The role of community based organisations' NGOs and farmers in technology transfer

Cassava (Manihot esculenta Crantz) and sweetpotato (Ipomoea batatas) are key food crops in Tanzania in general and in the lake zone in particular. Cassava and sweetpotato are household food security crops in addition to being a source of household income. Availability of the new improved varieties to farmers has been a problem in Tanzania. A project was initiated to transfer improved varieties of both cassava and sweetpotato in the lake zone to farmers. In collaboration with community-based organisations (CBOs), non-government organisations (NGOs) and farmer groups, the project distributed different varieties of cassava and sweet potato in Shinyangu and Mwanza regions through CIP/ASARECA. The CBOs, NGOs and farmer groups were very instrumental in facilitating the delivery of improved varieties to farmers. Through this informal seed delivery system using CBOs, NGOs, and farmers groups, farmers have been able to access, use and adopt improved varieties suitable for their areas. The project has also established a system that can be used for future technology transfer activities. through this system more than 988,000 and 1,752,711 cuttings of improved cassava and sweet potato varieties respectively were distributed in three regions of the lake zone. The distribution activity went hand in hand with training of farmers in rapid multiplication techniques of planting materials

Effect of leaf harvesting frequency on growth and yield of sweetpotato in the Lake Zone of Tanzania

The objectives of this study were to assess the effects of leaf harvesting frequency on growth and yield of sweetpotato (Ipomoea batatus L.); to determine the suitable varietal types for use as source of leaf vegetable and to determine the suitable leaf harvesting frequency(ies) for reduced detrimental effects on growth and yield of sweetpotato. Two narrow leafed varieties Budagala and Mwananjemu and two broad leafed varieties SPN/O and Biganana were used in a randomised complete block design with 3 replications. Plot size was 8.4 m2 . Tip cuttings of 20 cm long were used as planting materials. The fully expanded top and tender leaves were plucked, counted and weighed. Tender leaves were harvested once, twice and three times during the growing period. Results showed that there were small differences between varieties and harvesting frequencies, however, harvesting at one month intervals for three times gave the highest leaf vegetable production although the yield was affected tremendously. Harvesting twice in a growing period proved the best in leaf production as well as root yields. Overall, there were significant differences between varieties and harvesting frequencies. Key Words: Ipomoea batatus, leaf harvesting, Tanzania, tuber and vine yields (African Crop Science Journal 2001 9(1): 97-103

The agronomic performance and acceptability of orange fleshed sweetpotato varieties in the Lake zone of Tanzania

The introduction of improved orange-fleshed sweetpotato (Ipomea batatas) varieties from the International Potato Centre (CIP) was a result of recognising the negative health effects of vitamin A deficiency in Tanzania. Orange varieties, which are rich in β-carotene, were considered one of the sustainable strategies for addressing Vitamin A deficiency. Seven varieties from CIP, five of which were orange-fleshed, were tested on farm for two seasons (2001- 2002) in the Lake zone of Tanzania. Different sweetpotato recipes were prepared and tasted as alternative to boiled sweetpotato roots. Among the introduced orange varieties, Zapallo, NC 1560 and Tainung No 64 produced between 6.04 and 11.86 t ha-1 of fresh total root yield compared to 7.59 t ha-1 of the control variety. Mafutha and Japon tresimesino gave poor yields. Farmers ranked high Zapallo, Tainung No. 64 and NC 1560 for agronomic performance. However, Mafutha, Japon tresimesino and Tainung No. 64 were rated high for cooking quality. Zapallo and NC 1560 were rated high for dry texture. For children, internal root colour was the most important attribute for accepting a variety. Sweetpotato products prepared from orange fleshed varieties were preferred more by both adults and children than those prepared from white fleshed varieties. The over all acceptability of orange varieties and sweetpotato products was high. Key Words: β-carotine, CIP, Ipomea batatas RÉSUMÉ L'introduction des variétés améliorées de la patate (Ipomea batatas) douce orange graissée par le Centre International de la Patate (CIP) était le résultat de la reconnaissance d ‘effets négatifs de la carence en vitamine A en Tanzanie. Les variétés oranges qui sont riches en carotène-β, étaient considéré comme l'une des stratégies durables pour résoudre la carence en vitamine A. Sept variétés du CIP dont cinq oranges graissés, étaient testées sur fermes pour deux saisons (2001-2002) dans la région du lac Tanganyika. Différentes recettes de la patate douce étaient préparées et goûtée comme alternatives a la patate douce. Parmi les variétés oranges introduites, Zapallas, NC 1560 et Tainung No 64 ont produit entre 6.04 et 11.86 t ha-1 des racines fraîches comparé a 7.59 t ha-1 de la variété de contrôle. Mafutha et Japon tresimesino donnerent des rendements faibles. Les fermiers classèrent supérieure les performances agronomiques de Zapallo, Tainung No 64 et NC1560. Cependant, Mafutha, Japon tresimesino et Tainung No 64 étaient bien cotés pour la cuisson. Zapallo et NC1560 étaient bien cotés pour la texture à sec. Pour les enfants, la couleur interne était l'attribut le plus important pour accepter la variété. Les produits de la patate douce préparés des variétés orange graissées étaient préférés par les enfants et les adultes que les ceux préparés des variétés graissées de couleur blanche. L'acceptabilité des variétés oranges et les produits associés étaient élevés. Mots clés: Carotène-β, CIP, Ipomea batatas African Crop Science Journal Vol.12(3) 2004: 229-24

Decentralised sweetpotato (Ipomoea batatas) vine multiplication in Lake Zone, Tanzania: Five years later

Farmer-based seed multiplication is widely promoted by development practitioners, but there is limited understanding of the individual or collective motivations of farmers to engage or disengage in specialised seed production. The objective of this study is to understand the factors influencing the continuity of sweetpotato vine multiplication enterprises in the Lake Zone of Tanzania, five years after support from a project ended. A total of 81 out of 88 trained group or individual decentralised vine multipliers (DVMs) were traced to assess their vine multiplication activities. Qualitative and quantitative data were collected through telephone and field interviews. Our data showed that 40% of the 81 DVMs had sold vines in the year prior to the study and 20% had maintained the improved varieties for their own use. Some group members had continued vine sales as individuals. The DVMs’ reasons for abandoning vine multiplication included climatic and water access issues, market factors and group dynamics. The DVMs did not engage in high volumes of commercial sales. Socio-economic norms and values underpin the transactions of sweetpotato vines. These norms may undermine the emergence of commercially viable enterprises yet seem navigable for a substantial number of the DVMs. Group DVMs seem less commercially successful than individuals