CIMMYT Publications Repository
Not a member yet
7809 research outputs found
Sort by
Population genomics and molecular epidemiology of wheat powdery mildew in Europe
No full textAgricultural diseases are a major threat to sustainable food production. Yet, for many pathogens we know exceptionally little about their epidemiological and population dynamics, and this knowledge gap is slowing the development of efficient control strategies. Here we study the population genomics and molecular epidemiology of wheat powdery mildew, a disease caused by the biotrophic fungus Blumeria graminis forma specialis tritici (Bgt). We sampled Bgt across two consecutive years, 2022 and 2023, and compiled a genomic dataset of 415 Bgt isolates from 22 countries in Europe and surrounding regions. We identified a single epidemic unit in the north of Europe, consisting of a highly homogeneous population. Conversely, the south of Europe hosts smaller local populations which are less interconnected. In addition, we show that the population structure can be largely predicted by the prevalent wind patterns. We identified several loci that were under selection in the recent past, including fungicide targets and avirulence genes. Some of these loci are common between populations, while others are not, suggesting different local selective pressures. We reconstructed the evolutionary history of one of these loci, AvrPm17, coding for an effector recognized by the wheat receptor Pm17. We found evidence for a soft sweep on standing genetic variation. Multiple AvrPm17 haplotypes, which can partially escape recognition by Pm17, spread rapidly throughout the continent upon its introduction in the early 2000s. We also identified a new virulent variant, which emerged more recently and can evade Pm17 resistance altogether. Overall, we highlight the potential of genomic surveillance in resolving the evolutionary and epidemiological dynamics of agricultural pathogens, as well as in guiding control strategies
Status and drivers of crop diversification in the Eastern Gangetic Plains of South Asia: Across borders and communities
No full textCrop diversification is indispensable for the development of Agriculture in the Eastern Gangetic Plains (EGP) of South Asia. Given policy imperatives encouraging crop diversification, significant evidence, and knowledge gaps remain, with a lack of integrative studies that quantitatively and qualitatively assess the diverse and intricate dimensions of crop diversification within the broader context of the EGP. The study assesses the spatiotemporal patterns of crop diversification, aiming to elucidate the nuanced challenges associated with transitioning to more diversified cropping systems and identifying country-specific determinants within the EGP. Uses cross-sectional data from 1397 farm households across 72 communities in India, Nepal, and Bangladesh. Combine descriptive and quantitative analysis to explore seasonal and regional aspects of crop diversification. Besides, the Herfindahl-Hirschman Index (HHI) to assess current crop diversification levels. A Tobit Regression Model is used to identify the country-specific determinants of crop diversification. Results revealed significant variation in crop diversification across the EGP, with notable seasonal and regional differences. Family size influences diversification in all three countries, while factors such as joint decision-making with a spouse, solar-powered irrigation, and orchard ownership vary regionally. Rice remains dominant during the summer monsoon (kharif) season, but there is a shift towards greater diversification in the winter (rabi) season, suggesting potential for further diversification. This study provides a comprehensive overview of diversification patterns and their drivers in the EGP, capturing broad trends and local nuances. It offers valuable baseline information for promoting crop diversification and underscores the need for tailored approaches to enhance sustainability in this poverty-dense and agriculturally dependent region
Fortalecimiento de las redes locales y casas comunitarias de semillas en Colombia
No full textLa conservación de recursos fitogenéticos es crucial para la biodiversidad, seguridad alimentaria, identidad cultural y desarrollo económico, pero está amenazada por el cambio climático. Las casas y bancos comunitarios de semillas, gestionados por redes de custodios y organizaciones de pequeños productores, son esenciales para preservar variedades locales. Sin embargo, muchas organizaciones carecen de conocimientos e infraestructura adecuados. Este estudio busca fortalecer el conocimiento técnico de estas redes mediante conversatorios sobre el manejo adecuado de semillas durante el almacenamiento y la entrega de equipamiento para el manejo de semillas en Nariño, Putumayo, Valle de Cauca y Cesar. La selección de casas de semillas se basó en un análisis de redes sociales del sistema local de semillas y la decisión de los agricultores de fortalecer sus procesos. Se realizaron 82 entrevistas semiestructuradas, analizadas con el software KeyPlayer2. Se seleccionaron 12 casas de semillas, de las cuales ocho fueron propuestas por los agricultores y cuatro recomendadas por el estudio. Además, se capacitaron a más de 180 personas, con énfasis en mujeres (61.3%), participación indígena y una baja participación de jóvenes (30.3%). La percepción de los agricultores al termino de esta intervención fue positiva para seguir colaborando con los centros de investigación desde sus territorios y problemáticas locales.12 page
