Research Topics

EPAR Technical Report #310
Publication Date: 11/20/2015
Type: Literature Review
Abstract

Cereal yield variability is influenced by initial conditions such as suitability of the farming system for cereal cultivation, current production quantities and yields, and zone-specific potential yields limited by water availability. However, exogenous factors such as national policies, climate, and international market conditions also impact farm-level yields directly or provide incentives or disincentives for farmers to intensify production. We conduct a selective literature review of policy-related drivers of maize yields in Ethiopia, Kenya, Malawi, Rwanda, Tanzania, and Uganda and pair the findings with FAOSTAT data on yield and productivity. This report presents our cumulative findings along with contextual evidence of the hypothesized drivers behind maize yield trends over the past 20 years for the focus countries.

EPAR Research Brief #312
Publication Date: 07/30/2015
Type: Literature Review
Abstract

This brief reviews the evidence of realized yield gains by smallholder farmers attributable to the use of high-quality seed and/or improved seed varieties. Our analysis suggests that in most cases, use of improved varieties and/or quality seed is associated with modest yield increases.  In the sample of 395 trials reviewed, positive yield changes accompanied the use of improved variety or quality seed, on average, in 10 out of 12 crops, with rice and cassava as the two exceptions.

EPAR Technical Report #298
Publication Date: 03/23/2015
Type: Literature Review
Abstract

Cassava production is prone to many constraints throughout the production cycle, including biotic, abiotic, and management constraints. This brief reviews the literature on the production impacts of two key cassava stressors: cassava bacterial blight (CBB) and postharvest physiological deterioration (PPD). We summarize available estimates of the frequency and magnitude of these constraints relative to other drivers of cassava production losses that affect smallholder farmers in Sub-Saharan Africa (SSA), review the control strategies proposed in the literature, report on the views of several experts in the field, and identify research gaps where relatively little appears to be known about CBB or PPD yield impacts or best practices for CBB or PPD management. 

EPAR Technical Report #115
Publication Date: 12/14/2010
Type: Literature Review
Abstract

As part of the Crops & Climate Change series, this brief is presented in three parts: 1) An evaluation of the importance of Sorghum and Millet in SSA, based on production, net exports, and caloric need, 2) A novel analysis of historical and projected climate conditions in Sorghum and Millet growing regions, followed by a summary of the agronomic and physiological vulnerability of Sorghum and Millet crops, 3) A summary of current resources dedicated to sorghum and millet, based on research and development investments and National Adaptation Programmes of Action. Our analysis indicates that sorghum and millets may become increasingly important in those areas of SSA predicted to become hotter and subject to more variable precipitation as a result of climate change. Although sorghum and millet are currently grown on marginal agricultural lands and consumed for subsistence by poorer population segments, climate change could render these drought- and heat-tolerant crops the most viable future cereal production option in some areas where other cereals are currently grown. Fewer international development resources are currently devoted to sorghum and millet than are devoted to other cereal grains, and current resource allocation may not reflect the increased reliance on these grains necessitated by projected climactic changes.

EPAR Technical Report #114
Publication Date: 12/14/2010
Type: Literature Review
Abstract

As part of the Crops & Climate Change series, this brief is presented in three parts: 1) An evaluation of the importance of wheat in SSA, based on production, net exports, and caloric need, 2) A novel analysis of historical and projected climate conditions in wheat-growing regions, followed by a summary of the agronomic and physiological vulnerability of wheat crops, 3) A summary of current resources dedicated to wheat, based on research and development investments and National Adaptation Programmes of Action. Overall, this analysis indicates that the importance of wheat as an imported product remains high throughout SSA, though food crop production and dependence is concentrated in a relatively small area. Wheat-growing regions throughout SSA are likely to face yield decreases as a result of predicted rises in temperatures and possible changes in precipitation. Resources intended to aid adaptation to climate change flow primarily from public sector research and development efforts, though country-level adaptation strategies have not prioritized wheat.

EPAR Technical Report #62
Publication Date: 10/23/2010
Type: Literature Review
Abstract

Researchers expect that agriculture in Sub-Saharan Africa (SSA) will experience major impacts from climate change, leaving the already food-insecure region subject to the largest contractions of agricultural incomes and food availability. As part of the Crops & Climate Change series, this brief presents an evaluation of the importance of maize in SSA, a novel analysis of historical and projected climate conditions in maize-growing regions, and a summary of current resources dedicated to maize adaptation. Overall, this analysis indicates that the importance of maize as a food crop remains high throughout SSA. Significant portions of maize-growing SSA will face climate conditions outside the range of country- and continent-level historical precedent. Rising temperatures and changes in precipitation are predicted, and reductions in maize yield and production will likely follow. Resources intended to aid adaptation to climate change flow primarily from public sector research and development efforts. Country-level adaptation strategies are often hampered by lack of funding and insufficient institutional capacity. Strategies for adaptation include improved agricultural practices and technology as well as infrastructure and program investments to absorb the impacts of climate change.

