In most urban markets in Tanzania, sweetpotato [Ipomoea batatas (L.)] is purchased in sacks or bamboo baskets and then sold to consumers in heaps at fixed prices. Heaps vary in total weight and quality. Two complementary methodological approaches for assessing the relationship between quality and economic value of fresh sweetpotato are described. The first approach used a range of participatory ranking and valuation exercises to gain an impression of the major quality issues, seasonality of marketing, and the impact of specific types of quality deterioration on retail value. This was supported by a statistical analysis of heaps of produce being retailed in the market. This second approach allowed the impact of different quality characteristics to be quantified. Application of these methods is demonstrated through analyses of the impact of different quality characteristics on retail value during low season marketing in Mawanza, Tanzania.
Ndunguru, G., Thomson, M., Waida, R., Rwiza, E. and Westby, A. Methods for examining the relationship between quality characteristics and economic value of marketed fresh sweet potato. Tropical Agriculture (Trinidad) (1999) 75 (1) 129-133.