Multi-environment variety test plots are located at several locations including farmers fields. Most of these locations have inherent spatial variability. Varietal responses may be influenced by their location within the spatial variability. Blocking is intended to remove the spatial variability, but it is rare when all the variability falls within the blocks. We compared the Alkaike Information Criteria (AIC) from a row and column adjustment and unadjusted data using Proc Mixed of SAS. An analysis of 61 corn, soybean, and wheat trials in 2004 showed that 20 trials did not benefit from row-column adjustment (AIC = 2.4 better for unadjusted) while 41 trials improved with row-column adjustment (AIC = 50.6 better for adjustment).
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