EPAR Technical Report #71
Publication Date: 10/22/2010
Type: Literature Review
Abstract

Agriculture in Sub-Saharan Africa is expected to experience major impacts from climate change, leaving the already food-insecure region subject to the largest contractions of agricultural incomes and food availability. As part of the Crops & Climate Change series, this brief presents an evaluation of the importance of rice in SSA, a novel analysis of historical and projected climate conditions in rice-growing regions in relation to rice's agronomic requirements, and a summary of current resources dedicated to rice. This three-pillared approach serves to identify gaps in resources dedicated to rice productivity in SSA in light of the crop’s resilience to projected changes in climate and increasing importance in the region’s food security. Overall, this analysis indicates that the importance of rice in SSA is increasing even as climate change is projected to have significant effects on the temperature in rice-growing regions. The current resources dedicated to rice research and dissemination of improved methods are insufficient to meet Africa’s rice production needs, and may not reflect the importance of the crop for the region’s food security under the future projected climate.

EPAR Technical Report #98
Publication Date: 10/12/2010
Type: Literature Review
Abstract

Cereals and pulses are important food and cash crops for farmers and rural households in Ethiopia. Despite the economic and food security importance of these crops, data and opinion suggest a yield gap: actual smallholder farm yields do not achieve estimated potential yields for wheat, sorghum, maize, lentils and peas. Furthermore, cereal prices in Ethiopia fall between import and export parity prices, limiting their international trading prospects. Although there are significant wheat imports, these reflect the influx of food aid, rather than competitive trade on the international market. The purpose of this brief is to estimate yield gaps in important Ethiopian crops in order to identify potential areas for productivity gains. We find that wheat, sorghum and maize all exhibit the potential for yield gains to increase domestic food availability. Additionally, all three crops experienced significant spikes in yield in the 2006 season. Further investigation into the climate conditions and policy in place that year may generate potential strategies to increase future yields. Analysis of Ethiopian lentil and pea yields suggest that productivity gains may be possible to increase food availability. Limited access to improved technologies appears to be the main constraint to pulse productivity in Ethiopia. Opportunities to increase lentil and pea yields appear to exist through increasing cultivation of improved varieties.

EPAR Technical Report #28
Publication Date: 08/10/2009
Type: Literature Review
Abstract

Smallholder farmers in Africa are largely located in poor rural areas, are often geographically dispersed, and have limited access to road and communication infrastructure, thus raising the cost of market participation. This is especially true for farmers growing relatively low value staple crops. This literature review summarizes research on the challenges and innovations in linking smallholder producers of staple grains to markets in Sub-Saharan Africa, with a focus on post-harvest issues including storage, aggregation, and transportation. For each post-harvest stage, we describe challenges faced by farmers and current efforts to address these challenges. In our review, we find a large amount of literature on the constraints to smallholder production and marketing but relatively few examples of innovative or novel technologies designed to improve storage and transportation for rural smallholder producers in Africa. Existing technologies have often been available for some time but have not seen widespread adoption, apparently due to high costs or inadequate funding for on-farm testing and extension. We conclude that the literature is somewhat divided as to whether interventions linking smallholder farmers to markets should be entirely market-driven and focus on linkages that can be profitable without subsidization, or whether NGO- and donor-driven interventions should play a role.

EPAR Research Brief #79
Publication Date: 07/29/2009
Type: Literature Review
Abstract

The Government of Kenya (GoK) has historically encouraged its farmers to use fertilizer by financing infrastructure and supporting fertilizer markets.  From 1974 to 1984, the GoK provided a fertilizer importation monopoly to one firm, the Kenya Farmers Association.  However, the GoK saw that this monopoly impeded fertilizer market development by prohibiting competing firms from entering the market and, in the latter half of the 1980s, encouraged other firms to enter the highly regulated fertilizer market. This report examines the state of fertilizer use in Kenya by reviewing and summarizing literature on recent fertilizer price increases, Kenya’s fertilizer usage trends and approaches, market forces, and the impact of government and non-government programs. We find that most studies of Kenya’s fertilizer market find it to be well functioning and generally competitive, and conclude that market reform has stimulated fertilizer use mainly by improving farmers’ access to the input through the expansion of private retail networks. Overall fertilizer consumption in Kenya has increased steadily since 1980, and fertilizer use among smallholders is among the highest in Sub-Saharan Africa. Yet fertilizer consumption is still limited, especially on cereal crops, and in areas where agroecological conditions create greater risks and lower returns to fertilizer use.