Welcome to the International Institute of Tropical Agriculture Research Repository
Journal and Journal Articles: Recent submissions
Now showing items 41-60 of 5157
-
Urea briquettes combined with a fertilizer blend reduces fertilizer costs and improves yields of irrigated rice in Rwanda
(2023-04-06)We evaluated the yield and potential economic impact in Rwanda of replacing the standard lowland rice (Oryza sativa L.) fertilizer recommendation from the current practice of 200 kg NPK 17-17-17 ha−1 and 100 kg urea ha−1 with a basal blend of 74 kg diammonium phosphate (DAP), 57 kg potassium chloride (KCl), and deep placement of 112.5 kg urea briquettes ha−1 at 4 weeks after transplanting. Experiments were carried out in nine diverse marshlands across Rwanda in the long and short rainy seasons of ... -
What shapes yields of East African Highland banana? An explorative study from farmers’ fields
(2024-05)Context or problem East African Highland banana is a main staple and cash crop for millions of people in the Great Lakes region of Africa. Reliable methods for banana yield estimation are lacking and factors underlying yield variability are not well understood. Objective or research question We studied the interrelations and relative importance of yield components (yield per mat, mat density, bunch weight, cycle duration and the number of bunches harvested per mat per year or per hectare per ... -
Haplotype-resolved genome of heterozygous African cassava cultivar TMEB117 (Manihot esculenta)
(2023-12-09)Cassava (Manihot esculenta Crantz) is a vital tropical root crop providing essential dietary energy to over 800 million people in tropical and subtropical regions. As a climate-resilient crop, its significance grows as the human population expands. However, yield improvement faces challenges from biotic and abiotic stress and limited breeding. Advanced sequencing and assembly techniques enabled the generation of a highly accurate, nearly complete, haplotype-resolved genome of the African cassava ... -
Datasets from fertilized improved and local varieties of cassava grown in the highlands of South Kivu, Democratic Republic of Congo
(2024-02)The use of mineral fertilizer and organic inputs with an improved and local variety of cassava allows (i) to identify nutrient limitations to cassava production, (ii) to investigate the effects of variety and combined application of mineral and organic inputs on cassava growth and yield and (iii) to evaluate the profitability of the improved variety and fertilizer use in cassava production. Data on growth, yield and yield components of an improved and local variety of cassava, economic analysis, ... -
Enhancing smallholder maize shelling mechanization through the collective business model: the case of Northern Ghana.
(2024)This paper assessed the conditions contributing to the success of smallholder farmer groups in northern Ghana using mechanical maize shellers (MMS) based on a collective business model. A sample of 156 farmers from 18 intervention communities was analyzed using qualitative comparative analysis (QCA) to examine the conditions necessary to increase usage of MMS. The results revealed a single configuration for achieving high group MMS usage, observed in about 24 percent of the cases. This configuration ... -
Distribution and diversity of emergent Banana bunchy top virus infecting banana and plantain in Cameroon, Central Africa
(2024-03-05)Invasions of arthropod vectors and viruses are the main factors associated with emerging plant viral diseases. The presence of the Banana bunchy top virus (BBTV, genus Babuvirus), an aphid-transmitted virus responsible for the banana bunchy top disease (BBTD), was first confirmed in 2008 in the South region of Cameroon. This study reports on surveys over 14 years to determine the status of BBTV spread and virus diversity in Cameroon. A total of 544 fields extending through 81 districts in 7 regions ... -
Do farmers' perceptions and socio-economic factors drive cocoa agroforestry and sustainable soil carbon management practices in West Africa?
(2024-01-09)We evaluated the farmer’s local knowledge and perceptions of sustainable cocoa agroforestry and sustainable soil carbon management in Ghana and Côte d'Ivoire using a social survey research methodology. We employed in-depth interviewing and focus group discussions to solicit information from identified key stakeholders in the cocoa supply chain focusing on the perception of sustainable cocoa agroforestry and soil carbon management. Our results revealed that about 83% and 50.5% of smallholder cocoa ... -
Factors influencing gender and youth integration in agricultural research and innovation in Africa
(2024)Integrating gender and youth in Agricultural Research and Innovation (R & I) is important for strengthening the impact and inclusiveness of the research initiatives. The integration is more critical in Africa due to the prevalence of exclusive gender and age norms that undermine the place and role of women and youth in the food systems. The consideration of women and youth as ‘helpers’ instead of farmers aggravated inequalities in accessing and controlling over land and other resources, opportunities ... -
Insecticide contamination in organic agriculture: evidence from a long-term farming systems comparisons trial
(2024-03)Synthetic pesticides applied in conventional agriculture to control pests tend to compromise ecosystem services, and their residues may contaminate organic agriculture. To understand the significance of this contamination, also in small-scale farming systems in sub-Saharan Africa, quantitative data is required. Therefore, we compared synthetic insecticide and botanical/biopesticide residues in conventional and organic agricultural production systems after nine years of continuous cultivation of a ... -
Climate change impact and adaptation of rainfed cereal crops in sub-Saharan Africa
(2024-02-24)Sub-Saharan Africa’s (SSA) demand for cereals is projected to more than double by 2050. Climate change is generally assumed to add to the future challenges of the needed productivity increase. This study aimed to assess (i) the potential climate change impact on four key rainfed cereals (maize, millet, sorghum and wheat) in ten SSA countries namely Burkina Faso, Ghana, Mali, Niger, Nigeria, Ethiopia, Kenya, Tanzania, Uganda, and Zambia using local data and national expertise, and (ii) the potential ... -
