The present study evaluated selected East African (EA) sweetpotato varieties for storage root dry matter and nutrient content and obtained information on the potential contributions of the varieties to alleviate vitamin A and mineral deficiencies. Roots obtained from 89 farmer (white- and orange-fleshed) varieties and one introduced variety (‘Resisto’) were analyzed for storage root quality using near-infrared reflectance spectroscopy technology. Location differences were only significant for starch content. The variance was significant (P < 0.01) for all the traits except sucrose content. Overall, the farmer varieties had higher dry matter, higher starch, and lower sucrose contents than the control clone, ‘Resisto’. It is these qualities that make sweetpotato attractive as a starchy staple in EA. A low population's mean β-carotene content (19.0 ppm) was observed. However, deep orange-fleshed farmer varieties, ‘Carrot_C’, ‘Ejumula’, ‘Carrot Dar’, ‘Mayai’, and ‘Zambezi’, had β-carotene content that can meet 350% or greater of recommended daily allowance (RDA) with 250-g serving to a 5- to 8–year-old child. More but light orange-fleshed farmer varieties ‘K-118’, ‘K-134’, ‘K-46’, ‘KMI61’, ‘MLE162 Nakahi’, ‘PAL161’, ‘Sowola6’, ‘Sponge’, ‘SRT34 Abuket2’, ‘SRT35 Anyumel’, ‘SRT52’, and ‘Sudan’ can provide 50% to 90% RDA of pro-vitamin A for the child. The root minerals’ content was generally low except for magnesium whose content can meet 50% or greater RDA in many farmer varieties. However, in areas with high sweetpotato consumption, varieties ‘Carrot_C’, ‘Carrot Dar’, ‘KRE nylon’, ‘MLE163 Kyebandula’, and ‘SRT49 Sanyuzameza’ can make good intakes of iron, zinc, calcium, and magnesium. In conclusion, some EA farmer varieties can contribute greatly to alleviation of vitamin A deficiency and substantial mineral intakes.

The Social Sciences Working Paper Series is intended to advance social science knowledge about production and utilization of potato, sweetpotato, and root and tuber crops in developing countries to encourage debate and exchange of ideas. The views expressed in the papers are those of the author(s) and do not necessarily reflect the official position of the International Potato Center. Comments are invited.

Sweetpotato [Ipomoea batatas (L.) Lam] farmer varieties are still the backbone of production and breeding programs in Sub-Sahara Africa. Usually, farmer varieties in Sub-Sahara Africa are white-or cream-fleshed sweetpotato (WFSP), but recently orange-fleshed sweetpotato (OFSP) were found in East Africa. The objective of the study was to characterize WFSP and OFSP germplasm from East Africa. Eighty-five East African farmer varieties (29 OFSPs and 56 WFSPs) and seven varieties of non-African origin as check clones were analyzed for diversity using 26 simple sequence repeat (SSR) markers. A total of 158 alíeles were scored with an average of 6.1 alíeles per SSR loci. The mean of Jaccard's similarity coefficients was 0.54. The unweighted pair group method analysis (UPGMA) revealed a main cluster for East Africa germplasm at a similarity coefficient of 0.52. At a similarity coefficient of about 0.55 subclusters within the East African germplasm were observed, but these were neither country nor flesh color specific. Analysis of molecular variance (AMOVA) found a significant difference between East African and non-African germplasm and a nonsignificant difference between OFSP and WFSP germplasm. In conclusion, the East African germplasm appears to be distinct from non-African germplasm, and OFSP and WFSP farmer varieties from East Africa are closely related. Orange-fleshed sweetpotato farmer varieties from East Africa might show similar adaptation to Sub-Sahara African environments as WFSP and a big potential in alleviating vitamin A deficiency.

BackgroundDiagnostic delay in patients with tuberculosis (TB) leads to ongoing TB transmission, higher mortality rates and increased patient and government health expenditure. Qualitative research focussed on patients’ self-perceptions of disease and their care-seeking behaviour helps to guide health education programmes by providing us with the understanding of the knowledge, attitudes and practices that underlie diagnostic delay.Patients and methodsSemi-structured interviews with 28 recently diagnosed TB patients and four traditional healers were conducted. The interviews were audio-recorded and content analysis was performed.ResultsThe median total delay was 188 days. The health provider delay (31 days) was longer than the patient delay (21 days) and the health system delay (26 days). The health system delay was longest in patients not being diagnosed at their first hospital visit and subsequently visiting other health care providers, mostly traditional healers.ConclusionsA poor knowledge of TB signs and symptoms and patients’ beliefs about curses as the origin of diseases lead to delayed care-seeking at the hospital level in an area of North-Western Tanzania. Failure to identify TB cases by formal and non-formal health providers indicates that the education of both communities as well as health workers is essential in order to reduce diagnostic delays.

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Sweetpotato is an important staple crop in East Africa with great potential for introducing improved cultivars, but little is known about which sensory characteristics are desirable. Over a 2 year period, 600 consumers were interviewed at three locations (urban and rural) in the Lake Zone of Tanzania and their preference of 14 locally available sweetpotato cultivars in cooked form was evaluated. A simple questionnaire based on consumers first-choice preference was used followed by socio-economic questions. A trained sensory panel profiled the cooked sweetpotato samples, enabling comparisons with preference, location and season. Cluster analysis based on the sensory attributes was used to classify the cultivars into three groups; one cluster comprised the most preferred cultivars and another contained the least. Some cultivars were consistently preferred over the 2 year period while others were not. The location where the cultivars were grown also influenced preference. Stepwise regression indicated that the most discriminating sensory attributes were starch and stickiness. Target levels based on the mean intensity scores of these attributes are suggested as a means of screening new cultivars. The implications of these findings are discussed.

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