This publication presents a GIS-based approach for revising the definitions of global maize production environments, called “mega-environments” (MEs), used by CIMMYT and its partners. A cluster analysis was performed on climate data, representing a four-month growing season, for key maize producing locations. Assuming rainfed production, the onset of the growing season was determined based on the month when the ratio of precipitation over potential evapotranspiration exceeds 0.5. Diagnostic criteria for mapping MEs were based on cluster analysis results and expert knowledge. The resulting maps can be used to select appropriate target environments for maize germplasm and trials, as well as in priority setting and site selection for global maize breeding programs.

Maize is an important crop and the demand for as both food and animal feed is expected to grow by 235 million tonnes between now and 2030. In many countries it will be difficult to increase the area under cultivation, so gains will have to come from increased productivity and intensification of the cropping system. This book looks at all aspects of tropical maize production from physiology, growing environments, pest and diseases, plant breeding and crop management and it is a substantial information resource necessary for the development of the crop.

This new volume offers a multi-pronged perspective on maize science, bringing together important recent research advances from several disciplines. The volume covers maize from origin to biotechnology. It provides an overview of recent world maize production along with technological advancements and green strategies in maize science. The authors cover the background of maize, its origin and domestication, ideotypes, botany, taxonomy, physiology of crop growth, methods of cultivation, production, nutritional functions, biotic and abiotic stress impacts, postharvest management and technology, maize grain quality, and advances in breeding and biotechnology, filling a gap in the literature of maize.

Incidence and intensity of drought and low N stresss in the tropics; Case studies strategies for crop production under drought and low n stresses in the tropics; Stress physology and identification of secondary traits; Physiology of low nitrogen stress; Breeding for tolerance to drought and low n stresses; General breeding strategies for stress tolerance; Progress in breeding drought tolerance; Progress in breeding low nitrogen tolerance; Experimental design and software.