How has scientific literature addressed crop planning at farm level: A bibliometric-qualitative review
No full textCrop planning (CP), being the core of farm management and decision-making, remains significant as the selection and allocation of appropriate crops determine the economics and sustainability of farming system. A systematic literature review was conducted to obtain a structural overview and consolidate the knowledge from CP literature, given the dearth of review articles in this domain. The methodology included systematic selection of literature in phases and mixed-method systematic review process consisting of bibliometric analysis and qualitative review. This enabled an understanding the main characteristics of CP literature and answer how CP has been addressed at farm level. 1516 publications were selected in first phase after which 652 were screened using bibliometric analysis software, VOSviewer and CiteSpace, in second phase to identify research hotspots and recent trends. Optimization, irrigation, sustainability, adaptation were certain hotspots, while a shift in research trend was observed from decision support, crop allocation and bioenergy to climate change, water resources and big data. Last phase focussed on qualitative review of 31 publications on farm. Three broad themes of articles emerged namely "farmer's decision-making", "soil-water-agroecology" and "merits of innovative technologies". The study proposed several recommendations for small farming systems which were largely ignored in literature. These include factorial design for crop combinations, choices in options, estimation of crop diversity index and relative time- dispersion in yields. The current review produced a macroscopic overview of accumulated knowledge on CP and provided future directions to harness the unexplored potential in this field
Rainfall forecasts, learning subsidies and conservation agriculture adoption: Experimental evidence from Zambia
No full textAdapting smallholder rainfed farming systems to climate change requires adoption of technologies that build resilience to climate shocks. One such technology is conservation agriculture, yet its adoption by smallholders in Southern Africa is not widespread. We use incentivized economic field experiments in Zambia to test, ex-ante, whether providing rainfall forecasts and a time-bound learning subsidy can help increase the adoption of conservation agriculture. We found that providing rainfall forecasts predicting low rainfall significantly increased the probability of adopting conservation agriculture by 8 percentage points, while offering a subsidy increased the chances of adoption by 11 percentage points. Bundling rainfall forecasts and subsidies did not significantly influence adoption, perhaps because these were not complementary. Having experienced normal rainfall in the previous experiment round (cropping season) was associated with 6 percentage points higher odds of adopting conservation agriculture, while past exposure to low rainfall significantly reduced the probability of adoption by 6 percentage points. These results suggest that farmers do not expect two subsequent seasons to be the same given the increase in rainfall variability in the region. Other important drivers of adoption are hosting demonstration plots and education level of the participant. These findings provide evidence that providing rainfall forecasts and time-bound learning subsidies may be effective ways to enhance the adoption of conservation agriculture in Zambia and imply a need to reframe conservation agriculture as means to address low and erratic rainfall. Future research can evaluate the persistence of such effects using randomized controlled trials
The influence of improved wheat and maize varieties on infant mortality in China
