Research Topics

EPAR Technical Report #239
Publication Date: 08/20/2013
Type: Literature Review
Abstract

This research brief provides an overview of the banana and plantain value chains in West Africa. Because of the greater production and consumption of plantains than bananas in the region, the brief focuses on plantains and concentrates on the major plantain-producing countries of Ghana, Cameroon, and Nigeria. The brief is divided into the following sections: Key Statistics (trends in banana and plantain production, consumption, and trade since 1990), Production, Post-Harvest Practices and Challenges, Marketing Systems, and Importance (including household consumption and nutrition). West Africa is one of the major plantain-producing regions of the world, accounting for approximately 32% of worldwide production. Plantains are an important staple crop in the region with a high nutritional content, variety of preparation methods, and a production cycle that is less labor-intensive than many other crops. In addition to plantains, bananas are also grown in West Africa, but they account for only 2.3% of worldwide production. Bananas are more likely than plantains to be grown for export rather than local consumption. Major constraints to banana and plantain production include pests and disease, short shelf life, and damage during transportation.

EPAR Technical Report #233
Publication Date: 05/21/2013
Type: Literature Review
Abstract

Whiteflies are vectors for viral diseases such as cassava mosaic disease (CMD) and cassava brown streak disease (CBSD), which can reduce yields substantially. The flies can also cause direct damage, more common on disease-resistant cassava varieties than on local cultivars, by feeding on the crop and causing root yield reductions. In this report we provide background on whitefly damage to cassava as well as evidence on the effectiveness of four control strategies: breeding for host plant resistance, intercropping and other planting strategies, insecticides and Insecticide Resistance Management (IRM), and biological control through parasitoids, fungus, and predators. Though we group information by strategy, most researchers report that controlling whiteflies and the viruses for which it is a vector requires a multifaceted approach. 

EPAR Research Brief #219
Publication Date: 01/27/2013
Type: Literature Review
Abstract

This report provides a genderal overview of the sweet potato value chain in Ethiopia. The first section describes trends in sweet potato production and consumption since the early 1990s. The second section describes the uses and importance of sweet potatoes in Ethiopia. The final section discuss major issues in production, post-production, and marketing. The literature available on sweet potetoes in Ethiopia was quite limited and draws on the wider literature on sweet potatoes in East Africa where needed. We find that Ethiopia ranks fifteenth in the world in terms of sweet potato production. Production has been rising quickly since 2008, following a period of slow decline in the early 2000s. Yields have also been rising slowly since 2008, but are below their peak from 2001. Sweet potato roots are consumed domestically, mostly by poor rural households. The vines also provide an important source of feed for livestock during the dry season. Major constraints to sweet potato production in Ethiopia include a lack of quality planting materials, pests and disease, and underdeveloped markets.

EPAR Research Brief #217
Publication Date: 01/23/2013
Type: Literature Review
Abstract

Uganda is the biggest sweet potato producer in Africa in terms of area harvested and production, although Burundi, Rwanda and Madagascar have significantly higher yields.  Sweet potato is a major crop in Uganda, ranking third in cultivated area following plantains and cassava. Sweet potato ranks fourth in gross agricultural production value. The Government of Uganda has recognized sweet potatoes as an important crop for the country and a research priority, especially through establishing the National Agricultural Research Organization potato center. This report provides a general overview of the sweet potato value chain in Uganda. The first section describes trends in sweet potato production and consumption since 1996. The second section describes the varieties grown and their uses. The final section summarizes current practices and constraints in production, processing, and marketing.

EPAR Technical Report #218
Publication Date: 01/13/2013
Type: Literature Review
Abstract

This desk study reports on the small-scale machinery sector in China and a selection of SSA countries: Ethiopia, Tanzania, Nigeria, Burkina Faso, and Uganda. The report is organized into three sections. Section 1 discusses the current state of small-scale agricultural machinery in SSA for crop and livestock production in each of the SSA countries identified. It also seeks to identify major areas of need in terms of agricultural mechanization and major constraints to agricultural machinery adoption, dissemination and maintenance. Section 2 focuses on the agricultural machinery sector in China and Chinese Africa relationships in agricultural development. It also identifies the major government players in the Chinese agricultural machinery sector. Section 3 is a “directory” of small-scale agricultural machinery manufactured in China with potential relevance for SSA smallholder farmers. We divide machines by function (e.g. threshing) although many Chinese machines are multi-function and can serve multiple purposes. We also note applicable crops, if listed by the manufacturers, and technical specifications as available.

