Performance of various marketing channels for sweet potato value added products

Transcription

1 Journal of Agricultural Economics and Development Vol. 2(2), pp , February 2013 Available online at ISSN Academe Research Journals Full Length Research Paper Performance of various marketing channels for sweet potato value added products Joel. J. Mmasa 1 *, Elibariki. E. Msuya 2 and Melchior Mlambiti 3 1 School of Economics and Business Studies, Department of Economics of University of Dodoma, P.O. Box 259, Dodoma, Tanzania. 2 Department of Agricultural Economics and Agribusiness, Sokoine University of Agriculture, P.O. Box 3007, Chuo Kikuu, Morogoro, Tanzania. 3 Department of Economics, Faculty of Social Science and Communication, St. Augustine University of Tanzania, P.O. Box 307, Mwanza, Tanzania. Accepted 29 January, 2013 The objective of this study was to assess the performance of various marketing channels for sweet potato value added products. The study used cross sectional design. It used individual interviews, focused group discussions; review of relevant practical documents and discussions with key informants. Data collected were summarized using Statistical Package of Social Science (SPSS) and Excel. Moreover the study adopted Structure- Conduct- Performance (S-C-P) model to analyze the performance of sweet potato value added products marketing system. Furthermore, the study employed gross margin analysis to measure profitability of various market channels. Regarding sweet potato prices, it was found to vary from one node to another. The analysis revealed that there is no market transparency in the sweet potatoes value added products marketing system due to poor coordination on prices information, grades and quality and standard weights of the product in question. Furthermore, bulkiness and perishability affected post-harvest system of the products which acts as barriers. Other serious challenges facing the subsector were lack of improved seeds (33.1%), low capital (26.8%), unpredictable weather (20.6%) and pests attack (13.9%). The sub-sector seems not to perform efficiently and hence there is poor economic performance due to poor production, lack of market information, low prices, and poor quality of both the sector and the product. Key words: Sweet potato, structure-conduct-performance, value added products, consumption, efficiency. INTRODUCTION Background information This paper analyses the performance of various marketing channels for sweet potato value added products in Tanzania. Its approach looks at various levels involved in the sub-sector from input supply, production by smallholder, farmers, processing, wholesale business, retail business and transportation that cut across the value chains levels. Sweet potato production in Tanzania Tanzania produced a total of 1,322,000 MT of sweet potatoes in 2007 (FAO, 2007). In Tanzania, sweet potato (Ipomoea batatas) is grown mainly for survival, though in some regions it is the primary staple crop (Smith, 2004). Sweet potato in Tanzania ranks twelfth by value and sixth by quantity (FAO, 2007). The crop provides employment and it is important in sustaining food security and livelihood for the rural poor. Sweet potato in Tanzania is grown as a subsistence crop for food security and as a cash crop (URT, 2007). The average yield of sweet potatoes in Tanzania is 6 metric tons per hectare on dry weight basis, however the low yield in Tanzania is caused by many factors including susceptibility to pests and diseases, declining soil fertility, moisture stress, low level of crop husbandry and management, and poor accessibility to markets (URT, 2007). Moreover, according to Statistics Unit, Ministry of Agriculture, Food Security and Cooperatives (2007/2008), the data *Corresponding author. joel_mmasa@yahoo.co.uk.

