SOME ASPECTS OF THE PERFORMANCE OF 'GRASSLANDS PAWERA' RED CLOVER IN SOUTHLAND

Grazing experiments investigating some factors determining the dry matter production and oestrogenicity of Pawera red clover are described. The legume content of the summer dry matter yield was double that of Ruanui and Huia pasture following overdrilling of lightly paraquated pasture with 4 or 8 kg/ha of Pawera. Persistence of Pawera was demonstrated by its ability to survive in sufficient density under grazing to contribute 35% of total summer dry matter production in its fourth year after direct drilling into lightly paraquated pasture. A Pawera sward when overdrilled with Tama ryegrass or Rahu ryecorn produced the same annual yield as Ariki/ Huia pasture, but the seasonal distribution was markedly different, with production from the overdrilled Pawera being greater in winter and summer. Pure Pawera swards produced some 70% more dry matter during December-February than Ariki/Huia pasture. The significance of this is related to conservation practices in Southland. Oestrogenicity of pure swards of Pawera was determined by measuring the cervical mucus response in ovariectomized ewes. Responses to grazing were equivalent to a single injection of 9 to 31 ug of oestradiol-17B