PhD Thesis
Round potato (Solanum tuberosum L) has been an important food and cash crop in the
southern highlands of Tanzania since its introduction in the 1920s. However, the extent to
which it contributes to household food security was empirically unknown. Therefore, this
study was conducted in Mbeya and Makete Districts to contribute to this knowledge gap.
The purpose of the study was to determine the contribution of round potato production to
household food security. The specific objectives of the study were to: (i) determine the
impact of round potato production on household food security, (ii) determine the
contribution of round potato production to household income, (iii) establish the status of
food security incidences based on monetary and caloric poverty lines and (iv) apply
theories of food insecurity to explain food status in the southern highlands of Tanzania.
Multistage sampling was used to select 233 households in Mbeya and Makete Districts.
The research was a cross-sectional one and was conducted through structured interviews
using a questionnaire, focus group discussions using an FDG guide and key informant
interviews using a checklist of items for discussion. The Statistical Package for Social
Sciences (SPSS) was used to analyse quantitative data. Multiple linear regression was
used to assess impacts of independent variables on the dependent variable that was food
security in terms of dietary energy consumed per adult equivalent per day and monetary
values of all food items consumed. Dietary Energy Consumed from round potato showed
positive significant (p<0.1%) impact on dietary energy consumed per adult equivalent per
day. Based on this finding, it is concluded that round potatoes are a reliable source of food
in the study area. Moreover, there was positive significant (p<0.1%) impact of income
from round potato on household income. Based on this finding, it is concluded that round
potato is a main source of income and that, if it were given due attention and care, it
would contribute greatly to household income. One-way ANOVA was used to compareiii
levels of food status based on kilocalories consumed and monetary values of food
consumed. Using the national food monetary and caloric poverty lines, 82.8% and 79.0%
of the sampled households were food secure in Mbeya and Makete Districts respectively.
Multiple linear regression was used to analyse the extents to which Malthusian and Anti-
Malthusian theories, the entitlement to food approach by Sen, and Woldemeskel’s
contentions explain food security in Mbeya and Makete Districts. With respect to the
Malthusian theory, population in terms of household size was the most important factor
influencing food security negatively. Contrary to prior expectations, food security was not
significantly different between households which used different numbers of agricultural
improved technologies and different amounts of fertilizer per unit area. Moreover,
entitlement to food security in terms of number of cattle owned, non-agricultural activities
and farmers’ group membership were found to be more important factors enhancing food
security. On basis of these findings, it is concluded that addressing these factors could
improve food security in the study area. Therefore, it is recommended that the
government and policy makers should support farmers through training sessions on
improved round potato technologies, and enhance timely availability of farm inputs at
affordable prices. Moreover, policy makers, Non-Governmental Organizations and other
development partners are urged to support other income generating activities so as to
increase income and hence increase farmers' purchasing power and access to food.
Tanzania Commission for Science and Technology (COSTECH)