Ten zero-grazed foraged grasses and an uncut legume cover were grown in association with a rubber clone, leaving a free space of 1.0 or 1.5m radius around the trees. The moderately fertilized grasses averaged about 8 t DM ha-1 yr-1. Guinea A and Guinea B were the most productive, green panic and Brachiarai miliiformis at least. Although in general the more productive grasses appeared to compete with the ruvver, there was no significant correlation between DM yield of the grasses and growth 1.0m that 1.5m away from the trees. In a second experiment, two grasses that were grown separately in association with each of five Hevea clones were more competitive than a Peuraria cover, but there were no interactions between the clones and grasses with respect to either three growth or grass yield.