TukeyHSD, and glht in the multcomp package, are designed for aov objects. They do not have methods for aovlist objects.
The workaround is to download and install the HH package and look at the maiz example. library(HH) ?MMC In that example I show how to get the same sequential sum of squares without the Error() term as you would get with the Error term. Rich ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.