Enhanced diagnostics for the spatial analysis of field trials
We report an analysis of a series of uniformity field trials using the technique proposed by Gilmour, Cullis, and Verbyla. In particular, we clarify the role of the sample variogram and present a range of enhanced graphical diagnostics to aid the spatial modeling process. We highlight the implications of the presence of extraneous variation related to commonly used agronomic practices, such as serpentine harvesting.
Key wordsAgronomic practice Coverage interval Mixed model Residual maximum likelihood Spatial modeling Variogram
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