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The use of a reference variety for comparisons in incomplete series of crop variety trials

Forkman, Johannes (2013). The use of a reference variety for comparisons in incomplete series of crop variety trials. Journal of applied statistics. 40, 2681-2698
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Official URL: http://dx.doi.org/10.1080/02664763.2013.825703

Abstract

In series of crop variety trials, `test varieties' are compared with one other and with a `reference' variety that is included in all trials. The series is typically analyzed with a linear mixed model and the method of generalized least squares. Usually, the estimates of the expected differences between the test varieties and the reference variety are presented. When the series is incomplete, i.e. when all test varieties were not included in all trials, the method of generalized least squares may give estimates of expected differences to the reference variety that do not appear to accord with observed differences. The present paper draws attention to this phenomenon and explores the recurrent idea of comparing test varieties indirectly through the use of the reference. A new `reference treatment method' was specified and compared with the method of generalized least squares when applied to a five-year series of 85 spring wheat trials. The reference treatment method provided estimates of differences to the reference variety that agreed with observed differences, but was considerably less efficient than the method of generalized least squares.

Authors/Creators:Forkman, Johannes
Title:The use of a reference variety for comparisons in incomplete series of crop variety trials
Series/Journal:Journal of applied statistics (BIB2829535)
Year of publishing :2013
Depositing date:6 October 2017
Volume:40
Page range:2681-2698
Publisher:Taylor and Francis
Language:English
Publication Type:Journal article
Refereed:Yes
Article category:Scientific peer reviewed
Version:Accepted version
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 101 Mathematics > 10106 Probability Theory and Statistics
Agrovoc terms:statistics, field experimentation, evaluation
Keywords:Agricultural field trials, Crop variety evaluation, Generalized least squares, Series of experiments, Value for cultivation and use
URN:NBN:urn:nbn:se:slu:epsilon-e-4401
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4401
Additional ID:
Type of IDID
DOI10.1080/02664763.2013.825703
ID Code:14418
Faculty:NL - Faculty of Natural Resources and Agricultural Sciences (until 2013)
Department:(NL, NJ) > Dept. of Crop Production Ecology
Deposited By: Johannes Forkman
Deposited On:06 Oct 2017 12:01
Metadata Last Modified:06 Oct 2017 13:10

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