Hard seed breakdown patterns of unprocessed forage legume seed sown into dry soil in summer in southern Australia

The patterns and extent of hard seed breakdown of dormant seeds and pods following burial in the soil in February (summer) varied for up to 19 accessions of 12 species of annual forage legumes. The experiments, at six sites across southern Australia, were designed to identify legumes whose patterns of hard seed breakdown would suit them to agronomic evaluation in a summer sowing research program. For a subset of accessions, sufficient hard seed breakdown was demonstrated between February and April to allow a high proportion of seed to germinate in late autumn-a desirable pattern for summer sowing. Although there was a large G x E interaction, some cultivars of Ornithopus sativus Brot., O. compressus L. and Trifolium spumosum L. had a pattern that was reproducible at all sites. The experiments also identified accessions of Biserrula pelecinus L. and T. glanduliferum Boiss., which had the desirable pattern in regions of south-eastern Australia, but not Western Australia. A pragmatic approach for selection of forage legume accessions in situ for evaluation within a summer sowing program was demonstrated.

Automated summary

The patterns and extent of hard seed breakdown of dormant seeds and pods of annual forage legumes buried in the soil in February varied across different accessions. However, some cultivars showed reproducible patterns across all sites, while others showed desirable patterns only in certain regions of Australia. The experiments demonstrated a pragmatic approach for selecting forage legume accessions suited for evaluation in a summer sowing program.