Some general results on the existence of trend-free and partially trend-free designs are given for both varietal and factorial experiments. In particular, trend-free properties of cyclic and generalized cyclic designs are investigated. It is shown that, for factorial experiments, certain designs which are not completely trend-free are nevertheless trend-free for estimating a subset of the main effect and interaction contrasts.
"Trend-Free Block Designs for Varietal and Factorial Experiments." Ann. Statist. 19 (3) 1582 - 1596, September, 1991. https://doi.org/10.1214/aos/1176348263