14 research outputs found
The household welfare impacts of an agricultural innovation platform in Uganda
Technical approaches to food production are important to the food security of growing populations in developing countries. However, strategic investments in research and farm-level adoption require greater coherence in agricultural, societal, and local policies. The Agricultural Innovation System (AIS) and the formation of the Cassava Innovation Platform (CIP) in Uganda were designed to stimulate interactions between researchers and farmers, leading to the development of improved cassava varieties through Participatory Plant Breeding (PPB) and Participatory Variety Selection (PVS). Moreover, the establishment of a community-based commercialized seed system allied Cassava Seed Entrepreneurship (CSE) has made an important contribution to the rapid multiplication and dissemination of clean planting materials in Uganda. The impact of CIP participation on rural household welfare was measured by household consumption expenditure per capita. The Endogenous Switching Regression (ESR) model was applied to data from a formal household survey conducted in the Eastern, Northern, and Mid-Western regions of Uganda. The education, farm size, livestock size, access to credit, cost of cassava planting materials, access to extension service, access to training, and social group membership are significantly associated with CIP participation. CIP participation resulted in a 47.4% increase in household consumption expenditure. This important evidence highlights the need to promote agricultural innovation platform for improving rural livelihoods. Moreover, CIP participation has impact heterogeneity within the participant group that is conditional on household characteristics such as the gender of the household head, pointing to the need to tailor specific interventions and target specific groups within farm households
Genetic Gains for Yield and Virus Disease Resistance of Cassava Varieties Developed Over the Last Eight Decades in Uganda
Achieving food security for an ever-increasing human population requires faster development of improved varieties. To this end, assessment of genetic gain for key traits is important to inform breeding processes. Despite the improvements made to increase production and productivity of cassava in Uganda at research level, there has been limited effort to quantify associated genetic gains. Accordingly, a study was conducted in Uganda to assess whether or not genetic improvement was evident in selected cassava traits using cassava varieties that were released from 1940 to 2019. Thirty-two varieties developed during this period, were evaluated simultaneously in three major cassava production zones; central (Namulonge), eastern (Serere), and northern (Loro). Best linear unbiased predictors (BLUPs) of the genotypic value for each clone were obtained across environments and regressed on order of release year to estimate annual genetic gains. We observed that genetic trends were mostly quadratic. On average, cassava mosaic disease (CMD) resistance increased by 1.9% per year, while annual genetic improvements in harvest index (0.0%) and fresh root yield (−5 kg per ha or −0.03% per ha) were non-substantial. For cassava brown streak disease (CBSD) resistance breeding which was only initiated in 2003, average annual genetic gains for CBSD foliar and CBSD root necrosis resistances were 2.3% and 1.5%, respectively. It’s evident that cassava breeding has largely focused on protecting yield against diseases. This underpins the need for simultaneous improvement of cassava for disease resistance and high yield for the crop to meet its current and futuristic demands for food and industry
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Expansion of the cassava brown streak pandemic in Uganda revealed by annual field survey data for 2004 to 2017
Funder: Uganda Government Association for Strengthening Agricultural Research in Eastern and Central AfricaFunder: Bill and Melinda Gates Foundation (Bill & Melinda Gates Foundation)Abstract: Cassava brown streak disease (CBSD) is currently the most devastating cassava disease in eastern, central and southern Africa affecting a staple crop for over 700 million people on the continent. A major outbreak of CBSD in 2004 near Kampala rapidly spread across Uganda. In the following years, similar CBSD outbreaks were noted in countries across eastern and central Africa, and now the disease poses a threat to West Africa including Nigeria - the biggest cassava producer in the world. A comprehensive dataset with 7,627 locations, annually and consistently sampled between 2004 and 2017 was collated from historic paper and electronic records stored in Uganda. The survey comprises multiple variables including data for incidence and symptom severity of CBSD and abundance of the whitefly vector (Bemisia tabaci). This dataset provides a unique basis to characterize the epidemiology and dynamics of CBSD spread in order to inform disease surveillance and management. We also describe methods used to integrate and verify extensive field records for surveys typical of emerging epidemics in subsistence crops
The effect of cassava mosaic disease on the genetic diversity of cassava in Uganda
Cassava (Manihot esculenta) is a tropical crop that is grown in Africa, Latin America and Southeast Asia. Cassava was introduced from Latin America into West and East Africa at two independent events. In Uganda a serious threat to cassava’s survival is the cassava mosaic disease (CMD). Uganda has had two notable CMD epidemics since the introduction of cassava in the 1850s causing severe losses. SSR markers were used to study the effect of
CMD on the genetic diversity in five agro-ecologies in Uganda with high and low incidence of CMD. Surprisingly, high gene diversity was detected. Most of the diversity was found within populations, while the diversity was very small among agro-ecological zones and the high and low CMD incidence areas. The high genetic diversity suggests a mechanism by which diversity is maintained by the active involvement of the Ugandan farmer in continuously testing and adopting new genotypes that will serve their diverse needs. However, in spite of the high genetic diversity we found a loss of rare alleles in areas with high CMD incidence. To study the effect of the introgression history on the gene pool the genetic differentiation between East and West Africa was also studied. Genetic similarities were found between the varieties in Uganda and Tanzania in East Africa and Ghana in West Africa. Thus, there is no evidence for a differentiation of the cassava gene pool into a western and an eastern genetic lineage. However, a possible difference in the genetic constitution of the introduced cassava into East and West Africa may have been diminished by germplasm movemen
