Types of Research
- (-) Remove Household Well-Being & Equity filter Household Well-Being & Equity
- (-) Remove Agricultural Inputs & Farm Management filter Agricultural Inputs & Farm Management
- (-) Remove 2015 filter 2015
- (-) Remove Literature Review filter Literature Review
- (-) Remove Environment & Climate Change filter Environment & Climate Change
- (-) Remove Labor & Time Use filter Labor & Time Use
- (-) Remove Agricultural Productivity, Yield, & Constraints filter Agricultural Productivity, Yield, & Constraints
- (-) Remove 2014 filter 2014
- (-) Remove 2012 filter 2012
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.
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.
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.
This brief draws on recent reports by the OECD, the World Bank, the Overseas Development Institute (ODI), the Climate Policy Initiative (CPI) and others to provide an overview of climate finance in developing countries. The brief is divided into three sections: (i) sources of global climate finance; (ii) country-level flows of climate finance; and (iii) applications of climate finance in developing countries. The brief is designed to give a concise overview of financial flows directed at climate change mitigation and adaptation globally and in developing countries, with an introduction to climate finance accounting such that climate financial flow volumes can be compared to aid volumes in other sectors. Total global climate finance flows were approximately USD $364 billion in 2011 (Buchner et al., 2012) and $359 billion in 2012. However the vast majority of these flows - 76%, or $275 billion - was finance generated and spent within a country’s own borders (domestic finance) (Buchner et al., 2013). The “Fast-Start Finance” period from 2010-2012 saw $35 billion in new aid mobilized for climate finance in developing countries. Developed countries have recently committed to mobilize an additional $100 billion per year by 2020.
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.
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.
This report provides a general overview of the markets for yams in Nigeria. The first section describes trends in yam production and consumption and international trade since 1990. The second section summarizes the varieties grown in Nigeria and their uses, followed by a discussion of the importance of yams as a source of nutrition and household income. The final section provides details about the production and marketing systems for yams in Nigeria, including environmental and gender considerations. Nigeria is the world’s largest yam producer in terms of quantity. Yam production and consumption have increased over the past twenty years, though more recently, production has been somewhat in decline and yields have been stagnant. The Nigerian government has played a more active role in improving agricultural production and export of root and tuber crops including yams in recent years, but so far with limited success. Yam producers and traders report diverse constraints to their full participation in the market, including high cost of inputs, planting materials and labor, lack of credit, limited access to proper, secure storage facilities, and high transportation costs.
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.
This report provides a general overview of the markets for sweet potatoes in Nigeria. The first section describes trends in sweet potato production and consumption and international trade since 1990. The second section summarizes the varieties grown in Nigeria and their uses, followed by a discussion of the importance of sweet potatoes for food security and as a source of nutrition and household income. The following section reviews and presents details about the production and marketing systems for sweet potatoes in Nigeria, including environmental and gender considerations.
This report provides a general overview of the market for yams in Ghana. We begin by describing historical trends in yam production and consumption since 1996, recent international trade, and prices. The second section summarizes the varieties grown in Ghana and their uses. The next several sections review available information about the production and marketing systems, followed by a discussion of the importance of yams as a source of nutrition and household income. The limited information available on sweet potato production in Ghana is presented in the appendix. We find that yam production in Ghana has increased steadily over the last 15 years, and that while yam yields have increased from 12.8 MT/Ha in 1996 to 15.6 MT/Ha in 2011, an estimated yield gap of 33.4 MT/Ha persists. Yam export levels have varied over the past 15 years, but show a generally positive trend. Most yam farmers are male smallholders with low levels of education, while most retailers, wholesalers and cross-border traders are women.