Post-harvest systems have been defined as a set of operations and functions between production and consumption of agricultural commodities which are fulfilled by different actors in order to achieve an effective and efficient food supply. Isolated development activities which had been often directed to specific operations in the chain were found to be less successful for overall systems development.
The present study is the first in a series of country studies which are to be conducted by the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) and the Food and Agricultural Organisation (FAO) in order to develop guidelines for post-harvest sector analysis in an integrated and holistic way. These guidelines shall be used for the planning and evaluation of integrated programs in the subsector.
The GTZ working group on post-harvest systems development chose Kenya as a case study site Based on workshop results from preparatory studies in May 1996, potato and sweet potato crops have been selected as case study crops. The field studies took place in February and March 1997 in the main production regions, which are Meru district for potato and Kisii district for sweet potato. Study hypotheses on potential constraints in the chain of post-harvest operations have been derived from key informant interviews, thus guiding the selection of study sites and analysis. Rapid appraisal techniques were used in order to give a quick overview on the systems' characteristics.
The potato post-harvest chain is characterised by a diversified system of actors and operations (see figure 1). On-farm operations (harvesting, sorting) are generally done in a way that they meet the demand of the market. There are various marketing options of the individual farmer in the major production region including farm-gate selling. Storage is done according to price expectations and cash needs. The marketing system in the rural areas is well developed which has led to the establishment of potato growing as a major cash crop for smallholders. Transport costs to major urban centres, where steadily increasing demand is found, are reasonable. Although wholesale market facilities are overloaded, the market of potato is fast clearing with no major storage requirements or product losses in the different stages. Processing to chips (french fries) and crisps is expanding.
Sweet potato is in its initial stage of commercialisation. Depending on the access to the major rural centre Kisii, sales of sweet potato have increased significantly in recent years. On-farm operations include harvesting, sorting and washing. Processing is done to a small extent, but demand for processed products in rural areas is limited. Marketing by the farmer is usually through village agents who make firm orders prior to harvesting. Quantities are then assembled and transhipped via Kisii to urban centres (see figure 2). Women play a considerable part in performing the marketing operations for this crop. Although sweet potato has a potential to substitute other staple food crops, consumption in urban centres is still limited.
Both commodities are characterised by their bulkiness and in the case of sweet potato, its perishability. The post-harvest system has coped well with these specific characteristics and is successful in meeting demand in urban areas. The marketing system is fairly efficiently organised with little reported losses in the chain. Given the variety of operations to be fulfilled, marketing margins are competitive. Price signals are effectively bridging demand, and supply and farmers usually know the prices in the nearer markets.
The following improvements are recommended to overcome existing constraints:
· Rural infrastructure, especially roads, should be improved in order to reduce transport costs and give further access to markets· Weights and measures should be standardised on a national scale following the example from Meru district in order to raise transparency in the market.
· The research-extension system should consider sweet potato as an upcoming cash crop and explore opportunities for rural and urban processing.
· Heavy congestion and overspilling of wholesale market facilities should be eased.
· A solution for the lack of certified seed which is limiting potato production potential should be found. The collapse of parastatal seed production was not followed by replacing activities of the private sector.
· There is a need to further study the consumption characteristics of sweet potato in the urban centres, in particular the relationship in the demand for sweet potato and other food crops.
