THE CONSTRUCTION OF EFFICIENT 2-REPLICATE ROW-COLUMN DESIGNS FOR USE IN-FIELD TRIALS

Two-replicate row-column designs are often used for field trials in mu ltisite tree or plant breeding programmes. With only two replicates fo r each trial, it is important to use designs with optimal or near opti mal efficiency factors. This paper presents an algorithm for generatin g such designs. The method extends the contraction approach of Bailey and Patterson to any set of parameters and uses the factorial design c onstruction algorithm of Williams and John to generate designs. Our ex perience with the algorithm is that it produces designs that are at le ast as good as, and often much better and more quickly generated than, those obtained by other recent computer algorithms.