2 Mmasa et al. 066 Figure 1. Graph data obtained from the FAOSTAT database produced by the Food and Agriculture Organization of the United Nations (FAO). Source: FAO (2003). revealed that in 2004/2005, a total of 576,000 ha were cultivated, production were 2,424,000 tons and yield were 4.21 tons/ha (Table 11). On the other hand, export quantity of sweet potatoes in United Republic of Tanzania ( ) was shown in the table and graph data (Figure 1) obtained from the FAOSTAT database produced by the Food and Agriculture Organization of the United Nations (FAO). Tanzania exported sweet potato that amounted to 9, 2 and 21 tons in 1974, 1997 and 2003 year, respectively. However, no official data were obtained for other years. According to National Sample Census of Ministry of Agriculture (2002/2003), it was revealed that Shinyanga is the leading region due to the fact that it cultivated a total of 253,000 and 210,000 ha in 2003/2004 and 2004/2005 seasons respectively; Kigoma region followed after cultivating a total of 207,000 and 238,000 ha in 2003/2004 and 2004/2005 seasons respectively; Kagera region cultivated 202,000 and 193,000 ha in 2003/2004 and 2004/2005 seasons respectively; Rukwa region cultivated a total of 187,000 and 145,000 ha in 2003/2004 and 2004/2005 seasons respectively; and Mwanza region cultivated 145,000 and 132,000 in 2003/2004 and 2004/2005 seasons respectively. However, the least cultivating regions were Mtwara which cultivated 230 and 40 ha; Kilimanjaro cultivated 5060 and 270 ha and Lindi cultivated 510 and 300 ha in 2003/2004 and 2004/2005 season respectively. Moreover, the national data obtained revealed that a total of 1,414,000 ha were cultivated in Tanzania mainland. Sweet potatoes play a big role in various economies and they act as a staple food crop in many countries. In US Mississippi, sweet potatoes contribute $19 million to the state s economy (NCSPC, 2008), while in Zimbabwe, the net economic return for sweet potatoes was Z$3 605,000 (US$36.05) per hectare (Smith, 2004). Sweet potato is grown throughout the world. However, only about one percent of its production enters into world trade with Canada, the United Kingdom, France and the Netherlands being the major importing countries. Furthermore, the United States of America (USA) is the leading sweet potato earner with a total value of more than US$37 million followed by France and Israel (FAO, 2010). Surprisingly, Tanzania earns about one million US dollar from sales of sweet potatoes (FAO, 2004). The market for sweet potatoes products in international trade 1 for Tanzania products is in prospects, but we need to start in East African Community Countries before going to higher market. Conversely, this study s data showed that USA is the largest exporter of sweet potato accounting for 35% of world trade (41,000 MT), followed by France with capacity of exporting 16,000 MT (13%), Israel with capacity of exporting 12,000 MT (12%), Netherlands (9%), Indonesia (7%) and China (6%) (FAO, 2010) (Figure 2). Most of the products are used for table consumption with a small percentage going into industry uses and animal feed. However, no data was obtained for United Republic of Tanzania on export of sweet potato value added products. It should be taken into cognizance that local suppliers of agricultural export commodities are not (yet) sufficiently organized to negotiate with international traders. As a result of the reforms, farmers are forced to behave more as an entrepreneur in the chain as they receive little support from the government. Nevertheless, initiatives like Agricultural Sector Development Plan 1 Is the exchange of capital, goods, and services across international borders or territories. In most countries, such trade represents a significant share of Gross Domestic Product (GDP).

3 J. Agric. Econ. Dev. 067 Figure 2. Sweet potato export value in the world. Sources: FAOSTAT, (2010). (ASDP) (URT, 2003b), Kilimo Kwanza and currently National program known as Comprehensive Africa Agriculture Development Plan (CAADP) under Tanzania Agriculture and Food Security Investment Plan (TAFSIP) has objective to combat the problem of food insufficiency in African countries. This program/strategies promised to assist small scale farmers. There is change in agricultural trade system. The shifts in governance 2 have resulted in a redistribution of power and in a redistribution of gains from trade. As a result of reforms also, the social and institutional context in which small-scale producers of agricultural export commodities in developing countries operate has changed. Shifts in local and global governance structures and shifts in social and institutional context cannot be regarded as independent processes, as they interact with each other. The way they interact is likely to influence the direction upgrading takes in a liberalized economy. Porter (1990) designed the analysis to examine organizational production and support processes and their contributions towards developing greater competitive advantage. He argued that competitive advantage could not be understood simply by looking at a firm as a whole. It stemmed from the many discreet activities a firm performs in designing, producing, marketing, delivering, and supporting its product. 2 Meaning interaction between firms along the value chain exhibits some reflections of the organization rather than being simply random Meanwhile, International Trade Center (ITC) (2003) defined value chain organization and described the institutional set up of the marketing agents in the value chain. Moreover, it examines the relationship between actors along the value chain and how the trade is conducted. The value chain organization described the marketing channels together with the flows of goods and services in the chain. Karel et al. (2004) described value chain coordination as it deals with organization coordination between functions and activities in the supply chain (for example, customer orientation, competitor orientation, logistic management, operation management and supply management). Coordination is considered to be one of the crucial components in an organization s effort to achieve efficient and effective value chain management practices. Likewise, sweet potatoes value chain organization and coordination in Tanzania is weak. Structure-Conduct-Performance (S-C-P) model Agricultural marketing has been defined in various ways by different authors depending on the schools of thought. For the purpose of this study, the definition by Gittinger (1982) has been adopted. Gittinger (1982) defined agricultural marketing as the point of initial agricultural production until the same goods are in the hands of ultimate consumer. By this definition, it means the performance of marketing system will depend very much on the efficiency by which the marketing functions are