African cassava whitefly, Bemisia tabaci, resistance in African and South American cassava genotypes
The whitefly, Bemisia tabaci, is a major pest of cassava, particularly in Africa where it is responsible both for the transmission of plant viruses and, increasingly, for direct damage due to feeding by high populations. To date, there have been no practical solutions to combat this emerging problem, due to the inability of the subsistence farmers that grow cassava to afford expensive inputs such as insecticides. A programme of research was carried out linking institutes in Africa, the UK and South America, to identify possible resistance sources in cassava to the whitefly, Bemisia tabaci. The South American genotype MEcu 72 and several Ugandan cassava landraces including Ofumba Chai, Nabwire 1 and Mercury showed good levels of resistance to B. tabaci. Field and screen-house experiments showed that all of the improved, high-yielding cassava mosaic disease (CMD) resistant cassava genotypes assessed were highly susceptible to B. tabaci and supported high populations of all life stages. These data support the hypothesis that the continuing high populations of cassava B. tabaci in Uganda are due, in part, to the widespread adoption of CMD-resistant cassava varieties during the CMD pandemic. They also show that the whitefly, Aleurotrachelus socialis, resistance present in the South American cassava genotypes could have broader applicability in the Old World
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Expansion of the cassava brown streak pandemic in Uganda revealed by annual field survey data for 2004 to 2017.
Cassava brown streak disease (CBSD) is currently the most devastating cassava disease in eastern, central and southern Africa affecting a staple crop for over 700 million people on the continent. A major outbreak of CBSD in 2004 near Kampala rapidly spread across Uganda. In the following years, similar CBSD outbreaks were noted in countries across eastern and central Africa, and now the disease poses a threat to West Africa including Nigeria - the biggest cassava producer in the world. A comprehensive dataset with 7,627 locations, annually and consistently sampled between 2004 and 2017 was collated from historic paper and electronic records stored in Uganda. The survey comprises multiple variables including data for incidence and symptom severity of CBSD and abundance of the whitefly vector (Bemisia tabaci). This dataset provides a unique basis to characterize the epidemiology and dynamics of CBSD spread in order to inform disease surveillance and management. We also describe methods used to integrate and verify extensive field records for surveys typical of emerging epidemics in subsistence crops
Household welfare impacts of an agricultural innovation platform in Uganda
Technical approaches to food production are important to the food security of growing
populations in developing countries. However, strategic investments in research
and farm-level adoption require greater coherence in agricultural, societal, and local
policies. The Agricultural Innovation System (AIS) and formation of the Cassava
Innovation Platform (CIP) in Uganda were designed to stimulate interactions between
researchers and farmers, leading to the development of improved cassava varieties
through participatory plant breeding (PPB) and participatory variety selection
(PVS). Moreover, the establishment of a community-based commercialized seed
system called Cassava Seed Entrepreneurship (CSE) has made an important contribution
to the rapid multiplication and dissemination of clean planting materials
in Uganda. The impact of CIP participation on rural household welfare was measured
by household consumption expenditure per capita. The Endogenous Switching
Regression (ESR) model was applied to data from a formal household survey conducted
in the eastern, northern, and mid-western regions of Uganda. The education,
farm size, livestock size, access to credit, cost of cassava planting materials, access to
extension service, access to training, and social group membership are significantly
associated with CIP participation. CIP participation resulted in a 47.4% increase in
household consumption expenditure. This important evidence highlights the need to
promote agricultural innovation platform for improving rural livelihoods. Moreover, CIP participation has impact heterogeneity within the participant group that is conditional
on household characteristics such as the gender of the household head, pointing
to the need to tailor specific interventions and target specific groups within farm
households.http://wileyonlinelibrary.com/journal/fes3am2020Agricultural Economics, Extension and Rural Developmen
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Assessing the crop productivity and household welfare effects of adopting certified seeds of improved Cassava varieties in Uganda
This article identifies the determinants, crop productivity, and household welfare impacts of adopting certified seeds of improved cassava varieties (c-ICVs) in Uganda. The determinants were identified using the two-part model while the crop productivity and household welfare impacts were assessed using the endogenous switching regression model. The data came from 609 farm households in Uganda’s three major cassava-growing regions (Eastern, Northern, and mid-Western). The results showed that adopters of c-ICVs experienced a considerable increase in productivity (stem and root yields) and improvement in welfare outcomes (cash income and consumption expenditure). The results provide evidence of the effectiveness of the country’s seed certification and genetic improvement efforts over recent years and justify increased investments in genetic improvement and seed certification. However, it is essential to note that farmers’ widespread adoption of the high-yielding uniform c-ICVs could come at the cost of the diverse landraces, reducing cassava varietal diversity. Replacing the landraces could increase the crop’s genetic vulnerability to biotic and abiotic stresses. It is also important to be cautious that farmers’ widespread adoption of the c-ICVs could come at the cost of biodiversity loss as adoption of c-ICVs is often accompanied by increased application of agrochemicals (pesticides for disease control) that negatively impact the environment