Test elements/plots are randomly distributed in test blocks on a test facility. All test members are grown in several replicates and randomised within a test block.
Many plant trials are laid out in a complex design involving multiple randomisation steps.
Keywords: randomised trial design, random allocation (of plants), randomised block design, randomisation, randomisation scheme.
The purpose of a randomised block layout is to achieve that test members/variants are arranged using a random mechanism. This reduces the probability that certain influences are due to the arrangement of the test members and not to the test member itself. Thus, known and unknown properties are evenly distributed.
In practice, a library is often created that contains the randomisation plans. These can then be used again each year.
An trial with five variants and three repetitions can be created in a block so that the repetitions lie on top of each other.
