Field Assistants: I.R. Rose S.P. Davis Soil Analysis: I.A. Pritchard. A. Screening trials M. polymorpha var brevispina. M. truncatula. T. cherleri - 84KA41, 84KA42, 84KA43, 84KA47. B. Large scale M. polymorpha evaluation - 84KA38, 84KA39, 84KA40, C. Long term Medic species evaluation - 82KA44, 82KA45. D. Species characterization trials - 83KA66, 83KA67. E. M. murex evaluation - 83KA45. F. Dwalganup replacement subclovers - 83KA69. Since 1981, the major emphasis of the Katanning pasture programme has been to select pasture species suitable for replacing ryegrass on soils where Annual Ryegrass Toxicity (ARGT) has been a major problem. These soils have traditionally been the hardsetting sandy loam soils of acid to alkaline reaction trend. Subterranean clover has failed to persist in these areas due to problems of burr burial, transient waterlogging and a lack of hardseededness.
Screening work to date has successfully identified the species Medicago polymorpha var brevispina to be a suitable alternative to ryegrass and as such, a considerable proportion of resources were directed into a more detailed evaluation of the species