4 Mmasa et al. 068 carried. Some theoretical framework to guide tools used in studying marketing efficiency have been given by Silomba (2000). These are the Internal Productive Efficiency (IPE) of marketing enterprises, the Structure- Conduct-Performance (S-C-P) model and the Food System Framework (Ashimogo, 2001). The first one is a measure of the firm level s economic efficiency which is a combination of technical and operational efficiency. It is a good theoretical framework for measuring costs, and analyzing the efficiency of individual firms. Under this school, the method of descriptive analysis of accounting data is commonly used. Secondly, the Structure-Conduct-Performance (S-C-P) model emphasizes on the relationships between functionally similar firms and their market behavior as a group that is given certain basic conditions. The performance of particular industries depends on the conduct of its sellers and buyers which in turn is strongly influenced by structure of relevant market. The model is not the internal organization of firms. Lastly, the work by Shaffer (1983) emphasizes that the Food Systems Framework emerged from the concern that the Internal Productive Efficiency model and S-C-P model have horizontal relationships between firms in assessing market performance. Furthermore, it fails to identify binding constraints in the system, and opportunities for enhancing its productivity and performance. As a result, the Food Systems Framework combines elements of both the previous tools. It looks at the constraints on and opportunities for markets to contribute to improved economic performance (Scarborough and Kydd, 1992). Such constraints and opportunities are defined either through interviews with the market participants or through classical market analysis tools. METHODOLOGY This study adopted Structure-Conduct-Performance (S- C-P) model to study marketing performance. Researchers analyzed the performance of sweet potato processed products market, which is referred to as the impact of structure and conduct. The variable envisaged for measuring performance are prices (at different market levels), costs and volume of outputs. Under the Structure- Conduct-Performance (S-C-P) model framework, the researchers drafted useful questions regarding the market structure, market conduct and performance of the processed sweet potato products in the markets (Silomba, 2000). Attributes of the industry 3 structure define the range of options and constraints a firm has to face. In highly competitive industries, firms have a very limited motion 3 Refers to the production of an economic good or service within an economy space as they are only left with a very few options with too many constraints when compared to the options. In such setting, both firm s conduct and long term performance are determined by the industry structure making (in general) firms that are only able to gain competitiveness (not competitive advantage). On the other hand, in less competitive industries, firms have the liberty of large ranges of conduct options and fewer constraints, enabling capable firms to gain competitive advantages. However, even at this type of setting, the industry structure can impact on firms critically such as deciding how long a firm can maintain its competitive advantage. Ethical contemplation In this work, the issue of confidentiality was taken into consideration at all times in such a way that unauthorized persons were not in position to have access to the data collected and the identity of the respondents remained known only to the researcher; this was done in effort of protecting the subjects. The issuer of voluntariness was also observed as respondents participated in the research voluntarily. It should be noted that no one was forced into participation. Data quality Reliability The consistency with which repeated measures produce the same results across time and across observers is referred to as reliability (Patton, 2000). To ensure reliability, this study employed three methods of data collection namely questionnaires, documentary reviews and interviews. Validity Babie (1992) and Bailey (1994) defined the term validity to mean the extent to which the concept one wishes to measure is actually being measured by a particular scale or index, that is, the extent to which an account accurately represents the social phenomena to which it refers. To ensure validity of measures, the data were gathered from various categories of respondents, including producers, processors, traders and consumers of various characteristics. Moreover, data were also collected from Shinyanga and Mwanza regions and District agricultural offices, Sokoine National Agricultural Library (SNAL), Tanzania Bureau of Statistics (TBS), Dar-Es-Salaam University library and other sources relevant to the study and websites were explored. Primary data on specific issues of the study coincide with the secondary data. RESULTS Table 1 revealed that 80.7% of the simple household

