IMPROVED PERFORMANCE FROM SCREENING AND HYBRIDISING OF WHITE CLOVER GERMPLASM IN SOUTHLAND

A range of white clover populations from the Mediterranean, Europe, and New Zealand together with ecotypes collected from Southland and North Island hill country were evaluated as spaced plants or small plots between 1975 and 1982. Plants were screened for seasonal productivity, persistence under grazing, morphology, and disease tolerance. The clover lines with potential fell into two distinct types, persistent and productive. Persistent types (ecotype material) had small leaves, many stolons and an active spring/summer growth pattern suited to the climate of Southland. In a pasture, the prostrate morphology of these types was associated with an efficient transfer of nutrients from clover to grass. Productive types (Huia, Pitau, and French material) had larger leaves, fewer stolons, competed well with associated grasses, and were tolerant of leaf diseases, but were less persistent. A hybridisation programme produced material combining desirable features of both persistent and productive types. Some of the best hybrids have a dense morphology, and produce 201l7o greater spring/summer and up to 40% greater annual yields than the cultivar Grasslands Huia. Final selections from these highproducing, persistent hybrids will be used to produce a clover cultivar suited to southern New Zealand.