994 research outputs found
Typescript Bill H.R. 20819 for the Construction of Roads and other Permanent Improvements
No full textTypescript draft of Bill H.R. 20819 to provide for the construction of roads and other permanent improvements at or near the Grand Canyon. The sum of $110,000 dollars is to be appropriated for the project under the direction of the Secretary of Agriculture
Identificación de problemas en la producción de maíz tropical: guía de campo
No full textEl propósito de esta guía es ayudar a los agrónomos a identificar, en forma sencilla y gradual, los problemas que presenta la producción de maíz en el campo. También puede ayudar a eliminar la variación en las observaciones agronómicas realizadas durante las visitas al campo y a identificar las preguntas que se deben plantear en las entrevistas a los agricultores. Una vez diagnosticados los problemas, la lista de posibles soluciones puede servir para determinar los factores que se incluirán en los experimentos. La información presentada incorpora los conocimientos de muchos científicos expertos en el maíz. Los procedimientos de diagnóstico indicados en esta guía no pretenden reemplazar la experimentación sino, más bien, ayudar a aumentar la eficiencia de la identificación de problemas y la utilidad de los experimentos orientados a generar recomendaciones agronómicas. No obstante, en el diagnóstico de problemas en el campo siempre se deben considerar las circunstancias particulares de cada región y, por consiguiente, se aconseja a quienes usen esta guía que interpreten y, cuando sea necesario, adapten las pautas de diagnóstico presentadas a sus propias condiciones agronómicas y ambientales. También se sugiere a los usuarios que envíen sus comentarios a la sede del CIMMYT con el fin de mejorar las pautas y procedimientos aquí indicados.122 page
Identifying production problems in tropical maize: a field guide
No full textThe purpose of this guide is to help agronomists identify, in a simple, stepwise fashion, maize production problems in the field. The guide may also contribute to improved consistency in agronomic observations and to identifying important questions for farmer interviews. Once problems are diagnosed, the lists of possible solutions may help in identifying factors to include in experiments. The information presented represents the collective knowledge of many experienced maize scientists. The diagnostic procedures found in this guide are not intended to replace experimentation but rather to help improve the efficiency of problem identification and the appropriateness of experiments designed to generate agronomic recommendations. Readers are encouraged to interpret and, when necessary, modify the diagnostic guidelines presented to match more closely their particular agronomic and environmental circumstances. Please feel free to send comments to CIMMYT headquarters on the guidelines and procedures.122 page
Interpreting cultivar x environment interactions for yield in upland rice: assigning value to drought-adaptive traits
No full textEfficiency of secondary traits for improving maize for low-nitrogen target environments
No full textConsideration of secondary traits could improve selection efficiency under stress conditions. This study assesses the value of secondary traits for improving lowland tropical maize (Zea mays L.) for low‐N target environments. Nineteen experiments grown with no N applied at CIMMYT, México, between 1986 and 1995 were analyzed for grain yield, anthesis‐silking intervai (ASI), number of ears per plant, leaf chlorophyll concentration, and an estimate of leaf senescence. Broad‐sense heritabilities of traits, genetic correlations between secondary traits and grain yield, and predicted response of grain yield to selection for single or multiple traits were calculated. Multiple traits were combined using an unrestricted selection index (Smith‐Hazel index). Broad‐sense heritabilities averaged 0.46 for grain yield, 0.52 for ASI, 0.44 for ears per plant, 0.35 for leaf chlorophyll concentration, and 0.60 for leaf senescence. Genetic correlations of secondary traits with grain yield averaged −0.47 for ASI, 0.78 for ears per plant, 0.24 for leaf chlorophyll concentration, and 0.42 for leaf senescence. Direct selection for grain yield was superior to selection for single secondary traits in most experiments. When information on all traits was combined in a Smith‐Hazel index, selection efficiency improved by 14% on average over selection for grain yield alone. Among secondary traits, ears per plant and leaf senescence discriminated high‐yielding genotypes the best. Leaf chlorophyll concentration, and in some instances ASI, provided information on environmental variation within experiments. We conclude that secondary traits can increase the efficiency of selection for grain yield in maize breeding programs targeting low‐N environments
Temperature effects on radiation use and biomass partitioning in diverse tropical maize cultivars
No full textInnovative Ways of Dealing with Existing Problems: How to reliably Assess the Cause of Damage of Masonry Structures in an Area with Man-induced Earthquakes?
No full textGroningen, a province in the northern part of the Netherlands, suffers from earthquakes because of gas drilling. The residential building stock in Groningen was not designed for these loads. Over the years a lot of smaller and larger damage has developed, possibly - but not necessarily - caused by the effects of gas drilling. Delft University of Technology was asked by the Dutch government to come up with a method to reliably assess the cause of damage of masonry structures in Groningen. This paper discusses the developed approach for reliably assessing the causes of failure of masonry structures in earthquake-prone areas and the way innovative monitoring techniques were applied.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Mechanic
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