Research Topics

EPAR Technical Report #363
Publication Date: 02/10/2019
Type: Data Analysis
Abstract

Studies of improved seed adoption in developing countries almost always draw from household surveys and are premised on the assumption that farmers are able to self-report their use of improved seed varieties. However, recent studies suggest that farmers’ reports of the seed varieties planted, or even whether seed is local or improved, are sometimes inconsistent with the results of DNA fingerprinting of farmers' crops. We use household survey data from Tanzania to test the alignment between farmer-reported and DNA-identified maize seed types planted in fields. In the sample, 70% of maize seed observations are correctly reported as local or improved, while 16% are type I errors (falsely reported as improved) and 14% are type II errors (falsely reported as local). Type I errors are more likely to have been sourced from other farmers, rather than formal channels. An analysis of input use, including seed, fertilizer, and labor allocations, reveals that farmers tend to treat improved maize differently, depending on whether they correctly perceive it as improved. This suggests that errors in farmers' seed type awareness may translate into suboptimal management practices. In econometric analysis, the measured yield benefit of improved seed use is smaller in magnitude with a DNA-derived categorization, as compared with farmer reports. The greatest yield benefit is with correctly identified improved seed. This indicates that investments in farmers' access to information, seed labeling, and seed system oversight are needed to complement investments in seed variety development.

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.

EPAR Technical Report #223
Publication Date: 12/10/2012
Type: Literature Review
Abstract

Cassava is a tuber crop originating in South America and grown in tropical and subtropical areas throughout the world. Cassava use varies significantly by region. In Africa, cassava is primarily grown for food. In Asia, production is typically for industrial purposes, including ethanol, while in Latin America and the Caribbean it is commonly used in animal feed. Both roots and leaves are consumed, though most information on production focuses on roots. There are bitter and sweet varieties; bitter cassava has a high cyanide content and must be processed prior to consumption, while sweet varieties can be eaten directly. This report presents information about current production, constraints, and future potential of cassava. We discuss cassava’s importance in Africa, current worldwide production, projections for supply and demand, production constraints, and current policies affecting cassava production and trade. We include global information but focus on Africa, particularly Nigeria, Ghana, Uganda, and Tanzania.

EPAR Technical Report #201
Publication Date: 09/12/2012
Type: Data Analysis
Abstract

This brief explores how two datasets – The Tanzania National Panel Survey (TZNPS) and the TNS-Research International Farmer Focus (FF) – predict the determinants of inorganic fertilizer use among smallholder farmers in Tanzania by using regression analysis. The (TZNPS) was implemented by the Tanzania National Bureau of Statistics, with support from the World Bank Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA) team and includes extensive information on crop productivity and input use. The FF survey was funded by the Bill and Melinda Gates Foundation and implemented by TNS Research International and focuses on the on the behaviors and attitudes of smallholder farmers in Tanzania. The two datasets produce relatively comparable results for the primary predictors of inorganic fertilizer use: agricultural extension and whether or not a household grows cash crops. However, other factors influencing input use produce results that vary in magnitude and direction of the effect across the two datasets. Distinct survey instrument designs make it difficult to test the robustness of the models on input use other than inorganic fertilizer. This brief uses data inorganic fertilizer use, rather than adoption per se. The TZNPS did not ask households how recently they began using a certain product and although the FF survey asked respondents how many new inputs were tried in the past four planting seasons, they did not ask specifically about inorganic fertilizer.

EPAR Technical Report #199
Publication Date: 07/27/2012
Type: Literature Review
Abstract

Over the past 20 years, global wheat production and consumption have increased significantly. Production has increased 28%, or about 1.3% annually, and consumption has increased about 24%, or 1.1% annually. A small number of countries consistently account for over 90% of the export market, but the import market is more diversified and involves many more countries. Wheat is primarily used for food, seed, and industry; only 20% of wheat production is used for animal feed. This brief provides a global overview of the wheat value chain, but with specific attention to three focus countries: Ethiopia, India (specifically the Bihar region), and Bangladesh. While these three countries currently have a limited impact in the global wheat market, projections of wheat production and demand suggest that over the next 20 years demand in Bangladesh and Ethiopia will increasingly exceed supply, while India will become a net importer by 2030.

EPAR Technical Report #204
Publication Date: 07/27/2012
Type: Literature Review
Abstract

This report provides a general overview of the wheat market in Ethiopia. The first section describes trends in wheat production and consumption over the past twenty years and summarizes recent trade policy related to wheat. The second section presents the findings of a literature review of the wheat value chain in Ethiopia, beginning with seed research and ending with sales. The third section outlines the nutritional content of wheat as well as potential substitutes. Finally, wheat consumption in Ethiopia is discussed in more depth, including the role of wheat in Ethiopian diets, substitute grain markets, and projected consumption in 2030. We find that over the past twenty years, wheat production and consumption have both increased in Ethiopia despite the existence of strong markets for potential substitute grains. The Ethiopian government has played an active role in wheat markets, such as making large investments in extension programs and adopting protectionist policies to ensure government control of all commercial grain imports. Despite these efforts, Ethiopia is expected to face a growing supply deficit in the absence of increased domestic productivity and/or changes to government policy. 

EPAR Research Brief #187
Publication Date: 07/11/2012
Type: Data Analysis
Abstract

This brief present our analysis of maize cultivation in Tanzania using data from the 2008/2009 wave of the Tanzania National Panel Survey (TZNPS), part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA). We find that Maize was the most commonly grown crop in Tanzania – cultivated by 83% of farming households. Eighty-two percent of agricultural households reported consuming maize flour during the week prior to being surveyed. About half of those households grew nearly all of the maize they consumed, making maize production an integral part of the farming household diet. A separate appendix includes details on our analyses.

EPAR Research Brief #188
Publication Date: 07/11/2012
Type: Data Analysis
Abstract

This brief presents our analysis of rice paddy cultivation in Tanzania using data from the 2008/2009 wave of the Tanzania National Panel Survey (TZNPS), part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA). We find that Paddy was the sixth most commonly cultivated priority crop. Nationally, paddy was cultivated by 17% of farming households, with male- and female-headed households cultivating paddy at a similar rate.2 Cultivation rates varied widely across zones, ranging from 51% of households in Zanzibar to only 5% in the Northern Zone. A separate appendix includes additional detail on our analyses.

EPAR Research Brief #196
Publication Date: 06/12/2012
Type: Data Analysis
Abstract

This brief presents our analysis of market access in Tanzania using data from the 2008/2009 wave of the Tanzania National Panel Survey (TZNPS), part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA). The TZNPS asked few direct questions about market access. However, farmers reported information about market participation that sheds light on several important components of the value chain: input markets, including both goods and services; crop storage, processing, and transport; and sales of outputs. A separate appendix includes additional detail on our analyses.

EPAR Research Brief #189
Publication Date: 04/09/2012
Type: Data Analysis
Abstract

This brief presents our analysis of legume cultivation in Tanzania using data from the 2008/2009 wave of the Tanzania National Panel Survey (TZNPS), part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA). We find that Tanzanian farmers reported growing eight different varieties of food legumes: beans, groundnuts, cowpeas, mung beans, chickpeas, bambara nuts, field peas, soya beans, and pigeon peas. Fifty-seven percent of households in Tanzania grew at least one of these crops during the long and/or short rainy seasons.  A separate appendix includes details on our analyses.