The simple analysis of variance for the experimental data has the structure shown:


Source df


Blocks 5
Herbicides 5
Cover crops 1
Planting dates 2
CxP 2
Error 20


All information on main effects and the Cx P interaction is fully efficient. Some information on the H x C
and H x P can be recovered if a statistical package such as Genstat is used.

If the design with twelve plots in each of three blocks is used then the design will be:


Block 1 Block 2 Block 3


ciplhl clplh2 clplh3
clplh4 clplh5 clplh6
clp2h2 clp2h6 clp2h4
clp2h3 clp2hl clp2h5
clp3h5 clp3h4 clp3hl
clp3h6 clp3h3 clp3h2
c2plh3 c2plh6 c2plh4
c2plh5 c2plh2 c2plhl
c2p2h6 c2p2h3 c2p2h5
c2p2hl c2p2h4 c2p2h2
c2p3h4 c2p3hl c2p3h6
c2p3h2 c2p3h5 c2p3h3