5 J. Agric. Econ. Dev. 069 Table 1. Percentage distribution and land possession. Variable Frequency Percent Yes No Total Table 2. Percentage distribution and land sizes (ha) owned. Sizes of land owned (ha) Frequency Percent Total Table 3. Percentage distribution and training attended. Variable Frequency Percent Yes No Total Table 4. Percentage distribution and storage methods/facilities. Storage methods/facilities Frequency Percent Polythene sacks Bags Both polythene sacks and bags Total possessed their own land, while the data in Table 2 showed that majority of the respondents (62.0%) possessed 1-15 ha of land for cultivation purposes. Regarding farmers training, data revealed that 52 respondents had attended training (34.7%) related to agriculture improvement (Table 3). Moreover, the data in Table 4 revealed that majority of the sampled households store their produce in polythene bags (86%) which are now very common in rural vicinity due to availability and costs. Others were reported to store their products in vihenge (This is a local made food storage structure that is constructed with trees, mud and cow dung) as a traditional way that many Tanzanians practice in rural areas. Moreover the data in Table 5 revealed that majority of respondents (84.7%) showed the need of extension services to contribute to farming activities. Farmers need to incur necessary cost of productions in producing sweet potatoes at small scale levels, hence the average costs of weeding, harvesting, storage of one bag, processing, planting, preparation and making ridges are Tsh 25, , Tsh 31, , Tsh 7, , Tsh 25, , Tsh 20, , Tsh 22, and Tsh 28, respectively (Table 6). It was observed that weeding and harvesting were the most expensive operation that farmers incurred. However, when

6 Mmasa et al. 070 Table 5. Percentage distribution and need to extension services. Variable Frequency Percent Yes No I don t know Total Table 6. Descriptive data. Variable N Minimum Maximum Mean Std. deviation Variance Cost of weeding E8 Cost of harvesting E9 Cost involved in storing one bag E8 Cost of processing E8 Costs of planting per acre E8 Cost for ridges preparations per acre E8 Cost for making ridges matuta per acre E8 Table 7. Percentage distribution of respondents and major type of crop cultivated. Variable N Percent Percent of cases Maize Rice Sweet potatoes Groundnuts Total 375* * *Multiple responses data. Table 8. Percentage distribution of respondents and farming tools. Variable N Percent Percent of cases Hand hoe Oxen plough Ox cart Panga Total 216* * *Multiple responses data. households decide to use their own household labour to take these activities, they will reduce production costs to significant level, hence increase profit. It was further noticed that majority of respondents cultivates maize and sweet potatoes (Table 7). Others were rice and groundnuts. It was further revealed that majority of farmers used rudimental technology in production, hence 59.7% reported that they used hand hoe in production and 40.3% used both hand hoe and oxen plough (Table 8). Regarding market information, it was revealed that 46.7% of the sampled respondents received the information from their fellow farmers and

