT, 1997/1998; FAOSTAT, 2015) in annual production. Presently within the global market trend, sweet potato is ranked 27^th, 0.3% shares of world imports  and  also  ranked  117^th,  0.0%  shares  in  global exports market. China (67.1%) is the current leading producers of sweet potato followed by Nigeria (3.7%); but United States (1.4%) which is the 9^th producing countries controls the largest share in export (38.9%) market of sweet potato than China (6.5%) and Nigeria (0.0%) and United Kingdom as the top importers in the world (statistics of HS code 071420, 2016). Among the root and tuber crops, it is the only crop that has a positive per capita   annual   rate  of  increase  in  production  in   sub-Saharan Africa (Bashaasha and Mwanga, 1992).

Sweet potato is cultivated in all the 14 districts in Sierra Leone and the north is recorded as the highest producing region. Its contributes 2.9% towards the total national food production which indicates that, the number of households producing sweet potatoes is relatively lower than those producing cassava and rice in Sierra Leone. The sweet potato crop is used for both subsistence and commercialization purposes and hence 11% of agricultural household’s countrywide sold all their sweet potato crop, 62.8% sold part of their crop and 26.2% sold none at all locally (SSL, 2004). Marketing opportunities for sweet potato abound; demand for sweet potato roots and leaves, especially in the urban areas is large but the market is not adequately organized. The potential for the industrial use of sweet potatoes (especially high yielding improved varieties) exists but is currently not being exploited. Value-added activities are limited to preparing into other food forms. Preserving the fresh produce shelf-life remains a major challenge to farmers, traders and consumers across Sub-Sahara Africa. Traders often attempt to sell-off their sweet potato produce within 3-4 days upon arrival to avoid decay losses. The practice of disposing off the harvested produce results in seasonal glut; this leads to low prices which affect the economic returns to sweet potato value chain actors. Its bulkiness and perishability with a low shelf life after harvesting limit its economic viability. About 22% of agricultural households produce sweet potato (USAID-BEST 2009). Similar to the case of cassava, post-harvest losses are high. Nonetheless, national production is considered to exceed the national requirement (WFP, 2013). Local traditional sweet potato varieties are grown in Sierra Leone, but vitamin-fortified varieties are not present

Notwithstanding the potential of sweet potato in helping to meet Sierra Leoneans food needs and reduce poverty levels through income generation, detailed information on the sweet potato demand relations is not available to enable the farmers, wholesalers and retailers plan their sweet potato production and marketing activities. The lack of proper planning as a result of insufficient market information is partly evidenced by the high poverty levels in the major sweet potato growing regions. According to Arene (1999), efficiency is used to evaluate marketing performance. Performance can be achieved using the following approaches-marketing margin, net-returns and marketing efficiency ratios. Therefore, there is the need to assess the performance of the market to determine the efficiency of the sweet potato marketing system in Sierra Leone. Hence, the study aims at identifying the socio-economic characteristics of sweet potato traders, assessing the general sweet potato trading activities, identifying the various sweet potato roots distributional channels, determining the marketing margins and net profits and identifying the drivers and barriers of sweet potato trading in Sierra Leone.

Sweet potato production has been found  to  be profitable (Ogbonna et al., 2007). Considering its profitability and the increases in sweet potato production after the war and the dreadful Ebola virus and the inability of the increases to be reflected in the marketing system as stated by Low et al. (2009), the attributes towards the inefficiencies in the marketing system of sweet potatoes are inadequacies of storage, processing, transportation and perishability. This is because, the production data of sweet potato from 2000 to 2016 show that, the sweet potato production level has been increasing in Sierra Leone but the increase has not been able to trigger the export of any of its sweet potato products in the international market and therefore ranked 1577^th, 0.0% shares of Sierra Leone's exports. The question to be addressed is how efficient is the sweet potato marketing system? Or how well is the sweet potato marketing system performing?  Sweet potatoes - yield of Sierra Leone increased from 30,769 hg/ha in 1969 to 74,149 hg/ha in 2018 growing at an average annual rate of 3.10%. This study reports the findings of the profitability and channels of distribution of sweet potato production in the study area. The specific objectives of this study are to:

(i) Determine the socio-economic characteristics of the sweet potato growers in Sierra Leone

(ii) Identify the channels of distribution of sweet potato in Sierra Leone

(iii) Analyse the profitability of sweet potato and

(iv) Identify the drivers and barriers faced by sweet potato growers in Sierra Leone.

