Preliminary evaluation of diverse lucerne (Medicago sativa sspp.) germplasm to identify new material for livestock and cropping based farming systems in Australia

Abstract

A preliminary evaluation protocol is described of Medicago sativa that enables a diverse range of germplasm from different winter-activity groups to be evaluated in the same experiment. The protocol was used to compare the seasonal growth patterns of very winter-dormant M. sativa sspp. falcata and caerulea accessions with highly winter-active M. sativa ssp. sativa accessions. Herbage production was strongly related to winter activity in the cumulative first year of growth and in second-year winter months, but completely unrelated in 3 cuts in the following spring. The vertical measurement of plant height was confirmed to be a good indicator of herbage production in winter, but neither stem height nor length were good indicators of spring production. The preliminary evaluation protocol identified highly winter-active class 10–11 germplasm with high winter production and excellent recovery after cutting, and accessions of M. sativa sspp. caerulea and falcata (winter activity class 1) with excellent spring and summer production. These wild relatives of lucerne have great potential to increase the area of cultivated M. sativa in Australia, largely as a component in pasture mixtures. They also offer improved quality traits over winter-active Lucerne, including a higher leaf to stem ratio, and a lower stem thickness and internode length.