7 J. Agric. Econ. Dev. 071 Table 9. Percentage distribution of respondents and market information sources. Market information sources Wards Itwangi Tinde Iselamagazi Salawe Nyida Total N Percent N Percent N Percent N Percent N Percent N Percent Direct visit to the market Cross check with fellow farmers Hear from friends Total % received market information after hearing from their friends (Table 9). The study revealed that in 2009/2010, Mwanza region cultivated a total of 69,000 ha which produced 126,000 tons with average yield of 1.8 ton/ha. It was noted that Geita District was the leading producer in the region followed by Sengerema, while Ilemala District was the lowest producer in the region (Table 13). For Shinyanga region in 2009/2010, a total of 149,000 ha which produced 589,000 tons with an average yield of 3.94 ton/ha was cultivated and Bukombe District was the leading producer with a total production of 300,000 tons followed by Bariadi and Kahama, while Shinyanga urban district has the lowest production (URT, 2009) (Table 14). The data obtained from the National Sample Census of Agriculture (2002/2003) revealed that in 2003/2004, Kigoma region on average produced a total of 11, kg/ha; Dar-Es-Salaam produced 7,341 kg/ha; Shinyanga produced 1, kg/ha; Mwanza produced 1, kg/ha, and Lindi region was the least producing region with only 1,000 kg/ha (Table 12). DISCUSSION The sweet potato value chain analysis involved a number of functions and institutions. It has both backward and forward integrations. Small holder farmers as growers are at the central point. Farmers are linked with input suppliers (backward integration). The inputs include sweet potato seeds, fertilizers, and chemicals. Other linkages with sweet potato growers involve oxen-plough, ox-carts and tractors owners who do farm tillage operations and transportation for farmers. After harvesting sweet potato roots (fresh), farmers do process to Michembe and Matobolwa, a number of routes are involved in the forward integration. In order to reach sweet potatoes consumers, farmers may sell directly to the consumers or sell through the middlemen, village hawkers or an open market. Under this route, transporters have a function of transporting fresh sweet potato or value added products to the retailers or consumers. In the Lake zone, producers play a dual role as a producer and processor; on the other hand, processing is done at small scale level. The current business practice is the dried sweet potato supply chain which is through spot transaction relationships between traders, middleman and farmers. Processors/producers also have no linkages with suppliers of machineries, utility suppliers, spare parts and packaging materials, hence they process at local levels. There are a number of activities involved after production of Michembe, Matobolwa by processors. The activities include: sun drying for few days, washing, peeling, slicing into reasonable size, drying for few days (sun drying) and packing into polythene sacks/vihenge. On the other hand, Matobolwa is prepared in similar procedures but there is cooking before grating and slicing. In many places of Tanzania, growers do process products from sweet potato for home consumption. Hence there is need to capture niche market 4 for sweet potato value added products. Firstly, producers (processor) sell directly to consumer. This channel was the shortest one where consumers purchased products directly from producers or from local market. Secondly, producers/processors sell to retailers, where producers/processors sell products in bulk to retail traders. This is a common channel where consumers purchase products from different retail outlets such as an open market and local markets. Thirdly, producers/processors sell to middlemen/village vendors. This middleman is a very small portion of the sweet potato market channel. Furthermore, this study showed that 146 sampled households reported that sweet potato ranks as the most important food crop after maize, groundnuts and paddy, whereas sweet potato ranks as the world s seventh most important food crop after wheat, rice, maize, potato, barley, and cassava, as it constitutes a substantial source of carbohydrate and carotene (CIP, 2000; FAO, 2002). Sweet potatoes prices in international market are not known. Sweet potato prices were found to vary from one 4 Is the subset of the market on which a specific product is focusing