No full textThe diffusion of high-yielding crop varieties has been a key driver for agricultural productivity. This study examines the relationship between the adoption of high-yielding crop varieties of two staple crops-wheat and maize-and infant mortality in rural China. Using data from 1954 to 1987, we find a significant reduction in infant mortality linked to high-yielding crop varieties diffusion, an association that remains robust even after excluding the Great Famine years. We investigate potential mechanisms driving this relationship, including increased grain production, improved infant nutrition, and changes in maternal characteristics. Additionally, our analysis unveils a spectrum of heterogeneous relationships between high-yielding crop varieties adoption and infant mortality across factors such as infant gender, maternal characteristics, and policy regulation. These findings reaffirm the positive and lasting benefits of dissemination of high-yielding crop varieties for human welfare and provide valuable policy insights for developing nations grappling with food and nutritional insecurity
Exploratory single crosses of purple maize for pericarp and cob pig-ment production
No full textIntroducción. Los pigmentos vegetales son una opción para sustituir los artificiales y consumir alimentos sanos. Objetivo. Evaluar en campo y laboratorio cruzas simples exploratorias (CSE) de maíz con grano y olote morado, formadas con líneas aleatorias, para analizar la integración del patrón heterótico B-49N x B-41N. Materiales y Métodos. La investigación se llevó a cabo en Tepatitlán, Jalisco, México durante el 2021-2022. Se formaron CSE entre seis líneas S5 de la población B-49N y cuatro S3 de B-41N con grano y olote morado. En 2022, las cruzas y cinco testigos se evaluaron, en temporal, en la misma localidad mediante un diseño experimental de bloques completos al azar con tres repeticiones. Tamaño de parcela, consistió de un surco de 4 m de largo, 0,8 m de ancho y 0,16 m entre plantas con 25 plantas por surco. Se tomaron datos de planta y mazorca. En siete cruzas se evaluó el contenido de antocianinas total en grano (CATg) y olote (CATo). Se hicieron análisis de varianza y pruebas de medias en todas las variables con el programa estadístico SAS. Resultados. Se obtuvieron 12 CSE con rendimiento igual (p < 0,05) que el testigo blanco, pero con grano y olote morado. Se observó una variación significativa (p < 0,05) en antesis (de 80 a 90 días), acame de tallo (de 0 a 12,6 %) y calificación de mazorca (de 1,5 a 2,7). El grano de las CSE fue suave a muy suave. No hubo asociación entre el rendimiento y contenidos altos de CATg y CATo. Conclusión. Los resultados de CSE muestran avances positivos en la integración del patrón heterótico de maíz morado B-49N x B-41N, pero, en el futuro, deberá aumentarse el contenido de antocianinas en grano y olote, y dureza del grano.Introduction. Plant based pigments could replace artificial pigments and consume healthy food products. Objective. To evaluate in the field and laboratory exploratory purple grain and cob maize single cross hybrids (CSE), formed with random lines, to analyze the integration of the B-49N x B-41N heterotic pattern. Material and methods. The research was carried out in Tepatitlán, Jalisco, Mexico during 2021-2022, CSEs were formed be-tween six S5 lines from population B-49N and four S3 from B-41N with purple grain and cob. The crosses and five controls were evaluated in 2022 in the same location. A randomized complete block experimental design with three repetitions was used. Plot size, a row of 4 m long, 0,8 m wide and 0,16 m between plants with 25 plants per row. Plant and ear data were taken. In seven crosses total anthocyanin content in grain (CATg) and cob (CATo) were evaluated. Analysis of variance and tests of means were performed on all variables using the statistical SAS program. Results. There were 12 CSEs with the same yield (p < 0,05) as the white control, but with purple grain and cob, significant variation (p < 0,05) in anthesis (from 80 to 90 days), stem lodging (from 0 to 12,6 %). and ear grade (from 1,5 to 2,7). The grain of the CSEs was soft to very soft, and there was not association between yield and high CATg and CATo contents. Conclusion. CSE results show positive progress in the integration of the heterotic purple maize pattern B-49N x B-41N, but, in the future, the anthocyanin content in grain and cob, and grain hardness, should be increased
Farm resilience to climatic risk. A review
No full textIncreasing our understanding of farm resilience drivers to climate-related risks is critical for designing innovative farm systems, especially for smallholders that are highly vulnerable to climatic hazards and expected to follow a pathway toward sustainable development. However, the literature is fragmented on the concepts and methods to measure farm resilience. Moreover, quantitative assessments of options to enhance farm resilience to climate risks are scarce. Resilience can be defined as the ability of a system to recover, reorganize and evolve following external stresses and disturbances. Such definition can be applied to farm systems. In this study, we systematically reviewed how changes in resilience-enhancing attributes (reserves, openness, modularity, tightness of feedbacks