International Maize and Wheat Improvement Center

About: International Maize and Wheat Improvement Center is a nonprofit organization based out in Texcoco, Mexico. It is known for research contribution in the topics: Population & Agriculture. The organization has 1976 authors who have published 4799 publications receiving 218390 citations.

Bayesian Genomic Prediction with Genotype × Environment Interaction Kernel Models

Abstract: The phenomenon of genotype × environment (G × E) interaction in plant breeding decreases selection accuracy, thereby negatively affecting genetic gains Several genomic prediction models incorporating G × E have been recently developed and used in genomic selection of plant breeding programs Genomic prediction models for assessing multi-environment G × E interaction are extensions of a single-environment model, and have advantages and limitations In this study, we propose two multi-environment Bayesian genomic models: the first model considers genetic effects [Formula: see text] that can be assessed by the Kronecker product of variance-covariance matrices of genetic correlations between environments and genomic kernels through markers under two linear kernel methods, linear (genomic best linear unbiased predictors, GBLUP) and Gaussian (Gaussian kernel, GK) The other model has the same genetic component as the first model [Formula: see text] plus an extra component, F: , that captures random effects between environments that were not captured by the random effects [Formula: see text] We used five CIMMYT data sets (one maize and four wheat) that were previously used in different studies Results show that models with G × E always have superior prediction ability than single-environment models, and the higher prediction ability of multi-environment models with [Formula: see text] over the multi-environment model with only u occurred 85% of the time with GBLUP and 45% of the time with GK across the five data sets The latter result indicated that including the random effect f is still beneficial for increasing prediction ability after adjusting by the random effect [Formula: see text]

Rethinking technological change in smallholder agriculture

Abstract: The concept of technology adoption (along with its companions, diffusion and scaling) is commonly used to design development interventions, to frame impact evaluations and to inform decision-making...

Molecular marker-assisted breeding options for maize improvement in Asia

Abstract: Maize is one of the most important food and feed crops in Asia, and is a source of income for several million farmers Despite impressive progress made in the last few decades through conventional breeding in the “Asia-7” (China, India, Indonesia, Nepal, Philippines, Thailand, and Vietnam), average maize yields remain low and the demand is expected to increasingly exceed the production in the coming years Molecular marker-assisted breeding is accelerating yield gains in USA and elsewhere, and offers tremendous potential for enhancing the productivity and value of Asian maize germplasm We discuss the importance of such efforts in meeting the growing demand for maize in Asia, and provide examples of the recent use of molecular markers with respect to (i) DNA fingerprinting and genetic diversity analysis of maize germplasm (inbreds and landraces/OPVs), (ii) QTL analysis of important biotic and abiotic stresses, and (iii) marker-assisted selection (MAS) for maize improvement We also highlight the constraints faced by research institutions wishing to adopt the available and emerging molecular technologies, and conclude that innovative models for resource-pooling and intellectual-property-respecting partnerships will be required for enhancing the level and scope of molecular marker-assisted breeding for maize improvement in Asia Scientists must ensure that the tools of molecular marker-assisted breeding are focused on developing commercially viable cultivars, improved to ameliorate the most important constraints to maize production in Asia

Participation in Rural Land Rental Markets in Sub-Saharan Africa: Who Benefits and by How Much? Evidence from Malawi and Zambia

Abstract: We use nationally representative household-level panel survey data in two neighboring countries in Southern Africa—Zambia and Malawi—to characterize the current status of rural land rental market participation by smallholder farmers, and their subsequent welfare impacts. Rural rental market participation is much higher in densely-populated Malawi than in lower-density Zambia, reflecting the role of land scarcity in driving rental market development. Consistent with previous literature, we find evidence that rental markets contribute to efficiency gains within the smallholder sector by facilitating the transfer of land from less-able to more-able producers, on average, in both countries. Furthermore, we find that rental markets serve to re-allocate land from relatively land-rich to land-poor households. We examine the impacts of participation on a number of welfare outcomes and find evidence for generally positive returns to renting in land in both countries, on average. However, our analysis also indicates that the returns to renting in land vary strongly with scale of production: tenants who produce more have larger returns to renting in, and many of the smaller producers who rent in do so at an economic loss. The impacts of renting out (i.e., participating in markets as landlords) are decidedly more mixed, with overall negative returns to landlords in Malawi and negligible returns to landlords in Zambia. The findings in this article highlight the need for researchers and policymakers in sub-Saharan Africa to stay attuned to how land rental market participation and its impacts evolve in the near future.