8 Mmasa et al. 072 Table 10. Percentage distribution of respondents and critical problems in sweet potato sub-sector. Critical problems in sweet potato sub-sector N Percent Lack of improved seeds Low capita Unpredictable weather Lack of manpower Pest attack Poor storage facilities Total 504* *Multiple responses data. node to another. Producers received significantly lower prices than the wholesalers. Irrespective of the value chain node, sweet potatoes value added products were relatively lower in rural areas as compared to urban areas. For example, one debe (10 kg) of michembe is sold at Tsh , whereas the same quantity is sold at Tsh in urban areas. The variation in prices between urban and rural areas complies with cost based pricing methods in which prices are determined by cost incurred in production and transportation. The wholesalers incur costs in transportation, storage, preservation and marketing levies if any. This finding complies with that of Pascal et al. (2005) where prices of green beans at wholesalers level were higher than that at farm levels. In both regions, sweet potatoes were bought in pieces without weighing them. In Shinyanga, wholesalers bought fresh product at Tsh per debe, while in Mwanza wholesalers bought fresh product at Tsh The products were bought without considering their grades, but the size of the tubers, wholesome and defects determine the value of the products. Small size and defects on sweet potato fetched relatively low price. The broken sweet potatoes were either rejected or being sold at throw away price. All payments were made in cash at the time of exchanging ownership of the item. At village level, although buyers negotiated price with producers on the price, the buyers had more market power and advantage of dictating the prices because producers find it uneconomical for an individual to transport one debe/bag or few bags of sweet potatoes to the urban markets. Structure-Conduct-Performance (S-C-P) Model The analytical core of this model is the analysis of markets on the assumption of the two way casual and feedback relationship between its major components: structure, conduct and performance (S-C-P) model (Ashimogo, 2006). Market structure is defined as organizational characteristics, which determine the relations of the sellers in the market to each other, of the buyers in the market to each other, of the sellers to the buyers, and of the sellers established in the market to other actual or potential supplies of goods including potential new participants that might enter the market (Ashimogo, 2006). Market transparency affects the intensity of competition. If buyers or sellers do not have proper knowledge about market conditions, the intensity of competition is low despite a sufficient number of market participations to ensure competition. The most important aspect of market transparency is information transmission in the marketing systems. This implies information about prices, grades and quality and standard weights of the product in question. In the study area, the pre-conditions for a high degree market transparency are poor. Buyers buy local processed products regardless of the quality. Farmers need to be empowered to process in modern technology in terms of training and equipments and be informed about the prices of processed products. Also quality of products obscures market transparency. These are due to poor agronomical, handling, processing, and distribution practices. All these factors indicate that there is no market transparency in the sweet potatoes value added products marketing system. Barriers to business entry or expansion to market reduce the threat of potential competition and therefore impede marketing efficiency. Barriers can result from limited know-how, capital requirement, institutional restrictions and non-competitive reactions of producers/sellers. The data revealed that three factors: lack of improved seeds (33.1%), low capital (26.8%) and unpredictable weather (20.6%) were the critical problems in sweet potato sub-sector business expansion. Other impediment factors were pests attack in the field, lack of storage facilities and manpower (Table 10). It was observed that at present, producers/processors were not deliberately targeted for credit schemes like SACCOS or other financial institutions to improve their performance. Moreover, acquisition of credit from formal institutions such as bank follows very long and bureaucratic producers. It can generally be concluded that market entry is not a serious problem because the

9 J. Agric. Econ. Dev. 073 Table 11. Sweet potatoes national area ('000'ha), production ('000'tons) and yield (tons/ha) in Tanzania. Data 2005/ / /2008* 2008/ /2010 Area ('000' ha) Production ('000' tons) 2, , , , Yield (tons/ha) Source: Statistics Unit-Ministry of Agriculture, Food Security and Cooperatives. *National Sample Census of Agriculture 2007/2008. Table 12. Sweet potatoes yield per hectare in kilograms by region. Region 1998/ / / / /2003** 2003/ /2005 Arusha 2, , , , , , , Coast , , DSM , , , Dodoma 3, , , , , , Iringa 2, , , , , , , Kagera 2, , , , , , , Kigoma 2, , , , , , , Kilimanjaro 3, , , , , , , Lindi , , *Manyara , , , Mara 2, , , , , , , Mbeya 2, , , , , , , Morogoro 2, , , , , , , Mtwara , , , , , Mwanza 3, , , , , , , Rukwa 2, , , , , , , Ruvuma 2, , , , , , , Shinyanga 1, , , , , , Singida 1, , , , , , , Tabora 1, , , , , , , Tanga 2, , , , , , Average 2, , , , , , , Source: Statistics Unit-Ministry of Agriculture, Food Security and Cooperatives. * New region. ** National Sample Census of Agriculture (2002/2003). factors mentioned do not really prevent producers entering the market, these factors act as barriers to sweet potatoes value added products trade expansion. Market conduct Market conduct refers to the patterns of behaviors which a participant follows in adapting to the markets in which they sell or buy. For instance, pricing and selling tactics, producers cooperation, and research and development activities. In the study area, producers/processors did not organize themselves to form a cooperative (they operate randomly) or union in which they would monopolize the business in the area, though they are still the ones to determine buying and selling prices or mode of payment to be adopted. Market performance Market performance is defined as the way which market and marketing contribute to various aspects of economic performance. Sweet potatoes sub-sector is not performing efficiently due to poor economic performance, poor production, low prices, and poor quality of both the sector and the product. CONCLUSION AND RECOMMENDATIONS Results of this study showed that land size of the respondents in hectares and number of years in school

