Previous PageTable Of ContentsNext Page

Medicago orbicularis (l.) bart.- a potential new medic for the cereal belt of southern Australia

R.J. Saunders, J.H. Howie and G.C. Auricht

Department of Agriculture, PO Box 1671, Adelaide SA 5001

Medicago species are the dominant annual pasture legumes in the lower rainfall (250-450 mm), alkaline soil areas of the cereal-livestock zone of southern Australia. Relatively few of the total number of identified species of annual medic have been commercially exploited although the variability of environmental factors and management strategies in this zone suggest a need for greater genetic diversity.

Through evaluating the performance of a number of lines, the species M. orbicularis has been identified as a potential new source of genetic material for selection and breeding. Of particular interest because of its high seed production is the line SA 8460. M. orbicularis is widely distributed throughout the Mediterranean. The pods are discoid, 8-18 mm in diameter, soft and spineless and contain ten or more triangular seeds. Measurements indicate a high level of hardseededness with a slow rate of seed softening.


Pasture accessions were direct drilled at 10 kg/ha in small plots at 10 sites across SA over two years, covering a wide range of soil types (sand-clay loam) and rainfall (275 - 475 mm). Trials were of a randomised block design with four replicates. Production and seed quality data were collected and compared with standard commercial cultivars.

Results and discussion

The major criterion for ranking performance is clean seed yield. In low rainfall areas seed production is regarded as the primary gauge of pasture persistence and productivity.

Table 1. Seed yield of SA 8460, three standard cultivars and % of best performed cultivar.

These figures highlight the adaptability of SA 8460 and demonstrate the potential of the species M. orbicularis. This and other M. orbicularis lines will be monitored in further trials to investigate their persistence and productivity under established farming systems.

Previous PageTop Of PageNext Page