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Improving Precision of Cocoa Progeny Trials Using Calibrator Trees

Published online by Cambridge University Press:  03 October 2008

G. Lockwood
G. Lockwood
Affiliation:
Cocoa Research Institute, PO Box 8, Tafo-Akim, Ghana†
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Summary

In nine breeding trials with cocoa in Ghana the experimental trees were interplanted with temporary trees of a standard variety as ‘calibrators’. The calibrators were removed after 2–2½ years before there was strong competition with the permanent trees. Trunk diameters of the calibrators were used as covariates in analyses of trunk size and yield of dry cocoa up to 7 years after planting, giving reductions in standard errors of differences between progenies of up to 25% in analyses of size and 15% in analyses of yield.

Type
Research Article
Information
Experimental Agriculture , Volume 15 , Issue 3 , July 1979 , pp. 209 - 215
Copyright
Copyright © Cambridge University Press 1979

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References

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