A comparison of six red clover varieties in association with three grass species.

The productivity, in terms of i) clover, ii) grass, iii) mixed herbage dry matter and iv) crude protein content, of six red clover varieties (S.123, S.151, Rea, S.123 Nomark, Resistenta and Altaswede) when grown with each of three grass species (S.48 timothy, S.22 Italian ryegrass and New Zealand perennial ryegrass) is described. The experimental plots were grazed at each harvest except the second in each of the 3 years 1962-64. No significant interaction between grass and clover was found for any of the characters measured. Clover varieties differed in seasonal productivity, Resistenta being the earliest variety. Over all harvests, S.123 was the most vigorous and Altaswede the poorest. In general, swards with the most vigorous clover varieties also had the highest yield of mixed herbage. Differences between the three grass species were mainly in the seasonal pattern of production rather than in annual yield of mixed herbage, S.48 timothy swards were poorest in spring but grew rapidly in May/June and gave highest yields at the second harvest in each year. During mid-summer New Zealand ryegrass swards were least productive.