 

Study locations

The market study was conducted within the five major districts in Sierra Leone which is a Representative of all the regions such as Western (Western Area), North (Bombali), South (Moyamba and Bo) and East (Kenema). The criterion for selecting those districts was based on Njala Agricultural Research Centre (NARC) Research operational zones especially on the Orange Flesh Sweet Potato (OFSP). Due consideration was also given to the production and marketing level of sweet potato tubers within each region. From Figure 1, the red dots within each district indicate the locations where the market data were collected in Sierra Leone.

 

 

Sampling frame, selection procedure and size

The sampling frame consists of sweet potato marketers. The frame comprises key marketers within the sweet potato marketing systems in Sierra Leone. Those traders were selected using a multi-stage sampling procedure. The first stage involved the selection of districts using purposive sampling technique which is supported by Kothari (2004). The second stage involved the selection of markets within each district through simple random sampling and the final selection stage (respondent’s selection) was through snowballing sampling technique. Traders were selected by scientists with collaboration with heads of markets (Chairperson)  who had ideas of traders of sweet potatoes and their locations. This

snowballing sampling technique is often used in hidden populations which are difficult for scientist to access. Sweet potato traders in Sierra Leone were scarce and scattered within the various markets hence majority of those traders who were operating during the data collection timeframe were included in the study. A total of 150 sweet potato traders (30 respondents per district) were selected  for the interview (Table 1).

 

 

Data collection

Both primary and secondary data were  collected  for  this  study  to obtain sufficient and realistic information from traders. Primary data involve both qualitative and quantitative collected through individual interviews and personal observation, while secondary data were collected from scientific reports and statistical abstracts used as additional sources of data. The individual interviews were conducted with android devices programme with the Census and Survey Processing System (CSPro 6.3) software package. The process is called electronic data capture. The types of data collected include socio-economic characteristics of traders, general trading activities, market distributional channels, profitability coefficients and drivers and barriers of sweet potato trading.

Data analysis and presentation

Data collected from the individual marketers’ interview were uploaded and exported to various statistical packages: Statistical Analysis Systems (SAS 9.3), Microsoft Excel 2010 and Statistical Package for the Social Sciences (IBM SPSS Statistics 21) for analysis using different analytical tools. Descriptive statistics (mean, frequency percentages and diagrams) was used to analyze the profile of sweet potato traders, general trading activities, market distributional channels, drivers and barriers of sweet potato trading in the study locations. The study also used simple budgeting techniques to determine the market margin (s) and the benefit-cost ratio (BCR) for the various districts. The market margin or the farm-to-retail price spread is the difference between the farm value and the retail price. It represents payments for all assembling, processing, transporting, and retailing charges added to farm products. Marketing margin was computed using Mendoza (1995)’s formula and marketing costs/net returns according to Scarborogh and Kydd (1992)’s formula.

Where:

П = Net Profit (s), GP = Gross Profit, TRS = Total revenue from sales per bag of sweet potato, TTC = Total transaction costs (includes both the cost of the product and the market transaction cost), CPP = Cost price of the product per bag of sweet potato, GMM = Gross marketing margins per bag of sweet potato, NMM = Net marketing margins per bag of sweet potato, BCR = Benefit-cost ratio per bag of sweet potato.

 

 

 

 

Socio-economic characteristics of sweet potato traders

Table 2 shows the gender and marital status of sweet potato traders in the study area. The result in the study area shows that, 94.7% of the traders interviewed were females while 5.3% were males. This implies that sweet potato trading is dominated by females because; the dominance cuts across all districts with Bombali having 100% females. The district with more men in sweet potato trading is Moyamba (13.3%) because most producers see the crop as a cash crop and the production level is very high.

