Abstract
1. In a 3 x 3 x 3 factorial experiment of two replications, with three-factor interactions partly confounded with block effects, the effects of lucerne variety (du Puits or one of two Institute synthetics), tall fescue variety (S.170 or one of two Institute bulks) and spacing (mixed drills 6 in. apart, alternate grass and lucerne drills 6 in. or 12 in. apart) and their two-factor interactions were studied on yield of dry matter and proportion of lucerne. Data are reported for the total of fourteen cuts, for the annual total for three harvest years and for spring, summer and autumn cuts.