10 Mmasa et al. 074 Table 13. Sweet potatoes area ('000'ha), production ('000'tons) and yield (tons/ha) by region, district and year. Region District Data Mwanza Geita Year 2005/ / /2008* 2008/ /2010 Area ('000'ha) Production ('000'tons) Yield (tons/ha) Ilemela Area ('000'ha) Production ('000'tons) Yield (tons/ha) Kwimba Area ('000'ha) Production ('000'tons) Yield (tons/ha) Magu Area ('000'ha) Production ('000'tons) Yield (tons/ha) Misungwi Area ('000'ha) Production ('000'tons) Yield (tons/ha) Nyamagana Area ('000'ha) Production ('000'tons) Yield (tons/ha) Sengerema Area ('000'ha) Production ('000'tons) Yield (tons/ha) Ukerewe Area ('000'ha) Production ('000'tons) Yield (tons/ha) Mwanza area ('000'ha) Mwanza production ('000'tons) Mwanza yield (tons/ha) Source: Statistics Unit - Ministry of Agriculture, Food Security and Cooperatives. *National Sample Census of Agriculture (2007/2008). Table 14. Sweet potatoes area ('000'ha), production ('000'tons) and yield (tons/ha) by region, district and year. Region District Data Shinyanga Bariadi Year 2005/ / /2008* 2008/ /2010 Area ('000'ha) Production ('000'tons) Yield (tons/ha) Bukombe Area ('000'ha) Production ('000'tons) Yield (tons/ha)

11 J. Agric. Econ. Dev. 075 Table 14 Contd. Kahama Area ('000'ha) Production ('000'tons) Yield (tons/ha) Kishapu Area ('000'ha) Production ('000'tons) Yield (tons/ha) Maswa Area ('000'ha) Production ('000'tons) Yield (tons/ha) Meatu Area ('000'ha) Production ('000'tons) Yield (tons/ha) Shinyanga (Rural) Area ('000'ha) Production ('000'tons) Yield (tons/ha) Shinyanga (Urban) Area ('000'ha) Production ('000'tons) Yield (tons/ha) Shinyanga area ('000'ha) Shinyanga production ('000'tons) Shinyanga yield (tons/ha) Source: Statistics Unit - Ministry of Agriculture, Food Security and Cooperatives. *National Sample Census of Agriculture (2007/2008). (education level attained) were significant factors affecting the proportion of sweet potato value added products consumed. We must interpret any correlation between these traits and the quantity of sweet potato value added products consumed. However, we must bear in mind that some of such correlations can arise either because the quantity of sweet potato value added products consumed itself causes the characteristic in question, or because something associated with the quantity of sweet potato value added products consumed does, or because something about the quantity of sweet potato value added products consumed causes people to make different decisions about sweet potato. In line with the results of this study, the following recommendations were made: (1) Local council should sensitize and promote sweet potato commercial farming. (2) Non Governmental Organisations (NGOs) should facilitate formation of producers and marketing cooperative groups. ACKNOWLEDGEMENTS The authors greatly acknowledge the financial support by High Education Students Loan Board (HESLB) and the United Republic of Tanzania. The authors are also grateful to the University of Dodoma (UDOM) and the key actors in the sweet potatoes value chain for participating in this work. REFERENCES Ashimogo GC (2001). Marketing of Agricultural Products. Lecture notes Compendium for undergraduate courses in Agricultural Economics and Agribusiness at Sokoine University of Agriculture, Morogoro, Tanzania.pp109. Bailey K (1994). Methods of Social Research. Fourth Edition. The free press. A Division of Macmillan Inc., New York. p District Agricultural Development Plans (DADPS) (2010). Shinyanga Rural District Council Plan, Shinyanga, Tanzania.

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