 

 

Majority of the sweet potato traders in the study area were married (70.0%), followed by single (18.7%), widow (9.3%) and separated (2.0%). This shows that, sweet potato marketing is dominated by married traders and this dominance goes across all districts within the study locations which is a very good indication of sober market. The district with more married couples among the districts is Moyamba (80.0%), with more singles is Bo (46.7%), more widow and divorced traders can be found in Kenema (20.0% and 6.7%) respectively) (Table 2).

Majority of the traders interviewed at least have formal (54.2%) and non-formal (45.8%) education but bulk of them stop at primary level (27.5%) which is still not sufficient to be literate (Figure 2). Majority of traders that did not attend any formal school can be found in Kenema (63.0%), with primary education in Wester Area (43.0%), junior secondary school in Bo, Bombali and Kenema (each 20%) and at least attempt senior secondary  school in Bo (17.0%) district. These results showed that, majority of the respondents are not literate enough to effectively keep records of their sweet potato marketing business transactions.

 

 

General sweet potato trading activities

The majority (96.7%) of the traders interviewed  were  the owners of the sweet potato business and 56.0% of them do sweet potato trading as their main economic activity. Own/self-financing (45.3%), loan (30.7%), other sources (16.0%) and remittances (8.0%) were the initial source of capital for their sweet potato trading activities (Figure 3). The bulk of the traders contacted are sweet potato roots trader (98.0%) and the remaining 2.0% may either sell the leaves or other sweet potato products such as sweet potato chips, pourage etc. (Figure 4).

 

 

 

Sweet potato roots distributional channels in Sierra Leone

The marketing channel for sweet potato is shown in Figure 5. The distribution or marketing of sweet potato operates through the activities of many actors in both rural and urban markets. The results of the study showed that, the sweet potato marketing channels comprise two key channels such as the single and the multi-stage channel systems. 86.7% of respondents are retailers; 11.3% are wholesalers and the remaining 2.0% for other traders (Middlemen/SMEs processors). 52.2% of traders buy directly from farmers, 29.0% from wholesalers/ aggregators, 9.4% produce the sweet potato sold (own farm) and 9.4% from other sources. The traders engaged in sweet potato trading sell their products in daily village/town markets followed by periodic markets, roadside markets, own farm/gardens and street markets. The major share of the sweet potato business in Sierra Leone is being controlled by retailers (88.4%) and wholesaler (10.9%) followed by other market intermediaries, with 0.7%. It is evident from the study that retailers and wholesalers are important players in the sweet potato marketing chain.

 

 

Marketing margins and net profits of sweet potato traders

Table 3 shows the buying cost, transaction cost and the total revenue generated from the sale of sweet potato roots for the various districts and the study area. The total average revenue from the selling of 50 kg bag of sweet potato roots in the study area was Le 71,198. The highest revenue generated from the sales of 1 bag of sweet potato roots was in the Western area (Le 81,667), followed by Kenema (76,310), Moyamba (74,000), Bo (68,900) and Bombali (55,283). The average total cost in sweet potato root trading in the study area was Le 59,152.

 

 

The least cost for buying 50 kg bag and other transaction cost was in Bombali (Le 40,567) followed by Kenema (Le 62,179), Bo (Le 62,678), Moyamba (Le 62,767) and Western Area (Le 67,419). Since, the least transaction costs and revenue were incurred in Bombali, therefore, the highest net profit from the sale of 1 kg of sweet potato roots was obtained from that district. The higher profit from sweet potato root trading in Bombali may be due to the fact that traders got lower prices due to the large scale of production of sweet potato roots. The next district with highest net profit was Western area (Le 14,248) followed by Kenema (Le 14,131), Moyamba (Le 11,233) and Bo (Le 6,222). The average net profit in the study area was Le 12,046 (Table 3). The benefit-cost ratio of sweet potato root trading in each of the districts and overall was  greater  than  one,  which  indicates  that sweet potato roots trading business is profitable. That is, for every Le 1.00 invested in sweet potato root trading; there is a gain of Le 0.36 in Bombali, Le0.23 in Kenema, Le 0.21 in the Western Area, Le 0.18 in Moyamba, Le 0.10 in Bo district and Le 0.20 in the study area. This clearly shows that sweet potato root trading is a profitable business venture in Sierra Leone (Table 3).

