Base water potential of selected Echinochloa crus-galli populations

This study investigated the base water potential (Ψb) for germination and associated seed traits in four European populations of Echinochloa crus-galli originating from Spain, Greece, Norway, and the Czech Republic. Seeds collected in 2023 were subjected to dormancy-breaking treatments and germination assays conducted at 24 °C under a range of water potentials simulated with polyethylene glycol (PEG 6000). Germination dynamics were modelled to estimate Ψb, and physical seed traits were quantified using image analysis. Significant inter-population variability was observed in both Ψb and seed morphology. The Norwegian population exhibited the lowest Ψb, indicating greater tolerance to water stress, whereas the Spanish and Czech populations showed the highest Ψb values, with no significant differences between them. Seed size and shape also varied significantly among populations, with Spanish seeds being smaller and more spherical, Greek seeds the largest, and Norwegian seeds the most elongated. These results highlight substantial eco-physiological differentiation among E. crus-galli populations and provide key parameters for improving weed emergence models and developing more targeted management strategies.