The emergence, productivity and competitive effects that occur in the early growth period between 'Grasslands Nui' ryegrass, 'Grassland Matua' prairie grass and 'Grassland Apanui' cocksfoot when grown as pure swards and in binary mixtures are examined. The results indicate that the species compete for the same environmental resources and prairie grass suppresses the growth of the other two species while ryegrass has a similar effect on cocksfoot. Prairie grass and mixtures containing a major proportion of prairie grass outyield all other sward types and the yields of mixtures are seen to be between the monoculture yields of the component species over the period of study. Practical implications of these results are considered.