Drivers and barriers of sweet potato trading in Sierra Leone

Table 4 illustrates a SWOT analysis of the factors considered by traders which influence sweet potato root trading. The strengths and weaknesses are characteristics intrinsic to the trader, whilst opportunities and threats relate to external factors that condition the balance between the strengths and weaknesses.

 

 

Drivers (strengths and opportunities)

From Table 4, the three major strengths of sweet potato root traders computed were easy access to smaller market (32.8%) facilities, having high business techniques  (23.8%)  and  storage  facilities (23.2%).  The three major opportunities for sweet potato root trading were the availability of sweet potato roots (28.8%), easy access to markets for buying sweet potato roots (24.4%) and high demand for sweet potato roots (19.4%).

Barriers (Weaknesses and threats)

The three major weaknesses to sweet potato root trading were lack of finance and credit facilities (44.6%), low availability of sweet potato roots during certain period of the year (26.8%) and lack of big market facilities (16.7%). The three major threats to sweet potato root trading were no external funding for sweet potato trading activities (27.0%), high transportation costs (22.0%) and high taxation and market dues (18.1%) (Table 4).

 

 

 

 

 

 

 

The results of educational status showed that, majority (54.2%) of the sweet potato traders at least has some form of formal education but the level of formal education is very low to effectively help them take and keep records of their sweet potato marketing transactions. This is because, bulk (27.5%) of the traders stop at early elementary school (Class 1 to 6). This result is supported by International Growth Centre policy brief (2018) which indicates that, the educational status of traders in Sierra Leone crossing the official borders, more than half of exporters (54%) and importers (56%) completed primary education. Natson et al. (2017) reported the same educational status but holds this view; by implication, most of the traders at least had the required skill to keep record of activities and to tap into modern trends and existing market prices to make reasonable profit. This result is also in agreement with the results of Ocholiali et al. (2017) (Figure 2).

From Figures 3 and 4, majority (96.7%) of the sweet potato traders interviewed were the owners of the business. Sweet potato trading is the main economic activity (56.0%); their initial source of capital is mostly from own source or family funding (45.3%) and from informal loan (30.7%) and almost 98.0% of respondents interviewed were sweet potato root traders.  Therefore, the ownership of the business, sweet potato trading as their main economic activity and the initial source of capital coming from them show how committed are they during their sweet potato trading activity. The results also revealed the nature of sweet potato trading as a petty trading that does not demand huge initial capital for start-up. This finding is in consonance with earlier findings by Ocholiali et al. (2017) and Abah et al. (2015). Ocholiali et al. (2017) found that, majority of sweet potato traders in Benue State, Nigeria depend on personal or family funding for their business.

From Figure 5, the marketing channel shows the different (alternate) routes through which sweet potato passes from the producer to the final consumer. The sweet potato marketing channels in the study area are made up of single and multi-stage channels. The single channel consists of the flow of sweet potato products from the producer to the consumer directly without any intermediary. The multi-stage channel system consists of middle-men (intermediaries) before it gets to the final consumer. The multi-stage channel system is made up of the sweet potato farmers and different categories of traders (wholesalers, retailers and aggregators). All these categories of intermediaries are in mutual agreement because the producer can decide to sell directly to the wholesalers and retailer (Tewe et al., 2003). In Sierra Leone, it is difficult to ascertain who is a wholesaler or retailer in the market. This is because some distributors are engaged in both wholesaling and retailing activities at the same time and place. However, categorization of wholesalers and retailers is based on the quantity of roots sold and more pronounced activity a wholesaler or retailer does. The implication of multi-stage system is that, as commodities pass through many intermediaries, it tends to increase marketing costs which will be borne by the consumers.