Segmental duplications drive the evolution of accessory regions in a major crop pathogen
(2024)Many pathogens evolved compartmentalized genomes with conserved core and variable accessory regions (ARs) that carry effector genes mediating virulence. The fungal plant pathogen Fusarium oxysporum has such ARs, often spanning entire chromosomes. The presence of specific ARs influences the host range, and horizontal transfer of ARs can modify the pathogenicity of the receiving strain. However, how these ARs evolve in strains that infect the same host remains largely unknown. We defined the ... -
A qualitative exploratory study of the political commitment for nutrition programming: a case study of Anambra and Kebbi States of Nigeria
(2024-02-24)In Nigeria, varying levels of malnutrition across states present a critical challenge to public health, demanding tailored policy responses. This paper delves into the specific issues and dynamics influencing nutrition programs in the country. Advocating for nutrition-sensitive actions requires analyzing context-specific political commitment. This article presents a case study on two Nigerian states with varying malnutrition profiles to explore the political economy of nutrition. The study used ... -
A robust DayCent model calibration to assess the potential impact of integrated soil fertility management on maize yields, soil carbon stocks and greenhouse gas emissions in Kenya
(2023)Sustainable intensification schemes that increase crop production and soil fertility, such as integrated soil fertility management (ISFM), are a proposed strategy to close yield gaps and achieve food security in sub-Saharan Africa while maintaining soil fertility. However, field trials are insufficient to estimate the potential impact of such technologies at the regional or national scale. Upscaling via biogeochemical models, such as DayCent, from the field-scale to a larger region can be a suitable ... -
Drought vulnerability of central Sahel agrosystems: a modelling-approach based on magnitudes of changes and machine learning techniques
(2023-07-24)Agricultural drought is a complex phenomenon with numerous consequences and negative implications for agriculture and food systems. The Sahel is frequently affected by severe droughts, leading to significant losses in agricultural yields. Consequently, assessing vulnerability to agricultural drought is essential for strengthening early warning systems. The aim of this study is to develop a new multivariate agricultural drought vulnerability index (MADVI) that combines static and dynamic factors ... -
Anticipating social differentiation and unintended consequences in scaling initiatives using GenderUp, a method to support responsible scaling
(2024-03)CONTEXT A key strategy in progressing towards the Sustainable Development Goals (SDGs) is scaling innovations to improve livelihoods of marginalized populations globally. Consequently, there has been a heightened emphasis on Agriculture Research for Development (AR4D) innovation teams' ability to swiftly identify innovations that can be scaled for broad impact. However, insufficient attention has been paid to the equitable distribution of benefits among different demographic groups, leading to ... -
Improving the adoption of stress tolerant maize varieties using social ties, awareness or incentives: insights from Northern Benin (West-Africa)
(2023-11-08)Maize is the staple food of most households in sub-Saharan Africa. The adoption of stress-tolerant maize varieties (STMV) is being promoted due to climate change. There are various methods applied to disseminate these varieties. Unfortunately, the adoption at the household level is still unsatisfactory. This study evaluated the effectiveness of the dissemination methods used in Benin. We identified dissemination methods from key informants involved in STMV seed dissemination projects. The performance ... -
Identification of the Loci associated with resistance to banana xanthomonas wilt (Xanthomonas vasicola pv. musacearum) using DArTSeq markers and continuous mapping
(2024)Banana Xanthomonas wilt, caused by Xanthomonas vasicola pv. musacearum (Xvm), is a devastating disease that results in total yield loss of affected plants. Resistance to the disease is limited in Musa acuminata, but it has been identified so far in the zebrina subspecies. This study identified markers associated with tolerance to Xvm in Monyet, a tetraploid banana from the zebrina subspecies which was identified to be partially resistant to the bacterium. We used a triploid progeny of 135 F1 hybrids ... -
The importance and determinants of purchases in rural food consumption in Africa: implications for food security strategies
(2024-01-23)We analyze rural households’ purchases of food (cereals and non-cereals) in Sub-Saharan Africa using nationally representative data with 65,000 observations covering 7 countries over a decade. We distinguish between three strata of countries: lower stratum in income and urbanization, middle stratum, and upper stratum. The paper breaks ground by the breadth and time length of the sample. We find that purchases form the majority of rural food consumption whether in favorable or unfavorable agroecological ... -
Smallholder aquaculture diversifies livelihoods and diets thus improving food security status: evidence from northern Zambia
(2024-01-05)Much has been made of the potential for aquaculture to improve rural livelihoods and food and nutrition security in Africa, though little evidence exists to back such claims. This study, conducted in northern Zambia, assessed the benefits of adopting aquaculture by comparing a sample of households with (n = 177) and without fishponds (n = 174). -
Rhizoglomus variabile and Nanoglomus plukenetiae, native to Peru, promote coffee growth in Western Amazonia
(2023-11-29)Coffee (Coffea arabica) is among the world’s most economically important crops. Coffee was shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) in traditionally managed coffee plantations in the tropics. The objective of this study was to assess AMF species richness in coffee plantations of four provinces in Perú, to isolate AMF isolates native to these provinces, and to test the effects of selected indigenous AMF strains on coffee growth. AMF species were identified by morphological ...
