Indian Society of Genetics & Plant Breeding
Success of a crop breeding programme depends on the efficiency of evaluation of the
available genotypes and identifying high yielding types adapted to a given environment
and management conditions. Crop growing environments in tropics and subtropics are
highly diverse and complex due to the effect of abiotic and biotic factors and the varying
crop management systems. For such environmental complexities it is almost impossible to
define the environment under which varieties should be selected. A reasonable
compromise is to test the materials over;a sample of a wide range of the conditions in the
target growing environment. Identification of broad agroecological regions (zones) and
common and uncommon features between the test sites within a region allows the
determination of an optimum regional and national testing programme. The paper
discusses the importance of G x E interactions caused by weather, edaphic and biological
factors in an apparently homogeneous geoclimatic subdivision analysis of abiotic and
biotic factors, but also the cultivar response to environment for improving the efficiency of
a testing network. Recent developments in the analytical techniques for delineating
environments and their relevance to the national testing network in the developing
countries are indicated.
Keywords: G x E interaction, ecosystem, agIO-ecological regions, microenvironment, environmental index.
Year: 1997
Volume: 57
Issue: 1
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906
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