The results from Table 3 show that, the marketing margin is very high (Le 24,816) per selling of 50 kg bag of sweet potato with a net profit (Le 12,046), Gross marketing margin (34.85), Net marketing margin (16.92) and a benefit cost ratio of greater than 1 (BCR>1). This clearly reveals how lucrative and profitable sweet potato trading is in Sierra Leone.  Ocholiali et al. (2017) and Natson et al. (2017)’s findings support the above statement by saying, sweet potato trading is a profitable and a lucrative business venture that is worth investing in.

From Table 4, combining those strengths and opportunities, the three major drivers to sweet potato root trading were: traders having access to market and storage facilities for sweet potato root trading, sweet potato roots are always available in the markets and high demand for sweet potato roots in the market. Combining those weakness and opportunities, the three major barriers to sweet potato root trading were: lack of financial support to trader for sweet potato root trading, low availability of sweet potato roots during certain periods of the year and high transportation costs from buying locations to the market. Ocholiali et al. (2017), Achike and Anzaku (2010) and Fawole (2007) also mentioned lack of financial support or low initial investment, high transportation cost as key constraint towards marketing of agricultural produce especially for roots and tubers.

 

Sweet potato root is the major product of sweet potato sold in the various markets (on-farm, daily village or town, road side and periodic) in Sierra Leone. The trade is more dominated by women and is very profitable. The profitability is with regards to income levels generated in marketing. Sweet potato trading investment has a net positive return. After the calculation of the cost benefits analysis, the benefit-cost ratio of sweet potato root trading in each of the districts was greater than one, which indicates that sweet potato roots trading business is profitable. The revenue generated in the sale of one bag of sweet potato is high. That is, an average of 20% profit is realised from the 1 bag (50 kg) that is bought and sold and the highest profit was realised in Bombali District.

The sweet potato marketing channels in Sierra Leone are made up of single and multi-stage channels. The single channel consists of the flow of sweet potato products from the producer to the consumer directly without any intermediary. The multi-stage channel system consists  of  middle  men  or intermediaries (Wholesalers, retailers and other agents) before it get to the final consumer. The major drivers to sweet potato root trading are traders having access to market and storage facilities for sweet potato root trading, sweet potato roots are always available in the small markets and the high demand for sweet potato roots in the market. The major barriers are lack of financial support to trader for sweet potato root trading, low availability of sweet potato roots during certain periods of the year and the high transportation costs from buying locations to the market. The study also revealed considerable numbers of factors that militate against an efficient marketing system of the crop. Based on the findings of this study, it is recommended that:

(i) Sweet potato marketers should form groups for them to build a unified front for higher bargaining power in price and also to obtain loans from financial institutions easily to increase their initial capital base. Loans will be easily acquired from financial institutions without bottlenecks in form of groups than individually. Innovation Platforms (IP) involving all actors in the sweet potato value chain should be encouraged to allow actors take advantage of various opportunities in the areas of easy access to inputs at lower cost and guaranteed access to financial support.

(ii) To overcome those barriers towards sweet potato trading, government should ensure a reliable pricing and market policy (government regulates the commodity prices directly depending on world market conditions and welfare of the traders) and also enact policies that would enable traders to easily access credit facilities for trading of agricultural commodities, support farmers with agro inputs, equipment and machinery to increase sweet potato production throughout the year and improve on the road network in order to facilitate easy and affordable means transportation of agricultural produce from the farm to market.

 

The authors have not declared any conflict of interests.

 

The research is supported by Helen Keller International and funded by Irish Aid. Thanks to Sierra Leone Agricultural Research Institute (SLARI) authorities for their technical advised; Dr. Abdul Rahman Conteh (Acting Director- Njala Agricultural Research Centre) and Mr. Moses Joseph Tucker (OFSP former Project Coordinator) for their inputs in this study; as well as the present SLARI Acting Director General Dr. Matthew L.S. Gboku for his supervision and support.