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 Technical Report #307
Publication Date: 09/30/2015
Type: Literature Review
Abstract

This report reviews and summarizes the existing evidence on the impact of access to financial services/products on measures of production, income and wealth, consumption and food security, and resilience for smallholder farmers  and other rural customers and their households in Sub-Saharan Africa. This study covers four main types of financial products/services: 1) credit; 2) savings; 3) insurance; 4) transactional products. We also review the very limited evidence on the effectiveness of bundling these products/services together and of combining them with other offerings such as trainings or support for access to markets, and of providing them via digital channels. We note when financial products/services have been specifically designed to serve the needs of rural customers or smallholder farmers, since the needs of these groups are often very different from those of other stakeholders.

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 #295
Publication Date: 02/22/2015
Type: Literature Review
Abstract

This report reviews the literature on textural attributes of Root, Tuber, and Banana (RTB) crops with a focus on studies relevant for crop research and development in Sub-Saharan Africa. The texture of cooked root and tuber crops is often cited as a primary determinant of consumer acceptability of new varieties, including those produced through traditional breeding and through genetic engineering. Evidence from texture-related consumer preferences studies for the RTB crops tropical yam, sweetpotato, banana/plantain, cassava, and potato, as well as the results of physicochemical and genetic studies detailing the current scientific understanding of drivers of textural traits, is reviewed and synthesized.

EPAR Technical Report #283
Publication Date: 12/11/2014
Type: Literature Review
Abstract

Donors and governments are increasingly seeking to implement development projects through self-help groups (SHGs) in the belief that such institutional arrangements will enhance development outcomes, encourage sustainability, and foster capacity in local civil society – all at lower cost to coffers. But little is known about the effectiveness of such institutional arrangements or the potential harm that might be caused by using SHGs as ‘vehicles’ for the delivery of development aid.  This report synthesizes available evidence on the effectiveness of Self-Help Groups (SHGs) in promoting health, finance, agriculture, and empowerment objectives in South Asia and Sub-Saharan Africa. Our findings are intended to inform strategic decisions about how to best use scarce resources to leverage existing SHG interventions in various geographies and to better understand how local institutions such as SHGs can serve as platforms to enhance investments. 

EPAR Technical Report #269
Publication Date: 05/21/2014
Type: Literature Review
Abstract

The commercial alcohol industry in Africa may provide opportunities to increase market access and incomes for smallholder farmers by increasing access to agriculture-alcohol value chains. Despite the benefits of increased market opportunities, the high costs to human health and social welfare from increased alcohol use and alcoholism could contribute to a net loss for society. To better understand the tradeoffs between increased market access for smallholders and societal costs associated with harmful alcohol consumption, this paper provides an inventory of the societal costs of alcohol in Sub-Saharan Africa (SSA). We examine direct costs associated with addressing harmful effects of alcohol and treating alcohol-related illnesses, as well as indirect costs associated with the goods and services that are not delivered as a consequence of drinking and its impact on personal productivity. We identified resources using Google Scholar and the University of Washington libraries, and utilized the Global Burden of Disease (GBD) database by the Institute for Health Metrics and Evaluation (IHME) and the World Health Organization’s Global Information System on Alcohol and Health (GISAH) database. We also utilized FAOSTAT to retrieve raw data on national-level alcohol production and export statistics. We find that hazardous alcohol use contributes to early mortality and morbidity, loss of productivity, property damage, and other social costs and harms for drinkers and those around them. Drinking also affects vulnerable segments of the population disproportionately. Policymakers, local authorities, and donor agencies can use the information presented in this paper to plan and prepare for the higher consumption levels and subsequent social costs that may follow through agricultural development and economic growth in the region.  

EPAR Research Brief #228
Publication Date: 04/18/2014
Type: Literature Review
Abstract

Cassava (Manihot esculenta Crantz) is a widely-grown staple food in the tropical and subtropical regions of Africa, Asia, and Latin America. In this brief we examine the environmental constraints to, and impacts of, smallholder cassava production systems in Sub-Saharan Africa (SSA) and South Asia (SA), noting where the analysis applies to only one of these regions. We highlight crop-environment interactions at three stages of the cassava value chain: pre-production (e.g., land clearing), production (e.g., soil, water, and input use), and post-production (e.g., crop storage). At each stage we emphasize environmental constraints on production (poor soil quality, water scarcity, crop pests, etc.) and also environmental impacts of crop production (e.g., soil erosion, water depletion and pesticide contamination). We then highlight good practices for overcoming environmental constraints and minimizing environmental impacts in smallholder cassava production systems. Evidence on environmental issues in smallholder cassava production is relatively thin, and unevenly distributed across regions. The literature on cassava in South Asian smallholder systems is limited, reflecting a crop of secondary importance (though it is widely found elsewhere in Asia such as South East Asia), in comparison to cassava in much of SSA. The majority of the research summarized in this brief is from SSA. The last row of Table 1 summarizes good practices currently identified in the literature. However, the appropriate strategy in a given situation will vary widely based on contextual factors, such as local environmental conditions, market access, cultural preferences, production practices and the policy environment.

EPAR Technical Report #254
Publication Date: 03/20/2014
Type: Literature Review
Abstract

This overview introduces a series of EPAR briefs in the Agriculture-Environment Series that examine crop-environment interactions for a range of crops in smallholder food production systems in Sub-Saharan Africa (SSA) and South Asia (SA). The briefs cover the following important food crops in those regions; rice (#208), maize (#218), sorghum/millets (#213), sweet potato/yam (#225), and cassava (#228).

Drawing on the academic literature and the field expertise of crop scientists, these briefs highlight crop-environment interactions at three stages of the crop value chain: pre-production (e.g., land clearing and tilling), production (such as water, nutrient and other input use), and post-production (e.g., waste disposal and crop storage). At each stage we emphasize environmental constraints on crop yields (including poor soils, water scarcity, crop pests) and impacts of crop production on the environment (such as soil erosion, water depletion and pest resistance). We then highlight best practices from the literature and from expert experience for minimizing negative environmental impacts in smallholder crop production systems.

This overview (along with the accompanying detailed crop briefs) seeks to provide a framework for stimulating across-crop discussions and informed debates on the full range of crop-environment interactions in agricultural development initiatives.

A paper based on this research series was published in Food Security in August 2015.

EPAR Technical Report #211
Publication Date: 12/14/2012
Type: Literature Review
Abstract

This report provides a general overview of the sweet potato value chain in Tanzania. The first section describes trends in sweet potato production and consumption since 1990. The second section describes the uses and importance of sweet potatoes in Tanzania. The final section outlines current practices and constraints in production, post-production, and marketing. Tanzania ranks fifth in the world in quantity of sweet potatoes produced. Production and consumption of sweet potatoes have been relatively constant over the past 10 years, although both production and consumption in this period have been high in comparison to earlier decades. We find that sweet potato yields increased in the early 2000s, but have stagnated since, and are far short of potential yields. Sweet potato consumption is almost entirely domestic and plays an important role in nutrition and food security for smallholder farmers. Sweet potato production faces a variety of constraints, including pests and disease, short shelf life, lack of planting materials, damage during handling, and lack of market access.