and diversity) impacted farm performance and resilience to climate-related risks, with a specific attention to smallholder farms. Our analysis showed that reviewed studies assessed farm resilience using the agricultural and economic dimensions of performance, often excluding the socio-environmental dimensions. To assess performance, the average value of indicators was most commonly employed, sometimes combined with variability metrics or the probability of exceeding a critical threshold. Improving one resilience attribute increased one dimension of farm performance for a given metric in most of the studies, but some studies showed the opposite effect. The lack of comprehensive assessments exploring different attributes and their impact on several dimensions of performance using diverse metrics prevents a robust conclusion on how to improve farm resilience to climate-related risks. Therefore, we recommend to pay more attention to quantitative assessments of farm resilience, including a systematic investigation of the temporal variability of performance and the socio-environmental dimensions of performance. Finally, we emphasize the need to focus on the recovery of smallholder farms after a disturbance, with the goal of achieving growth in farm performance rather than simply reverting to their current state of food insecurity and poverty
Enhancing farmer learning and adoption of digital extension: A case study report of sorghum and millet farmers in western Kenya
No full textAgricultural extension services remain critical for bridging the gap between agronomic research and on-farm adoption, yet systemic inefficiencies such as low farmer-to-agent ratios, fragmented knowledge dissemination, and limited accessibility of traditional methods of learning hinder progress. Digital tools offer transformative potential through scalability, real-time interaction, and tailored content delivery. However, their impact is often constrained by poor usability, lack of farmer-centric design, and uneven technological access. In 2023, we piloted a case study in Western Kenya’s Siaya and Busia counties, focusing on sorghum and millet cultivation. The initiative tested a hybrid extension model integrating GeoFarmer, a digital platform, with existing farmer networks. We explored the following research questions: 1. What insights can be drawn from the integration of peer-to-peer learning and two-way knowledge exchange in digital extension platforms? What specific mechanisms and interactions appear to facilitate or hinder knowledge sharing within the examined agricultural community? 2. How do farmers with varying technological backgrounds engage with a Human-Centred Design (HCD) digital platform? Which design elements ease adoption, and what challenges persist in the studied communities? 3. What emerging patterns suggest how digital extension networks can complement traditional in person demonstration methods to support the wider adoption of improved agronomic practices?22 page
Hard and soft climate-smart investments in aquaculture in Bangladesh: Conditioning factors and decision space
No full textClimate change and its' associated weather variabilities and extremes are posing significant risks to aquaculture productivity, particularly in the coastal regions of Bangladesh. Concurrently, the increasing population and shifting consumption patterns are driving higher demand for aquacultural products. This study investigates the impact of floods, heavy rainfall, tidal surges, high temperatures, droughts, erratic rainfall, and water quality parameters (Dissolved Oxygen, ammonia, pH) on investments in "hard" assets, such as specific fish-farm equipment (aquaculture nets, fish cages, thermometers, irrigation pumps), to enhance climate resilience. Additionally, the study explores "soft" investments in information services that provide advanced forecasts on monsoon onset, heavy rainfall, dry spells, high temperature and cold spells. The results indicate that the level of investment in climate-smart aquaculture is currently influenced by climate stresses, investment capacity (farm size, family size), aquaculture system characteristics (pond size and depth, type of fish, aggregate yields), and market-related factors (proximity to roads and markets). In the context of climate-informed decision-making, forecast-based advisory services can facilitate the transition to climate-smart aquaculture. However, the benefits of the information services are often linked to substantial investments in hard infrastructure that ensure the effective utilization of climate information and advisory services. This absence of accessible climate information services and the capacity to invest in climate smart equipment that makes the information actionable, hinder the transition to climate smart aquaculture by smallholder farmers and hence threaten their livelihood and nutritional security