R. Kapinga, B. de Steenhuijsen Piters, W. Heemskerk, B. Chirimi, M. Mutalemwa, J. Kabissa and P. Kapingu
Sweetpotato plays a great role as a household food security crop for many families in the Lake Zone (LZ) of Tanzania. However, varieties are not adapted to the wide variety of ecological conditions and socio-economics requirements. To address this, on-farm variety trial was conducted from 1995 through 1997 in 7 villages representing 4 different farming systems zones. In 1995/96 cropping season, 6 varieties: Sinia-B, Iboja, Budagala, SPN/0, Mwanamonde and Biganana were tested, and in 1996/97 3 more varieties SP/93/2, SP/93/34 and SP/93/23 were added in 2 locations only. All fields were characterized with respect to biophysical properties and fanners’ practices. Some 49 farmers participated in the trial. At harvest, 172 farmers assessed the performance of the varieties through participatory research approach which involved: field assessment and taste test evaluations, preference ranking according to criteria set by fanners and group assessment through pairwise comparison of all varieties. Varieties SPN/0, Mwanamonde and Iboja gave higher yields at several sites indicating their stability over other varieties. New varieties SP/93/23 and SP/93/2 performed well in some aspects. Farmers only rejected variety Budagala due to very low yields, but no other varieties tested, and indicated specific uses for each of them. The experiment provided a flexible recommendation that specifies the properties of all varieties and conditions for the optimal performance. Adaptive trials by extension agents and Farmers Extension Groups (FEGs) can further develop flexible recommendations in other agro-ecological zones. The diffusion of selected varieties is expanding in the LZ through networking with community based organizations which fund aspects of multiplying and distributing planting materials to farmers in several farming systems. To-date a total of 2,974,900 sweetpotato cuttings enough to cover 90 ha have been distributed to farmers through networking with three NGOs: Plan International, ACORD and Christian Center of Tanzania (CCT). Also three Government’s Research and Development Projects based in the zone. These include Mara Region Farmers Initiative Project (MRFIP); Bukoba District Rural Development Program (BDRDP); and Southern Africa Root Crops Research Network (SARRNET) all linked up to the Lake Zone Client Oriented Research Program.