ROW-COLUMN DESIGNS FOR SUGAR-BEET VARIETY TRIALS

Two different types of experimental designs suitable for sugar beet va riety trials, both laid out in rows and columns, are compared. In one of them, a row-column design (RCD), orders between rows and between co lumns are completely randomized. The design has been in use in Swedish official trials since 1984, except in 1988-89. In these two years the rows (as many as varieties) were divided into four groups, each group containing exactly one replicate of the varieties. The orders between groups and between rows within groups were randomized as well as the order between the columns. This type of design is called a resolvable row-column design, abbreviated RRCD. By comparing standard errors for differences between variety means it is shown that the RCCD may be som ewhat more precise.