Percussion as an effective seed treatment for herbaceous legumes (Fabaceae): implications for habitat restoration and agriculture

Legumes are particularly useful in agriculture and in habitat restoration, increasing soil fertility and facilitating the establishment of other plant species. Seeds are important for these activities, but the use of legume seeds can be problematic due to seed coat-imposed dormancy. Although various seed scarification treatments have been proposed, there have been few attempts to monitor their effects on subsequent seedling establishment. Furthermore, literature about the use of percussion treatments is limited. In our study, seeds of six herbaceous Fabaceae species widely distributed in Europe and Asia, were used to investigate the response of seed germination and seedling establishment to percussion (for 1, 2, 5, 10 and 20 minutes) compared with standard treatments such as immersion in sulphuric acid (for 1, 5, 10, 20 and 40 minutes) and hot water (at 60, 70, 80, 90 and 100°C for 30, 60 and 300 seconds). Immersion in sulphuric acid (for 20 and 40 minutes) and percussion (for 10 and 20 minutes), elicited the highest germination (80-95%) in all species, without injury. In contrast, hot water was only effective on half of the species and often caused abnormal germination. Although seedling establishment was high (c. 95%) and plants grew similarly after both acid and percussion treatments, percussion was found to be the most effective, safe and user-friendly. Its implementation for large-scale seedling production may have important economic and technological benefits.