Intensive cropping influences the success of seed dormancy breaking methods in Australian collected Hordeum, Avena, and Bromus sp

Background: Seed dormancy is a critical evolutionary trait that enhances the persistence of plant populations under both natural and managed conditions. It is influenced by genetic and environmental factors, with crop management practices like tillage and herbicide use reportedly selecting for increased seed dormancy in weeds. This study aimed to compare the success of seed dormancy breaking methods between weed populations collected from intensively managed crop fields and unmanaged ruderal locations.

Results: Weeds from intensively managed fields, including Hordeum glaucum, H. leporinum, Avena fatua, Bromus diandrus, and B. rigidus exhibited significantly higher seed dormancy and didn't respond largely to seed dormancy breaking methods compared to those from unmanaged areas. Dormancy-breaking treatments such as sandpaper scarification were effective in barley grass, while endosperm excision followed by cold stratification alleviated dormancy in brome grass and wild oat. Dark incubation consistently improved germination across all species, enhancing the efficacy of treatments like cold stratification, sandpaper scarification, and gibberellic acid (GA3).

Conclusion: Weeds in managed fields develop greater seed dormancy, likely as an adaptive response to agricultural practices. Techniques such as tillage, which incorporate seeds deeper into the soil, may help mitigate seed dormancy traits by reducing light exposure. These findings highlight the importance of dormancy management in controlling persistent weed populations. © 2024 Society of Chemical Industry.