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Modeling the consequences of water limitations at flowering and nitrogen shortage in tropical maize germplasm

By: Elings, A | Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico).
Contributor(s): Edmeades, G.O [coaut.] | Edmeades, G.O.|Banziger, M.|Mickelson, H.R.|Peña-Valdivia, C.B [eds.] | White, J.W [coaut.].
Material type: materialTypeLabelBookAnalytics: Show analyticsPublisher: Mexico, DF (Mexico) CIMMYT : 1997ISBN: 968-6923-93-4.Subject(s): Drought stress AGROVOC | Flowering | Germplasm | Nitrogen content | Simulation models | Water deprivation | CIMMYT | Zea mays AGROVOCDDC classification: 633.153 Summary: The ear of the maize plant at flowering has a relatively weak sink capacity. When this is coupled with low current carbohydrate availability, due, for example, to limited water availability, it leads to reduced ear growth, low number of grains per ear, or completely barren plants. Low grain yield is the consequence. One symptom of these reductions in the flux of assimilates to the ear is delayed silking, and an increase in the anthesis-silking interval (ASI). Our working hypothesis is that the length of the ASI can be related to the photosynthetic rate or growth rate per plant at flowering, and that this is modified by genetic parameters. Quantification of this relationship would enable explanatory simulation of ASI of a maize crop that experiences some sort of growth limitation, especially drought, but also low nitrogen or low amounts of intercepted radiation per plant (as in high plant density). Various simulation approaches, varying in the level of detail with which underlying physiological processes are treated, can be chosen. Detailed photosynthesis modules, and modules that convert intercepted photosynthetically active radiation with a light use efficiency coefficient to crop growth rate, are readily available. However, these rely on accurate simulation of leaf area development, which is often problematic. In addition, existing phenology modules for temperate maize need testing and parameterization. Realistic modelling furthermore depends on the accuracy of the soil description, simulation of root growth, and quantification of water supply and demand. Simpler models that lese a coefficient that relate crop growth to water availability may have greater utility in studies of some types of drought. Simulation studies are performed to investigate sensitivity, in terms of phenology, growth and production, to changes in the model's integration level, and to its input parameters. Modules describing specific functions can then be developed. This leads to an assessment of the module's validity domains, and to a prioritization of research needs.Collection: CIMMYT Publications Collection
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Conference proceedings CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Publications Collection 633.153 EDM (Browse shelf) 1 Available 1E624179
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The ear of the maize plant at flowering has a relatively weak sink capacity. When this is coupled with low current carbohydrate availability, due, for example, to limited water availability, it leads to reduced ear growth, low number of grains per ear, or completely barren plants. Low grain yield is the consequence. One symptom of these reductions in the flux of assimilates to the ear is delayed silking, and an increase in the anthesis-silking interval (ASI). Our working hypothesis is that the length of the ASI can be related to the photosynthetic rate or growth rate per plant at flowering, and that this is modified by genetic parameters. Quantification of this relationship would enable explanatory simulation of ASI of a maize crop that experiences some sort of growth limitation, especially drought, but also low nitrogen or low amounts of intercepted radiation per plant (as in high plant density). Various simulation approaches, varying in the level of detail with which underlying physiological processes are treated, can be chosen. Detailed photosynthesis modules, and modules that convert intercepted photosynthetically active radiation with a light use efficiency coefficient to crop growth rate, are readily available. However, these rely on accurate simulation of leaf area development, which is often problematic. In addition, existing phenology modules for temperate maize need testing and parameterization. Realistic modelling furthermore depends on the accuracy of the soil description, simulation of root growth, and quantification of water supply and demand. Simpler models that lese a coefficient that relate crop growth to water availability may have greater utility in studies of some types of drought. Simulation studies are performed to investigate sensitivity, in terms of phenology, growth and production, to changes in the model's integration level, and to its input parameters. Modules describing specific functions can then be developed. This leads to an assessment of the module's validity domains, and to a prioritization of research needs.

English

9801|AGRIS 9702|anterior|R97-98PROCE|FINAL9798

Jose Juan Caballero

CIMMYT Publications Collection

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