Maize Production Environments Revisited

Maize Production Environments Revisited
A GIS-based Approach

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Abstract.- 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.

Contents

Executive summary (154.52KB)

Introduction (50.49KB)

Previous ME classification methods

GIS-based approaches

Methodology for this study

Results and discussion

Conclusions

References (11.81KB)

Tables

Table 1.	Descriptions, regions, countries, and key sites associated with global maize mega-environments.
Table 2.	Agroclimatic criteria used for the maize environment classification by Dowswell et al.(1996).
Table 3.	Maize ME Update Committee classification,1991.
Table 4.	Cluster mean values for variables: daylength, temperature difference, mean temperature, precipitation and evapotranspiration.
Table 5.	Cluster criteria for revised maize mega-environments, including subdivisions based on precipitation, for a 4-month growing season.

Appendices

Appendix A.	Estimated area and production percentages for maize mega-environments, derived from the 1987-1988 mega-environment survey.
Appendix B.	Maize mega-environment updates using FAO information,1990 and 1996.
Appendix C.	Maize mega-environments in South America using the 1991 classification criteria.
Appendix D.	Latin America maize mega-environment production breakdown created by overlaying crop distribution (Hyman et al.1998) and 1991 mega-environment area maps.
Appendix E.	Locations selected for GIS-based cluster analysis.
Appendix F.	Clusters for 220 unique maize international testing sites using four consecutive monthly environmental variables starting from the ‘best bet’ planting date.
Appendix G.	Post classification of selected locations according to the new and 1991 classifications.
Appendix H.	Zonal maps of maize mega-environments made using trigger season planting.

(Centerfold: A simplified map of maize mega-environments created by removing precipitation criteria.)

Published on July 2001

August, 2004

NRG Papers