Delivering new technologies to the Tanzanian sweetpotato crop through its informal seed system

摘要

The concept of integrated seed sector development (ISSD) for sweetpotato was tested in Shinyanga and Meatu districts of the Lake Zone of Tanzania. Agricultural Research Institute (ARI)–Ukiriguru documented the informal system. It comprised male and female vine multipliers with land close to water sources growing sweetpotato during the dry season. They sold vines during the rainy season, with male multipliers and those with larger crops selling more. The average multiplier supplied approximately 50 farmers who commonly travelled 20 km, each buying approximately 1–2 bundles of vine and provided an entry point for disseminating technologies. ARI–Ukiriguru organized demonstrations of rapid multiplication, inorganic and organic fertilizers and new cultivars on multipliers’ land. Fertilizer could economically more than double vine yields with huge potential benefits for an area where production is constrained by planting material; some multipliers immediately began using it. Multipliers took rapid multiplication and new cultivars to their home gardens for further experimentation, seeming likely to adopt especially the cultivar NASPOT 1. A strategy of growing large quantities of irrigated sweetpotato in Misungwi and selling the vines long-distance in Shinyanga, a marketing strategy derived from Uganda, was also adopted. These successes confirm the value of formal-informal seed sector interactions in ISSD.