EFFICIENCY OF ALPHA-LATTICE DESIGNS IN INTERNATIONAL VARIETY YIELD TRIALS OF BARLEY AND WHEAT

Use of an alpha-lattice design in 714 international yield trials of ba rley, durum wheat and bread wheat in 1990/91 to 1992/93 resulted in an average efficiency 18% higher than the randomized complete block desi gn when average variance was used as the comparison criterion. Alpha-l attice was generally most efficient when the c.v.s of the trials were high. It was also slightly more efficient for low-yielding than for hi gh-yielding trials, and for rainfed than for irrigated trials. Since t he changeover to alpha-lattice designs requires no new major input or changes in present field layout, its use for international trials is r ecommended.