These standard errors do not account for the randomization process and error structure of a Split-Plot design. Mean separation tests based in Split-Pplot designs based on PROC GLM of SAS are thus not correct . The noitprint option suppresses printing of the iteration history in the model fitting process. This term was included in the GLM statement to produce the mean square associated with this random component since it constitutes the denominator for F tests involving the whole-plot factor. This also leads to a particular calculation of degrees of freedom.
Several things are noteworthy.
2 w derived earlier. The additional advantage of REML estimation, is that it provides standard deviations and significance tests for the variance components. In the present case the p-values associated with the variance components are ignored, since both variance components are not subject to modelling, but an essential part of the analysis, capturing the randomization process. All tests are constructed in the correct fashion without specifying error terms for the fertility factor, for example. To carry out multiple comparisons, it is necessary to work with correct standard errors of the least squares means.