EPAR Research Brief #119
Publication Date: 12/17/2010
Type: Literature Review
Abstract

This brief summarizes the literature on caloric and lipid deficiencies and their contribution to nutritional outcomes, and identifies key studies and pieces of literature related to this topic.

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 #100
Publication Date: 09/28/2010
Type: Literature Review
Abstract

Without availability and access to a variety of foods, populations in the developing world are suffering from deficiencies in iron, zinc, iodine, vitamin A, and other micronutrients in addition to deficiencies in energy and protein. Supplementation and fortification programs have demonstrated effectiveness, but there is an increasing interest in potentially more sustainable solutions via agricultural interventions. The review examines the literature regarding agricultural interventions and pathways to diet diversification and whether desired nutritional outcomes are achieved.  We find a strong sentiment that agricultural interventions can improve dietary diversity, and that dietary diversity can improve nutrition and related health outcomes. The programs with demonstrated ability to improve nutrition outcomes are most often cross-cutting interventions, borrowing from the agriculture, nutrition, and public health traditions. While these multi-platform programs can be costly to evaluate and difficult to implement, the evidence supports their potential to create sustainable quality-of-life improvements in target regions. The pathways by which agricultural interventions achieve impact are not fully clear, however. The greatest knowledge gaps are directly related to the lack of integration between program design and evaluation. Many evaluations are based on small sample sizes, lack control groups or baseline data, are subject to selection bias, or face other challenges to rigorous statistical analysis. 

EPAR Technical Brief #96
Publication Date: 09/02/2010
Type: Literature Review
Abstract

The purpose of this literature review is to examine research and decision-making tools that model the impacts of agricultural interventions. We begin with a short explanation of what model features are being described. We then review decision-support tools and user-end modeling tools (menu-driven tools with an interface designed for easy use), as well as academic and professional research models for assessing the potential impacts of agricultural interventions. This review also includes decision tools and models for analyzing agricultural and environmental policies outside of technology impacts in Sub-Saharan Africa and South Asia. The other tools mentioned here, for example a tool that considers nutritional intervention impacts, are included to help provide a broader understanding of the structure and availability of user-end, decision-making tools. In the final section of this brief, we review the most complex models used more in academic research than for in-field decision-making.

EPAR Technical Report #65
Publication Date: 03/17/2010
Type: Literature Review
Abstract

Ecosystem services are the benefits people obtain from ecosystems, such as provisioning of fresh water, food, feed, fiber, biodiversity, energy, and nutrient cycling. Agricultural production can substantially affect the functioning of ecosystems, both positively and negatively. The purpose of this report is to provide an overview of the impacts of agricultural technologies and practices on ecosystem services such as soil fertility, water, biodiversity, air, and climate. The report describes the environmental impacts of different aspects of intensive cropping practices and of inputs associated with intensification. We further explore these impacts by examining intensive rice systems and industrial crop processing. Although this report focuses on the impacts of agricultural practices on the environment, many of the practices also have implications for plant, animal, and human health. Farmers and others who come in contact with air, water, and soils polluted by chemical fertilizers and pesticides may face negative health consequences, for instance. By impacting components of the ecosystem, these practices affect the health of plants and animals living within the ecosystem. We find that the unintended environmental consequences of intensive agricultural practices and inputs are varied and potentially severe. In some cases, sustaining or increasing agricultural productivity depends upon reducing impacts to the environment, such as maintaining productive soils by avoiding salinization from irrigation water. However, in other cases, eliminating negative environmental impacts may involve unacceptable trade-offs with food provision or other development goals. Determining the appropriate balance of costs and benefits from intensive agricultural practices is a location-specific exercise requiring knowledge of natural, economic, and social conditions.