Using the shifted multiplicative model to search for “separability” in crop cultivar trials

Cornelius, P. L. and Seyedsadr, M. and Crossa, J. (1992) Using the shifted multiplicative model to search for “separability” in crop cultivar trials. TAGTheoretical and Applied Genetics, 84 (1-2). pp. 161-172.

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The shifted multiplicative model (SHMM) is used in an exploratory step-down method for identifying subsets of environments in which genotypic effects are ldquoseparablerdquo from environmental effects. Subsets of environments are chosen on the basis of a SHMM analysis of the entire data set. SHMM analyses of the subsets may indicate a need for further subdivision and/or suggest that a different subdivision at the previous stage should be tried. The process continues until SHMM analysis indicates that a SHMM with only one multiplicative term and its ldquopoint of concurrencerdquo outside (left or right) of the cluster of data points adequately fits the data in all subsets. The method is first illustrated with a simple example using a small data set from the statistical literature. Then results obtained in an international maize (Zea mays L.) yield trial with 20 sites and nine cultivars is presented and discussed.

Item Type: Article
Uncontrolled Keywords: Genotype x environment interaction, Shifted multiplicative model, Separability, Concurrent regression model, Crossover interaction, Qualitative interaction
Author Affiliation: University of Kentucky
Subjects: Crop Improvement
Divisions: General
Depositing User: Mr Siva Shankar
Date Deposited: 24 Jul 2012 08:48
Last Modified: 24 Jul 2012 08:48
Official URL:

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